OPTIONAL ANNEXES
Identifiers:
Project Number: PIMS: 0096 UNDP: RAF00G31
Project Name: Implementation of the Strategic Action Program (SAP) Toward Achievement of the Integrated Management of the Benguela Current Large Marine Ecosystem (LME)
Annex 5: Transboundary Diagnostic Analysis
Annex 6: Strategic Action Programme
Annex 7: Summary of the Functions and Responsibilities of the Interim Benguela Current Commission (IBCC)
Annex 8: Thematic Reports Prepared During the PDF-B Project Phase
Annex 9: Stakeholders Involvement Description and List of the Stakeholders Participants 2
ANNEX H
BENGUELA CURRENT LARGE MARINE ECOSYSTEM PROGRAMME (BCLME)
A regional commitment to the sustainable integrated management of the Benguela Current Large Marine Ecosystem by Angola, Namibia and South Africa
TRANSBOUNDARY DIAGNOSTIC ANALYSIS (TDA)
UNDP
WINDHOEK, OCTOBER 1999 3
TABLE OF CONTENTS Page
Background and Introduction 1
* The Benguela: a unique environment 1 * Fragmented management: a legacy of the 2 colonial and political past * The need for international action 3 * The success story of BENEFIT 4 * The emerging BCLME Programme 6 * What has been achieved 6 * Towards a sustainable future: the next steps 8
Users Guide to the Transboundary Diagnostic Analysis 11
* Definitions and TDA objective 11 * Design of the TDA 11 (a) Level One: Synthesis (b) Level Two: Specifics * More information 12
BCLME Transboundary Diagnostic Analysis 13
* Geographic scope and ecosystem boundaries 13 * Level One: Synthesis 14 * Synthesis Matrix 16 * Level Two: Overview 17 * Analysis Tables and Explanatory Notes 19 A: Sustainable management and Utilization of resources B: Assessment of Environmental variability, ecosystem impacts and improvement of predictability C: Maintenance of ecosystem health and management of pollution
Supporting Documents
* Report on First Regional BCLME Workshop * Report on Second Regional BCLME Workshop * Thematic Reports 1-6 1
BACKGROUND AND INTRODUCTION
The Benguela: A Unique Environment
The Benguela Current Large Marine Ecosystem (BCLME) is situated along the coast of south western Africa, stretching from east of the Cape of Good Hope in the south equatorwards to the Angola Front which is situated near the northern geopolitical boundary of Angola (see Fig.1). It encompasses one of the four major coastal upwelling ecosystems of the world which lie at the eastern boundaries of the oceans. Like the Humboldt, California and Canary systems, the Benguela is an important centre of marine biodiversity and marine food production. The BCLME's distinctive bathymetry, hydrography, chemistry and trophodynamics combine to make it one of the most productive ocean areas in the world, with a mean annual primary productivity of 1.25grams of carbon per square metre per year - about six times higher than the North Sea ecosystem. This high level of primary productivity of the BCLME supports an important global reservoir of biodiversity and biomass of zooplankton, fish, sea birds and marine mammals, while near-shore and off-shore sediments hold rich deposits of precious minerals (particularly diamonds), as well as oil and gas reserves. The natural beauty of the coastal regions, many of which are still pristine by global standards, have also enabled the development of significant tourism in some areas. Pollution from industries and poorly planned and managed coastal developments and near-shore activities is, however, resulting in a rapid degradation of vulnerable coastal habitats.
The Namib Desert which forms the landward boundary of a large part of the BCLME is one of the oldest deserts in the world, predating the commencement of persistent upwelling in the Benguela (12 million years before present) by at least 40 million years. The upwelling system in the form in which we know it today is about 2 million years old. The principal upwelling centre in the Benguela which is situated near Lüderitz in southern Namibia, is the most concentrated and intense found in any upwelling regime. What also makes the Benguela upwelling system so unique in the global context is that it is bounded at both northern and southern ends by warm water systems, viz. the tropical/equatorial Eastern Atlantic and the Indian Ocean's Agulhas Current respectively. Sharp horizontal gradients (fronts) exist at these boundaries of the upwelling system, but these display substantial variability in time and in space - at times pulsating in phase and at others not. Interaction between the BCLME and the adjacent ocean systems occurs over thousands of kilometers. For example, much of the BCLME, in particular off Namibia and Angola, is naturally hypoxic - even anoxic - at depth as a consequence of subsurface flow southwards from the tropical Atlantic. This is compounded by depletion of oxygen from more localised biological decay processes. There are also teleconnections between the Benguela and processes in the North Atlantic and Indo-Pacific Oceans (e.g. El Niño). Moreover, the southern Benguela lies at a major choke point in the "Global Climate Conveyor Belt" whereby on time scales of decades to centuries warm surface waters move from the Pacific via the Indian Ocean through into the North Atlantic. (The South Atlantic is the only ocean in which there is a net transport of heat towards the equator!). As a consequence not only is the Benguela at a critical location in terms of the global climate system, but it is also potentially extremely vulnerable to any future climate change or increasing variability in climate.
Centuries before the arrival in southern Africa of the first European explorers and settlers, indigenous coastal peoples harvested intertidal and near-shore marine life. Commercial exploitation in the BCLME commenced in the first part of the seventeenth century with the harvesting of fur seals and was followed by extensive whaling operations in the eighteenth and nineteenth centuries. Commercial trawling started around 1900 and commercial purse-seine fishing for sardine some 50 years later. Fisheries expanded rapidly in the 1960s and 1970s during a period when there was heavy exploitation of resources by foreign fleets - resulting in the severe depletion and collapse of several fish stocks. Superimposed on this fishing pressure was the impact of the inherent natural environmental ecosystem variability and change. Together with the other factors mentioned in the following paragraphs, this has made the sustainable use and management of BCLME living resources difficult.
Fragmented Management: A Legacy of the Colonial and Political Past 2
Following the establishment of European settlements at strategic coastal locations where victuals and water could be procured to supply fleets trading with the East Indies, the potential wealth of the African continent became apparent. This resulted in the great rush for territories and the colonisation of the continent - mostly during the nineteenth century. Boundaries between colonies were hastily established, often arbitrary and generally with little regard for indigenous inhabitants and natural habitats. Colonial land boundaries in the Benguela region were established at rivers (Cunene, Orange). Not only were the languages and cultures of the foreign occupiers different (Portuguese, German, English, Dutch) but so were the management systems and laws which evolved in the three now independent and democratic countries of the region - Angola, Namibia and South Africa. Moreover, not only were the governance frameworks very different, but a further consequence of European influence was the relative absence of inter-agency (or inter-ministerial) frameworks for management of the marine environment and its resources and scant regard for sustainability. To this day mining concessions, oil/gas exploration, fishing rights and coastal development have taken place with little or no proper integration or regard for other users. For example, exploratory wells have been sunk in established fishing grounds and the well- heads (which stand above of the sea bed) subsequently abandoned. Likewise the impact of habitat alterations due to mining activities and ecosystem alteration (including biodiversity impacts) due to fishing have not been properly assessed.
Prior to the coming into being of the United Nations Convention on the Law of the Sea and declaration and respecting of sovereign rights within individual countries' Exclusive Economic (or Fishing) Zones, there was an explosion of foreign fleets fishing off Angola, Namibia and South Africa during the 1960s and 1970s - an effective imperialism and colonisation by mainly First World countries of the BCLME, and the rape of its resources. This period also coincided with liberation struggles in all three countries, and associated civil wars. In the case of Namibia, over whom the mandate by South Africa was not internationally recognised, there was an added problem in that prior to independence in 1990, an EEZ could not be proclaimed. In an attempt to control the foreign exploitation of Namibia's fish resources, the International Commission for the South-east Atlantic Fisheries (ICSEAF) was established, but this proved to be relatively ineffectual at husbanding the fish stocks. In South Africa prior to 1994, environmental issues and sustainable management were low on the political agenda. Moreover, the legacy of the past has resulted in a marked gradient in capacity from south to north in the region. Consequences of the civil wars have been the human population migration to the coast, localised pressure on marine and coastal resources (e.g. destruction of coastal forests and mangroves), and severe pollution of some embayments.
While mineral exploration and extraction and developments in the coastal zones obviously occur within the geographic boundaries of the three countries, i.e. within the EEZs, and can to a large degree be independently managed by each of the countries, mobile living marine resources do not respect the arbitrary geographic borders. This has obvious implications for the sustainable use of these resources, particularly so in the case of straddling and shared fish stocks.
Thus the legacy of the colonial and political past is that the management of resources in the greater Benguela area has not been integrated within countries or within the region. The real challenge of the BCLME will be to develop a viable joint and integrative mechanism for the sustainable environmental management of the region as a whole, i.e. at the ecosystem level.
The Need for International Action
In the BCLME the issue of sustainable ecosystem management under conditions of environmental variability and uncertainty within a developing regional context presents an ideal opportunity for the international community to provide material assistance to enable the three countries, via a joint partnership, to establish and implement the appropriate framework for management actions. Countries such as Norway and Germany are already providing much needed expertise and assistance through the coordinated regional BENEFIT mechanism (discussed in the next section), but there is a clear need for greater international involvement to enable the region, for example, to repair the damage done by the ravages of gross over-exploitation of fish resources by foreign fleets in the 1960s, 1970s and 1980s. As has been previously mentioned there exists a sharp capacity gradient (human and infrastructure) from 3 south to north in the BCLME, and while there is a very obvious willingness in the region to share knowledge, expertise and facilities with those who are more disadvantaged, international commitment from the GEF (Global Environmental Facility) International Waters Programme towards capacity and institutional strengthening, and integrated management will greatly help accelerate this process.
As has been noted, the mobile components of the BCLME do not respect the arbitrary geopolitical (country) boundaries. Several fish stock straddle or are shared between the countries or otherwise migrate through the Benguela. Actions by one country, e.g. over-exploitation or habitat destruction, of their part of a migrating or shared resource could in effect negatively impact on one or both neighbouring countries. Joint management and protection of shared stocks is one of the few available options to the countries bordering the BCLME. In this manner, a better sense of ownership of the regions' resources can be attained, and "owners" tend to protect their property more so than those enjoying a free service. There is thus a strong need for harmonising legal and policy objectives and for developing common strategies for resource surveys, and investment in sustainable ecosystem management for the benefit of all the people in the Benguela region. Only concerted regional action and enablement from the international community to develop regional agreements, and legal frameworks and assessment/implementation strategies will in the longer term protect the biological diversity of the greater Benguela.
While shared living resources present the most obvious case for co-management, there are many activities and issues which can benefit from expertise and management structures developed and implemented in individual countries. These include inter alia mining, declining coastal water quality (pollution abatement and control, oil spill clean-up technology) oil/gas extraction, coastal zone development, tourism and eco-tourism development, mitigation of the effects of introduced species (aliens) and harmful algal blooms - which can also have system-wide impacts.
The BCLME Programme, which builds on existing regional capacity and goodwill, could serve as a blueprint for the design and implementation of LME initiatives in other upwelling regions and elsewhere in the developing world. Moreover, the BCLME Programme will address key regional environmental variability issues that are expected to make a major contribution towards understanding global fluctuations in the marine environment, including climate change.
The Success Story of BENEFIT
In April 1997 a major regional cooperative initiative was launched jointly by Angola, Namibia and South Africa together with foreign partners "to develop the enhanced science capacity required for the optimal and sustainable utilization of living resources of the Benguela ecosystem by (a) improving knowledge and understanding of the dynamics of important commercial stocks, their environment and linkages between the environmental processes and the stock dynamics, and (b) building appropriate human and material capacity for marine science and technology in the countries bordering the Benguela ecosystem". This BENEFIT (BENguela-Environment-Fisheries-Interaction & Training) Programme evolved out of a Workshop/Seminar on "Fisheries Resource Dynamics in the Benguela Current Ecosystem" held in Swakopmund in mid-1995 which was hosted by the Namibian Ministry of Fisheries and Marine Resources in partnership with the Norwegian Agency for Development Co-operation (NORAD), the German Organisation for Technical Co-operation (GTZ) and the Intergovernmental Oceanographic Commission (IOC) of UNESCO. BENEFIT was developed in the region by Angola, Namibia and South Africa and is jointly managed and directed by the three countries. BENEFIT has attracted substantial incremental support from overseas countries and international donor agencies. It remains, however, essentially a regional "self help" initiative, and has been endorsed by the Southern African Development Community (SADC) and accepted as a SADC programme. It is providing a unique opportunity for development of partnerships within and beyond the southern African region in science and technology to promote optimum utilization of natural resources and thereby greater food security in the region.
BENEFIT has been planned in two five-year phases (1997-2002, 2002-2007). The science and technology component of BENEFIT has three foci, viz resource dynamics, the environment (of the 4 resources) and linkages between resources and the environment. These foci are increasing knowledge of resource dynamics through improved research on the resources and their variable environment. The capacity development component of the Programme is being addressed through a suite of task- orientated framework activities to (a) build human capacity, particularly in areas of greatest need and greatest historical disadvantage, (b) develop, enhance and maintain regional infrastructure and cooperation, and (c) to make the countries in the region and the region as a whole more self-sufficient in science and technology. The BENEFIT Secretariat is based in Namibia, while management meetings are held on a rotating basis in Angola, Namibia and South Africa.
The launch of BENEFIT in April 1997 coincided with two major research cruises/surveys of the Angola-Benguela Front which focused on fisheries and environment. (This front is situated west of Angola and is thought to play an important role as a permeable internal "boundary" within the BCLME, and demarcates the northern extent of pronounced coastal upwelling). During the past two years BENEFIT increasingly gathered momentum with funding for priority projects being allocated and real progress in human capacity development being made. Some recent achievements are briefly as follows:
* Several reports and scientific/technical papers have been published on the results of the 1997 Angola-Benguela Front surveys, and several regional scientists and technicians received hands on training at sea, in the laboratory and in data analysis * A German sponsored BENEFIT Training Course was conducted in Namibia in 1997 and a number of regional scientists received subsequent further training in Germany and in Norway * Fifteen fisheries and fisheries-environment (incremental) projects have been approved for funding in 1999 * Two training workshops have taken place (1998 and 1999) and a BENEFIT Training Plan to complement the Science Plan is under development this year * In the first half of 1999 over 50 persons from the broad SADC region have been trained during three BENEFIT cruises, including a 40-day survey of resources and the environment which extended between Cape Town and Luanda, primarily funded by the African Development Bank and The World Bank.
In addition to the above, strong links have been built between BENEFIT and three parallel (but distinctly different) programmes, viz South Africa's established and internationally acclaimed Benguela Ecology Programme (BEP), ENVIFISH (a three year European Union funded project between seven EU states and Angola, Namibia and South Africa which focuses primarily on the application of satellite data in environment-fisheries research and management, and which commenced in October 1998) and VIBES (a bilateral French-South African initiative which focuses on the variability of pelagic fish resources in the Benguela and the environment and spatial aspects of the system - which also commenced in 1998). In all of these initiatives the emphasis is on science of technology per se, and not on the much-needed transboundary management issues.
BENEFIT and related activities provide clear evidence of the desire and capability of Angola, Namibia and South Africa to work together to solve common problems in the Benguela region in partnership with the international community. This can form a strong base on which to develop integrated management structures.
The Emerging BCLME Programme
The seed for the BCLME Programme was sown at the Workshop/Seminar on Fisheries Resource Dynamics in the Benguela Current Ecosystem held in Swakopmund, Namibia, in May/June 1995 - the same meeting which laid the foundation for BENEFIT. However, whereas BENEFIT focuses on science and technology as applied to fisheries and the fish environment and science capacity development, the focus of the BCLME Programme is different. In contrast to BENEFIT, the Benguela Current LME programme is a broad based multi-sectoral initiative aimed at sustainable integrated management of the Benguela Current ecosystem as a whole. It will focus on a number of key sectors including fisheries and environmental variability, sea-bed mining, oil and gas exploration and production, coastal zone management, ecosystem health and socio-economics and governance. 5
Transboundary management issues, environmental protection and capacity strengthening will be of primary concern to the BCLME programme.
Inspired by the 1995 Workshop/Seminar and the progress being made on sustainable management of other LMEs - the Black Sea LME in particular - and in order to develop a viable action plan to ensure the sustainable management of the greater Benguela ecosystem, the three countries bordering the Benguela (Angola, Namibia and South Africa) requested support from the Global Environmental Facility, GEF, a fund established in 1991 under the management of The World Bank, the United Nations Development Programme (UNDP) and the United Nations Environmental Programme(UNEP)). An embryonic GEF/PDF Block B Grant application was developed by a small group in late 1995, subsequently refined with the assistance of UNDP staff, and submitted to the GEF. Following grant approval, US$344000 was made available by the GEF in 1998 to enable the development of a comprehensive project proposal including the necessary instruments such as the synthesis and assessment of information on the BCLME (contained in six comprehensive Thematic Reports), a Transboundary Diagnostic Analysis (this document), Strategic Action Programme, and Project Brief.
What Has Been Achieved?
Following the approval of the PDF Block B Grant a small Management Committee was established, with members being appointed to represent the governments of the three countries, UNDP and some donors. A Project Coordinator was appointed, based in Windhoek, Namibia, with logistical, administrative and infrastructure support provided by the Namibian Ministry of Fisheries and Marine Resources (as implementing agency) and administrative assistance by the UNDP Office in Windhoek.
In July 1998 the First Regional BCLME Workshop was held in Cape Town, which was followed by a formal meeting of key stakeholders. The Workshop was attended by approximately 100 regional and international experts and stakeholders representing a broad cross-section of the public and private sectors in Angola, Namibia and South Africa. The following inter alia were among the organisations in the three countries represented at the workshop:
From Angola: Ministry of Fisheries, Ministry of Environmental Affairs, Ministry of Science and Technology, Augostino Neto University, TEXACO, National Oil Company(SONANGOL), National Fishing Industry, Swedish International Development Agency (SIDA) From Namibia: Ministry of Environment and Tourism, Ministry of Fisheries and Marine Resources, Ministry of Agriculture Water and Rural Development, Ministry of Works Transport and Communication, Ministry of Trade and Industry, Ministry of Mines and Energy, NAMPORT, Meteorogical Service, BENEFIT Secretariat, Southern African Development Community (SADC), Desert Research Foundation, National Petroleum Corporation of Namibia (NAMCOR), Shell Exploration Namibia, Lalandii, UNDP, Namibian Minerals Corporation (NAMCO), German Organisation for Technical Co-operation (GTZ). From South Africa: Department of Environmental Affairs and Tourism, Department of Mineral and Energy Affairs, National Parks Board, Cape Nature Conservation, Western Cape Provincial Administration, Northern Cape Provincial Administration, SA Pelagic Fishing Industry Association, SA Deep Sea Trawling Industry Association, University of Cape Town, Port Nolloth Sea Farms, Eco-Africa, University of the Western Cape, SOEKOR, CSIR, PORTNET, Ocean Diamond Mining, South-east Coast Inshore Fishing Association, Tuna and Linefish Association, De Beers Marine, various consultancies. (For further particulars and details of international participants, refer to Workshop documentation)
The workshop which was moderated by an independent international facilitator, generated a wealth of information and ideas relevant to the development of a viable BCLME Programme. The objectives of the Workshop were to identify issues and problems/constraints in the Benguela, to attempt to prioritise these and propose possible solutions, to forge consensus among the various stakeholders and role- players, to develop an implementable work plan and a mechanism for consultation and cooperation. The success and output of this First Workshop can be gauged by the content of the Workshop Report which is appended as a supporting document. At the Workshop keynote addresses were delivered on other 6
LMEs (Yellow Sea, Baltic, Bay of Bengal, Gulf of Guinea), the LME concept, International Waters and the GEF and on various aspects of the Benguela per se viz the environment, fisheries, oil and gas industries, mining, coastal zone management and pollution. These overviews provided useful inputs for the subsequent group discussions from which the consensus on problems and priorities emerged. The Stakeholders Meeting held after conclusion of the Workshop addressed issues such as communication, the budget, donor involvement, studies/consultancies, project coordination and the workplan.
Subsequent to the First Regional Workshop, consultants were appointed to prepare comprehensive syntheses and assessments of information on the BCLME. This resulted in the production of six Thematic Reports ("Integrated Overviews") on:
* Fisheries * Oceanography and Environmental Variability * Diamond Mining * Coastal Environments * Off-shore Oil and Gas Exploration/Production * Socio-economics of Some Key Maritime Industries
A Second Regional BCLME Workshop was held at Okahanjo near Windhoek, Namibia, during April 1999. At this Workshop the thematic reports were briefly reviewed. These syntheses, together with the output from the First Workshop, served as a basis for the development of a draft Transboundary Diagnostic Analysis (TDA). Many of those who had attended the First Regional BCLME Workshop participated in the Second Workshop, and this provided a fair balance across the various stakeholders in the three countries. Although there were necessarily fewer participants(40) all were either acknowledged regional experts on the BCLME representing the main stakeholders or otherwise international LME experts (refer to the Report of the Second Regional Workshop for more comprehensive information). At the Workshop the participants divided into three groups to address the three major issues in the BCLME, viz (1) utilization of resources, (2) environmental variability and (3) ecosystem health and pollution. A breakdown of the sectoral and stakeholders involvement in each of these three groups is appended at the back of this document. Excellent progress was made at the Workshop thanks to quality of the leadership provided by the facilitator, the guidance by the international representatives of UNDP-GEF and NOAA (LME concept) and the spirit of cooperation and goodwill of the participants. The essential elements for the TDA were formulated (and prioritised) as per the path: issues> problems> causes> impact> uncertainties> socio-economic consequences> transboundary consequences> activities/solutions> priority> outputs> costs. This consensus Workshop product forms the basis for the present TDA. Prior to the conclusion of the Workshop, the framework for the Strategic Action Plan was defined and a Work Plan to finalise the BCLME project development phase was formulated.
A small task team was appointed to draft a TDA document based on the output of the Second Regional BCLME Workshop. The draft TDA was circulated to the members of the BCLME Management Committee for comment in July 1999, and was revised so as to comply with GEFSEC requirements and endorsed as a meeting of the Management Committee held in Cape Town on 30 September - 1 October 1999.
Towards a Sustainable Future: The Next Steps
What was clear by the end of the Second Regional Workshop was that an enormous amount of goodwill, information and ideas has been generated within the region relevant to the sustainable management of the Benguela Current ecosystem. This bodes well for the future and provides a strong foundation, not only to develop a really viable LME approach to the Benguela Current region, but also to provide a blueprint for how "convex" or open system LMEs should be developed internationally. This contrasts the approaches for the existing predominantly "concave" or closed system LMEs that have already been developed: In other words, sustainable integrated management of a highly variable open-boundary ecosystem. 7
Correcting decades of over-exploitation of resources in the Benguela ecosystem and fragmented management actions (the consequence of the colonial/political past and greed) will require a substantial co-ordinated effort during the next decade, to be followed by sustained action on a permanent basis. A task of this magnitude will require careful planning not only by the government agencies in the three countries bordering the Benguela Current, but also by all the other stakeholders. There already exists the willingness on the part of the key players to collaborate to achieve this objective, but the real challenge will be to develop systems and structures that take cognisance of the naturally highly variable and potentially fragile nature of the BCLME and its coastal environments within the context of a changing society and world. The many issues and problems, as well as possible solutions, have been identified and prioritised in the Transboundary Diagnostic Analysis tables. The resolve of the governments of Angola, Namibia and South Africa to correct the wrongs of the past and move forward with a new vision to ensure that the BCLME can be sustainably utilized and enjoyed by future generations for the benefit of all is embodied in the elements of the Strategic Action Plan. This Plan is much more than just a piece of paper: It is a pragmatic, workable framework and unambiguous statement of common goals and objectives and the means of their achievement. Success will depend on thorough implementation of the principles, commitments and actions embodied in the Plan, both explicit and implicit.
In the TDA synthesis and analysis tables a number of major transboundary problems in the BCLME have been identified. These include inter alia, non optimal harvesting of living resources, uncertainty regarding ecosystem status and yields in a highly variable environment, deterioration in water quality, habitat destruction and alteration, loss of biotic integrity and threat to biodiversity, harmful algal blooms, introduction of alien species and inadequate regional capacity (human and infrastructure). Over-arching generic actions which are needed to address these transboundary problems must focus on capacity strengthening and training, policy development and harmonisation, and development of regional collaboration or networking in respect of surveys and assessment of the ecosystem status. These actions are appropriate within the context of a GEF project and it is envisaged that the role of the GEF in the implementation phase of the BCLME Programme will take the form of institution building, strengthening capacity needed in the region to facilitate integrated management, and sharing the costs of the actions with the three governments and donors. The GEF should be catalytic in helping to leverage sustainable (long term) funding and mobilise private sector funding. Through such a process it is anticipated that, following the conclusion of the GEF funded BCLME component, the necessary capacity and institutional structures and sustainable funding will be available in the region to ensure the on-going integrated management of the BCLME. Specific actions in which the GEF will play a role will include inter alia:
* development of appropriate transboundary frameworks and mechanisms at regional, national and local levels for consultation, coordination and cooperation * development of institutional capacities of the key agencies and institutions in the region that contribute to the integrated sustainable management of the BCLME * effective ecosystem assessment and development of an early warning system for ecosystem change * actions to fill the gaps in our understanding of the BCLME, its functioning, and the factors which affect it (biophysical, social, economic and political) * harmonization of policies and legislation relating to activities affecting BCLME * increased external support for activities to minimise and mitigate the negative impacts of development (mining, urbanisation, tourism development, resource exploitation) through the promotion of sustainable approaches and the use of appropriate tools * measures to improve sustainable resource management * measures to protect biological diversity * quantification of the role of BCLME as a source/sink of CO2 and clarification of the role of BCLME as a targeted early warning site for global change.
This is seen as compatible with the three elements of the GEF-funded International Waters activities to meet incremental costs of: 8
1. assisting groups of countries better understand the environmental concerns of their international waters and work collaboratively to address them 2. building capacity of existing institutions, or through new institutional arrangements, to utilize a more comprehensive approach for addressing transboundary water-related environmental concerns, and 3. implementing sustainable measures that address priority transboundary environmental concerns.
Policies, structures and actions developed during the implementation phase of the BCLME Programme, i.e. over the next five years, must by the end of the period be self-sustainable in the region. To achieve this it is essential that mechanisms be in place to encourage, indeed ensure, a substantial degree of co- financing of activities. This can best be done by involving and developing partnerships with maritime and coastal industries, the international community and present and future beneficiaries, i.e. all those who have a stake in the long-term health and viability of the Benguela as a LME. 9
USERS GUIDE TO THE TRANSBOUNDARY DIAGNOSTIC ANALYSIS (TDA)
Definitions and TDA Objective
A Transboundary Diagnostic Analysis is a scientific and technical assessment, through which the water-related environmental issues and problems of a region are identified and quantified, their causes analysed and their impacts, both environmental and economic, assessed. The analysis involves the identification of causes and impacts (and uncertainties associated with these) at national, regional and global levels, and the socio-economic, political and institutional context within which they occur. The identification of the causes should, where appropriate, specify sources, locations and sectors. The TDA assessment should indicate which elements are clearly transboundary in character and list and prioritise activities or solutions to address the issue/problem and the root causes.
Within the context of the TDA, transboundary environmental issues include inter alia:
* regional/national issues with transboundary causes/sources * transboundary issues with national causes/sources * national issues that are common to at least two of the countries and that require a common strategy and collective action to address * issues that have transboundary elements or implications (e.g. fishery practices on biodiversity/ecosystem resilience).
The objective of the Benguela Current TDA is to provide, on the basis of clearly established evidence, structured information relating to the degradation and changing state of the Benguela Current LME, to scale the relative importance of the causes and sources of the transboundary water-related problems, and to elucidate practical preventative and remedial actions to ensure the sustainable integrated management of this unique environment. The TDA provides the technical basis for the development of a Strategic Action Plan (SAP), and the Project Brief, for the BCLME within the International Waters Area of the GEF.
Design of the TDA
Comprehensive information about the status of the BCLME, the principal issues and problems, their causes and impacts, generated at the First Regional BCLME Workshop in mid-1998 and through a suite of Thematic Reports subsequently prepared by regional/international experts was examined at the Second Regional BCLME Workshop (April 1999), synthesised and then condensed into a series of analytical tables. These are presented in this document.
The current TDA has been designed at two operational levels. These are as follows:
(a) Level One: Synthesis: The issues and perceived main transboundary problems, root causes and areas where action is proposed
This level, consisting of a Synthesis Matrix and some explanatory text about the transboundary characteristics of the BCLME serves as a logistical "map" for the TDA. It considers the main issues and major perceived environmental problems which must be addressed for the sustainable integrated management of the BCLME. It examines the transboundary elements of the problems (i.e. elements shared by at least two of the three countries) and then relates them to their major underlying institutional, societal or global root causes. In all cases the root causes are common to a large number of problems and require changes to the role given to environmental issues within the priorities of the governments and the public in general. The matrix identifies three generic areas (issues) where proposals for action can be formulated, viz utilization of resources, environmental variability and pollution/ecosystem health. For each of these generic areas a number of more specific issues ("sub- issues") are identified. These are extensively developed at the next level of the TDA. A simplified version of the Synthesis Matrix is given in Fig.2. 10
(b) Level Two: Specifics: Comprehensive information on the issues, sub-issues, problems, causes, impacts, uncertainties, socio-economic consequences, the perceived solutions, priorities, outputs and costs
Working on the basis of the issues and major problems perceived in Level One, the tables and text which comprise Level Two examine the nature of the specific problems identified as contributors to ecosystem degradation and change in the Benguela Current region. They examine the management uncertainties (in the case of environmental variability, the uncertainty of the variability per se) and knowledge gaps which need to be filled. They present priority practical and implementable proposals for inclusion in the BCLME SAP and the cost of the required international action where possible. Finally the series of tables identify the outputs (products) which should be obtained through the successful implementation of the action and lists the stakeholders for each problem and action area identified. Explanatory text is provided for each sub-issue table.
More Information
Readers requiring more information about the BCLME, present state of knowledge about ecosystem structure and functioning, its complexity, ecosystem status, ongoing work and principal management problems are referred to the following:
* Report on the First Regional BCLME Workshop (73pp) * Report on the Second Regional BCLME Workshop (72pp) * Background Papers for the First Regional BCLME Workshop * Synthesis and Assessment of Information on the BCLME: Thematic Reports 1-6 * Proceedings of the International Symposium on Environmental Variability in the South-east Atlantic, March/April 1998 (approx 600pp) * Proceedings of the Workshop on Environmental Variability, Environmental Monitoring and Environmental Strategic Planning, April 1998 (28pp) * The Benguela and Comparable Ecosystems (South African Journal of Marine Science, Vol.5, 1987: 957pp) * Benguela Trophic Functioning (South African Journal of Marine Science, Vol.12, 1992: (1108pp) * Benguela Dynamics (South African Journal of Marine Science, Vol.19, 1999: 512pp) 11
BCLME TRANSBOUNDARY DIAGNOSTIC ANALYSIS
Geographic Scope & Ecosystem Boundaries
Conducting a comprehensive transboundary analysis is only possible if the entire LME, including all inputs to the system, is covered in the study. In the case of the Benguela, which is a very open system where the environmental variability is predominantly remotely forced, this should then include the tropical Atlantic sensu latu, the Agulhas Current (and its link with the Indo-Pacific) the Southern Ocean and the drainage basins of all major rivers which discharge into the greater Benguela Current region including the Congo River. Clearly such an approach is impracticable, and more realistic and pragmatic system boundaries have to be defined in order to develop and implement a viable ecosystem management framework. The principal external and internal system boundaries are shown in Fig.1.
* Landward boundary: With the exception of the Congo River, the main impact of discharges from rivers flowing into the South-east Atlantic tends to be episodic in nature, i.e. in terms of significant transboundary concerns, these are limited to extreme flood events. (Their drainage basins nevertheless do include a major part of the southern African hinterland). The Congo River, however, exerts an influence which can be detected over thousands of kilometers of the South Atlantic and drains much of Central Africa. From a practical poing of view, it is quite beyond the scope of the BCLME to attempt to include the development of any management structures for a river such as the Congo. With respect to land sources of pollution in the BCLME (excluding the Congo River area), these are only really significant in the proximity of the principal port-cities, e.g. Cape Town, Luanda, Walvis Bay, and the effects are generally very localised. Nevertheless, some of the problems experienced in these areas are common in nature and could be addressed through similar remedial actions. Like coastal development, their impacts generally do not have a transboundary character. (Pollution from ships, major oil spills, introduction of alien species and associated harmful algal blooms, etc. are, in contrast, transboundary concerns). From a BCLME perspective, the landward boundary can thus, for all practical purposes, be taken as the high water mark at the coast. Specific allowances can be made in some areas on a case by case basis (e.g. during episodic flooding from the Orange and Cunene Rivers which are situated at the country boundaries of South Africa-Namibia and Namibia-Angola respectively).
* Western boundary: The Benguela Current is generally defined as the integrated equatorward flow in the upper layers of the ocean in the South-east Atlantic between the coast and the 00meridian. The BCLME Programme will accordingly use 00 as the western boundary, but for practical management purposes the focus will be on the areas over which the three countries have some jurisdiction, i.e. their Exclusive Economic Zones which extend 200 nautical miles seawards from the land.
* Southern/eastern boundary: The upwelling area of the BCLME extends around the Cape of Good Hope, seasonally as far east as Port Elizabeth. This extreme southern part of the ecosystem is substantially influenced by the Agulhas Current, its Retroflection (turning back) and leakage of Indian Ocean water into the Atlantic south of the continent. As the variability of the BCLME is very much a function of the complex ocean processes occurring in the Agulhas Current - Retroflection area, this will be taken as the southern boundary with 27 0E longitude (near Port Elizabeth), being at the extreme eastern end.
* Northern boundary: While the Angola-Benguela Front (more correctly a series of fronts) comprises the northern extent of the main coastal upwelling zone, upwelling can occur seasonally along the entire coast of Angola. There are, in any event, strong linkages between the behaviour of the Angola-Benguela Front (and the oceanography of the area to the south of it) and processes occurring off Angola, especially the Angola Dome and the Angola Current. Unless these are considered as an integral part of the BCLME, it will not be feasible to evolve a sustainable integrated management approach for the Benguela. Moreover, there is a well- defined front at about 50S, viz the Angola Front which is apparent at sub-surface depths. It is 12
this front which is the true boundary between the Benguela part of the South Atlantic and the tropical/equatorial Gulf of Guinea system. A northern boundary at 50S would thus encompass the Angola Dome, the coastal Angola Current and the area in which the main oxygen minimum forms and the full extent of the upwelling system in the South-east Atlantic. A pragmatic northern boundary is thus at 50S latitude, which is in the vicinity of the northern boundary of Angola (Cabinda) and the southern extent of the Gulf of Guinea Large Marine Ecosystem(GOGLME). Strong links will need to be built between the BCLME and the GOGLME (and other initiatives in the tropical Atlantic) in order to develop an eventual holistic approach to the management of the South-east Atlantic Ocean.
Level One: Synthesis: The Issues and Perceived Main Transboundary Problems, Root Causes and Areas where Action is Proposed
Seven perceived major transboundary problems have been identified. These are listed below, together with a short description of the transboundary characteristics of each of them. The Synthesis Matrix or "logistical map" and Fig.2 which then follow the description encapsulate the essence of the TDA. They highlight the transboundary elements and root causes associated with each problem and schematically show how the proposed actions serve to address the causes and help solve the problems:
Problem (i): Decline in BCLME commercial fish stocks and non-optimal harvesting of living resources Transboundary Characteristics: Country boundaries do not coincide with ecosystem sub-boundaries; most of the regions' important harvested resources are shared between countries, or move across national boundaries at times. Over-harvesting of a species in one country can therefore lead to depletion of that species in another, and in changes to the ecosystem as a whole. Moreover, many resource management difficulties are common to all the countries.
Problem (ii): Uncertainty regarding ecosystem status and yields in a highly variable environment Transboundary Characteristics: The Benguela environment is highly variable and the ecosystem is naturally adapted to this. However, sustained large scale environmental events such as Benguela Niños, episodic hypoxia/anoxia, Agulhas intrusions and changes in winds, affect the ecosystem as a whole, compounding the negative effects of fishing. These events and changes generally have their origin and cause outside of the BCLME, but are of such a scale that the impacts occur in ther international water areas of all three countries i.e. the changes propagate across external BCLME boundaries and internal geopolitical boundaries. The poor ability to predict the events and change limits the capacity to manage effectively system wide. In addition the BCLME is believed to play a significant role in global ocean and climate processes and may be an important site for the early detection of global climate change.
Problem (iii): Deterioration in water quality - chronic and catastrophic Transboundary Characteristics: Although most impacts of chronic deterioration in water quality are localised (national issues), they are common to all of the countries and require collective action to address. Moreover, chronic pollution can favour the development of less desirable species, and result in species migration. Catastrophic events (major oil spills, maritime accidents) can impact across country boundaries, requiring co-operative management and sharing of clean-up equipment and manpower.
Problem (iv): Habitat destruction and alteration, including inter alia modification of seabed and coastal zone and degradation of coastscapes Transboundary Characteristics: Although most impacts may appear localised, habitat alteration or loss due to fishing and mining can cause migration of fauna and system-wide ecosystem change. Uncertainties exist about the regional cumulative impact on benthos resulting from mining and associated sediment re-mobilisation. Moreover, certain mining activities are conducted close to national boundaries and negative consequences may be transmitted across into the adjacent country’s EEZ. Inadequately planned coastal developments result in degradation of coastscapes and reduce the regional value of tourism.
Problem (v): Loss of biotic integrity (changes in community composition, species and diversity, introduction of alien species, etc.) and threat to biodiversity/endangered and vulnerable species 13
Transboundary Characteristics: Most harvested fish species are shared between countries and straddle geopolitical boundaries. Past over-exploitation of targeted fish species has altered the ecosystem as a whole, impacting at all levels, including on top predators and reducing the gene pool. Some species, e.g. African penguin, are threatened or endangered. Exotic species have been introduced into the Benguela. (This is recognised as a global transboundary problem).
Problem (vi): Inadequate human and infrastructure capacity to assess the health of the ecosystem as a whole (resources and environment, and variability thereof) Transboundary Characteristics: There is inadequate capacity, expertise and ability, in the region to monitor and assess adequately the shared living resources and system-wide environmental variability. Moreover, there is unequal distribution of this capacity between the three countries.
Problem (vii): Harmful algal blooms (HABs) Transboundary Characteristics: HABs occur in all three countries, who face similar problems in terms of impacts and management, and which require collective regional action to address. 14
Benguela Current Transboundary Diagnostic Analysis Transboundary Diagnostic Analysis (TDA)
LEVEL ONE
Synthesis Matrix 15
Level Two: Action Areas: An Overview of Specific Transboundary Problems, Causes, Impacts, Actions Required and Anticipated Outputs
In Level One: Synthesis, three broad action areas were identified in order to address the perceived major BCLME problems and the main root causes of these problems. The action areas correspond to the three main issues in the BCLME, namely utilization of resources, environmental variability, and ecosystem health and pollution. For each action area a set of more specific actions was specified in the Synthesis Matrix. These specific actions were formulated collectively through consensus among stakeholders at the Second Regional BCLME Workshop to identify the specific problems associated with each main issue. These have been prioritised and the outputs or solutions emanating from the specific actions have been listed and costed. The essential information has been summarised in the set of analysis tables which follow. These tabular summaries are necessarily brief - often in point form - and where additional clarification has been deemed necessary, this has been provided following each table in the form of explanatory notes.
What is not immediately apparent from the Level Two tables which were developed by consensus at the Second Workshop is that there are a number of generic actions which cut across the specific actions within each of the three broad action areas, and indeed even between the broad action areas. For the sake of completeness the essence of this alternative but complementary approach is as follows:
Action Area A: Sustainable management and utilization of resources Generic Actions: * Capacity strengthening and training Joint surveys and assessments of shared resources and intercalibration Policy harmonization and integrated management Co-financing with private sector/industry Development of new industries (e.g. mariculture, tourism)
Action Area B: Assessment of environmental variability, ecosystem impacts and improvement of predictability Generic Actions: * Capacity strengthening and training re transboundary concerns Regional networking and international linking Development of regional early warning system, assessment and prediction capability (including re- assessments) and joint response policies Cross-cutting demonstration projects
Action Area C: Improvement of ecosystem health and management of pollution Generic Actions: * Capacity strengthening and training Policy harmonization, and development Development of regional framework for assessment Establishment of effective surveillance and enforcement agencies Development of stakeholder participation structures
What emerges quite clearly from the above approach is that generic actions, such as capacity strengthening and training, the development of regional collaboration or networking in respect of surveys and assessments, and policy development and harmonization, are over-arching actions. These are obvious priorities for GEF support. 16
Benguela Current Transboundary Diagnostic Analysis Transboundary Diagnostic Analysis (TDA)
LEVEL TWO
Analysis Tables and Explanatory Notes
Note: The numbering of these tables corresponds with the action areas identified in the Level One Synthesis Matrix 17
BENGUELA CURRENT LARGE MARINE ECOSYSTEM PROGRAMME
TRANSBOUNDARY DIAGNOSTIC ANALYSIS TABLES
TABLE A 1-5 Sustainable Management and Utilization of Resources
A1 Facilitation of Optimal Harvesting of Living Resources A2 Assessment of Mining and Drilling Impacts and Policy Harmonization A3 Responsible Development of Mariculture A4 Protection of Vulnerable Species and Habitats A5 Assessment of Non-Harvested Species and their Role in the Ecosystem
TABLE B 1-3 Assessment of Environmental Variability, Ecosystem Impacts and Improvement of Predictability
B1 Reducing Uncertainty and Improving Predictability B2 Capacity Strengthening and Training B3 Management of Consequences of Harmful Algal Blooms
TABLE C1-5 Maintenance of Ecosystem Health and Management of Pollution
C1 Improvement of Water Quality C2 Prevention and Management of Oil Spills C3 Reduction of Marine Litter C4 Retardation/Reversal of Habitat Destruction/Alteration C5 Conservation of Biodiversity 18
`
SYTHESIS MATRIX
Perceived Major Transboundary Major Proble m Elem e n t s Root Caus e s Decline in BCLME Most of the regions 1,2,3,4,5,6 A,B (C) commercial fish important harvested ,7 stocks and non- resources are shared optimal harvesting between countries, or of living resources move across national boundaries at times, requiring joint management effort Uncertainty Environmental 1,2,3,7 A,B,C regardin g variability/change ecosystem status impacts on ecosystem and yields in a as a whole, and poor highly variable predictive ability limits environment effective management. The BCLME may also be important to global climate change Deterioration in While most impacts are 2,3,4,5,7 C water quality - localised, the problems chronic and are common to all three catastrophic countries and require collective action to address Habitat destruction Uncertainties exist 2,3,5,6,7 A,C (B) and alteration, about the regional includin g inter alia cumulative impact from modification of mining on benthos and seabed and coastal ecosystem effect of zon e and fishing. Degradation of degradation of coastscapes reduce coastscapes regional value of tourism Loss of biotic Fishing has altered the 1,3,5,6 A,C (B) integrity* and ecosystem as a whole, threat to reduced the gene pool, biodiversity/ and caused some endangered and species to become vulnerable species endangered or threatened. Introduced *Changes in alien species are a comm u nity global transboundary composition, species problem diversity, introduction of alien species etc. Inadequate There is inadequate 1,2,5,7 A,B,C capacity to assess capacity in the region to ecosystem health assess the shared (resources and resources and the environment, and system- wide variability thereof) environmental variability, and unequal distribution of the capacity between 19
countries Harmful algal HABs are a common 1,2,3,6,7 A,B,C blooms (HABs) problem in all three countries and require collective action to address Activit y Areas 20
Main Root Cause
1 Complexity of ecosystem and high Changing state of the Benguela degree of variability (resources and Inadequate information and understanding environment) Difficulty in monitoring and assessment Poor predictability
Colonial/political past Institutional downsizing and braindrain 2 Inadequate capacity development Limited inter-country exchange (training) (human and infrastructure) and training Regionally incompatible laws and 3 regulations Ineffective environmental laws and Poor legal framework at the regional regulations and national levels
4 Inadequate compliance and enforcement Inadequate implementation of (over fishing, pollution) available regulatory instruments Indifference and poor communication Posts not filled (some inappropriately) 5 Inadequate intersectoral coordination Poorly planned coastal developments Inadequate planning at all levels Limited time horizon of planners Rapid urbanisation and informal settlements
6 Lack of awareness and public apathy Conflicts about rights of access Insufficient public involvement
7 Low country GDPs Ineffective economic instruments Inadequate financial mechanisms and Insufficient funding for infrastructure and support management; poor salaries
Areas Where Action is Proposed
A Sustainable management and Facilitation of optimal harvesting of living utilization of resources resource s Assessment of mining and drilling impacts and policy harmonization Responsible development of mariculture Protection of vulnerable species and habitats Assessment of non-harvested species and role B Assessment of environmental Reducing uncertainty and improving variability, ecosystem impacts and predictability improvement of predictability Capacity strengthening and training Management of consequence of harmful algal blooms C Maintenance of ecosystem health and management of pollution Improvement of water quality Prevention and management of oil spills Reduction of marine litter Retardation/reversal of habitat destruction/alteration Conservation of biodiversity 21 GENERIC ROOT CAUSES
Inadequate Poor legal Inadequate Inadequate Insufficient capacity framework at implementation planning at all public development the regional and of available levels involvement (human and national levels regulatory infrastructure) instruments and training
MAJOR TRANSBOUNDARY PROBLEMS Complexity of Inadequate ecosystem and Decline in BCLME commercial fish stocks financial high degree of mechanisms variability and non-optimal harvesting of living and support resources Uncertainty regarding ecosystem status and yields in a highly variable environment Deterioration in water quality - chronic and catastrophic Habitat destruction and alteration, including inter alia modifications of seabed and coastal zone and degradation of coastscapes Loss of biotic integrity and threat to biodiversity Inadequate capacity to assess ecosystem health Harmful algal blooms
Sustainable Assessment of Maintenance of management environmental ecosyst e m and utilization of variability, health and resources ecosyst e m management of impacts and pollution improvement of predictability
AREAS WHERE ACTION IS REQUIRED
Fig 2 Major transboundary problems, generic root causes and areas requiring action 22
TABLES A: SUSTAINABLE MANAGEMENT AND UTILIZATION OF RESOURCES
TABLE A1: FACILITATION OF OPTIMAL HARVESTING OF LIVING RESOURCES PROBLEMS CAUSES IMPACT RISKS/ SOCIO- TRANS- ACTIVITIES/ PRIORITY INCRE- ANTICIPATED UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y)
A1. Non optimal harvesting of • Fishing • High by-catch & • Irreversible • Variable and • Most harvested • Provision of 1 $ 500 000 • Optimal living resources: Non optimal overcapacity undersize ecosystem change uncertain job resources are information: to sustainable harvesting includes over • Inadequate tools catch • Biodiversity market shared between facilitate regional resource harvesting, such as overfishing, • Non-sustainable • Fisheries impacting Change • Loss of national countries or cross assessments of utilization as well as wastage through productivity • Habitat revenue national borders. shared resources • Improved dumping of bycatch and the utilization of resources cycle destruction • Lack of food Over fishing in and ecosystem forecasting catching and dumping of under- one country can impacts. • Lack of • Ecosystem change • Collapse of security: • Establishment of size fish. It also includes not cause depletion in • 1 • Resource depletion artisanal Joint surveys and a regional forum taking advantage of resources collaborative commercially neighbour $ 2 000 000 assessment and • important stocks /industrial assessments • Prevention of with the potential to offer Human population country. • 1 monitoring • Erosion of Gathering and irresistable sustainable development movements (local & • Common $ 400 000 opportunities (e.g. seaweed, • Inadequate regional) sustainable calibration of ecosystem problems baseline some invertebrates). This often information • Large variation in livelihoods change • • Shared solutions information results from a lack of • Inadequate landings Missed 1 • Analysis of technology or knowledge of the management • Variation in food opportunities $ 400 000 socioeconomic opportunities available. • Inadequate control (under-utilization supply for birds, seals consequences for • etc. & wastage) Lack of • the whole collaborative • Conflict (e.g. Loss of competitive edge ecosystem 2 management of artisanal vs. • on global Assessment of $ 1 000 000 shared resources commercial vs. potential of new • recreational; conflict markets International resources 1 with mining) policy on seal • Establish a $ 800 000 • Exploding seal harvesting regional forum for population stock assessment, • Competition for ecosystem exploited resources assessment and annual advice
A1 EXPLANATORY NOTES. PROBLEM: NON-OPTIMAL HARVESTING OF LIVING RESOURCES
Causes Fishing overcapacity – Too many fishers, too many boats, excess processing capacity. Inadequate tools for assessment – Currently available tools for assessment do not always produce effective results, data for assessment are not equally available and are not in a uniform format. Assessment tools that are available are not applied equally within the region, and fishing methods are not sufficiently selective. Non-sustainable utilization of resources due to overfishing, high bycatch, catches of small fish and non-targeted species. This is a tradition in worldwide fisheries management. Lack of collaborative assessment and monitoring – there is no effective mechanism within the region to ensure that collaborative assessment takes place. Inadequate information – the biology of all harvested and potentially harvested species is not always well known. In the latter, some groups with economic potential, such as seaweeds and some invertebrates, are very poorly known within the region. Inadequate management – management due to insufficient information, vulnerable to pressure from industry, over-riding socioeconomic and political pressures. Lack of informed advice sometimes results in ill-advised management decisions. Inadequate control – even when assessments and quotas are used to manage fisheries, the control and enforcement mechanisms are often lacking Lack of collaborative management of shared resources. 23 International policy on seal harvesting – Conservation pressure on national governments prevents utilization of seals, and contributed to the increase in seal populations, with implications for other components of the ecosystem.
Impacts Resource depletion – This is an obvious effect of over-harvesting, a depletion of the resource below optimal levels. High bycatch & undersize fish catch – This reduces the productivity of fisheries, and may lead to ecosystem change (uncertainty) and decreased yields. Fisheries impacting productivity cycle – The depletion of, for example, a grazer such as pilchard from the system could cause the diversion of production into eutrophication with subsequent sulfur eruptions that might kill off zooplankton grazers and further shift the system out of balance. Changes in the system could reduce yields in other ways too, e.g. changes that favour large gelatinous plankton. Recruitment fisheries result in productivity and yields that are less than what they could be under better management. Ecosystem change – Over-harvesting of ecologically important species may change the nature of the ecosystem, such as diverting productivity into decompositional pathways that may lead to increases in frequency/intensity of anoxic event (S.Afr. J. Mar Sci. 12) Human population migration (local & regional) – Declines in opportunities in resource harvesting at the coast leads to increased migration into cities, and the expansion of urban poverty, exacerbated by large slumps in catches.(BCLME Thematic Report 6) Large variation in landings – results should be precautionary approach leading to reduced levels of over-harvesting. Regularity of employment, reliability of markets, etc. all suffer when variation is great. Variation of food supply for birds, seals etc. Humans and other organisms compete for food. Over-harvesting of resources by humans may lead to a decrease in food supply available to seabirds, seals, and other marine organisms that may themselves be important as tourism resources (S.Afr. J. Mar Sci. 12). Conflict (e.g. artisanal vs. commercial vs. recreational) – Artisanal, recreational and commercial fishers often compete for the same resources. Conflicts among these sectors may increase when resource become depleted. Exploding seal population. Competition for exploited resources – harvesting of pelagic resources has had a huge impact on food availability for other top predators.
Risks/uncertainty Irreversible ecosystem change – The degree to which changes that take place in the ecosystem (as a result of over-harvesting) are reversible, is not known. Biodiversity change – Changes in biodiversity (genetic, species, ecosystem) may occur as a result of the over-harvesting of resources, but the lack of good baseline data makes this difficult to assess. Hence we do not know the degree to which overfishing affects biodiversity. Habitat destruction – The degree to which over-harvesting affects habitat through impacts on dominant species, or directly through impacts of the harvesting technology (e.g. bottom trawls) is unknown. Baseline data are lacking. Actions in one country can cause collapse of a shared commercially important stock(eg. Collapse of Benguela hake stock in 1970s as result of gross overfishing by foreign fleats)
Socioeconomic consequences Financial & job numbers – Over-harvesting of resources reduces the number of jobs and the financial gain accruing to coastal communities. Jobs lost in one country may result in an increase in job opportunities in another country due to changes in employment opportunities. Loss of national revenue – If resources are over-harvested, or if opportunities to developing new resources on a sustainable basis are missed, then the contribution of those resources to the national revenue base is reduced. Lack of food Security (artisanal/industrial) – artisanal fishers depend on fisheries resources directly for protein; over-harvesting by the industrial sector may erode the food security of coastal artisanal fishers and their families. Loss of jobs in the industrial sector may also increase poverty, and decrease food security. Erosion of Sustainable livelihoods – livelihoods of coastal people may often depend on activities that are based on assets (e.g. fish resources) that are harvested by other sectors. Over-harvesting of those assets, either by coastal dwellers themselves or by industrial harvesting, may erode the livelihoods of coastal people, and bring about increased urban migration and increases in urban poverty and the spreading of poverty-related diseases. Missed opportunities (under-utilization & wastage) – There may be many opportunities for the novel utilization of marine resources. Examples include drugs from both inshore and deep-water invertebrates, as well as drugs and other low-volume, high-value products from seaweeds. A coordinated regional assessment of such resources and coordinated development could bring regional benefits in this area. Competitive edge on global markets – Lost markets are difficult to regain, could have global impacts (retain dominating role in hake market, regain role in fishmeal market). Increases or reductions in yields in one area may impact upon another area (country), resulting in market competition among the BCLME countries. To retain a competitive edge in rapidly changing markets, stability of the throughput and quality enhancement that comes with that stability are essential.
Transboundary consequences Most of the regions important harvested resources are shared between countries(i.e. stradle national boundaries), or move across national boundaries at times. (See Oceanogr. Mar Biol. Ann. Rev. Vol 25, pp 353 – 505, and also BLCME Thematic Report 1). Over-harvesting of a species in one country can therefore lead to depletion of that species in another, and in changes to the ecosystem as a whole. (For example the collapse of the Namibian sardine in the 1970’s followed the collapse of the sardine in South African waters) 24 Inappropriate management of regional resources endangers sustainability of resources and consistency of catches, and leads to sub-optimal use. Lower food production, loss of jobs & national revenue, and increase reliance on foreign aid. Potential irreversible changes in nature of ecosystem due to depletion of widely distributed ecologically important species. (S.Afr. J. Mar. Sci 12) Movement of vessels and humans across borders in response to depletion of resources. Increased local and regional conflicts. (Refer to ICSEAF reports) Depletion and/or large-scale distributional shifts in predator species in response to reduced prey abundance. (see S.Afr. J. Mar. Sci 12) For example there is evidence that Namibian seals population was severly depleted and some animals migrated into Angola and South African waters following the 1995 Benguela Niño.
Activities/solutions Co-financing with industry –Co-financing from the fishing industry and other donors is a priority for effective management. Provision of information to facilitate regional assessments of shared resources. This will be argumented by BENEFIT ouputs(co-financed). A structure should be established to conduct regional stock assessments, ecosystem assessments, evaluate resource-environmental linkages, and facilitate post-harvest technology. Joint surveys & assessments – Carried out cooperatively will help produce enhanced management and optimal utilization. These joint surveys will be offered as a 5-year demonstration of the benefits to the individual nations of joint transboundary assessments. Gathering and calibration of baseline information - This should be done on resources, potential resources before harvest, as well as ecosystems. Cooperative analysis of socioeconomic consequences - Analyses of the socioeconomic consequences of non-optimal and improved use of resources should be done with a view to appropriate intervention within the framework of improving sustainable livelihoods. Cooperative training - Cooperative training will be essential to generate regional capacity needed to address the transboundary issues, and to promote sustainable intergrated management. Cooperative training targeted at communities will so be necessary. Training – in management, enforcement, and the creation of new opportunities. Cooperative assessment of potential new transboundary resources. Many biological resources and potential new resources in both offshore and inshore areas are common to the BCLME, and assessments should be conducted cooperatively.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activites which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Optimal resource utilization – This is the most obvious output from the suggested solutions; there will be a reduction in the exploitation level of resources that are deemed to be over-harvested so that stocks can be rebuilt to optimum levels, and an increase in the benefit to coastal communities from the improved utilisation of resources. Improved forecasting – Joint assessment will enable improve predictions of sustainable resource-harvest levels. Establish regional structure – This regional structure will be responsible for producing annual stock assessment reports, annual ecosystem reports, and provide advice or suggestions of resource harvesting levels, and other matters related to resource use, particularly fisheries. Training packages on management, enforcement, and opportunity creation – all at the regional level to advance the concept of susatinable intergrated management of the BLCME. 25 TABLE A2: ASSESSMENT OF MINING AND DRILLING IMPACTS AND POLICY HARMONIZATION. PROBLEMS CAUSES IMPACT RISKS/ SOCIO- TRANS- ACTIVITIES/ PRIORITY INCRE- ANTICIPATED UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y)
A2. Mining and drilling impacts: Pipelines Habitat destruction Cumulative impacts Financial & Τhree countries share Policy 1 $ 100 000 Environmental Exploration for oil and gas and Drilling & dredging Seabed modification Effects on benthos employment benefits common problems harmonization management plan minerals such as diamonds is Seismic exploration Coastal soil, beach, Change of bio- -ve: exclusion Cumulativects Enhanced 2 [$ 100 000] Integrated expanding throughout the intertidal and subtidal diversity +ve: reserves impacts are unknown consultation sectoral management Benguela. This involves profile destruction Cost/ benefit Reduced artisanal but may be and regional Solution to drilling, dredging and seismic Conflicts (fish, fisheries substantial Cumulative impact capacity problem exploration. There is diamonds, gas) Coastal tourism Shared solutions assessment for 1 $ 500 000 substantial oil extraction in Behaviour of resources Onshore BCLME [$ 500 000] northern Angola (Cabinda) Mortality of larvae development industry while the development of Effects on coastal oil/gas fields (with pipelines) communities, post- are planned further south (e.g. mining Namibia). Capped wellheads hamper fishing while drill cuttings and hydrocarbon spills impact on the environment. Extensive diamond mining is being conducted using dredging equipment along the coasts of and continental shelves of Namibia and South Africa. Ecosystem effects of these activities are not fully known.
A2 EXPLANATORY NOTES. PROBLEM: MINING AND DRILLING IMPACTS
Causes Pipelines Drilling & dredging Seismic exploration
Impacts Habitat destruction – Habitat destruction from drilling may be localized, but dredging for diamonds disrupts large areas of seabed, disturbs the sediments and changes the particle size distribution. The impact of this on benthos and other resources, particularly fisheries resources, needs to be assessed and mitigated if necessary. Seabed modification – Seabed modification, related to habitat destruction, may impact on the exploitation of other resources; for example, pipelines and wellheads and their potential impact on availability of bottom areas to trawl fishing. Coastal soil, beach, intertidal and subtidal profile destruction. Coastal mining moves the coastal soils, alters the beach profile and destroys coastal vegetation, and intertidal and subtidal habitats. Conflicts (fish, diamonds, oil & gas). Conflicts may arise between different sectors. Appropriate strategies are needed to decrease the potential for conflict, and to resolve conflicts that arise (e.g. lobster / diamond, fishing / oil). Behaviour (e.g. scaring of mammals and fish during seismic surveys) & mortality (e.g. mortality of larvae) of resources – Fish migrating away from, and fish larvae being killed by activities. 26 Risks/uncertainty Cumulative impacts – The cumulative impacts of lots of smaller impacts from mining, as well as the cumulative effects over time, are unknown, but may be significant within the context of the ecosystem. Effects on benthos – The effects of mining on benthic communities are uncertain. Change of biodiversity – It is not known whether mining impacts lead to a reduction in biodiversity in the mined areas Cost/benefit – Costs and benefits to the environment from mining and drilling in this perspective are unknown.
Socioeconomic consequences Negative: Exclusion zones around mining operations, wellheads on Agulhas Bank Positive: Reserves – A negative effect of mining is the closure of large areas of coastline, restricting access to living resources by coastal dwellers or potential dwellers. A positive effect is that exclusion zones could act as biotic reserves. Reduced artisanal fisheries - This is a negative effect of the exclusion, as well as the impact of mining-related coastal activities. Coastal tourism – The closure of large areas of coast reduces the potential for tourism development in affected areas. Onshore development – Onshore development increases opportunities for jobs, but also modifies habitats through construction and pollution. In addition, coastal migration, urbanization and poverty may be an impact where open towns are adjacent to mining areas. Effects on coastal communities post mining - Mines eventually close, leaving former mine workers without obvious sources of sustainable employment.
Transboundary consequences Mining activities occur in all three countries (see BCLME Thematic Reports 3 and 5). Most of the impacts are localized but uncertainty exists regarding cumulative impacts of oil/gas and diamond mining which added to impacts of fishing and pollution could be significant, especially regarding benthos. As such as assessment of the cumulative impacts of mining/drilling is a prerequisite for sustainable intergrated management of the BCLME. The mining industry in RSA, Namibia and Angola undertake EIA’s for all projects. The oil/gas and diamond industry in RSA and Namibia are working together to consolidate baseline information. This results in an apreciable level of co-financing. All three countries share common problems. For example, conflicts between resource users and lack of post mining opportunities. Regulation of mining activities needs to be standardized within the region.
Activities/solutions Policy harmonization - Cooperative harmonization of mining policies, particularly related to shared resources and cumulative impacts and their mitigation, will be needed. Cumulative impact assessment for BCLME (industry co-funding) - An overall impact assessment of the mining industry is needed. Enhanced consultation (sectoral & regional) is needed to reduce impacts of mining and ensure benefits accrue and conflicts are reduced. Cooperative training will be needed for the effective management of mining impacts, as well as developing activities following cessation of mining.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activities which address transboundary problems requiring incremental funding are listed. 27 Anticipated outputs Environmental management plan – An overall environmental management plan for the whole BCLME will be produced, including management plans for mitigating mining and other impacts. Integrated management – will be the output of the above plan. Solution to capacity problem – This will be the result of training to improve assessment and management capacity with respect to the transboundary isues. Regional training packages on managing mining impacts, community development following mine closure 28 TABLE A3. RESPONSIBLE DEVELOPMENT OF MARICULTURE PROBLEMS CAUSES IMPACT RISKS/ SOCIO- TRANS- ACTIVITIES/ PRIORITY INCRE- ANTICIPATED UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y)
A3. Mariculture is under-developed Inadequate policy Threat to biodiversity Environmental Employment & Biological invasion Undertake 1 $ 300 000 Report on but this is rapidly changing: Differential regional Diseases variability sustainable to adjacent country socioeconomic and socioeconomic Mariculture has the potential policy - policies Conflict over Market uncertainty livelihoods by alien species feasibility assessment throughout the Benguela region to differ in the three space/markets Feasibility Revenue Threat to assessment as basis Feasibility report provide labour-intensive countries Eutrophication Potential growth biodiversity for and Harmonised policy employment, protein and foreign Space industry Common problems, harmonisation of and regional policy currency from export of high value Lack of information shared solutions national policy and Training package products. The responsible develop regional development of a mariculture policy to mitigate industry is hampered by lack of against potential information and capacity and lack problems and of harmonised/regional policy. promote responsible development of Ecosystem effects of mariculture moriculture in developments are uncertain; for BCLME example introduction of exotic species and transboundary consequences thereof.
A3 EXPLANATORY NOTES. PROBLEM: MARICULTURE REQUIRES RESPONSIBLE DEVELOPMENT
Causes Introduction of exotics – Mariculture may use exotic species, which can create threats to biodiversity & ecosystem function. Inadequate policy – While some countries have policies in place, others do not. Policy may not be enacted even where it exists, although at least Namibia apparently has a good policy that is about to be enacted. Differential regional policy – Policies differ among the three BCLME countries. It will be necessary to harmonize policies to minimize transboundary effects of mariculture. Space – The coastline of the region experiences mostly a high energy wave climate. This means that sheltered water space needed for mariculture is limited, and other sectors also make use of sheltered water, including ports, fisheries and tourism. This results in conflict with other sectors. Lack of information. One of the reasons mariculture is poorly developed in the region is lack of information and lack of capacity. This is particularly true when it comes to the use of mariculture to develop and broaden the livelihoods of coastal communities.
Impacts Threat to biodiversity – The introduction of exotic species for mariculture purposes may threaten indigenous biodiversity by displacing indigenous species. Diseases – Introduction of species for mariculture may spread disease, and cause other unwanted side effects. Conflict over space/markets – Conflicts among sectors for limited sheltered water space are common. Transboundary conflicts over markets may occur, and countries without clear policies may be denied certain markets. Eutrophication is a consequence of uncontrolled development of feed-based mariculture systems. Such development must occur only within the confines of strictly enforced guidelines.
Risks/uncertainty Environmental variability – This creates uncertainty about the suitability of the limited sheltered water space for mariculture. Market uncertainty – Means that the development of mariculture carries high risk for potential entrepreneurs Feasibility – The feasibility of mariculture is not known for many potential species. Threat to biodiversity, introduction and spread of diseases.
Socioeconomic consequences 29 Employment & sustainable livelihoods – Mariculture has the potential to allow the broadening of the livelihoods of coastal communities if developed with a sustainable community development policy Revenue – Revenue may accrue not only to entrepreneurs but also to local communities and to the national revenue base. However, the latter will be small due to the limited water space available. Potential growth industry – Mariculture is one of the few industries based on living resources that has growth potential. There is very limited capacity for the expansion of harvesting from the wild. Clear sight must be kept of the limited space availability though.
Transboundary consequences Mariculture is underdeveloped in all three countries and is being activity promoted throughout the region in view of its economic and employment potential. Co-operative transboundary activities that promote the responsible development of mariculture will minimise negative enviromental consequences and also help reduce pressure on traditionally (over) harvested resources. Differences in policy among countries in the BCLME could lead to conflicts(e.g. as a result spread of disease from one country to another, alien species invasion of the ecosystem from a country point source, market conflicts etc), and differential development of the mariculture industry. Harmonization of policy will reduce the potential harmful effects of differential development. The introduction of exotic species into the region for mariculture, by any one country, has the potential to lead to transboundary biological invasions of the target organism or other species accidentally introduced with it. Such invasions have the potential to be a threat to the biodiversity of the BCLME as a whole.
Activities/solutions Socioeconomic assessment of potential – A full socioeconomic assessment needs to be conducted into the ability of mariculture to contribute to regional economy and the improvement in the living conditions of coastal communities. Feasibility assessment – The feasibility of mariculture for particular species in certain areas of the region needs to be assessed, and the best species for development need to be chosen on the basis of this assessment. Formulate harmonized policy for the region – Crucial if the negative effects of one country’s policy on the economic potential of another are to be precluded. Training – Training will be needed, particularly in terms of promoting community-based mariculture, as well as the overall management of mariculture in the region.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Report on socioeconomic assessment – will include advice for action, particularly targeted at communities Feasibility report - will include advice on recommended species and areas for regional initiatives Policy statement - should look at overall and community potential Training package aimed at managers, communities and potential entrepreneurs. 30 TABLE A4. PROTECTION OF VULNERABLE SPECIES AND HABITATS PROBLEMS CAUSES IMPACT RISKS/ SOCIO- TRANS- ACTIVITIES/ PRIORITY INCRE- ANTICIPATED UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y)
A4. Threats to vulnerable species: Salt production Threat to global • None given • Tourism Most vulnerable Assessment of status 1 $ 500 000 Ecosystem status Human impact on the Population migration biodiversity of coastal species occur of vulnerable species assessment and ecosystem by way of fishing, to coast birds throughout the and habitats - both report increasing pressure on the Pollution Ecosystem change region or migrate those which are coastal zone, pollution etc. has Reduction of prey Loss of wetlands between countries. shared between impacted negatively on through fishing Population reduction National activitiies countries and those components of the system, in Historical Competition for have transboundary which play a key particular top predators such as harvesting exploited resources consequences. role in whole coastal birds, e.g. penguins and Competition for Common Problems, ecosystem. gannets. space & prey (seals, shared solutions. birds, humans) Vulnerability of habitats: Several habitats, in particular coastal habitats have been perturbed or lost as a consequence of development and other human impacts, e.g. loss of wetlands, destruction of mangroves, lagoons, etc. These have transboundary consequences and may be significant globally.
A4 EXPLANATORY NOTES. PROBLEM: THREATS TO VULNERABLE SPECIES AND VULNERABILITY OF HABITATS
Causes Salt production – Changes to wetlands and lagoons Population migration to coast – especially mangroves. This is a worldwide trend. Logical consequence is a threat to habitats and resources that are attractive to tourists. Pollution – Impacts on threatened populations, especially penguins. Reduction of prey through fishing – Humans catch fish that are the food of seals & seabirds, reducing food available for them, and can lead to breeding failures in some years as an example. Historical harvesting – Especially penguins & gannets, particularly eggs and guano. This is one of the reasons these populations are in a depressed state. Competition for space & prey (seals, birds, humans) – Seals & seabirds compete with one another for food and breeding space. Both are in competition for food and space with human populations.
Impacts Threat to global biodiversity of coastal birds eg. African penguins, bank cormorants. Various sciencific publications by R.J.M Crawford and co-workers refer - also see BCLME Thematic Reports 1-5 for overviews and references to changes documented in the BCLME. Ecosystem change. Various sciencific publications by R.J.M Crawford and co-workers refer - also see BCLME Thematic Reports 1-5 for overviews and references to changes documented in the BCLME Loss of wetlands. Various sciencific publications by R.J.M Crawford and co-workers refer - also see BCLME Thematic Reports 1-5 for overviews and references to changes documented in the BCLME Population reduction – This has happened to several resources. Competition for exploited resources – Harvesting of pelagic resources has had a huge impact on food availability for other top predators. 31 Risks/uncertainty None were identified. Transboundary consequences Most vulnerable species, including several endemics, occur throughout the region and in some cases internationally. Some vulnerable habitats occur regionally (e.g. wetlands and lagoons), others in one country (e.g. mangroves), but many are of importance to migratory species. Therefore the consequences of any actions, whether national, regional or international, will have direct transboundary consequences and may be of significance globally. National policies to enable protection of vulnerable species and habitats need standardization throughout the region.
Socioeconomic consequences Tourism – Marine mammals, seabirds, turtles & vulnerable habitats (e.g. wetlands) contribute extensively to tourism.
Activities/solutions Assessment of status of vulnerable species and habitats –Work has started in some countries, but a holistic regional study is sought.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those transboundary activities whihc address transboundary problems requiring incremental funding are listed
Anticipated outputs Ecosystem report – A report on the status of the ecosystem, and the impacts of human activities on the relationships among non-consumptive resources, together with management advice. 32 TABLE A5. ASSESSMENT OF NON-HARVESTED SPECIES AND THEIR ROLE IN THE ECOSYSTEM. PROBLEMS CAUSES IMPACT RISKS/ SOCIO- TRANS- ACTIVITIES/ PRIORITY COST (5y ANTICIPATED UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS OUTPUTS CONSEQUENCES CONSEQUENCES
A5. Role of non-harvested species in • Lack of • All impacts are Unable to predict Food security Many non-targeted Dedicated joint 1 $ 1 000 000 Information on the ecosystem is unknown. information unknown impacts of changes potential species have surveys and non-harvested Assessments of non-harvested in abundance of Jobs transboundary assessments of non- species, assessment species (except for some unharvested species Revenue distributions. Some harvested of ecosystem role. seabirds and marine mammals) upon harvested have potential for transboundary Ecosystem model are not conducted. Some of species harvesting, but role species to provide for management. these species probably have Predator/prey in ecosystem is baseline for high biomass (e.g. light and relationships uncertain. Action by integrated ecosystem lantern fish), have potential for Large unknown one country could management. harvesting (and with it job and biomass disturb ecosystem in wealth creation), yet the Market potential absense of info. consequences of harvesting on Economic the food webs and presently viability Common problem, harvested species are uncertain. Unknown impact of Shared solutions There is a general lack of harvest knowledge on the subject. Ecosystem impact of pollution
A5 EXPLANATORY NOTES. PROBLEM: UNKNOWN ROLE OF NON-HARVESTED SPECIES IN THE ECOSYSTEM
Transboundary consequences Many unused or underused taxa in the BCLME have transboundary distributions, and therefore any exploitation or shared knowledge gained in one country would have an effect in all countries. Such ecosystem effects ought to be addressed in a dedicated manner by gaining basic knowledge of what is in the system, its biology, and what role it plays, and how it can be impacted by anthropogenic activity.
Activities/solutions Joint dedicated surveys & assessment – Such surveys need to be dedicated to the non-harvested species because of the special technology needed.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Information on non-harvested species and assessment of their role in the ecosystem. Ecosystem model as a tool for sustainable integrated management of the BCLME 33
TABLES B: ASSESSMENT OF ENVIRONMENTAL VARIABILITY, ECOSYSTEM IMPACTS AND IMPROVEMENT OF PREDICTABILITY.
TABLE B1. REDUCING UNCERTAINTY AND IMPROVING PREDICTABILITY. PROBLEMS CAUSES IMPACT RISKS/ SOCIO- TRANS- ACTIVITIES/ PRIORITY INCRE- ANTICIPATED UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y) B1. The BCLME is a complex and • Complexity of • Change to coastal • Long-term net • Uncertain Climate Change Develop regional 1 $ 1 600 000 Regional early highly variable system for processes ecosystems from change or natural employment (job • Contribution to early warning system warning systems which there is evidence of • Poor altered wind cycles? losses and gains) global climate for env. change for major env. system change and Targeted feasibility events/change. understanding of field/rainfall • Time periods • Variation in change (CO2, fragmentary but important processes and • Changes in coastline sufficient long to revenue methane flux) assessment of evidence of increasing PIRATA 1 $ 400 000 Quantification of cause and effect morphology detect changes? • Over- and under- Ecosystem instability/variability. Scales linkup/application to utility/ relationships • Damage to coastal • Shifts in of variability include: A.. utilization of BCLME application of • Poor distribution of large scale sustained events; infrastructure resources. Targeted PIRATA for • • biota B: decadal changes; and C: understanding of Unpredictable Lack of food transboundary SADC • Loss of species/ high frequency short-lived global driving variations in security assessment of 1 $ 250 000 Information events and/or episodic events. forces (linkages) zooplankton and fish • Human population biodiversity largescale needed to design • • Human impacts on the Lack of data/ egg/larval survival migration Altered food webs hypoxia/impacts monitoring/ BCLME (e.g. by fishing) is information • Unpredictable • High production • Disruption of Assess role of predictive • superimposed on the inherent Inadequate changes in fish costs faunal migrations upwelling system as systems natural variability, and the mathematical growth, mortality and • National/regional Fisheries CO2 source/sink Quantification of • combined effect of models recruitment conflicts Unsustainable Analyze plankton 2 [$ 300 000] CO2 flux • • anthropogenic disturbance Lack of capacity Unpredictable • Reduced capacity management of data archives for and this variability have been measurement of changes in species’ to support shared and implicated in ecosystem decadal change Record of abundance, artisanal fisheries straddling stocks change and the collapse of composition, • Develop 1 $ 100 000 decadal • Changes in Altered fish harvested resources. There is distribution and transboundary state ecosystem government spawning patterns also considerable uncertainty availability and population of the enviroment changes regarding ecosystem status • revenue, private analysis/reporting Regional Regime shifts income and shifts and yields. Lack of • Cross boundary • Unpredictable system. 1 $ 250 000 environmental information about and exports. Develop links with analysis/reportin movements of fish, fluctuations and understanding of CLIVAR g system/ seabirds and seals availability of fish environmental variability and Adapt/develop network • Change in flux of stocks system-wide impacts hampers • predictive models Knowledge and sustainable management of CO2, methane and Unpredictable and Establish regional expertise on BCLME resources and results H2S between variable advisory groups 2 [$ 50 000] global climate in the non-optimal utilization atmosphere, ocean distribution of Data gathering links of these resources. and sediments fishery benefits community projects 2 $ 300 000 Predictions and • Difficulties in • Regional Transboundary env models managing resources economic variability 2 $ 50 000 Regional sustainable instability and networking(incl. advisory groups • Operational unemployment internet) 2 $ 100 000 Availability of difficulties with • Regional conflicts Establish links with important/ useful resource utilization with other users the Gulf of Guinea data • Assessment of Coastal LME 1 $ 400 000 Regional env. anthropogenic infrastructure variability impacts difficult • Costly network. maintenance of Links with Gulf coastal 1 $ 50 000 of Guinea LME infrastructure
B1 EXPLANATORY NOTES. PROBLEM: HIGHLY VARIABLE SYSTEM, UNCERTAINTY REGARDING ECOSYSTEM STATUS AND YIELDS 34
Causes The Benguela upwelling area is a highly variable “convex” system with three open and variable boundaries. It is unique in that it is bounded at both equatorial and poleward ends by warm water (tropical) systems viz. Tropical Atlantic and Agulhas Current. It is sensitive to environmental events (variability and change) in the Atlantic, Indo-Pacific and Southern Ocean. Unlike the Humbolt Current there are few long-term data series to form a baseline against which changes can be predicted or assessed. There is an uneven spread of data between disciplines and between the participating countries. Difficulties in predicting changes in the system is a consequence of: Complexity of physical, chemical and biological interactions and processes, and the difficulties in predicting environmental variability Our limited understanding of cause and effect relationships, compounded by the problems of predicting not only the environmental variability but also ecosystem impacts Our limited understanding of driving forces (global linkages). There is evidence from case studies that inter-annual variability in the northern Benguela is associated with changes in zonal (east-west) winds in the equatorial Atlantic, and also that there are some common features in the variability of the north and south Atlantic. There is also fragmentary evidence linking variability in the Pacific El Niño/La Niña (ENSO). Thus, although there are pointers to the importance of remote physical (global climate) forcing of the Benguela, the linkages and mechanisms are not understood. Lack of data/information: Long-term data series are few, and except for the extreme southern Benguela, the ecological processes are poorly understood. Inadequate mathematical models applicable to the region: Very little mathematical modeling of the Benguela has been done internationally, and there is a general lack, in the region, of the capacity (skills and technology) to adapt available models from elsewhere, to run these or to develop new models. This applies to physical, chemical and biological (ecosystem) modeling. This is a serious drawback to developing predictive capacity. Lack of capacity, exacerbated by a south-north gradient in capacity (number of qualified personnel, equipment, vessels etc): The colonial political past in the region has resulted in insufficient persons with the necessary expertise/skills. Moreover, downsizing and emigration has resulted in further shrinkage of the skill pool. There is a marked north-south gradient in human and infrastructure capacity in the BCLME, with Angola being the worst off by far, yet with the greatest needs. Thus available capacity is barely sufficient to meet present national needs, and insuffienct to address the priority transboundary problems.
Impacts Processes that give rise to variability in the Benguela occur on three temporal and spatial scales (A: large scale sustained events; B: decadal changes; and C: high frequency short-lived events and/or episodic events). There is evidence that environmental change/variability does impact on the BCLME in a number of ways. However, in order that these changes can be predicted sufficiently well to be useful for ecosystem management, the cause and effect must be properly quantified. The impact of environmental variability/change includes inter alia the following:
Change to coastal ecosystems from altered wind field (strength and direction) and/or rainfall (quantity and distribution)(AB). Changes in wind frequency direction and strength impact on the supply of nutrients (for productivity), currents and stratification. In addition there is evidence that SST is related to rainfall in the region (although the process mechanisms are not understood). Changes in coastline morphology as a result of climatic regime changes and short term events (storms) (BC) Short term events (storms) leading to damage to coastal infrastructure (C) Variations in zooplankton and fish egg/larval survival and higher level impacts (A, B and C) through changes in primary production and stratification/turbulence caused by changes in wind frequency, direction and strength. Changes in species’ abundance, composition, distribution and availability (A, B and C) i.e. ecosystem response to environmental change. Changes in fish growth, mortality and recruitment (A, B and C) - these have major implications for resource management. Cross boundary movements of fish, seabirds and seals (A, B and C). The majority of harvested species of fish either straddle country EEZ boundaries or otherwise move across these boundaries from time to time. These movements/shifts are associated with the life histories of the species and also changes in the environment. The implications if this for sustainable management are obvious. Regime shifts i.e. increased variability or a net change towards altered state (B). For example switching between species such as anchovy and sardine (opportunistic) or between sardine and jellyfish (pessimistic!). These regime shifts can occur naturally – there is evidence in the sediment record of such occurrences having taken place historically (prior to fishing). The impact of fish exacerbates the problem. Moreover cyclical changes in wind stress result in north-south shifts in some straddling fish stocks. Change in flux of CO2, methane and H2S between atmosphere, ocean and sediments (B). It is not known with certainty whether the BCLME is a source or sink of CO 2, although it appears to be a net sink. Changes in climate could perturb this balance and feed back to climate. The BCLME could be a useful “targeted site” for assessing the role of climate change on upwelling systems and feedback to climate from CO2 release/uptake.
Risks/uncertainty 35 Limited understanding of this highly variable system means that it is uncertain whether the observed variability reflects sustained long-term net change or natural cycles, and whether the available data series are sufficiently long to enable us to determine this.
Socioeconomic consequences The quality of advice given to resource managers is reduced by the ability to predict, with confidence, short-, medium- and long-term changes in the Benguela system. A consequence of this is that responsible resource management must err on what is percieved to be (but which may not be) the conservative side. This leads to: Uncertain employment (job losses and gains) Variations in revenue Sub-optimal utilization of resources (particularly by artisanal fisheries) Lack of food security Human population movements in response to variable resource availability High production costs e.g. in fish processing National/regional conflicts Changes in government revenue, private income and exports
Transboundary consequences Sustained major environmental events (e.g. Benguela Niños), decadal change and major short-term perturbations (e.g. 10- or 50-year storm events) do not respect country EEZ boundaries, but rather impact on the BCLME as a whole. In other words the types of environmental variability/change which are the focus of the BCLME programme are system-wide and in essence transboundary. Moreover, the BCLME is believed to play a significant role in global ocean and climate processes besides its importance to Angola, Namibia and South Africa. Many of the transboundary consequences listed below would occur regardless of the high variability of the system. Nevertheless our ability to manage them effectively is limited by our predictive capability. Some of the consequences of increased variability or sustained change include: Ecosystem Shifts in distribution of biota - for example decadal scale shifts in sardine and anchovy from Namibia to Angola and back have been documented. Loss of species/biodiversity - Alien species have also displaced indigenous species(e.g. spread of Mediterranean(blue) mussel from near Cape Town to Central Namibia) Altered food webs Disruption of fish, bird and mammal migrations - cf 1995 Benguela Niño Fisheries Unsustainable management of shared and straddling stocks Altered fish spawning patterns and population shifts Unpredictable fluctuations and availability of fish stocks e.g. collapse of anchovy stock around 1990 Unpredictable and variable distribution of fishery benefits e.g. which resulted in the closure of fish canning factories Regional economic instability and unemployment Regional conflicts over declining resources/stocks Coastal infrastructure Costly maintenance of coastal infrastructure Climate Change Changes in the status and/or functioning of the BCLME may affect its contribution to global climate change through its role as a source/sink of CO 2 and source of methane. Moreover the geographic location of the Benguela at a choke a major route for the transfer of heat between the Indo-Pacific and Atlantic, means that the BCLME may be an important site for early detection of global change.
Activities/Solutions Without good baseline information and wider regional coordination and articulation, major problems and issues facing the three countries bordering the BCLME cannot be resolved. It is necessary to undertake targeted assessments of priority environment variability issues/problems and to develop appropriate systems, linkages and networking. Development of a suitable needs-driven, cost-effective regional environmental early warning system for the BCLME by cross linking existing national systems. Transboundary assessment of low oxygen water formation, dynamics and continuity and transboundary impacts. 36 Feasibilty assessment of extension of and/or link-up to the PIRATA moored buoy array in the tropical Atlantic to enhance understanding of links between weather, climate and fish. (PIRATA is an Atlantic equivalent but smaller version of an ocean buoy network in the Pacific, which is used to forecast EL Niños and La Niñas. The value of linking the BCLME with the PIRATA system would be in the forecasting of Benguela Niños and anomalous events originating in the tropical Atlantic.). If the feasibility assessment were to prove successful (and it looks like it will), then there is also an excellent chance of ongoing involvement between the region and PIRATA being funded from country sources and donors. Determination of role of upwelling systems as a CO2 source/sink and methane source. The value of this to the international community has previously been commented on. Moreover it will provide an obvious link between the International Waters and Climate Change components of GEF. A modest demonstration project would be appropriate. Development of community projects for cost effective environmental information gathering and environmental education. Public awareness and involvement are seen as essential components for the successful implementation of the BCLME Programme – both for cost effective information gathering/monitoring and also to help reduce anthropogenic environmental impacts on the ecosystem. Analysis of plankton archives and other (oceanographic) data collections – baseline information for measurement of decadal change. These collections are unique assets and initial indications are that they may hold the key to unraveling some of the decadal variability which has characterized the BCLME of the last 50 years and which has hampered sustainable harvesting of living resources. Develop state of the environment analysis/reporting system for use on a regional basis in the BCLME Develop links with CLIVAR and CLIVAR Africa (CLIVAR = Climate Variability and Predictability Project of the World Climate Research Programme) Adapt/develop predictive mathematical models applicable to the region – the utility of this has been referred to elsewhere. Establishment of regional advisory groups and networking centres. This is a low cost activity with potential large benefits. Develop transboundary environmental variability networking for region – this links in with the proposed early warning system(see above). It will make extensive use of the internet.. Establish links with the Gulf of Guinea LME – Clearly the BCLME does not function in isolation from the rest of the south Atlantic, so building bridges/networking with other LME projects could provide valuable spin-offs in both directions.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Proven/validated regional environmental early warning system appropriate for the BCLME in a form which could be used to leverage future country and donor co-financing for permanent implementation. Assessment of utility/application of a PIRATA-type buoy array for the BCLME Documented assessment of information needed to design monitoring/predictive systems Assessment of decadal ecosystem changes in the BCLME since the 1950s based on historical/archival data and collections An established regional environmental analysis/reporting system/network and activity centre Assessment using the best available knowledge and expertise links between the BCLME and the global climate system. Quantification of CO2 and methane source/sink relationships in the BCLME with an understanding of its applicability to other boundary systems and climate models Useful predictions and models Identification of cost-effective early-warning indicators of environmental changes that impact on fish stocks in the BCLME Establishment of regional enviroment network and reporting system - making full use of remotely sensed products and the internet, in a form that it can be self-sustaining operationally. 37 TABLE B2. CAPACITY STRENGTHENING AND TRAINING. PROBLEMS CAUSES IMPACT RISKS/ SOCIO TRANS- ACTIVITIES/ PRIORITY INCRE- ANTICIPATED UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y)
B2. There is a lack of capacity, Limited inter country Inability to participate Commitment to Sub-optimal or over Uncoordinated Assess capacity 1 $25 000 Capacity expertise and ability to monitor exchange (training) in regional decision supporting capacity utilization of resource needs to address development environmental variability, to Degrading and making processes development by renewable resources management, transboundary strategy for assess the linkages and downsizing of Regional imbalances in: governments of the due to lack of research and issues. region ecosystem impacts of this research institutions baseline information, BCLME region information, monitoring Devise strategy * for Strategy for job variability and to develop a Inadequate training predictive capacity, data Political and knowledge and programmes developing job creation (and predictive capability required programs collection ability etc. economic understanding Management of opportunities, N/A to GEF salaries) for sustainable integrative Lack of running Inadequate information uncertainty required for resource overall system by all salaries and BCLME management. There funds for finding indicators of management three countries is not infrastructure is also an unequal distribution Lack of skills to future change Unequal harmonized. Develop training Improved of availability capacity (human maintain equipment. Lack (low) interaction opportunities for Capacity gradient partnerships with 1 $250 000 regional and infrastructure) between Lack of equipment between institutions resource access/ (south-north) leads to private sector management of participatory countries. and supplies Information which is management uneven research Creation of regional resources and Lack of person not comparable/ cannot Absence of full monitoring effort in multidisciplinary establishment of power be integrated across the stakeholder the system as a whole working groups new institutional Low salaries region participation with consequences Devise, develop and networks Lack of concern from Creation of conflict for resource implement the policy makers on Poorly informed/ management appropriate training the ecosystem issues. advised governments Difficulties with courses Brain drain at all levels resource co-operation Interchange of Low institutional Inability to monitor personnel between Shared expertise sustainability or manage the system countries to gain/ 1 $25 000 as a whole transfer expertise and knowledge Improve networking via internet Improve public information/environ 1 mental education (pilot project) 2
B2 EXPLANATORY NOTES. PROBLEM: LACK OF CAPACITY, EXPERTISE AND ABILITY TO MONITOR ENVIRONMENTAL VARIABILITY
Causes The three countries (Angola, Namibia and South Africa) bordering the BCLME are developing countries with requirement to meet the basic living needs of their peoples. These countries have emerged from after long periods of colonialism and oppression and are attempting to develop their economies and social structures. Funding for marine monitoring and assessment activities are very limited and policy makers are not always fully aware of the importance of transboundary environmental variability/change in ocean management applications. Viewed collectively, the lack of capacity can be ascribed to the following: Lower priority placed on environmental issues by policy makers Limited inter country exchange of personnel for liaison, experience sharing and training Degrading and downsizing of research institutions as a result of pressure to reduce the size of the civil service Inadequate training/skill development programmes Limited funds to meet day to day running expenses, let alone to invest in hardware and capital items. Limited skills to maintain equipment. 38 Limited availability of equipment and supplies – most high tech equipment needs to be sourced abroad, and unfavourable local currency exchange rates have made this equipment unaffordable. Severely limited numbers of trained personnel – the lack of trained personnel is a direct consequence of colonialism and also the former apartheid policy applied in Namibia prior to 1990 and in South Africa prior to 1994. This has resulted in a legacy of a poor skills pool and an unequal distribution of skills within countries and between countries. Inadequate remuneration for government researchers (competition from the private sector). Brain drain; loss of personnel to the private sector and overseas because of salaries are not competitive and career prospects uncertain.
Impacts The consequences of insufficient funding of research in the BCLME include: Regional imbalances in baseline information, predictive capacity, data collection ability etc. There is a sharp gradient in the numbers of trained personnel from south to north. Limited ability to participate in regional decision making processes, as too few people are available to do the tasks at hand. Inadequate information for identifying indicators of future change Limited interaction between institutions. This problem is fast disappearing as a consequence of these countries to collaborate. Collection of information which is not comparable/cannot be integrated across the region
Risks/uncertainty Although the governments of the region are committed to capacity (skill/expertise development), this commitment is according to perceived national priorities. There is uncertainty with regard to the priority status of marine science, technology and management at the regional level. Political and economic uncertainty results in potential “recruits” choosing more lucrative careers – particularly those that favour mobility (emigration).
Socioeconomic consequences The underestimation by policy makers of the importance of developing and maintaining sufficient research capacity to manage the resources of the BCLME has resulted in numerous socioeconomic problems including: Sub-optimal or over utilization of renewable resources Unequal opportunities for resource access/management Absence of comprehensive stakeholder participation Creation of conflicts Poorly informed/advised governments at all levels Low institutional sustainability All of the above are in turn direct consequences of inadequate/inappropriate communication and in some case lack of trust between various players.
Transboundary consequences The Benguela ecosystem is believed to play a significant role in global ocean and climate processes besides its importance to Angola, Namibia and South Africa. Consequences of poor national and regional management practices thus have wide reaching consequences including: Non cost-effective resource management, research and monitoring activities (fragmented, poorly planned and unlikely to achieve the objectives of ensuring sustainable management). Management of overall system by all three countries is not harmonized. Capacity gradient (south-north) leads to uneven research monitoring effort in the system as a whole with consequences for resource management e.g. possible bias in information and advice leading to inappropriate decision making. Difficulties with co-operation in respect of sustainable resource utilization. A holistic approach to correct the damage done in the past from fragmentation and ad hoc “crisis” management. Inability to monitor or manage the ecosystem as a whole – The transboundary nature of the issues and problems in the BCLME necessitates a holistic approach
Activities/solutions The first action must be a comprehensive assess of the real needs for human capacity and infrastructural development/maintenance relevant to the identified transbouondary issues in which clear priorities are listed. This must be executed in co-operation with all stakeholders to ensure a proper balance and minimum vested interest bias. 39 Institutional downsizing, freezing/reduction/non-creation of posts, poor salaries and career prospects are limiting factors. If not addressed, recruitment and training initiatives will provide little or no long-term benefits. It is thus vital that a comprehensive strategy be developed to address the above (. (Much of the problem stems from incorrect perceptions and poor communication.). This activity although very important, is inappropriate for GEF funding, and will be pursued through other avenues. Develop training partnerships with private sector. This will promote private sector “buy-in” and provide a point of departure for long-term co-financing with industry and business. Devise, develop and implement appropriate training courses appropriate for the needs of the region. (The focus of courses developed for application in Western Europe and North America is not always suitable for implementation in developing countries.) Creation of regional multidisciplinary working groups. This will be a cost-effective mechanism for consultation, cooperation, skill development, trust building etc. Interchange of personnel between countries to gain/ transfer expertise and knowledge. To be successful this must be tri-directional. Improve networking via internet. It is envisioned that increased use of electronic is the key to the success of the BCLME programme at all levels. It will be particularly beneficial for training and system monitoring. Improve public information/environmental education (pilot project). There is a relative lack of public awareness about the BCLME, human impacts on the ecosystem, problems to be addressed to ensure its sustainable utilization and conservation of biodiversity, opportunities for job creation and wealth generation etc. A pilot project designed to increase awareness at all levels is seen as important.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Except for activity asterisked, only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Capacity development strategy for the region relevant to addressing transboundary concerns as per the Strategic Action Plan. Strategy to ensure secure posts for existing and newly trained personnel (including market related remuneration) New institutional networks taking advantage of the internet and world wide web Improved regional management of resources Increased multilevel public awareness of the issues and problems and the need for sustainable integrated management of the BCLME. Improved infrastructure and improved availability of persons with the necessary skills. 40 TABLE B3. MANAGEMENT OF CONSEQUENCES OF HARMFUL ALGAL BLOOMS. PROBLEMS CAUSES IMPACT RISKS/ SOCIO- TRANS- ACTIVITIES/ PRIORITY INCRE- OUTPUTS UNCERTAINTIES ECONOMIC BOUNDARY SOLUTIONS MENTAL CONSEQUENCES CONSEQUENCES COST (5y)
Harmful algal blooms are a Natural processes Poisoning and mortality Increase or decrease Human mortality Occurrence of Develop an HAB 2 $50 000 HAB regional conspicuous feature of upwelling Introduction of cysts of human consumers of in incidence and Loss of tourism harmful algal blooms reporting system for network systems. The frequency of in surface waters marine organisms intensity of HABs revenue in all three countries BCLME region as a occurrence, spatial extent and Nutrient loading of Mortality (mass) of Role of HABs in the Increased cost of Migrations of species whole duration of harmful algal blooms coastal waters from marine organisms system as a whole shellfish production across national Regional HAB Regional appear to be increasing in the anthropogenic Disruption of Contribution of (monitoring, testing, boundaries contingency plans 2 $100 000 contingency plan BCLME. The harmful effect of activities mariculture activities anthropogenic depuration) (See Notes) Community projects these blooms is manifested in two Changing state of the Interference with nutrient loading to Loss of fish/ linked to ministries 2 $50 000 Public education main ways: production of toxins Benguela ecosystem recreational use of the incidence of HABs shellfish/mariculture of health materials which cause mortalities of shellfish, Introduction of sea markets and jobs Mitigation of fish and human; and anoxia in exotic species Anoxia which in turn impacts of HABs 2 [$50 000] inshore waters which also can lead may cause massive Improve national Proactive to massive mortalities of marine mortalities of marine capacity to monitor management organisms. organisms toxins/species 2 (National)
B2 EXPLANATORY NOTES. PROBLEM: HARMFUL ALGAL BLOOMS (HABS)
Causes Natural processes – HABs occur naturally in the BCLME. Human impact can cause these HABs to spread, and introduce exotic HAB species into the BCLME. Introduction of cysts into surface waters – Human activities such as drilling, mining (dredging) and certain types of fishing disturb the sediments and release cysts of HAB species into the water column, thereby triggering new blooms, and expanding the area impacted by HABs. Nutrient loading of coastal waters from anthropogenic activities – Increased nutrient loading of coastal waters from e.g. sewage discharges and industries increase the probability of occurrence of HAB outbreaks. Perceived increase in frequency of HABs may be the result of changes in the state of the Benguela ecosystem. (System-wide monitoring for HABs would be required to discern any definite trend.) Nevertheless the changes in SST and wind stress observed in the BCLME this century would be compatible with an increase in HAB frequency and distribution. Introduction of exotic species (through ballast water, bilge water, mariculture operations etc.) – There is little or no control over the discharge of ballast water from ships entering national waters in the three countries, and there is a suspicion that these discharges may be responsible for the spread of HABs in the BCLME.
Impacts HABs affect a wide spectrum of activities in the marine environment. The impacts include: Poisoning and mortality of human consumers of marine organisms. There is documented evidence of human mortalities in the BCLME as well as non-fatal impacts. Mortality (mass) of marine organisms. The species at highest risk are the filter feeders (e.g. mussels) and organisms that consume these filter feeders. Mortality can be caused directly by toxins and clogging of gills, and indirectly by depletion of oxygen in the water column. Disruption of mariculture activities – Mariculture is dependent on good water quality. HABs result in disruption or closure of mariculture facilities necessitating expensive water treatment, isolation of facilities, etc. Depending on the nature of the mariculture venture and the HAB, the closure/disruption can be short-lived or permanent. Interference with recreational use of the sea – Apart from being toxic and unsightly, some HABs cause respiratory problems in swimmers and those living in close proximity to the sea. Anoxia which in turn may cause massive mortalities of marine organisms. For example, in a single episode in St Helena Bay, a biomass of rock lobster equivalent to or greater than the annual total allowable catch in the entire southern Benguela was lost as a result of a single HAB outbreak.
Uncertainties Increase or decrease in incidence and intensity of HABs as a consequence of insufficient monitoring. Role of HABs in the system as a whole Contribution of anthropogenic nutrient loading to incidence of HABs 41
Socioeconomic consequences Human mortality. Deaths have occurred and numerous people have suffered respiratory difficulties and gastro-intestinal problems as a consequence. Loss of tourism revenue (see impacts) Increased cost of shellfish production (monitoring, testing, depuration) Loss of fish/shellfish/mariculture markets and jobs. Mariculture is a potentially valuable growth industry in the BCLME. It is constrained by a general lack of information and knowledge, including lack of information about the extent of the HAB problem in the BCLME.
Transboundary consequences Incidence and effects of HABs are common to all three countries HAB outbreaks can be extensive and straddle national boundaries. In addition advective processes together with shipping operations, and bottom trawling, and mining(dredging) can redistribute cysts across national boundaries.
Activities/solutions Develop an HAB reporting system for BCLME region as a whole. This is seen as a high priority within the BCLME. It is also essential for the development of a sustainable mariculture industry. Community awareness projects linked to national ministries of health to alert the public to dangers associated with HABs Develop national/regional HAB contingency plans which include early warning systems and guidelines for medical practitioners to deal with HAB associated problems Improve national capacity to analyze for toxins and identify harmful species by sharing expertise between countries Mitigation of impacts of HABs on mariculture operations (e.g. relocation of mussels rafts, treat blooms with “herbicides”)
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Except for activities asterisked, only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Established HAB regional reporting network, with transboundary early warning system(to alert neighbouring state when required) Regional contingency plan for dealing with effects of HABs implemented in all three countries Public education materials prepared and distributed regionally Substantial contribution to the sustainable and responsible development of mariculture within the BCLME. Proactive integrated management in general. 42
TABLES C: MAINTENANCE OF ECOSYSTEM HEALTH AND MANAGEMENT OF POLLUTION
TABLE C1-3. IMPROVEMENT OF WATER QUALITY; PREVENTION AND MANAGEMENT OF OIL SPILLS; REDUCTION OF MARINE LITTER PROBLEMS CAUSES IMPACT RISKS/UNCERTA SOCIO- TRANS- ACTIVITIES/SOL PRIORITY INCRE- ANTICIPATED INTIES ECONOMIC BOUNDARY UTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y)
C1. Deterioration in coastal water Unplanned coastal Public health Few or no baseline Loss of tourism Transboundary Develop standard 1 $100 000 Shared solutions quality: Coastal developments development Reduced yields data Higher health costs pollutant transport environmental for water quality and rapid expansion of coastal Chronic oil pollution Unsafe edible organisms Performance Altered yields Migration of marine quality management cities, much of which was Industrial pollution Changes in species standards and Reduced resource organisms, e.g. seals indicators/criteria Regional protocols unforeseen or unplanned, has Sewage pollution dominance thresholds quality Negative impacts on Establish regional 1 $50 000 and agreements created pollution “hotspots”. Air pollution Ecosystem health and National Aesthetic impacts straddling stocks working groups Improved pollution Aging water treatment Mariculture resilience commitment to Lowered quality of “Hotspots” common Training in marine 2 $100 000 control infrastructure and inadequate Lack of policy on Loss of jobs at regional capacity-building life solutions pollution control Socioeconomic policy/monitoring/ enforcement waste & oil recycling level Cause-effect Loss of employment Plan/adapt regional uplift aggravates the problem. Growth in coastal relationships pollution monitoring 1 $50 000 informal settlements framework Establish effective enforcement agencies * 1 (National) Demo projects on pollution control and prevention Joint surveillance 2 $500 000
2 $200 000 C2. Major oil spills: A substantial Sea worthiness of Coastline degradation Recovery period Opportunity costs Resource sharing for Regional 1 $50 000 Regional volume of oil is transported vessels/ equipment Mortality of coastal Cost recovery (e.g. tourism, containment, contingency plan contingency plan., through the BCLME region and Military conflict fauna and flora mechanisms fisheries, salt surveillance, development shared resources, within it, and this is a Sabotage Return to peace in production) rehabilitation, etc. Research/ modeling rehabilitation significant risk of Human error Angola Altered yields Ramsar site of recovery periods 3 plans, regional contamination of large areas of Reduced resource protection (border Public awareness of protocols and fragile coastal environments quality wetlands) notification agreements from major accidents, damage Aesthetic impacts Transboundary procedures 3 to straddling stocks and coastal pollutant transport Port state control infrastructure. 3 C3. Marine litter: There is a serious Growth of coastal Faunal mortality Accumulation zones Loss of fishing Transboundary Litter recycling 2 Cleaner beaches growing problem throughout settlements Negative aesthetic Illegal hazardous income transport Harmonization of 3 Education the BCLME. Poor waste impacts waste disposal Public health packaging legislation material/ management Damage to fishing Cleanup costs Public awareness documents Little public equipment Loss of tourism Port reception available awareness and few Job creation in facilities 1 regionally incentives informal sector Regulatory 1 Standardized Illegal disposal from enforcement policies and vessels Standardized policies 2 $50 000 legislation on Poverty of coastal Seafarer education packaging/ communities 2 $100 000 recycling Ghost fishing incentives Fishing discards 1 $50 000 C1 EXPLANATORY NOTES. PROBLEM: DETERIORATION IN WATER QUALITY 43
Causes Activities are mainly focused around urban centers, increasing urbanization and associated knock-on effects. Worst effected areas are Luanda, Walvis Bay and Cape Town. Various sectors contributing to pollution, with varied degrees of cross sector co-operative management Knock-on effect of introduced mariculture species and associated water quality pollution effects in protected embayments Variable consistency in application of policy, both nationally and regionally Informal and formal settlements vary in their control of pollution discharges. Pollution is increasing due to urbanization. Shipping activities and hydrocarbon exploration and production are major sources of chronic oil pollution.
Impact Avariety of factors are responsible for deterioration of human health and ecosystem health/resiliance (Refer to BCLME Thematic Reports 1-6) Species invasion (poorly planned mariculture enterprises), changes in species dominance, reduced yields from ecosystem. Loss of jobs at regional level, reduction of regional tourism potential
Risks/uncertainty Limited data available from which to evaluate existing water quality, so it is difficult to establish a regional baseline. Validity of existing standards and thresholds within the regional context is uncertain. Tracing of impacts back to initial causes is difficult and causation is often unknown. Reduction of pollution in worst affected areas may not be practicable on short/medium term.
Socioeconomic consequences Input of nutrients and associated pollution may cause a short-term increase in production, combined with longer-term stock failure. These consequences are interrelated: pollution decreases tourism, which reduces jobs, which increases poverty, which in turn increases pollution.
Transboundary consequences Deterioration of water quality may cause species migration (temporary/permanent). Pollutants from industries/activities near to country borders can be transported across boundaries by prevailing currents. Impacts are (variably) common to each of the participating countries – a “generic” project with flexibility to meet nations’ needs should be established. Establishment of common policy is necessary to minimise transboundary impacts. Most water quality issues are common to at least two of the countries and require common strategy and collective action to address.
Activities/solutions An overall regional working group should be established to effectively co-ordinate integrated solutions to: Environmental quality indicators Marine pollution control and surveillance Regional monitoring/inspection of coastal zone Regional enforcement of standards Prevention of “polluters” slipping over the boarder.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Except where asterisked, only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs 44
Integrated local, national, or regional system implementation with decrease in pollution and associated long-term savings in clean-up and education costs. It is anticipated that the benefits which will be demonstrated by the proposed actions will be such that leverage of national or donor funding for continued implementation following the conclusion of the BCLME will be possible in view of the benefits which will acrue from a modest investment.
C2 EXPLANATORY NOTES. PROBLEM: MAJOR OIL SPILLS
Causes Variability of seaworthiness of vessels operational from the region, as well as transport through the region.
Impacts General coastal degradation (temporary habitat loss), with varied recovery rate, depending on species vulnerability and spill intensity. (Associated monitoring of fauna/flora recovery is essential.) Risks/Uncertainty Recovery period in system is sensitivity-dependent Regional and national peace and political stability are most conducive to programme success. General environmental deterioration leads to aesthetic deterioration and then tourism loss.
Socioeconomic impacts Revenue loss is a function of spill intensity and environmental sensitivity, and duration of spill.
Transboundary consequences Regional co-operation needed in use of equipment/manpower. Riparian/estuarine boundaries are particularly vulnerable. Co-operative management of spills moving across borders. (Management/clean-up of a major spill near country boundary can only be effective if comensurate actions are taken by the neighbouring state)
Activities/solutions Regional co-operation paramount in standards development: policy, equipment, and techniques.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Regional policy and optimal utilization of resources.
C2 EXPLANATORY NOTES. PROBLEM: MARINE LITTER
Causes Rapid urbanization and unplanned settlement, with variable and limited/no control by authorities. Existing formal infrastructure unable to cope with expanding formal developments. 45
Public apathy/indifference and difference in behavior across cultural groups. “Lost” fishing equipment and associated “wastes.” Non-returnable/disposabale nature of containers of packaging used in the region. (Absense of regulations and incentatives for return of containers and use of biodegradable materials)
Impacts Aesthetic and multiple impacts are associated with economic loss, although there may be job creation in the informal sector (waste management). Plastics and ropes (including fishing lines) present a significance amd growing hazard to marine mammals and seabirds (entanglement, ingestion)
Risks/uncertainty Volume of hazardous substances dumping unknown. Need to identify areas of waste accumulation through natural processes. Positive impacts (job creation in informal sector) are balanced by lack of incentives not to litter. Potential degree of transboundary movement. Issues common to all three countries – create a “blueprint” and apply flexibly to all countries.
Activities/solutions Public awareness is key to successful implementation and a sustained clean environment– primary focus is seafarers Common policy/practice and implementation – i.e. “return” (bottles) product incentives – common policy re boundary transfer and legislation (packaging) review.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Clean coastal zone Educated and up lifted public Improved legislation and standards implementated from local/national/ regional levels ~ coordinated Reduction in negative impacts on marine mammals and seabirds(particularly relevant to threatened/endagered species) 46
TABLE C4. RETARDATION/REVERSAL OF HABITAT DESTRUCTION/ALTERATION. PROBLEMS CAUSES IMPACT RISKS/UNCERTA SOCIO- TRANS- ACTIVITIES/SOL PRIORITY INCRE- ANTICIPATED INTIES ECONOMIC BOUNDARY UTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y)
C4. Habitat alteration/ destruction Diamond mining Increased turbidity Near-complete lack Costly infrastructure, Sediment transport Document fully 1 $ 50 000 Comprehensive (see also A4). Several habitats Demersal trawling (sediment plumes, etc) of data rehabilitation & Common problems, presented status status report have been altered or lost as a Variable river Benthic community No framework for maintenance e.g. erosion Adapt & apply consequence of development sediment input and destruction impact monitoring Loss in mariculture Redistribution of regional marine and 1 $150 000 Regional early and other human impacts. changing land use Mobilization of heavy Cumulative local production marine fauna as a coastal early warning system ad Impacts can be categorized into Oil/gas exploration/ metals vessel impacts Decreasing human consequences of warning system and action plan three areas, viz.: production and spills Faunal impacts e.g. Climate change health via heavy habitat alteration e.g. action plan Mariculture reproductive failure Distinguishing metal contamination hakes, seals Assess causality of Transboundary 1. Coastal – progradation/ Natural sediment Increased frequency of impacts from natural Loss of fisheries habitat alteration. 2 $100 000 causality redistribution; transport (altered HABs spatial and temporal productivity/ Adapt & apply established 2. Nearshore (< 30m) erosion) Coastal erosion variation revenue, e.g. rock standard 3. Shelf/slope (200 m) Built coastal Organic loading/anoxic lobster environmental 1 $50 000 structures conditions Opportunity costs quality criteria Human settlement Adapt & apply and resource use regional structure to Mangroves/coastal address problems 1 $100 000 Regional structures deforestation Adapt & apply and agreements Coastal vehicle expertise in coastal tracks processes Improved coastal 1/2 [$50 000] planning
C4 EXPLANATORY NOTES. PROBLEM: ECOSYSTEM HEALTH DECLINING
Causes Coastal progradation ~ former mining activities, subsequent longshore redistribution of sands – sedimentation of mangroves and other natural processes. Coastal destabilization due to anthropocentric activities. Natural sediment movement (natural rehabilitation of mined areas ~ masking actual impacts, which may possibly occur later and be more severe. Various fishing activities
Impacts Mining-generated sediment plumes ~ potential re mobilization of heavy metals (food chain impacts) and water quality deterioration. Mariculture can cause local organic loading and anoxic conditions. Habitat modifications impact on HABs.
Risks/uncertainty Incomplete/lack of data ~ severely limiting ~ but increasingly available due to mining companies’ existing programmes. Should standardize framework for evaluation of impacts. Impacts from multiple vessels in close proximity unknown ~ carrying capacity to be determined. Necessary to distinguish anthropogenic impacts from natural variability. Altered sediment structure and particle size composition with consequence for benthos and remobilization of certian minerals(metals).
Socioeconomic consequences Unknown costs of rehabilitation and subsequent evaluation of rehabilitation success. Human health affected through knock on effect in food chains. Loss of revenue from renewable resources. 47
Transboundary consequences Marine fauna migrating due to habitat loss. Sediment remobilization.
Activities/solutions The present status requires proper documentation, and establishment of baseline at regional level. Establish/identify regional parameters for approach to early warning systems and associated quality performance standards. Develop mechanisms of co-operation between industries, ministries and other stakeholders, and strengthen capacity Needs-assessment to improve coastal management expertise.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only those activities which address transboundary problems requiring incremental funding are listed . 48
TABLE C5. CONSERVATION OF BIODIVERSITY. PROBLEMS CAUSES IMPACT RISKS/UNCERTA SOCIO- TRANS- ACTIVITIES/SOL PRIORITY INCRE- ANTICIPATED INTIES ECONOMIC BOUNDARY UTIONS MENTAL OUTPUTS CONSEQUENCES CONSEQUENCES COST (5y
C5.Loss of biotic integrity: This Introduction of alien Local extinction Source of alien Loss in community Transfer of alien Harmonize regional 1 $50 000 Harmonized refers to ecosystem impacts species especially of benthic commensals? income from fishing species via shipping/ policies regional policy including changes in Selective fishing species Invasive ability? and mariculture mariculture Link with GEF 2 Co-Financing community composition, mortality (targeted Introduction of Beneficial or Potential public Natural processes ballast water project species diversity, and fishing) pathogens harmful? health impacts Fisher migration Regional fishing introduction of alien species – a Incident mortality Genetic impoverishment No baseline data Opportunity costs, Shared stocks policies co- 1 $30 000 Regional protocols set of measures of ecosystem bycatch/ discharges (loss of resilience) e.g. tourism management health. Pollution impact Political pressure to Identification of Establishment of Over-harvesting over-harvest MPAs (incl. negotiated marine Habitat alteration Lost income – Transboundary 1 $150 000 protected areas (e.g. destruction of prolonged recovery areas) Biodiversity mangrove areas) time Identify genetic conservation Lack of Uncertainty of populations baseline implementation of sustainable structures 2 $20 000 Reduction/ control international laws livelihoods Develop forum for of alien Modification of food stakeholder introductions, source of consumers participation and 1 $50 000 policy decisions, negotiation of forum established biodiversity code of conduct
C5 EXPLANATORY NOTES. PROBLEM: LOSS OF BIOTIC INTEGRITY
Causes Introduction of alien species Changes in community composition, population distribution and abundance due to overfishing, selective fishing (targeted at a particular species), and incidental (bycatch) mortality. Other identified causes included pollution impacts, habitat alteration (including mangrove destruction), and lack of implementation of international conventions (e.g. Convention on Biological Diversity and marine treaties). Lack of holistic approach to ecosystem management i.e. only management of individual species/components in isolation.
Impacts Introduction of pathogens and other commensal species: Alien species (intentionally or inadvertently imported) may arrive with unseen viruses, ectoparasites, and other commensals. Genetic impoverishment refers to the loss of genetic variability as a result of population ‘bottlenecks’ (severe crash in population numbers) which will normally reduce population resilience and fitness (ability to cope with future environmental change).
Risks/uncertainty Invasive ability: the ability of introduced species to survive, reproduce and replace indigenous species. Beneficial or harmful? The “beneficial” assessment is perceived as a socioeconomic one (e.g. mussels are tasty and easier to grow in mariculture than indigenous ones), but the “harmful” assessment is primarily an ecological one. (On the longer term, what may at present be perceived as beneficial may not be sustainable. This has serious implications for sustainable integrated management of the ecosystem.
Socioeconomic consequences Alien species: Potential public health impacts refer primarily to pathogens imported with ballast water aliens. 49
Opportunity costs: for example, alien infestations can cause a loss of diving tourism revenue. Fishing impacts: Political pressure to over-harvest: In a population recovery period, low quotas often cannot be implemented due to political pressure (leading to a very much longer recovery period). Loss of income: Prolonged recovery periods strain the industry through loss of revenue. Uncertainty of sustainable livelihoods: Government policy incentives are needed to encourage alternative job creation to sustain fishers during low yield periods, or a temporary industry shutdown. Modification of food source of consumers: in Namibia especially, some cultures will not willingly eat marine fish (although inland fish are eaten). It is a policy attempt to improve national food security, given that maize is imported and 80-90% of marine fish is exported. Not an option in present-day Angola. Migration of fishers -- when over-harvesting causes depletion of fish stocks, fishers may be forced to move.
Activities and solutions Cognisance is taken of the existing GEF international ballast water management project, in which Saldahna Bay is to be used as a model for a port management plan (cf SADC application). **NB: Angola is very concerned about uncontrolled dumping / flushing from ships generally (including bilge waters – not just marine litter and ballast water). Regional (BCLME region) policy on aquaculture / mariculture should be developed and then harmonized with those of neighbouring countries, including SADC region. (Refer to B-3) Regional (& national) management plan for biodiversity conservation must include a framework for assessment and prediction of environmental change impacts. Identification of marine protected areas: As the national borders within the BCLME region include two estuaries: a Ramsar site (Orange River mouth) and a proposed Ramsar site (Cunene River mouth), attention can also be given to possible transboundary marine protected areas. Identify genetic structure of populations: an essential component of a regional biodiversity conservation management plan. It has important implications for fisheries management (do countries manage the same or different stocks of individual species?). BENEFIT focuses on genetic structure of shared fish stocks in the region, but BCLME must focus on genetic diversity implications of marine resource management: genetic pollution, loss of heterozygosity, etc.
Activities/solutions Harmonisation of national policies and the development of a regional policy. Establish/identify regional parameters for approach to early warning systems and associated quality performance standards. Develop mechanisms of co-operation between industries, ministries and other stakeholders, and add capacity Needs-assessment to improve coastal management expertise.
Priority Proposed activities are ranked on a scale of 1-3 in terms of their perceived priority. Only activities which address transboundary problems requiring incremental funding are listed.
Anticipated outputs Regional quality indicators: Adapt and apply existing environmental quality indicators to the BCLME for specified variables. Policy decisions on allocation of seabed: There is a need for a policy decision on whether to renegotiate existing concessions, hold back the granting of new concessions. “Windows of opportunity” exist between the granting of exploration and production licenses, during which marine protected areas can probably be established. (However, this would lead to MPAs being restricted to areas rejected by industry, not the proactive establishment of biodiversity-rich MPAs). Harmonised regional policy and emergence of regional protocols The establishment of a forum for stakeholder participation in negotiating a biodiversity code of conduct is seen as an important outcome. 50 ANNEX I
FINAL DRAFT
STRATEGIC ACTION PROGRAMME
Integrated Management, Sustainable Development and Protection of the Benguela Current Large Marine Ecosystem (BCLME)
UNDP Windhoek, Namibia 1st November 1999 This Strategic Action Programme was adopted and signed by the Ministers of the respective countries:
On behalf of the Republic of Angola:
Minister of Fisheries and Environment
…………………………………………… Date:………………..
Minister of Petroleum
…………………………………………… Date:………………..
Minister of Energy and Mines
…………………………………………… Date:…………………
On behalf of the Republic of Namibia:
Minister of Fisheries and Marine Resources
……………………………………………….. Date:…………… 51 Minister of Environment and Tourism
……………………………………………….. Date:…………… Minister of Mines and Energy
……………………………………….………….. Date:……………
On behalf of the Republic of South Africa
Minister of Environmental Affairs and Tourism
…………………………………………………….Date: …………
Minister of Mineral and Energy Affairs
…………………………………………………….Date:…………… Desiring to manage development and protect the Benguela Current Large Marine Ecosystem in an integrated and sustainable manner,
The Governments of:
The Republic of Angola The Republic of Namibia The Republic of South Africa
Continuing in the spirit of the United Nations Declaration on Environment and Development (Rio Declaration) and Agenda 21;
Appreciating the progress that has been made towards sustainable development and environmental protection of the Benguela Current ecosystem through, inter alia, the actions taken by the Sector Co-ordinating Unit for Marine Fisheries and Marine Resources of the Southern African Development Community (SADC) and the Benguela Environment Fisheries Interaction and Training Programme (BENEFIT);
Welcoming the international support to regional initiatives such as BENEFIT and the efforts undertaken to sustainably manage and protect the living resources of the region through the development of the Benguela Current Large Marine Ecosystem (BCLME) programme;
Recognising the unique character of the BCLME with the many transboundary fisheries and environmental issues facing it and their potential global importance in relation to climate change;
Welcoming also the national initiatives taken to ratify or accede to international conventions to manage the living resources sustainably and to protect the environment of the Benguela Current ecosystem, including the work undertaken towards the adoption of MARPOL 73/78 and the London Convention in relation to marine pollution, the United Nations Agreement on Straddling and Highly Migratory Fish Stocks, the FAO Code of Conduct for Responsible Fishing , the Convention on Biological Diversity, the United Nations Framework Convention on Climate Change, the Abidjan and Nairobi Conventions on the Protection and Development of the Marine and Coastal Environment and Oil Spill Response around Africa, the Cape Town Declaration (ACOPS-UNEP), the Global Programme of Action (GPA) for the Protection of the Marine Environment from Land-based Activities , the Basle Convention on the Transport of Hazardous Materials as well as other Conventions in the Benguela Current such as the developing South East Atlantic Fisheries Organisation (SEAFO) and the Zone of Peace and Co-operation in the South Atlantic (ZOPCSA);
Conscious of the importance of the initiatives taken by non-governmental organisations towards conservation of living marine resources and protection of the environment of the BCLME; 52 Nevertheless concerned about the fragmented nature of regional management and the urgent need to strengthen and jointly engage member states in the co-ordination and conservation of the resources of the Benguela Current as an integrated ecosystem;
Convinced of the pressing need to take further concrete actions individually and collectively, at national and regional levels, to ensure transboundary co-operation and the integrated sustainable management and the protection of the living resources of the BCLME;
Committed to capacity strengthening for sustainable development at national and regional levels;
Acknowledging the significant contribution made through the results of the Transboundary Diagnostic Analysis (TDA) process in the development of the Strategic Action Programme (SAP) and towards integrating the information necessary for policy planning in the BCLME;
Commit themselves to establish the BCLME Programme and to agree on the following principles, policies and actions.
THE CHALLENGE: SUSTAINABLE INTEGRATED MANAGEMENT OF A CHANGING BENGUELA CURRENT LARGE MARINE ECOSYSTEM
The colonial and political past have left a legacy of fragmented management of the BCLME- an absence of co- ordinated planning and integration, poor legal frameworks and a lack of enforcement and implementation of existing regulatory instruments, insufficient public involvement, unbalanced regional capacity development and inadequate financial mechanisms of support.
These human factors superimposed on a complex ecosystem which transcends national/country boundaries which has a highly variable environment have manifested themselves in declines of fish stocks and some unsustainable practices of harvesting of living resources, uncertainty regarding ecosystem status and yields, increasing pollution, habitat destruction and alteration, loss of biotic integrity and threats to biodiversity, harmful algal blooms, and inadequate capacity to monitor and assess ecosystems. All of these have significant transboundary implications. The challenge is to halt this changing state of the BCLME and, where possible, to reverse the process through co-operative regional action to manage the ecosystem on an integrated and sustainable basis.
1. The over-exploitation of the commercial fish stocks and some unsustainable harvesting of the living resources of the Benguela Current ecosystem continue to be a cause of concern. Maritime boundaries do not coincide with ecosystem boundaries, and several of the region’s important harvested resources are shared between countries or at times move across national borders. Over-harvesting of a species in one country can therefore lead to depletion of that species in another as well as changes to the ecosystem as a whole. Moreover, many resource management difficulties common to all three countries are transboundary in nature and require collective and co-operative action by member states to address them fruitfully.
2. The environment associated with the Benguela Current is highly variable, and so the status and yield of the ecosystem as a whole are difficult to predict. Although the Benguela ecosystem is naturally adapted to a highly variable environment, sustained events such as Benguela Ninos, and Agulhas Current intrusions and changes in winds can have an impact on the whole system, compounding the negative effects of fishing, while poor predictive ability limits the capacity to manage effectively system-wide. In addition, the Benguela Current Large Marine Ecosystem is believed to play a significant role in global and ocean processes and may be an important site for the early detection of global climate change.
3. Deterioration in water quality poses a threat to the Benguela Current Large Marine Ecosystem at local and regional levels. Although most impacts of chronic deterioration in water quality are localised national issues, they are common to all countries, will increase as coastal populations increase and will ultimately require collective, transboundary action to address them. Moreover chronic pollution can favour less desirable species and result in the species migration across national boundaries. Catastrophic events such as major oil spills and large-scale system-wide anoxic events can have widespread transboundary consequences, requiring co-operative management and sharing of knowledge, equipment and technology. 53
4. Habitat destruction, degradation and modification of the sea bed and coastal zone in the BCLME are taking place at an increased pace. Although most impacts appear localised, habitat alterations attributable to fishing and mining can cause migration of biota and system-wide ecosystem change. Uncertainties exist about the transboundary and regional cumulative impacts on the benthos resulting from sea bed mining and associated sediment disturbance and movement.
5. Increased loss of biotic integrity, such as changes in community composition, species and diversity, and the introduction of alien species threaten the biodiversity of the Benguela Current as a whole. Past over-exploitation of targeted species has altered the ecosystem, causing impacts at all levels, including top predators, and reducing the genetic diversity. Endemic species such as the African penguin are now threatened or endangered. Alien species of phytoplankton have been introduced into the BCLME as a result of ballast water from ships, potentially destabilising the foodweb.
6. There is insufficient and limited institutional, infrastructural and human capacity at all levels to assess the status of the BCLME as a whole, and to jointly engage and assess the shared resources and other transboundary elements/components and variability thereof. Moreover there is unequal distribution of this capacity between countries.
7. During the past decade, there has been increased incidence in the occurrence of blooms of harmful algae in the coastal waters in many parts of the world as a result of highloading by nutrients and contaminants as well as the invasion by alien species. Harmful Algal Blooms (HABs) occur in coastal waters of all three countries of the Benguela Current and all three face similar problems in terms of assessment of the impacts, and monitoring the effects and management of the problems caused to fisheries and the quality of seafood. Collective regional and transboundary action will be required to co-operatively address this problem.
II. THE BASIS FOR CO-OPERATIVE ACTION
An organisation entitled the BCLME Programme is hereby established as an international body in terms of The United Nations Convention on the Law of the Sea (UNCLOS)
Principles
8. The concept of sustainable development shall be used in a way that does not destroy the integrity of the BCLME ecosystem, or otherwise foreclose on options for use and enjoyment for future generations.
9. The precautionary principle, where appropriate, shall be applied, preventative measures being taken when there are reasonable grounds for concern that an activity may increase the potential hazards to human health, living marine resources or marine ecosystems, damage amenities, or interfere with other legitimate uses of the sea, even when there is no conclusive evidence of a causal relationship between the activity and the effects and by virtue of which greater caution is required when information is uncertain, unreliable or inadequate.
10. Anticipatory and co-operative actions, such as contingency planning, environmental impact assessment and strategic environmental assessment (involving the conservation of living marine resources, the transboundary assessment of the environmental consequences of government policies, programmes and plans), shall be taken.
11. The use of clean technologies which require the replacement or phasing-out of high waste and waste- generating technologies that remain in use shall be encouraged.
12. The use of economic and policy instruments that foster sustainable development shall be promoted through, inter alia, the implementation of economic incentives for introducing environmentally friendly technologies, activities and practices; the phasing-out of subsidies which encourage the continuation of non-environmentally friendly technologies, activities and practices; the introduction of user fees and the polluter pays principle; as well as the auditing of natural resources and environment.
13. Environmental, ecosystem and human health considerations shall be included into all relevant policies and sectoral plans, especially those concerning marine industrial development, fisheries, mariculture and marine transport. 54
14. Co-operation among member states shall be promoted especially in the area of transboundary issues and activities.
15. The participation and co-operation of the private sector shall be encouraged and is seen as integral to the successful management and implementation of the SAP.
16. Recognising the interests of other states in the BCLME such states shall be encouraged to take part in, co-operate and jointly engage in activities.
17. Transparency, public participation and co-operation in the work of the BCLME shall be fostered through wide dissemination of information on the work undertaken to enhance the integrated and sustainable management of the BCLME, including environmental variability forecasting and protection.
Institutional arrangements
18. In order to implement the actions and policies agreed upon, it is imperative that existing regional mechanisms for co-operation among the member states be strengthened to ensure the necessary capacity building to promote sustainable integrated management of the BCLME. The member states will actively pursue a policy of co- financing with industry and donor agencies.
19. An Interim Benguela Current Commission (IBCC) shall be established to strengthen regional co-operation and be fully supported by a Programme Co-ordinating Unit (PCU) and subsidiary bodies, such as Advisory Centres and Groups. The IBCC should become a fully functional Benguela Current Commission (BCC) with a supporting Secretariat within a period of five years after formal commencement of the BCLME Programme.
20.The IBCC shall implement this Strategic Action Programme and shall establish at its first session such bodies as necessary to provide support for specific projects and processes related to it’s implementation.
21. The IBCC shall be structured as described in the Annex.
22. The IBCC shall be supported by Advisory Groups located and co-ordinated at Activity Centres in each of the member states. The following Advisory Groups are initially agreed upon in principle:
a) an Advisory Group on Fisheries and other Living Marine Resources an Advisory Group on Marine Environmental Variability and Ecosystem Health an Advisory Group on Marine Pollution an Advisory Group on Legal Affairs and Maritime Law an Advisory Group on Information and Data Exchange
23. The IBCC (later the BCC) shall regularly review the status and functions of the Advisory Groups and consider the establishment of ad hoc groups for the purpose of implementing this SAP.
24. The BCLME Programme Co-ordinating Unit will function as the IBCC Secretariat and shall be headed by a Regional Co-ordinator. The PCU shall perform all such tasks as delegated by the IBCC and in particular it shall (a) co-ordinate and administer the Programme including contract preparations, financial management, auditing and preparation of annual reviews b) assume responsibility for the operation and maintenance of an electronic communications system for purposes of facilitating interaction between the components of the BCLME institutional network, (c) liaise with Activity Centres to provide information on bibliography, data sources, status of the ecosystem, 55 environmental variability and assessment activities (d) where appropriate, organise bi-annual conferences based on the results of assessment of the changing state of the BCLME. The first such conference will be held in March 2002.
Wider co-operation
25.The IBCC (later the BCC) and member states shall individually and jointly encourage the following:
A) ENHANCED CO-ORDINATION BETWEEN REGIONAL BODIES AND INITIATIVES SUCH AS BENEFIT, THE FUTURE SOUTH EAST ATLANTIC FISHERIES ORGANISATION (SEAFO), AND NGOS WHICH CONTRIBUTE TOWARDS THE INTEGRATED MANAGEMENT, SUSTAINABLE DEVELOPMENT AND UTILISATION OF THE LIVING MARINE RESOURCES AND PROTECTION OF THE BENGUELA CURRENT LARGE MARINE ECOSYSTEM. THE IBCC MAY, WHERE APPROPRIATE, DEVELOP INSTITUTIONAL RELATIONSHIPS WITH SADC AND PROMOTE COLLABORATION WITH OTHER SADC STATES AND PROJECTS E.G. THE REGIONAL FISHERIES INFORMATION SYSTEM (RFIS).
b) Co-operation between the regional governmental bodies and NGOs through transparency of the negotiating process, widespread availability of information and documents and, where appropriate, open access to meetings.
c) Co-operation with donors, including multilateral financial institutions, bilateral aid agencies and private foundations, in the aim of securing funding for projects and policies identified in the BCLME SAP, to be further developed at national level.
d) Co-operation with appropriate international organisations, including UN Agencies and international NGOs in implementing this SAP.
E) CO-OPERATION WITH OTHER STATES WITH INTERESTS IN THE BCLME AND OTHER LMES THAT SHARE SIMILAR ATTRIBUTES AND ARE THE SUBJECT OF REGIONAL CO- OPERATION.
26. International agreements relevant to the aims and objectives of this SAP shall be implemented by each member state party to such agreement. Where this is appropriate and has not yet been done, member states shall consider ratifying or acceding to such agreements or otherwise consider implementing protocols relevant to the sustainable management of the BCLME. Consideration shall also be given to implementing other relevant international instruments.
27. Provisions for the settlement of disputes will be made by referring directly to the IBCC.
28. The boundaries of the BCLME for the purpose of this SAP will be as follows: (a) eastern landward boundary will be the high-water mark at the land-sea interface (b) the northern boundary will be located at 5 °S, (c) the southern boundary will be 38° 20’S (the southernmost extent of South Africa’s continental EEZ, and extending as far as 27°E and (d) the western boundary for the purpose of the BCLME is taken at the 0° meridian. The western boundary in terms of enforcible management actions under the SAP is however located at the seaward extent of the EEZs of the member countries i.e. 200 nautical miles offshore.
III. POLICY ACTIONS
A. Sustainable Management and Utilisation of Living Marine Resources
Living marine resources are harvested by commercial and artisanal and recreational fisheries throughout the BCLME, and fishing is important to the economies of all three countries. Most of the region’s important harvested resources are shared between countries, or at times move across national boundaries. Over-harvesting of a species in one country can therefore lead to depletion of that species in another, resulting in potentially irreversible changes 56 to the ecosystem as a whole. In contrast, there may be species that can provide opportunities for sustainable development (e.g. seaweed, some invertebrates) that are not optimally utilised. All principal harvested fish stocks in the BCLME have been subjected to over-fishing in the past – the consequence of colonialism, some inappropriate historical policies and greed. The decline in hake stocks in the 1960s and 1970s can be attributed to the rape of the ecosystem by foreign fleets, and the collapses of sardine and rock lobster were due to greed and mismanagement coupled with a lack of understanding about the impacts of environmental variability. Over-fishing has had a negative impact on other components of the ecosystem too, e.g. seabirds and marine mammals. In order to rebuild depleted stocks and to repair the damage done to the ecosystem by past actions, and at the same time to develop employment opportunities and socio-economic advancement, the governments of Angola, Namibia and South Africa have committed themselves to the development of sustainable integrated management and utilisation of living marine resources through the following suite of policy actions:
In order to ensure the sustainable management and utilisation of living marine resources of the BCLME and avoid foreclosure of options for future generations, the following policy actions which address identified priority transboundary issues are agreed to:
Regional structure
A regional structure will be established to conduct transboundary fish stock and ecosystem assessments, to evaluate transboundary resource-environment linkages and to provide advice in these areas to governments. The implementation of this transboundary structure will involve the national focal institutions in the three states.
(b) Joint surveys and assessment
Joint surveys and assessment of shared stocks of key species will be undertaken co-operatively over a five year period commencing in 2001 as a demonstration of the benefits to the individual nations of joint transboundary fisheries assessments. Integral within this collaboration will be the gathering of baseline data, comparisons and validation of survey and assessment methodology. The Activity Centre(s) responsible will give effect to the above and provide a basis for regional advice on shared stocks.
(c) Harmonising management of shared stocks
The IBCC shall, where appropriate, harmonise the management of shared stocks through, inter alia addressing technical issues such as fishing gear, mesh size/type, compatible data and assessment methodology. (Note: harmonising management does not necessarily imply joint management).
(d) Assessment of non-exploited species
Co-operative assessments of non-exploited species, both offshore and inshore, which are common to at least two of the countries, will be undertaken where appropriate. This will require the gathering and calibration of baseline information on these species, and assessment of the impact of any future harvesting on the ecosystem. The appropriate Activity Centre(s) will have the function of co-ordinating these activities.
Regional mariculture policy
Mariculture contributes sustainably to the regional economy and the improvement of living conditions of coastal communities. There is considerable potential for the expansion of mariculture regionally. However, it is essential to ensure that future growth of the industry does not at the same time have negative impacts on the ecosystem. The IBCC shall endeavour to develop a responsible regional mariculture policy in co-operation with SADC by December 2002 to harmonise national policies in such a manner that actions of one state do not impact negatively on the economic 57 potential of another, nor on the ecosystem as a whole. The policy shall provide for the implementation of appropriate monitoring actions, including monitoring of harmful algal blooms.
(f) Socio-cconomic analysis
Co-operative analyses of socio-economic consequences of various harvesting methods, the improved use of living marine resources and the economic value of the BCLME as an ecosystem, will be undertaken with a view to appropriate intervention within the framework of improving sustainable ecosystem use/management and quantifying regional and global benefits. Co-ordination of these activities will be undertaken by the appropriate Activity Centre.
Fishery conservation measures
National policies on protected areas and other conservation measures will be harmonised as far as possible.
(h) Code of conduct for responsible fishing
The governments of Angola, Namibia and South Africa commit themselves to compliance with the FAO Code of Conduct for Responsible Fishing.
B. Management of Mining and Drilling Activities
Exploration for oil, gas and minerals (e.g. diamonds) is expanding throughout the BCLME. There is substantial oil extraction in northern Angola (Cabinda Province), and development of oil/gas fields (with pipelines) farther south are planned (e.g. in Namibia). Capped abandoned wellheads hamper fishing, while drill cuttings and hydrocarbon spills impact on the environment. Extensive diamond mining is being conducted by dredging along the coasts and continental shelves of Namibia and South Africa. The ecosystem effects of these activities are not fully known, and conflicts can arise between different sectors (e.g. mining-fishing-conservation).
30. In order to further the objectives of responsible multi-sectoral utilisation of the BCLME and to minimise any negative impacts on the ecosystem of mining and drilling activities, the following policy actions are agreed to:
(a) Regional consultation framework
The IBCC shall develop by December 2002 a regional framework for enhanced consultation, with the objective of mitigating the negative impacts of mining, reducing inter-sectoral conflicts and ensuring that benefits accrue. The IBCC shall develop by December 2003 a Code of Conduct for responsible mining, including rehabilitation of affected areas, which would be voluntary.
(b) Policy harmonisation
The governments of the three countries will collaborate to harmonise mining policies relating to shared resources, cumulative impacts and their mitigation.
(c) Cumulative impact assessment
Impact assessment of the cumulative effects of mining activities on the BCLME will be undertaken. The principle of co-funding by industry is accepted and will be promoted.
(d) Co-ordination of actions relating to the offshore exploration and production of oil and gas 58 Co-ordinated actions for the assessment and mitigation of negative impacts on the ecosystem of oil and gas exploration and production will be facilitated.
C. Assessment of Environmental Variability, Ecosystem Impacts and Improvement of Predictability
The BCLME is unique among eastern boundary upwelling systems in that it is bounded at both northern and southern ends by tropical or sub-tropical regimes, which significantly impact on the ecosystem. It is a highly complex system that displays a high degree of environmental variability on a variety of time and space scales. Human impact on the BCLME (e.g. fishing) is superimposed on its inherent natural variability. The combined effect of anthropogenic disturbance and this variability has been implicated in ecosystem change and collapse of harvested resources. There is fragmentary but important evidence of increasing instability and variability. There is also considerable uncertainty regarding cause and effect of ecosystem status and yields. Lack of information about and understanding of environmental variability and its system-wide impact hampers the management of the BCLME resources and results in non-optimal utilisation of these resources. Moreover, there is evidence that environmental signals from the BCLME are useful predictors of rainfall in SADC countries. This has important implications for regional food security.
31. In order to assess environmental variability, ecosystem impacts and improve predictability in support of sustainable integrated management of the BCLME, the following policy actions are agreed to:
(a) Development of environmental early-warning system
A suitable needs-driven, cost-effective regional early warning system for monitoring major environmental events within the BCLME will be developed by 2003. This will include the cross-linking of existing national environmental monitoring systems, adapting these and then integrating and linking (networking) with ongoing international ocean monitoring activities through a demonstration project using an array of moored oceanographic buoys. Information on the state of the environment, which is the primary product of improved environmental assessment and networking, will be incorporated into the various decision-making support systems that underpin in particular living marine resource management, coastal zone management, pollution management e.g. oil pollution and disaster contingency planning and rainfall prediction. An Activity Centre will co-ordinate the development of the early warning system and the management application thereof for the region, establish requisite networking, and permit regular "state-of-the- environment" analysis and reporting in the three countries and for the region. Assessment of the utility of and feasibility of a regional link-up with the existing PIRATA moored ocean- monitoring buoy network in the equatorial Atlantic will be undertaken through a demonstration project to assess the feasibility of establishing an early warning system for environmental perturbations in the BCLME.
(b) Baseline establishment
Analysis of existing data series and material archives will be undertaken collaboratively to ascertain and provide a baseline against which to measure future transboundary variability/change, in particular decadal changes, and to ascertain the extent of and trends in variability and change, in particular decadal changes during the 20 th century. This work will be facilitated through one of the Activity Centres. The establishment of an environmental baseline for the BCLME is seen as a high priority regionally and is also important in a global context.
(c) Improving predictability of extreme events
Analysis and reassessment of available data and information, augmented where appropriate by new material, will be undertaken to determine the sources and large-scale impacts on the BCLME of variations in seawater oxygen level as well as other extreme episodes of inter-annual variability, with a view to improving predictability of their timing, extent and ecosystem consequences. The improved predictability of major transboundary perturbations will complement in particular resource assessment and modelling and resource management actions, coastal zone management and marine pollution contingency planning. It will also be used to enhance forecasting of regional rainfall and, as a consequence, better planning/management of terrestrial activities such as agriculture that depend on rainfall. This work will be jointly facilitated through the Activity Centres in all countries. 59
(d) Harmful algal blooms (HABs)
A regional HAB reporting network will be developed during 2001 with a view to its implementation in 2002. Regional contingency plans for assessing the transboundary effects of HABs will be developed and implemented by December 2002. Data on HABs will be an important input into the sustainable development of mariculture, and data requirements will be specified in a plan for regional mariculture policy harmonisation.
(e) Climate change
In view of the role that upwelling systems may play in climate change as sources and sinks of carbon, the three countries will collaborate with the international community to assess the carbon dioxide source/sink status of the BCLME and likely feedback mechanisms to climate.
D. Management of Pollution
Coastal developments and rapid expansion of coastal cities, much of which was unforeseen or unplanned, has created pollution "hot spots" in all three countries, with resultant deterioration in water quality. The problem is aggravated by an increase in marine litter from land and shipping activities. In addition, a substantial volume of oil is transported through the BCLME region and within it, and there is increasing exploration and extraction of oil and gas in the north. There is a significant risk of contamination of large areas of fragile coastal environments from major accidents, damage to coastal infrastructure and to straddling fish stocks.
32. The following joint policy actions to manage marine pollution in the BCLME and minimise ecosystem impacts are agreed:
(a) Harmonising environmental quality objectives
The IBCC will endeavour to provide effective regional communication to co-ordinate efforts to control marine pollution, minimise impacts and develop cost-effective solutions. This will include inter alia development of regional environmental quality indicators, proposals for marine pollution control and surveillance, regional monitoring/inspection of the coastal zone and regional enforcement of standards. The focus will be on prevention rather than cure. In the case of point source pollution, the member states will by June 2002 develop waste quality criteria for receiving waters.
(b) Oil pollution contingency plans and regional policy
All three countries have or shortly will have oil pollution contingency plans. The IBCC will endeavour to harmonise these plans as far as possible and to develop necessary mechanisms for sharing technology and expertise, and in the event of a major oil spill, for the sharing of clean-up equipment and provision of expert advice. An appropriate regional policy will be developed by 2003 to minimise transboundary (cross-border) impacts of oil pollution from activities in the EEZs of individual countries. Such activities will be co-ordinated by an Activity Centre.
(c) Implementation of MARPOL 73/78
The Commission will co-operate with the SADC initiative for devising a common strategy for the implementation of MARPOL 73/78 in the BCLME region which is to be devised by December 2000.
(d) Marine litter
The growing problem of marine litter will be addressed first by a regional public awareness campaign (which will have seafarers as its primary focus); and second by harmonising legislation, enforcement and implementation of standards at a regional level. Locally and nationally, activities will be facilitated and co-ordinated.
E. Maintenance of Ecosystem Health and Protection of 60 Biological Diversity
Human impact on the ecosystem by way of fishing, increasing pressure on the coastal zone, pollution etc. has negatively affected components of the system, in particular on top predators such as marine mammals, coastal birds, e.g. African penguins which are now threatened or endangered. Several habitats, in particular coastal habitats, have also been perturbed or lost as a consequence of development and other human impacts, such as loss of wetlands, destruction of mangroves and lagoon. These have transboundary consequences and may be important globally. Moreover, there has been a loss of biotic integrity, including changes in community composition, species diversity and the introduction of alien species.
33. In order to retard or reverse habitat alteration and destruction and to protect vulnerable species and biological diversity, the following regional policy actions are agreed to.
(a) Vulnerable species and habitats
A regional assessment of the status of the most vulnerable species and habitats will be undertaken collaboratively by December 2001. This assessment will be facilitated by one of the Activity Centres. Member states will endeavour to assemble the necessary baseline data and, where affordable, undertake focused research on perceived causality. A regional marine and coastal early warning system will be developed by December 2002 and incorporated into an action that will specify environmental quality criteria and propose the most appropriate regional structure to address the problems. Implicit in this is the development of mechanisms for co-operation between industries, governments and other stakeholders. A needs assessment to improve coastal management expertise will also be conducted. A suite of appropriate projects for marine and coastal areas suitable for GEF and donor funding will be elaborated during 2000. These will include inter alia a project to determine the carrying capacity of BCLME coastal zone for tourism.
(b) Ballast water policy
A regional policy on ballast water for the BCLME will be developed in tandem with the existing GEF international ballast water management project. The latter project will include a SADC-wide workshop to raise awareness on the problems associated with ballast water. South Africa can take the lead in this initiative.
(c) Marine biological diversity conservation
A regional marine biodiversity conservation management plan will be developed by December 2003. This plan will include a framework for assessment and prediction of the aspects of environmental change, an assessment of genetic diversity implications of marine resource management, and identification of priority marine protected areas, in particular possible transboundary protected areas. Close co-operation will also be maintained with the SADC programme “The Southern African Biodiversity Support Programme”. The GEF SIDS Programme for the South Pacific could serve as a useful framework for the identification and development of protected areas. The process of establishing a management plan will be facilitated by an Activity Centre.
F. Capacity Strengthening
The strengthening of human and infrastructure capacity and the maintenance of existing capacity has been identified as a high priority if not the highest priority, in the region. Existing capacity is stretched to the limit to address national priorities within the BCLME, and there is a serious lack of capacity to address the priority transboundary issues identified in the TDA and highlighted in this SAP. Appropriate strengthening of human and infrastructure capacity in the region is a prerequisite for the sustainable integrated management of the BCLME. This applies at all levels in all transboundary components including, inter alia, science and technology based activities and assessment, economic assessment, surveillance, overall management and policy development and regulation and enforcement.
34. Policy actions proposed to develop and maintain capacity in the BCLME are listed below. 61 (a) Strategic plan for capacity strengthening
A comprehensive collaborative study of human capacity and training and infrastructure needs to address priority transboundary issues will be undertaken during 2000, together with an assessment of the status of existing capacity and trends therein. This needs assessment will use as its point of departure the priority areas identified in the TDA, eg. transboundary resource assessment and management, environmental assessment and prediction of large-scale extreme events which impact across BCLME and national boundaries and ecosystem consequences of extreme events, transboundary pollution management, cumulative impact assessment of mining, system-wide protection of biodiversity, etc.. It will harmonise with other programmes and activity areas such as BENEFIT and the EU-SADC Monitoring- Control-Surveillance (MCS) initiative. It will form a basis for the collaborative development of a comprehensive but realistic regional strategic plan for capacity strengthening and maintenance within the context of the BCLME and focusing on transboundary needs, and will be finalised by June 2001.
(b) Implementation of capacity strengthening strategic plan
Following acceptance of the regional strategic plan for capacity strengthening and maintenance in the BCLME, each country shall endeavour to implement the strategy to the best of its ability.
IV. NATIONAL STRATEGIC ACTION PLANS
35. Each member state shall prepare by June 2000 a national BCLME strategic action plan (10 pages) or other corresponding document, which shall present details of additional national actions to further implement the SAP. These shall include details of responsibilities and specific projects where possible.
FINANCING THE STRATEGIC ACTION PROGRAMME FOR THE NEXT FIVE YEARS AND REVIEW
36. The countries will seek the necessary funding for the actions agreed upon in this Strategic Action Programme from national, regional and international sources, through private and general public funding or through the application of specific economic instruments, as well as through grants and loans. Specific projects for international funding will be prepared for bilateral or multilateral funding. Donor conferences for assisting in this process shall be held every five years, starting in the year 2000. Specific funding arrangements for the national policies and measures agreed on in this Strategic Action Programme shall be presented in the National SAPs to be adopted by each of the member states.
37. The SAP shall be reviewed from time to time and updated when and where necessary.
VI. ARRANGEMENTS FOR FUTURE CO-OPERATION
38. The implementation of this SAP over a five-year period will produce a revised programme that will lead to long- term measures to sustain and protect the BCLME. Member states agree to commit themselves to continuing the BCLME Programme beyond the GEF intervention, and will endeavour to (a) adopt appropriate legislation, (b) implement economic instruments and (c) establish a permanent Benguela Current Commission with a supporting Secretariat. A financial plan that will make provision for future sustainable funding will be prepared, including a study on the feasibility of establishing an Environmental Fund.
39. It is envisioned that the BCLME Programme will continue to develop strong links with institutions, NGOs and the private sector within member states and the SADC region as a whole, so promoting the overall objective of closer economic integration.
ANNEX J
SUMMARY OF THE FUNCTIONS AND RESPONSIBILITIES OF THE INTERIM BENGUELA CURRENT COMMISSION
The Interim Benguela Current Commission will consist of three representatives from each country, each with a vote. Decisions will be made with majority voting. The terms of office of the Commissioners shall be for six years, one-third retiring after two years and another one-third after four years. A chairperson shall be elected by the Commission and will be rotate every two years. There shall be equality between member states; The IBCC will also have non-voting representation from (a) SEAFO, (b) UNDP (c) UNEP (d) SADC (e) BENEFIT and (f) the Secretariat. The World Bank shall be represented on the IBCC for the duration of the BCLME Programme (five years ). Specialists and representatives of other stakeholders and regional or international organisations can be co-opted onto the IBCC from time to time as appropriate.
Advisory Groups and Activity Centres Associated with the Benguela Current Large Marine Ecosystem Strategic Action Programme (BCLME-SAP)
The purpose of the Advisory Groups is to provide the Secretariat or the PCU with the best possible advice and information on topics key to implementation of the BCLME Strategic Action Programme. In all cases, they will, as part of their duties, respond to requests for advice from the PCU and prepare proposals for the PCU’s consideration at their own initiative. The groups will include experts from specialised focal points of the member states. The Advisory Groups will work closely with other experts, bodies, institutions and industry as they, or the PCU, deem necessary. Involvement with relevant NGOs is also encouraged, particularly in the improvement of public participation and awareness in all of the focal areas they cover. Particular attention shall also be given to including experts in environmental law, environmental economics and public awareness, where appropriate.
Each Advisory Group shall seek to make best use of expertise and institutional capacity within the region and, within its work plan, approved on an annual basis by the IBCC, may request assistance from or assign specific tasks to, any institution or expert that it considers appropriate.
The BCLME-PCU will provide general co-ordination for the Advisory Groups, assigning the management of specific tasks to appropriate officers according to their technical specialisation.
The Advisory Groups shall be supported by three Activity Centres (one in each member state) which shall co-ordinate the necessary programme support and the provision of practical technical support for their work. The Activity Centres shall be created through in-kind contributions by member state governments, as well as with significant funding from donors, especially during the first three years.
Advisory Groups shall liaise with each other where appropriate and joint groups may be set up from time-to-time, particularly on such issues as resource assessment, fisheries development, ecosystem health, environmental variability and environmental impact assessment.
THE ADVISORY GROUPS TO BE LOCATED IN ACTIVITY CENTRES ARE DEFINED AND LISTED BELOW.
Advisory Group on Fisheries and Other Living Marine Resources
The Group will co-ordinate activities and provide technical support for the sustainable management, utilisation and protection of fisheries and other living marine resources of the BCLME. The Advisory Group will gather the basic source of information related to transboundary commercial fish stocks and management strategies including means of capture, installed capacity and protection measures and will be co-ordinate calibration/inter-calibrations for transboundary assessments; socio-economic assessments and serve as a regional forum for stock assessment advice. Information would also be collected on other potentially important living marine resources that are currently not harvested, as well as mariculture projects. These data will be gathered from all national authorities and should document past changes in Anchor Environmental Consultants the production and stock of the region and their relationship to changes in the Benguela Current ecosystem. They will provide the basic source of information for future management strategies, and for the implementation of any future fisheries convention.
The Group will develop proposals and, where appropriate, co-ordinate (1) harmonisation at the regional level of a legal and institutional framework aimed at sustainable use of living marine resources; (2) improvement of the fisheries resource assessment of the BCLME based on a regional approach; (3) development of projects for conservation, protection and rehabilitation of living marine resources; (4) development of specific techniques for mariculture that do not harm the environment or the biological diversity. The Group will collaborate with regional and international institutions, government bodies and the private sector.
Advisory Group on Environmental Variability and Ecosystem Health
THIS GROUP WILL CO-ORDINATE ACTIVITIES AND PROVIDE TECHNICAL SUPPORT FOR THE DEVELOPMENT AND IMPLEMENTATION OF AN EARLY WARNING SYSTEM FOR VARIABILITY AND CHANGE IN THE PHYSICAL, CHEMICAL AND BIOLOGICAL ENVIRONMENT OF THE BCLME. DEVELOPMENT OF MODELS TO PREDICT TRANSBOUNDARY ENVIRONMENTAL CHANGE AND ASSESS THE OVERALL HEALTH OF THE ECOSYSTEM WILL FORM A PRIMARY ROLE OF THIS GROUP. THE IMPLEMENTATION OF NEW TECHNIQUES FOR RAPID ASSESSMENT OF THE BENGUELA CURRENT OCEAN AND COASTAL ENVIRONMENTS WILL ALSO BE PURSUED. COST-EFFECTIVENESS WILL BE A GUIDING PRINCIPAL FOR GROUP ACTIVITIES.
THE GROUP WILL DEVELOP PROPOSALS FOR AND CO-ORDINATE (1) EFFECTIVE STATE OF THE ENVIRONMENTAL ASSESSMENT OF THE BENGUELA CURRENT LARGE MARINE ECOSYSTEM; (2) MODELING OF THE BENGUELA CURRENT ECOSYSTEM AND THE INTERACTION BETWEEN THE PHYSICAL, CHEMICAL AND BIOLOGICAL PARAMETERS WITH A VIEW TO IMPROVING PREDICTABILITY OF EXTREME EVENTS AND SYSTEM WIDE CHANGE; (3) THE METOCEAN DATA BUOY (PIRATA) DEMONSTRATION PROJECT IN SOUTHERN ANGOLA-NORTHERN NAMIBIA; (4) RAPID ENVIRONMENTAL ASSESSMENT TECHNIQUES USING TOWED UNDULATING OCEANOGRAPHIC INSTRUMENTS AND SATELLITE REMOTE SENSING; (5) REGIONAL TRAINING PROGRAMMES IN SCIENTIFIC AND TECHNICAL ASPECTS OF ENVIRONMENTAL MONITORING, DATA PROCESSING AND MODELING OF THE BCLME; (6) DEVELOPMENT OF A REGIONAL NETWORK, CONTINGENCY PLAN AND REPORTING SYSTEM FOR HABS; (7) MITIGATION IMPACTS OF HABS AND COMMUNITY INVOLVEMENT IN MONITORING.
3. Advisory Group on Marine Pollution
The Group will co-ordinate, and provide technical support for, project activities aimed at the prevention, reduction, control and monitoring of all sources of transboundary pollution in the BCLME area. Such activities will include (1) assessment of water quality in the BCLME area, including identification and comparative evaluation of sources of pollution; (2) development of regional protocols and agreements with a view to harmonising policies and standards on water and sediment quality, and on the control of marine litter; (3) development of a regional framework for the monitoring of marine pollution and enforcement of regulations; (4) assessment for the needs for training in marine pollution control, and identification of relevant opportunities and/or development of courses as necessary; (5) development of a regional oil spill contingency plan; (6) development of public awareness of marine pollution issues through the production of relevant educational material; (7) implementation of demonstration projects. In addition, the Advisory Group will liaise and collaborate with relevant regional and international institutions, government bodies, NGOs and the private sector (eg. industry).
4. Advisory Group on Legal and Maritime Affairs
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The Group will monitor and advise the PCU (Secretariat) on the emerging legal regimes of the BCLME, measures adopted under it and activities carried out within it, with a view to ensuring (1) the appropriate development of the regime and its efficacy; (2) the consistency of the regime with global international law regimes (such as UNCLOS, UNEP, pollution conventions, the Biodiversity Convention, etc.. (3) the consistency of the regime with regional and other related international law regimes (such as SADC and the projected SEAFO); (4) that harmonisation of national policies within the system are similarly consistent; The Group will where requested to do so by the PCU (Secretariat or a Member State) examine the compatibility of any national measure taken by any Member State with a view to assessing its consistency with the system and advising thereon.
Advisory Group on Information and Data Exchange
This group will focus its work on the improvement of information flow and data exchange. In particular, it will oversee (1) Updating the existing Benguela Current information on fisheries, oceanography, environmental variability and ecosystem health, diamond mining and other minerals and deposits, offshore oil and gas exploration and production, coastal developments, and socio-economics; (2) develop of an integrated regional data base and Geographic Information System (GIS) for the BCLME; (3) compile and update a bibliography of the region and a BCLME website; (4) strengthening the e-mail network and improve Internet connections to the web services for principal data centres and Ministries of Environment, Fisheries and Marine Resources and Energy and Mining for the exchange of information and data including meta-data; (5) develop a regional Internet facility comprising environmental data, sets of data obtained from various national, regional and international programmes, copies of historical data and datasets from global data centres such as the World Data Centre (WDC), the Global Ocean Observation System-Living Marine Resources (GOOS-LMR) and the Intergovernmental Oceanographic Commission (IOC); (6) co-operate with an NGO network in data exchange; Furthermore it will organise training on data exchange, promote and support UN agency sponsored distance-learning programmes such as the International Waters IW:LEARN and TRAIN- SEA-COAST Programmes and also assist other networks in the region.
A major part of the BCLME Programme activities will be implemented by a network of specialist institutions co-ordinated by Activity Centres. Each government will agree to host one of these centres. The centres will be based on national institutions selected by the Commissioners at the first meeting of the IBCC or by the Programme Steering Committee. The Activity Centres will work closely with the PCU in order to establish links with the national institutional focal points i.e. specialised institutions selected by Governments to participate in each of the networks. With the support of the PCU, the Activity Centres shall organise Working Parties , conduct training and present recommendations to the Programme Steering Committee.
The Activity Centres are as follows:
Activity Centre 1: Living Marine Resources and Biodiversity Conservation
Activity Centre 2: Environmental Variability, Ecosystem Health and Pollution
Activity Centre 3. Capacity Strengthening and Networking
(functions of Activity Centres to be defined) ANNEX K
SYNTHESIS AND ASSESSMENT OF INFORMATION ON THE BCLME
THEMATIC REPORT 3 Overview of Diamond Mining in the BCLME 64 Anchor Environmental Consultants
INTEGRATED OVERVIEW OF DIAMOND MINING IN THE BENGUELA CURRENT REGION
B.M. Clark, W.F. Meyer, C. Ewart-Smith, A. Pulfrich and J. Hughes
AEC Report # 1016/1 March 1999
Anchor Environmental Consultantscc
Department of Zoology University of Cape Town Rondebosch 7701 South Africa
Cell: 083 309 1231 Tel/Fax: +27 (21) 685 3400 Email: [email protected]
Overview of Diamond Mining in the BCLME 65 Anchor Environmental Consultants
CONDITIONS OF USE
1. This report is the property of the UNDP who may publish it provided that: Anchor Environmental Consultants (AEC) is acknowledged in the publication. AEC is indemnified against any claims from damage that may result from publication. AEC receives copies of any publications emanating from this work.
2. AEC will not publish this report without the prior written consent of the client. AEC may, however, use technical information obtained from the compilation of this report, but AEC will not identify either the client, or the subject of this study.
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SCOPE
Barry Clark of Anchor Environmental Consultants (AEC) was commissioned by United Nations Development Programme (UNDP) to prepare an integrated overview of marine diamond mining in the Benguela Current region (Angola, Namibia and South Africa). The report was to include the following written terms of reference, received by AEC on September 28, 1998. A Historical Perspective Areas of Activities (inter-tidal, shallow-water, offshore) Key Players and Stakeholders Diamond Mining Techniques Operational Practices Economic and Social Importance Environmental Policy and Legislation Environmental Impacts of Activities on Fisheries and Ecosystem EIA procedures and Mitigation Measures Environmental Management Plans Conflict Issues and Resolution Mechanisms
The report was also to document: Key problems, threats and issues to the environment/ecosystem from marine diamond mining Gaps in knowledge (environmental management, monitoring, mitigation) Transboundary issues
Due to the confidential nature of much of the literature used, references are not specified in the text but are appended in a bibliography.
The study was undertaken by B.M. Clark, W.F. Meyer, C. Ewart-Smith, A. Pulfrich and J. Hughes. Sue Lane (Sue Lane & Associates), Dr Gabi Schneider (Ministry of Mines and Energy, Namibia), Alison Dehrmann (Department of Mineral and Energy, South Africa) and Dr Mick O’Toole (Ministry of Fisheries and Marine Resources, Namibia) commented on earlier drafts of the manuscript.
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EXECUTIVE SUMMARY
Historical Perspective 1900’s: Early diamond discoveries on the southern Namibian coast result in the start of terrestrial mining operations 1920’s: First diamonds are discovered on the South African coast, leading to a southward spread in mining operations 1960’s: The first diamonds are recovered from the sea, initiating both small scale diver assisted mining in the nearshore zone and large scale dredging operations in the offshore zone off the coasts of South Africa and Namibia 1970’s: International diamond market slumps resulting in a temporary cessation in offshore dredging operations, but onshore and small-scale diver assisted mining continues in the nearshore zone 1990’s: As richer onshore deposits become exhausted, offshore mining operations recommence, initiating an increasing shift in emphasis from onshore to offshore operations
Major Players and Areas of Operation Currently, marine diamond mining operations are conducted only in South Africa and Namibia, largely controlled by a few large companies Major players in South Africa include De Beers and its affiliates, Alexkor and Trans Hex, with concession areas covering most of the west coast from Paternoster in the south (32°45’S) to the Orange River in the north, extending from 100 km inland out to 500 m depth offshore Major players in Namibia include Namdeb, Ocean Diamond Mining, Diamond Fields International and Arena Mining with concessions areas extending from 100 km inland to 3 km offshore, from the Orange River to 26°30’S Some prospecting has been undertaken off the Angolan coastline and several companies are negotiating the lease of potential mining areas, but no concessions have yet been allocated
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Mining Techniques and Operational Practices Onshore Mining Onshore mining is undertaken via large-scale open cast mines, using heavy-duty earth moving equipment Overburden is first stripped off to expose underlying diamondiferous gravel, which is then collected and transported to centralised processing plants Sometimes sea walls are used to extend terrestrial operations several hundred meters offshore of the original coastline Oversize tailings are generally deposited on mine dumps, while undersize material is pumped into slimes dams or directly into the sea Nearshore Mining Diver assisted suction equipment is deployed from the shore or small boats to collect gravel from littoral and sublittoral areas down to a depth of ~30 m “Blowers” are sometimes used to give divers easier access to the underlying orebody Diamondiferous concentrate is bagged and processed ashore while oversize and fine tailings are deposited overboard Nearshore mining is opportunistic and weather dependent, with divers generally operating fewer than 10 days per month Offshore Mining Remote operated dredges or drills with airlift systems, deployed from large (50-140 m) self contained vessels, are used to collect gravel at depths of up 120 m Gravels are processed into a concentrate onboard which is sent ashore for hand sorting All tailings generated during the sorting process are discharged to sea Semi-mobile jack-up rigs and bulk dredges may be introduced in the future to mine lower grade ores
Environmental Policy and Legislation Mining and associated activities in South Africa and Namibia are regulated by a suite of legislative Acts designed to mitigate their effects on the environment, including requirements for Environmental Assessments (EA’s) and Environmental Management Programmes (EMPs) Additional legislation also controls pollution at sea, the use of landing facilities, access to the coastal zone, and damage to natural or cultural resources in these two countries No information was available regarding Angolan legislation at the time of writing
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Environmental Issues, Impacts and Mitigation Marine diamond mining is the cause of a number of socio-economic and biophysical impacts in South Africa and Namibia, both positive and negative Major socio-economic benefits provided by the diamond industry include the creation of employment and tax revenue Negative aspects include problems associated with the influx of people into small towns, lack of facilities for waste disposal, gaps created by the shifting emphasis from on- to off-shore mining, conflict with other resource users and the foreclosure of future land use options through aesthetic impacts Little has been done to mitigate problems associated with negative socio-economic impacts, but attention is being given toward developing alternative land-use options (e.g. tourism and mariculture), alternative skills training and conflict resolution mechanisms The de-facto reserve status of the terrestrial diamond areas arising from restricted access represents the only major positive biophysical impact of diamond mining in the BCLME In terms of the overall aerial extent, mining affects less than 1% of the concession areas in South Africa and Namibia per annum and negative impact are largely deemed to be of low significance Several negative impacts have been identified on a local scale, including impacts on vegetation and soils, generation of sediment plumes, disruption of littoral and sublittoral benthic communities, kelp cutting, conflict with the fishing industry and disturbance of marine mammals and birds Mitigation measures have been introduced to address most of these impacts Most of the larger diamond mining companies and many of the smaller operators already have, or are in the process of drawing up Environmental Management Plans
Diamond Mining in the BCLME – Toward Integrated Environmental Management Integrated Environmental Management, as it applies to marine diamond mining, is evolving with steady improvement, but a few criticisms are warranted Socio-economic Environment EMPRs have generally not taken due cognisance of socio-economic impacts Steps must be taken toward reallocating diamond mining revenue toward upgrading infrastructure, stimulating development in the areas most severely affected by mining and redressing racial imbalances in the industry Biophysical Environment Shortcomings in terms of biophysical environmental management include the broad-scale nature of the baseline information, the desktop nature of most assessments and the high taxonomic level at which assessments have been undertaken (i.e. individual species may be ignored) Environmental Management as a Whole Cumulative impacts within the mining industry and amongst all users need to be addressed more fully Regular audits need to be undertaken of EMPRs to ensure that they include the latest information and technology Conclusions – The Way Forward In South Africa and Namibia, directed studies must be commissioned to address gaps in knowledge to improve integrated environmental management of activities in the BCLME The IEM process must be adopted in Angola and the necessary baseline information collected before marine and coastal mining is initiated
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TABLE OF CONTENTS
TABLES A: SUSTAINABLE MANAGEMENT AND UTILIZATION OF RESOURCES...... 22 TABLE A1: FACILITATION OF OPTIMAL HARVESTING OF LIVING RESOURCES...... 22 TABLES C: MAINTENANCE OF ECOSYSTEM HEALTH AND MANAGEMENT OF POLLUTION...... 42 C5 EXPLANATORY NOTES. PROBLEM: LOSS OF BIOTIC INTEGRITY...... 48 VI. ARRANGEMENTS FOR FUTURE CO-OPERATION...... 61 Conditions of Use...... i Scope...... ii Executive Summary...... iii TABLE OF CONTENTS...... vi 1. Introduction...... 1 2. Historical Perspective...... 2 3. Areas of Operation and Major Role Players...... 4 3.1 South Africa...... 4 3.2 Namibia...... 4 3.3 Angola...... 5 5. Environmental policy and Legislation ...... 16 5.1 Introduction...... 16 5.2 South Africa...... 16 5.3 Namibia...... 19 6. Environmental Issues, Impacts and Mitigation...... 22 6.1 Introduction...... 22 6.2 Socio-economic Environment – Positive Impacts...... 22 6.3 Socio-economic Environment – Negative Impacts...... 24 6.4 Biophysical Environment - Positive Impacts ...... 28 6.5 Biophysical Environment - Negative Impacts...... 28 7. Diamond Mining in the BCLME – Toward Integrated Environmental Management...... 54 7.1 Socio-economic Environmental Management...... 54 7.2 Biophysical Environmental Management...... 54 7.3 Environmental Management as a Whole...... 55 7.4 Conclusions – The Way Forward...... 55 8. Bibliography...... 57 9. People Consulted...... 60
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...... 60 Totals...... 30 Problem...... 79 Problem...... 80 Northern boundary...... 104 Southern boundary...... 105 Western boundary...... 106 Longshore fronts...... 106 Table of Contents...... 162 Brief Description of PDF-B Involvement...... 165
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1. INTRODUCTION
The Benguela Current Large Marine Ecosystem (BCLME), situated off the west coast of southern Africa, is one of 49 LME systems that have been described around the world. LMEs are defined as large bodies of water (200 000-sq. km) with distinctive bathymetry, productivity and trophically dependent populations. The Benguela Current LME is one of the most productive of these systems, supporting an important global reservoir of biodiversity and biomass of fish, sea birds and marine mammals.
Several issues of common concern to South Africa, Namibia and Angola, the three countries bordering the BCLME, are commercial fishing, recreation, diamond mining, oil and gas exploration and coastal zone development. These activities are putting escalating strain on the BCLME. With the advent of environmental concern, most countries have drafted legislation that seeks to ensure responsible and sustainable use of the environment for all users. The efficacy of both the legislation and enforcement, however, remain in question. A related concern is the potential for conflict between users of the BCLME, as escalating effort and technologies will see increasing overlap between the various sectors. With a view to resolving conflicts and responsible environmental management, there has been a call for an integrated and co-ordinated approach to the management of this system. To this end, the United Nations Development Programme has called for a Synthesis and Assessment of Existing Information on the BCLME, reviewing activities in the BCLME, their impact on the environment, and their management. This review will be used to assess the status quo, identify gaps and shortcomings in the management of activities affecting the BCLME, and direct further research, policy and funding through a Strategic Action Programme.
This document forms a part of the synthesis and assessment phase reviewing marine diamond mining in the BCLME. Specifically, it traces the history and development of marine diamond mining; outlines the key players and their areas of operation; describes the methods and equipment employed in extracting marine diamonds; reviews the legislation relevant to diamond mining activities; outlines how these methods impact the environment; reviews conflict and mitigation; and finally, highlights gaps and shortcomings and suggests methods by which integrated management of the BCLME can be achieved. Emphasis is placed on marine- based activities, although terrestrial aspects are discussed briefly, as they also affect future marine and coastal users.
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2. HISTORICAL PERSPECTIVE
Diamonds were formed aeons ago in the mantle of the earth, some 150-250 km below the surface. They are formed of carbonaceoyus material, subject to extreme heat and pressure, crystallised into diamonds as they were brought up to the surface in streams of molten magma. This diamondiferous magma, known as kimberlite spewed out in various places over the southern African subcontinent, solidifying on the surface and in magma pipes leading up to the surface. Over geological time (ca. 80 million years), this kimberlite material gradually eroded, with rivers carrying an estimated 3 billion carats of diamonds to the sea. Concomitantly, river mouths meandered up and down the coast, thereby building up extensive submarine deltas containing diamonds along much of the coast. Wave action removed much of the lighter and softer material, concentrating the heavier and harder material, such as diamonds, in beach terraces and paleo channels. Tectonic movements together with climatic changes resulted in immense fluctuations in sea level, and consequently diamonds became concentrated in a series of beaches or terraces both above and below the present day sea level, each terrace corresponding to former static sea levels.
Diamonds were first discovered in South Africa in 1866 on a farm south of Kimberly. This discovery was followed by further finds of both diamond-bearing kimberlite pipes and alluvial deposits in the drainage system of the Vaal River. The first discoveries on the west coast of southern Africa only occurred 42 years later, however, when a railway construction worker, Zacharia Lewala, found the first diamond near Lüderitz in 1908. Picking up the shiny stone, he passed it to his supervisor August Stauch an employee of the Deutsche Koloniale Gesellenschaft (DKG) responsible for keeping the newly constructed railway between Lüderitz and Keetmanshoop clear of sand. On the 20th of June 1908 Stauch reported his find to the DKG and applied for prospecting licenses, which they granted. In January 1909 rich deposits were found south of Pomona, which was soon followed by the discovery of deposits in the Bogenfels region. Word soon spread and people flooded into the area and settlements sprung up out of the desert almost over night.
At the time of the discoveries, South West Africa (SWA, now Namibia) was under German jurisdiction, with the exception of the port of Walvis Bay and a series of ’guano islands’ off the coast. In September 1908 the German government granted the DKG the sole right to search for and work mineral deposits between the Orange River in the south and 26ºS latitude in the north stretching 100km inland. This area, which became known as the Sperrgebiet, was fenced off and entrance was restricted to prevent the theft of diamonds. The Sperrgebiet remains closed to unauthorised persons today.
The Germans were to remain in control of SWA until WW1 when the territory was handed over to South Africa to Administer. In 1920 the Anglo American corporation of South Africa gained control of the diamond interests in SWA forming the Consolidated Diamond Mines of SWA (CDM).
The finds in the Lüderitz area inspired prospectors south of the Orange River in the new Union of South Africa. Eventually these efforts paid off, with discoveries by Jack Carstens near Port Nolloth in 1926. As mining and prospecting progressed in the Namaqualand region, Dr Merensky and Dr Reuning recognised the link between old marine terraces and diamond deposits. Armed with this information they soon discovered numerous rich deposits south of the Orange River mouth. These finds brought prospectors from the Lüderitz area to the beaches immediately north of the Orange River mouth. Here they were to find significant diamond deposits, and the focus of mining in the Sperrgebiet consequently shifted south, to what is today known as Mining Area 1.
It was not until 1961 that diamonds were mined offshore on the west coast of southern Africa. Sam Collins a rich Texan whose company specialised in submarine pipelines became interested in the theories that rich diamond deposits lay offshore of the Orange River mouth. His pipeline experience enabled him to develop techniques for dredging diamonds from the seabed. The feasibility of this venture was doubted, however, as it was accepted at that time that the deposits could not be mined economically. Sam Collins was not deterred and tenaciously stuck to the task, proving his critics wrong. His company Marine Diamond Company (Pty) Ltd successfully mined payable deposits in shallow water off Chamies and Bakers Bay. In the process he experimented with various sea going vessels, from small fishing boats, to large mining barges, to a converted 70 m ex-US Navy tank landing craft, using a combination of airlifts and centripetal pumps. Initially De Beers had thought that this would not be economical but admitted their error, eventually buying a controlling share of MDC in 1965. Soon after however, the diamond market slumped and MDC ceased offshore mining operations
Overview of Diamond Mining in the BCLME 2 Anchor Environmental Consultants in 1971. Smaller scale operators continued to mine from converted fishing vessels, however, while De Beers continued prospecting in deep water areas.
Small-scale shallow water operations continued to increase steadily over the years, but deep-water offshore mining operations only really started again in the early 1990s. These deep-water operations now represent the pinnacle of technological development in the diamond mining industry, requiring dedicated mining vessels, complex electronic navigation systems and specialised remotely operated mining tools. Onshore diamond mining operations along the coast are also a far cry from their early beginnings when diamonds were first collected by hand on moonlit nights. At first diamonds were excavated manually using shovels, which were then screened by various sieving techniques. Gradually mechanical excavators and concentrating devices were employed to process the large volumes of sediment required. Today large mining plants process millions of tons of gravel per year, utilising heavy-media separation, cyclones and x-rays in the concentration process.
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3. AREAS OF OPERATION AND MAJOR ROLE PLAYERS
The areas in which mining occurs in the Benguela ecosystem have been divided into 5 distinct categories and is discussed under two broad headings for the purposes of this document. These are defined as: Onshore Terrestrial mining – mining above the high water spring tide mark (HWS) Beach mining – mining of beaches into the subtidal through the construction of sea walls (coffer dams) Offshore Shallow water mining – Operations to a depth of 30 m, further divided into: Shore based mining – divers operating from the shore Boat-based – divers operating from small boats Mid-water mining – 30-75 m depth utilising remotely-operated tools, mostly air-lift dredges Deep-water mining – Operations deeper than 75 m, using customised mining vessels and specially designed remotely-operated mining tools
Diamond mining occurs across all of the above mentioned categories in distinct concession or license areas. Concession areas are allocated differently in Namibia and South Africa and these are discussed separately below with particular reference to the major role players involved.
3.1 South Africa
3.1.1 Onshore Mining Terrestrial concessions, including beach mining concessions, are mined between the Orange River mouth and an area slightly south of the Olifants River. Two major companies, Alexkor (a parastatal organisation which is currently being privatised) and De Beers Namaqualand (Pty) Ltd dominate diamond production along the shores of Namaqualand and the Northern Cape. Alexkor operates from the Orange River mouth to just south of Port Nolloth, while De Beers operates from Alexkor’s border to slightly north of the Olifants River (Figure 1). Around these major concessions are a number of smaller concessions operated by companies like Trans Hex Investments (Pty) Ltd.
3.1.2 Offshore Mining In South Africa the offshore concessions stretch from the border with Namibia off the Orange River mouth, to an area just south of Saldanha Bay (Figure 2). Each concession area is further split into four sub-areas in an offshore direction (Figure 3). The ‘a’ concession extends from low water to 31.5 m offshore, while the ‘b’ concession extends from the western boundary of the ‘a’ concession to a co-ordinated boundary approximately 5 km offshore (less from concession number 15-20). The ‘c’ concession runs from the western boundary of ‘b’ concession to the 200m isobath and the ‘d’ concession runs from the western boundary of ‘c’ concession to the 500m isobath.
The major players, including concession owners and concession operators in the offshore diamond industry of South Africa are listed in Table 1. Three companies dominate the offshore diamond industry: De Beers Consolidated Mines (mainly mid- to deep-water concessions), Alexkor (mainly shallow-water concessions) and Trans Hex (shallow and deep-water concessions). Other significant players are BHP-Benguela Nominees, Ocean Diamond Mining, De Beers Marine (undertakes all De Beers offshore operations), Namagroen prospecting, Benguela Concessions and Marine 17 Mining.
3.2 Namibia
3.2.1 Onshore mining Namdeb Diamond Company (Pty) Ltd (formally Consolidated Diamond mines of SWA) controls mining of the ‘Sperrgebiet’ under the Namdeb Agreement (1994). They have exclusive rights to prospect for and mine
Overview of Diamond Mining in the BCLME 4 Anchor Environmental Consultants diamonds within the Sperrgebiet until the year 2010. The Sperrgebiet stretches from the Orange River in the south to latitude 26ºS in the north, extending 100 km inland (Figure. 4). Namdeb is a 50/50 partnership between De Beers and the Namibian government and is responsible for the majority of onshore production in the southern parts of the Sperrgebiet (immediately north of Oranjemund), in their beach mining operations. Some smaller contractors also operate onshore on the Namibian coast, but they mine predominantly in the northern license areas.
3.2.2 Offshore mining Namibian offshore concessions cover the full length of counties coastline, extending from the Orange River to the Kunene (Figure. 5). Concession boundaries are not regulated by depth as in South Africa. Onshore mining licenses extend 3 km offshore, and Namdeb thus controls most of the shallow water mining activities (with the exception of the island concessions, which are operated by ODM). Offshore licenses are issued after specific application to government, which must include the co-ordinates of the intended mining area. he major companies involved in the Namibian offshore diamond industry are Namdeb, Ocean Diamond Mining (ODM)(of which Eiland Diamante is a subsidiary), the Namibian West Coast Mining Company - Diamond Fields International (DFI) group, the Namibian Minerals Corporation (NAMCO) - Arena Mining group, and Tidal Diamonds (an associate company of Namdeb). Numerous other companies like De Beers Marine, Yam Diamonds (who also own their own concession) and Windvogel Diamonds mine mainly on contract to the larger players.
3.3 Angola No coastal or offshore mining currently occurs in Angola. Prospecting and mining activities are continuing inland but the Angolan government has issued no licenses for coastal areas, preferring to concentrate their efforts on terrestrial operations.
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Figure 2. Map of the offshore concession areas of the Republic of South Africa. A key to the concession holders and operators is provided in Table 1 (provided by De Beers Marine).
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Table 1. Diamond mining concession holders and operators in the Republic of South Africa.
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Figure 5. Major coastal and offshore diamond mining concession areas of Namibia. (Original coverage provided by B. Beuthin, Geological Survey, Ministry of Mines and Energy, Namibia).
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4. Mining Techniques and Operational Practices Diamonds in the southern African coastal region are concentrated in the vicinity of paleo drainages, in bedrock gullies, potholes and depressions, along offshore ridges and south facing paleo bays, headlands and aeolian transport corridors. The greatest concentrations of diamonds usually occur near or on the bedrock. In order to retrieve diamonds, the overlying marine and terrestrial deposits (overburden) first has to be removed, followed by the collection of the diamondiferous gravel below. The techniques used to remove the overburden and to collect the gravel varies considerably according to where the gravel is located, the richness of the ore and the thickness of the overlying deposits. Basic distinctions can be drawn between operations conducted on land, and in shallow-, mid- and deep-water areas. These are elaborated separately below.
4.1 Terrestrial and Beach Mining Onshore mining activities immediately adjacent to the coast are undertaken mostly using heavy-duty earth moving equipment, operational in large-scale open cast mines. Five fairly distinct phases are involved in the mining operation, including prospecting, overburden stripping, excavation of terrace gravels, mineral processing and sorting. The precise methods used in each of these phases has been developed and improved upon over the years and varies somewhat between areas and from company to company. What follows here is a generic description of the methods currently in use.
The major form of prospecting involves the drilling of small diameter percussion holes, followed in some cases with large diameter auger drilling and/or the excavation of trenches of varying depth and length. Overburden material from the trenches is generally deposited in overburden dumps on the surface next to the trenches and the underlying gravel is removed for processing. These three methods of prospecting are used to locate, intercept and sample the terrace gravels. As terraces have eroded erratically and diamond occurrence is sporadic, prospecting is generally undertaken in a closely spaced pattern in order to delineate the ore bodies accurately.
The next phase, overburden stripping, is done using a variety of earth moving machines including bowl scrapers, bulldozers, mass excavators and in some areas bucket-wheel excavators. Excavation is generally undertaken on a block-by–block basis and the overburden removed is dumped into trenches from which the underlying gravel has been removed; piled into overburden dumps; or used to create a seawall, extending the shoreline several hundred meters out to sea.
By constructing protective seawalls, gravels up to 20m below sea level and several hundred meters beyond the present shoreline can be recovered using terrestrial operations. Once the overburden has been removed, the bulk of the diamond bearing gravel is excavated mechanically. Deposits remaining in gullies and potholes on top of the bedrock are then swept and collected manually using pick, broom and shovel teams or using suction equipment. All the ore is transported to treatment plants where the gravel is crushed, washed, sieved and concentrated in a solution of seawater and ferrosilicone using heavy media cyclones. The gravel concentrate is then dried, sorted by means of x-ray machines and finally the diamonds picked out by hand. Gravel, from which the concentrate has been extracted, is disposed on tailings dumps, while water containing sand and fine sediment is discharged into slimes dams or pumped directly into the sea. Most of the ferrosilicone is recovered before it leaves the plants and is recycled in the process.
4.2 Shallow-water Mining Shallow-water mining operations are conducted using small-scale, diver assisted suction equipment. Shore-based operators generally operate in the intertidal down to a depth of around 10 m, while the boat- based operators usually work in the 10-30 m depth range. This delineation is not strict, however, with the boat-based miners moving inshore in areas where access to the shoreline is difficult (where sea-cliffs abut directly onto the shore or in the offshore islands concessions).
The techniques used for shore- and boat-based operations are very similar, expect that boat-based operations generally employ larger equipment and more divers. A shore-based operation typically consists of 2-3 divers, their assistants and a tractor modified to drive a rotary classifier and centripetal pump to which an eight inch suction hose is attached. The divers, operating on surface-supplied diving equipment, guide the terminal end of the hose into the gravel deposits, which are sucked up and delivered directly to the classifier. Concentrate is bagged and brought to central sorting houses onshore. Large rocks are often moved by the divers (or pulled up onto the shore using a tractor) to allow the pump nozzle to reach deep layers of gravel where the heavy diamonds settle. Coarse material is allowed to build up on the shore, while fine material is returned to the sea. In some instances, kelp may be cut to facilitate access to shallow inshore ore bodies.
A typical boat-based operation consists of a 10-15m vessels with a 5-8 man crew, of which 2-3 are divers. The vessels are equipped with 1-2 hoses per boat, with the duration of their activities limited to daylight hours for 3-
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10 diving days per month. Some 20-22m vessels, offering surface decompression facilities and with 8-11 man crews, are also operational. These larger boats are able to work on a 24h basis for up to 21 days per month. However, due to the water depths involved, diving in nearshore mining operations necessitates strictly enforced decompression routines thereby limiting bottom working time. The diamondiferous concentrate is bagged onboard, and brought ashore for final processing in shore-based jig plants and sorting houses. On vessels operating further afield, the initial jigging may be conducted on board. Oversize tailings are either returned directly overboard to the mined area or transported further offshore in inflatable boats and dumped. The fines are washed overboard. In the mining process large rocks may either be exposed, or removed by divers to allow the suction nozzle to reach deeper gravel layers. The rocks are sometimes accumulated by the divers into rock piles.
Shallow-water mining is opportunistic in nature and highly dependent on weather and sea conditions. Due to the difficulty of employing modern geophysical survey techniques and large-boat sampling in shallow water nearshore areas, exploration and investigation in water depths <30m, is generally limited to irregular side-scan sonar mapping and prospecting dives from the shore or from small boats. These surveys are often based on historical recoveries. Small-scale sampling is undertaken by diver-assisted dredging, the gravel being bagged and processed ashore. Many of the nearshore operations are currently being enhanced by more sophisticated tracking and positioning systems to help focus efforts on the more productive areas. Both shore- and boat-based miners generally only operate in exposed rocky shore areas where gravel is pumped from deeper gullies, or on the edges of sandy bays where the layer of overburden is relatively thin. Mining off sandy beaches is generally unprofitable for these small- scale operators due to the large volumes of overburden that have to be removed before it is possible to gain access to the heavier gravel. However, the use of underwater ‘blowers’ to shift overlying fine sediment, initially used only when operating in shallow water (<8 m depth), is becoming more widespread as it allows for the exploitation of gravel deposits which were previously uneconomic to recover.
4.3 Mid-Water and Deep-Water Mining A variety of methods are used to mine marine diamond resources in water depths >30 m, which may be split into mid-water operations (down to a depth of 75 m) and deep-water operations (down to a depth of 200 m). The geophysical survey and prospecting methods in use are similar for both regions, and include high resolution side-scan sonar, shallow reflection seismic profiling, video, vibrocoring, rock drilling and grab sampling. The resulting data are used to produce maps of the seabed geomorphology, sediment and bedrock distribution, bathymetry and sediment type and thickness profiles. From these maps, areas of unconsolidated sediment suitable for sampling are identified, and a sampling grid is positioned over the area. Surveying activities are usually ongoing in order to develop geological models encompassing all the concession areas held by a company. Precise sediment sampling using penetrating tools is subsequently carried out on the grid.
Once a mineable ore reserve has been identified, bulk sampling is conducted in the sampling grid. The bulk sampling process is done in a scattered grid pattern and is similar to mining but on a smaller scale. Mineable marine ore reserves are divided into rectangular blocks of 50x50 m which are then systematically and contiguously dredged. While some block groups may only be a few 100 m long, others can stretch 1-2 km in length. Commonly, Wirth Drill or seabed crawlers are used to clear 50 m2 areas of sea floor to bedrock level. Seabed crawlers, equipped with anterior articulated cutting and/or sucking devices are lowered onto the seabed on a hoist rope, with power and signal umbilical cable attached and controlled remotely from a surface support vessel. The vehicle mines by systematically advancing along a specific ‘lane’ achieving precise coverage of the area to be mined. This mining tool is especially suitable on flat areas with few boulders and is capable of mining sediment thicknesses of up to 5 m in water depth of up to 150 m. The Wirth Drill is a vertically mounted, larger diameter drill-head used to recover diamond bearing gravel in a systematic pattern of overlapping circles over the mining block. The drill is capable of drilling through more than 5 m of sediment and penetrating rock in water depths to 150 m.
Mining using the above techniques involves the removal of only the unconsolidated superficial sediments. The dredged sediment-slurry is airlifted to the surface, discharged into a slotted circular tower and dropped onto a multi-decked screen, which separates the oversize and undersize fractions. These are immediately discarded overboard, care being taken to prevent covering unmined areas. Of the material airlifted to the surface, 99.9% is returned directly to the sea. Re-mining of an area occurs only when the initial coverage of a block by the mining tool was insufficient.
The fraction of interest (plantfeed) is fed through a ball mill to fragment the shell and clay components, before being mixed with ferrosilicone and pumped under pressure into a dense medium separation plant. Low-density materials (floats) are separated from the concentrated plantfeed and discarded overboard. The remaining high- density fraction is dried and passed through an x-ray sorting machine to separate the diamonds. Non-
Overview of Diamond Mining in the BCLME 12 Anchor Environmental Consultants fluorescent material is discarded overboard and the fluorescent fraction is automatically sealed in cans. On some of the smaller offshore vessels the high-density fraction is still hand sorted for diamonds.
The prospecting and mining vessels currently employed in offshore diamond recovery in Namibian and South African waters are semi-mobile platforms on a dynamic positioning system, or self-mooring systems comprising three to four anchors. These ships, which range in size from 50 m (26 crew) prospecting vessels to 140 m (90 crew) mining vessels, are fully self contained mining units operating on a 24 h basis through 11 months of the year.
Several new techniques are planned for the future that will reduce mining costs and allow for the exploitation of lower grade ores in the mid- and deep-water zones. These include jack-up rig platforms and bulk dredging operations. Jack-up rigs will be semi-mobile platforms housing the separation and recovery plants, which are fed slurried gravel via flexible hoses attached to multiple dredge crawlers. These platforms will be moved as required (probably not more than once or twice per year) and will be serviced by ship or helicopter from the nearest logistical base.
Massive sheet gravels occur in some mid- and deep-water areas that are uneconomic to exploit using currently available methodology. Plans are afoot, however, to begin exploiting this low-grade ore using high volume suction hopper dredges. These plans call for the use of large dredges on which under- and over-size material will be screened to separate hoppers, while plant feed material is transferred to processing plants at sea or on the shore. Tailings disposal would be back to the sea in designated tailings areas.
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5. ENVIRONMENTAL POLICY AND LEGISLATION
5.1 Introduction Numerous legislative Acts have been promulgated to regulate and mitigate effects of mining and associated activities in South Africa and Namibia. The main environmental provisions of Acts pertinent to the management of activities affecting the BCLME are described below. At the time that this report was prepared, no information was available regarding legislation controlling the exploitation of minerals in Angola.
5.2 South Africa
5.2.1 Minerals Act, 1991 (Act 50 of 1991) Prior to commencing prospecting or mining operations, section 39 of the Minerals Act requires a “layout plan and rehabilitation programme”, now referred to as an Environmental Management Plan Report (EMPR) to be submitted to the regional director Department of Mines and Energy (DME). Prior to approval of an EMPR, the regional director must consult with Cape Nature Conservation and/or Sea Fisheries Research Institute for comment. Exemptions from EMPRs may be granted in certain circumstances, however. Procedural, format and performance assessment requirements for these documents are detailed in Section 5.2.5 below.
The Act requires the holder of the prospecting permit or mining licence to rehabilitate the “surface of land” to the Regional Director’s satisfaction and to do this as an integral part of, and simultaneous with, prospecting or mining operations. On termination of prospecting and mining activities, all structures not required by the landowner are to be demolished and all debris removed. The mining licence holder is responsible for rehabilitation, until such time that the Regional Director issues a closure certificate. Before a mining or prospecting licence is granted, the applicant must demonstrate the financial ability to pay for rehabilitation by establishing a rehabilitation trust fund, submitting bank guarantees, lodging cash with the DME or by other mutually acceptable arrangements.
5.2.2 Environmental Conservation Act, 1989 (Act 73 of 1989) Regulations promulgated in September 1997 under the Environmental Conservation Act 1989, list activities which require an Environmental Assessment and the procedures to be followed. Although mining per se is not a listed activity (as it is in Namibia’s Draft Environmental Management Bill 1998) several land use activities ancillary to mining are listed. These include roads, harbours, structures and reclamation of land below the high water mark, dams, onshore infrastructure and services (sewage treatment, waste disposal), and industrial buildings.
5.2.3 National Environmental Management Bill of 1998 Provisions of the Environmental Conservation Act, 1989 and its regulations relating to listed activities and compilation of environmental impact reports will be repealed by promulgation of the National Environmental Management Bill of 1998. The aim of this bill is to co-ordinate the activities of all listed state departments having an influence on the environment, and to allow for revision of regulations on listed activities and environmental management procedures. Until new regulations on procedures, report contents and listed activities are gazetted, existing regulations for EIAs under the Environmental Conservation Act, 1989 and regulations for EMPRs under the Minerals Act 1991 remain in force. EMPR requirements are currently being revised by the DME in accordance with the National Environmental Management Bill, and are due for implementation in June 1999 (MME pers. comm.).
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5.2.4 Other Legislation Relevant to Environmental Aspects of Mining Activities Other statutory acts and regulations applicable to marine mining activities and employee behaviour on land and at sea are listed and described briefly below:
Pollution at Sea Prevention and Combating of Pollution of the Sea by Oil Amendment Act 24 of 1991 – regulates oil pollution from ships at sea Marine Pollution (Control and Civil Liability) Act 6 of 1981 (and Marine Notices) – establishes reporting requirements and procedures for oil spills and oil bunkering 1973 Convention for the Prevention of Pollution from Ships (MARPOL) – controls all waste disposal at sea (oil, hazardous waste, solid waste (plastics, tins, glass, organic matter etc, and sewage). RSA is a signatory on this convention. National Water Act 36 of 1998 – controls discharge of tailings, and sea and fresh water pollution on land
Air Pollution Montreal Protocol on Substances that Deplete the Ozone Layer was adopted in 1987 to which signatories undertake to control and limit the consumption of chlorofluorocarbons (CFCs) and not to import CFCs from states which are not parties to the Protocol.
Use of Harbours and Ports, Landing Facilities and Specific Tidal Rivers by Vessels Marine Living Resources Act 18 of 1998 and its regulations of September 1998 – regulates use of fishing harbours by vessels and staff South African Transport Services Act 65 of 1981 – regulates use of harbours under Portnet’s jurisdiction (e.g. Port Nolloth) Sea Shore Act 21 of 1935 and Environmental Conservation Act 73 of 1989 – controls construction of structures below high water mark (e.g. jetties) Nature and Environmental Conservation Ordinance 19 of 1974 – regulates boating on Verlorenvlei, the Olifants River, and lower Berg River
Vehicle Access to Coastal Zone and Other Sea Shore Activities Control of Vehicles in the Coastal Zone* (Regulations under Environmental Conservation Act 73 of 1989) – requires implementation of a permit system for beach use by vehicles, restricts vehicle use to non-sensitive areas (e.g. below high water mark, away from dunes) and to existing tracks * Specifically excludes approved diamond mining activities, although MME has pledged to apply these regulations through EMPRs (MME pers. comm.) Regulations and bylaws under the Sea Shore Act 21 of 1935 promulgated by local authorities – controls beach access, littering, camping, bathing, launching of boats, and in the case of the West Coast District Council, disturbance of animals, birds and plants below the high water mark
Disturbance or Damage to Natural and Cultural Resources Marine Living Resources Act 18 of 1998 and its regulations of September 1998 – licences required for cutting and removal of kelp, disturbance or collection of lobsters; and all other forms of fishing Sea Birds and Seals Protection Act 46 of 1973 – controls disturbance of sea birds and seals on islands (no- one may set foot on an island without permission) Nature and Environmental Conservation Ordinance (19 of 1974) – regulates hunting; disturbance of wild animals, collection and damage to plants, pollution of inland waters United Nations Convention on Biological Diversity – conservation of biodiversity, sustainable use of its components, and equitable share of the benefits arising from the use of genetic resources. National Monuments Act 28 of 1969* – disturbance and removal of archaeological and palaeontological sites and shipwrecks * This act excludes mining from disturbance to archaeological sites except shell middens and cave contents (i.e. the majority of sites in the coastal zone)
Health and Safety of Employees and Vessels Regulations under Mines and Works Act 27 of 1956 – regulates diver qualifications, diving equipment and diving procedures Merchant Shipping Act 57 of 1951 – regulates safety and licensing requirements for vessels Marine Traffic Act 1981 – regulates traffic of marine vessels
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Wreck and Salvage Act – regulates liability for removal of wrecks
5.2.5 Requirements for the Compilation of Environmental Management Plan Reports Procedures Compilation of EMPRs are based on Integrated Environmental Management (IEM) and involves but are not necessarily restricted to: Consultation with the Director: Mineral Development of DME and all relevant authorities to determine the scope of the EMPR Scoping with other interested and affected parties to further define the scope of the EMPR through identification of issues of concern Assessment and Evaluation of Impacts (involving I&APs) Compilation of a plan for management of impacts (involving I&APs) Submission of a draft EMPR to DME who will circulate it to relevant Government departments and make it available to the public Revision and resubmission (if needed) Approval unless further mitigatory planning is required and revisions necessary.
Contents of EMPRs As a minimum, EMPRs for offshore mining should be separated into three parts: Part A (EIA); Part B (EMPR) and Part C (Supporting References and Statutory Requirements) and should contain:
General Information Contact addresses and numbers, Maps showing concession area, proposed mining area, location of mining and onshore logistical facilities, other projects and activities in adjacent areas Description of proposed project (production rate, life expectancy, timetable of project phasing and sequencing) 2. Project Motivation Local, regional and national socio-economic benefits (mine expenditure, revenue, multiplier effects, infrastructure benefits etc. compatibility with other policies, plans and land users consideration of project alternatives 3. Detailed Project Description for all offshore and onshore activities including infrastructure and support facilities; mining methods including processing operations, transportation requirements and methods; all waste emissions and disposal methods; chemicals to be used; and use of water and electricity. 4. Description of Pre-mining Environment to provide baseline information to establish a reference for determining and evaluating impacts, and design of mitigation measures. The following environmental aspects should be described and mapped: geology and sediment; oceanographic patterns, physical nature of surrounding areas (coastal zone, sensitive areas e.g. wetlands, islands, dunes etc); fauna and flora that occur in the area and may be affected, particularly benthic organisms; climate; sites of cultural resources (archaeology, shipwrecks etc); recreational areas and transport routes; mariculture areas; fishing areas, and other marine harvesting areas e.g. kelp. Environmental Impact Assessment should include a quantitative and qualitative analysis of the nature of impacts of all project activities on all components of the natural, socio-economic and cultural environment before and after mitigation for each phase of mining: construction, operation, decommissioning and post closure. Each impact should be evaluated using the following criteria: nature; time of occurrence; spatial extent; duration; intensity; probability and significance. Environmental Management Plan. Measures to mitigate the effect of each impact on each environmental component (identified in Part A of the report) for each project phase should be described. The plan must include rehabilitation of disturbed areas, pollution control, emergency procedures, links with existing contingency plans, future public participation strategies, and outline of the decommissioning strategy. Monitoring of EMP Performance and Reporting Requirements. Describe the monitoring programmes to be implemented for each phase, and include a statement of objectives, targets for compliance, description of physical monitoring systems and frequency of monitoring. Describe the auditing system that will be followed to assess EMP performance (adequacy and appropriateness) and the reporting procedures to be followed (type, frequency and format of reports and other information to be submitted). Financial Provision. Indicate what financial provisions (complying with regulations under the Minerals Act) have been made to implement environmental management and rehabilitation.
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Supporting Documentation and Statutory Requirements. Include in this section permissions granted under other statutes, applications submitted, and future statutory requirements.
EMPR requirements for a) concessions and surf zone mining As an alternative to the above, a tabular format for EMPRs for companies mining in the a) concession and surf zone areas only can be completed and submitted together with a locality map (1:50 000 map), and a layout plan showing the location of all infrastructure including access roads.
Operating and Rehabilitation Requirements of the EMP The DME has compiled a set of standard operating and rehabilitation requirements for mining in the a) concession area and surf zone, which are legally binding on the mining operation after approval of the EMP has been given. These standards cover issues such as the requirement to update maps on a quarterly basis, minimum infrastructure requirements for construction camps, use and maintenance of access roads to beach and campsite areas; waste disposal; water pollution control; location of processing areas; deposition of tailings onshore and at sea, and rehabilitation.
Compliance with EMPRs: Performance Assessment and Monitoring Regulations for EMP Performance Assessment (PA) and Monitoring have been gazetted under the Minerals Act. These regulations stipulate the need for holders of prospecting and mining authorisations to undertake ongoing monitoring of the EMP and to compile performance assessments for submission to the Director: Mineral Development. EMP performance assessment and reporting should be done according to the period specified in the EMP; annually, or as agreed by the Director: Mineral Development. The PA report should contain information on the period applicable to the PA; procedures used for the assessment; information yielded from monitoring; criteria used in evaluation performance and the results; and recommendations on rectifying deficiencies identified and areas of non-compliance.
Responsibility for PA lies with the prospecting/mining authorisation holder and may be done by independent qualified consultants. Where a PA report is deemed inadequate by the Director: Mineral Development, the holder may be required to repeat the whole or relevant aspects of the EMP PA and resubmit a revised report or appoint an independent team to do so. A final EMP PA is required where closure of a mine is intended and should accompany or precede a closure application. The final PA will be assessed to ensure that all relevant legislation has been complied with; closure objectives as described in the EMP have been met and all residual and latent environmental impacts have been identified and arrangements finalised for managing their risk and/or occurrence.
The regulations do not specify whether the PA reports are circulated to other relevant government departments for comment prior to their approval by the Director: Mineral Development. PA reports are available on request.
5.3 Namibia
5.3.1 Minerals (Mining and Prospecting) Act, Act 33 of 1992 Application and Granting of Mining Licences An applicant for a mining licence must comply with the provisions of the Minerals (Mining and Prospecting) Act, Act 33 of 1992. Applicants are required to estimate the effect of mining or prospecting on the environment and the steps to be taken to counteract such effects. In line with the Minerals (Mining and Prospecting) Act, Act 33 of 1992, prior to consideration of a mining licence, the Minister may require an environmental impact study. Alternatively, the holder of a mining licence must prepare an environmental impact assessment (in a form determined by the Commissioner) before any mining or prospecting is undertaken. If pollution is likely to be caused by mining, an environmental management plan (EMP) is required.
The minerals act allows for various types of prospecting and mining licences, issued by the Mining Commissioner, covering both small-scale and formal activity: Mining Claims – available to Namibian citizens only, these claims are for the development of small-scale mines and mineral deposits. Up to a maximum of ten claims can be held at any one time, each valid for three years (with a possible two-year extension). Reconnaissance Licences – designed for regional, mainly remotely sensed exploration to facilitate the identification of exploration targets. Valid for six months on a non-renewable basis only.
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Exclusive Prospecting Licences – for exclusive exploration rights in areas up to 1000 km2. Valid for three years, but can be extended twice for two-year periods, but not beyond seven years without ministerial approval. Mining Licences – grant exclusive mining rights on a piece of property for 25 years or the life of the mine, with renewals valid for 15-year periods. Holders are required to demonstrate financial and technical ability to develop and operate a mine. Mineral Deposit Retention Licence – allows an exploration company to retain tenure on a prospecting licence, mining licence or mining claim without mining obligations. Valid for five years with two year renewal periods.
Responsibility of Licence Holders Social obligations of mineral licence holders to employees and to Namibia include: the need to give job preference to Namibian citizens possessing appropriate qualifications; conduct training programmes; use products produced and services available in Namibia, and co-operate with other Namibians involved in the mining industry to aid skills development. The licence holder is ultimately responsible for all actions of subcontractors and must ensure that all licence conditions are equally applied to subcontractors.
Environmental Protection Provisions of the Minerals (Prospecting and Mining) Act relating to environmental protection and rehabilitation are weak and unlikely to enforce compliance. Abandonment of a mining or prospecting area stipulates the need to give written notice to the Commissioner; to demolish accessory mining works (unless required by the landowner), and to “take all such steps” to “remedy to the reasonable satisfaction of the Minister any damage” caused by the mining or prospecting operation to the “surface of, and the environment on, the land in the area in question”. Further, contravention of these provisions may incur a fine not exceeding R8000 which is unlikely to be a deterrent to non-compliance.
Issuance of mining or prospecting licences requires the holder to sign a Pro-forma Environmental Contract with the Government of Namibia (represented by the Ministry of Environment and Tourism, the Ministry of Fisheries and Marine Resources and the Ministry of Mines and Energy). This contract obliges the holder to apply the Environmental Assessment Policy (see below) and to reduce and mitigate all environmental damage and to leave the environment in a reasonable state. The contract requires the licence holder to submit a bi- annual Environmental Report documenting compliance with the submitted and approved EMP.
5.3.2 Environmental Assessment Policy of 1995 and the New Environmental Management Act Namibia’s Environmental Assessment Policy, compiled in 1995 by the Ministry of Environment and Tourism, lists the activities for which an environmental assessment is required (which includes mining, mineral extraction and mineral beneficiation) and describes the procedure to be followed for undertaking and compiling them. The Ministry of Mines and Energy and the Ministry of Fisheries and Marine Resources do not have their own set of requirements in this regard. Recently an Environmental Management Act (Act X of 1998) has been compiled which prescribes the need for environmental assessments for listed activities and outlines their minimum requirements. Listed activities relating to marine mining include: mining and mineral extraction, the construction of harbours and associated structures, structures below the high water mark, reclamation of land below the high water mark, the erection of buildings and structures for industrial activity, construction of sewage treatment plants and dams or reservoirs, and the construction of waste sites or facilities for waste treatment. Environmental assessments are submitted to, and reviewed by, the Competent Authority and Environmental Commissioner. The latter, after full consideration, and possibly further consultation and external review, submits the EA with his/her recommendation to a Sustainable Development Commission. The Sustainable Development Commission (represented by officers from all key ministries, sustainable development specialists and NGO representatives) is responsible for issuing or refusing the granting of an Environmental Clearance, with or without conditions.
According to the Ministry of Environment and Tourism (MET) (Dohogne pers. comm.) a flexible system for environmental assessments and management plans is followed for mining whereby depending on the phase of
Overview of Diamond Mining in the BCLME 20 Anchor Environmental Consultants the companies programme further environmental information is requested. The different mining phases and requirements are: Survey activities: Simple environmental contract Sampling: EMPR including monitoring programme Mining: EA including EMPR and monitoring programme
5.3.3 Other Legislation Regulating Environmental Aspects of Mining Activities undertaken during marine mining are regulated by legislation dispersed through several Government Acts and Regulations. Several South African acts applicable in Namibia have not been altered since Namibia obtained independence in 1991. However, in South Africa some of these (e.g. the Water Act) have been revised while others (e.g. the National Monuments Act) are in the process of revision. Pertinent statutory legislation relevant to marine mining in Namibia is listed below:
Pollution at Sea Sea Fisheries Act 29 of 1992 – regulates pollution at sea and controls disposal of fish and household waste from ships; disturbance of rock lobsters marine invertebrates and aquatic plants, and restricts areas of seabed damage Prevention and Combating of Pollution of the Sea by Oil Amendment 24 of 1991 – regulates oil pollution from ships at sea 1973 Convention for the Prevention of Pollution from Ships (MARPOL) – controls all waste disposal at sea (oil, hazardous waste, sewage and solid waste) Water Act 54 of 1956 – controls tailings discharges and sea and fresh water pollution on land
Disturbance or Damage to Natural and Cultural Resources National Monuments Act 28 of 1969 – controls disturbance of shipwrecks and archaeological deposits, such as shell middens and cave contents Sea Birds and Seals Protection Act 46 of 1973 – controls disturbance of sea birds and seals on islands United Nations Convention on Biological Diversity – regulates conservation of biodiversity, sustainable use of its components, and equitable share of the benefits arising from the use of genetic resources.
Harbour Regulations Namibian Ports Authority Act 2 of 1994 – gives Namport the responsibility of protecting the environment within the harbour area Maritime Notice No 4 of 1994 – provides rules and procedures for collecting garbage in Namibian Waters.
Security a) Diamond Industry Protection Act 17 of 1939 as amended – tables laws relating to regulation, control, development and protection of the diamond industry in Namibia and illegal entry into prohibited areas. This act will soon be replaced by the New Diamond Bill to be tabled in March 1999.
Employee Regulations Labour Act 6 of 1992 –provides conditions of employment for employees of Namibian companies and Occupational Health and Safety Regulations. Parts of this Act are soon to be repealed and replaced by the Mine Health and Safety Regulations to be tabled as an amendment of the Minerals Act, 1992. Immigration Control Act 7 of 1993 – regulates employment and issuance of work permits and obliges employers to give job priority to Namibians.
5.3.4 Environmental Management Plan Reports (EMPRs) Namibian legislation requires that all new applicants for mining licences prepare an Environmental Management Plan. No specific guidelines exist for compiling EMPRs, and these are usually assessed according to the international literature and according to the specific programme proposed by the Mining Company. Since South African consultants compile most of the EMPRs, the South African EMPR guidelines (section 5.2.5) are usually followed.
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6. ENVIRONMENTAL ISSUES, IMPACTS AND MITIGATION
6.1 Introduction In the search for and extraction of ore bodies, the diamond mining industry by its very nature exploits the environment. Large amounts of sediment need to be removed and processed, stripping areas and producing tailings. These operations cause both positive and negative impacts on the Benguela Current marine ecosystem, and are the source of conflict with industries utilizing coincident resources.
To avoid these issues becoming a major political concern, and in keeping with the philosophy of Integrated Environmental Management adopted worldwide, a three stage process has generally been followed by the mining industry. Firstly, issues or impacts of major concern to the public, government authorities and conservation bodies are identified during scoping studies. Secondly, specialist or review studies are commissioned and the scale and extent of impacts resulting from the mining activities examined through strategic environmental impact assessments. Finally, in situations where the scale or intensity of the impact is considered to be significant, mitigation measures designed to minimize negative and maximize positive impacts on the environment are recommended. Collectively, this process leads to an Environmental Management Programme (or Plan), which is a dynamic set of documents updated as new mining techniques are employed and/or new information becomes available. Most of the larger diamond mining companies and many of the smaller operators already have, or are in the process of drawing up Environmental Management Plans.
The major issues that have been identified in the compilation of EMPs, and a summary of the pertinent research undertaken and mitigation measures adopted by the industry are outlined in this section and are summarized in Table 4.
6.2 Socio-economic Environment – Positive Impacts
6.2.1 Creation of Revenue and Employment South Africa South Africa has 66 registered diamond mining concerns (excluding about 1500 registered alluvial diggers), 49 of which produced rough diamonds in 1996 and 18 of which were from marine concessions. Production statistics (Source: Diamond Enquiry) for the last 10 years for South Africa as a whole indicate a fairly stable, but slightly increasing, level of annual diamond production at around 10 million carats. Diamond production from kimberlite sources has remained constant, accounting for 89% of diamond production, but there has been a shift over the last 4 years from alluvial to marine diamond production. Alluvial diamond production declined by 245 000 carats on average between the period 1987-1993 and the period 1994-1997, but increased in 1997 due to higher output at De Beers Namaqualand (DBNM) and some Trans Hex mines. In contrast, with the onset of deep-sea mining in 1991, annual average carat production for marine mining increased from 53 885 for the period 1987-1990 to an average of 147 833 for 1991-1993. Marine diamond production statistics show a decline since 1994, and particularly in 1995, as a result of reduced output from Alexkor’s beach and marine sources. Marine mining at present contributes about 10% of South Africa’s total diamond production.
Diamond revenues, levied through income tax on diamonds, mining leases, mining rights and diamond export duties, are put into the Central Revenue Fund from where they are allocated to various budgets by the Government. The proportional contribution of diamond revenues to overall tax revenue collections has declined over the last 17 years, and the diamond taxation system is under review by the Katz Commission.
Statistics for diamond mining in 1997 indicated that 473 male employees worked at sea, compared to a total diamond mining workforce of about 10 000 males and 900 females (Minerals Bureau 1997 statistics), providing roughly 54% to the Gross Geographic Product (down from 80% in the 1970s) and 66% of employment in the Namaqualand region. Quantifying financial input into local economies from diamond mining is very difficult as a result of the wide range of multiplier effects. Combined male and female earnings for all diamond mining in 1997 totalled almost R553.5 million, however, it is unclear what proportion of this may have entered the local economy since many of the higher income employees live outside the region.
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Namibia As in South Africa, Namibian onshore diamond mining is winding down and the future lies in offshore diamond mining. In 1996, beach and marine mining yielded 43% of total diamond production (compared to 10% in South Africa), estimated at 1.49 million carats. The diamond mining contribution to GDP was valued at N$2.1 million in 1997. As in South Africa, diamond mining revenues go to Namibia’s central government funds. Namdeb is the biggest taxpayer, exporter and private sector employer in Namibia. To prolong the life of its onshore activities, Namdeb invested in new dredge mining techniques in 1997 that led to increased production levels. Namdeb produces approximately 1.3 million carats of which its deep-water operator, De Beers Marine, contributes 35%. In contrast, ODM produced just over 58 000 carats in Namibia in 1997.
In 1993, 4500 workers (1% of Namibia’s workforce) were employed by Namdeb at its diamond mines in the Sperrgebiet. The majority of low-skilled employees originate from the northern regions of Namibia and send remittances to families back home. At rough estimate, a minimum of 800 people is employed at sea – excluding shore-based operations.
Angola In 1971 Angola, through formal production channels, produced 2.4 million carats, although production subsequently declined due to civil war and instability. The 1991 cease-fire led to an influx of thousands of “garimpeiros” (illegal diamond miners) to diamond fields, which has lead to widespread uncontrolled digging and smuggling. Estimates suggest that over 50% of the Angolan Government total potential revenue from alluvial diamonds has been lost to smugglers. In 1994 revised legislation was passed to provide order to the diamond industry, and in particular to provide for greater security. The new law gives ENDIAMA, the state mining company which has the sole rights for prospecting, mining and marketing of diamonds in Angola, powers of negotiation to attract foreign investors in new mining ventures either in joint ventures with ENDIAMA or as sole investors.
As a result, production has since increased to 3.7 million carats in 1996 contributing roughly 9% to Angola’s GDP, with most production from onshore mining. Significant interest has been shown in Angola’s diamond resources since they are known to be of particularly high quality. De Beers and ODM both have agreements with ENDIAMA to mine onshore diamonds. De Beers plans to spend $75 million on prospecting three prospects covering 63 000 km2 in Quela, Mavinga and Lunda Norte. De Beers has indicated its commitment to ensuring the stability of the diamond mining industry in Angola by investing in a 12-storey diamond sorting building in Luanda.
No authorised offshore prospecting and mining has been undertaken in Angola to date, although companies, such as De Beers, have been negotiating for rights with the Angolan Government for some years.
Table 2. Summary of total diamond production, contribution by marine and beach mining and total contribution by diamond mining to GDP for South Africa, Namibia and Angola. Total diamond Contribution from beach Contribution to GDP production (ct) and marine mining (U$D) South Africa 10 000 000 10% 7 300 000 Namibia 1 500 000 43% 350 000 Angola 3 700 000 0% ?
6.2.2 Human Resource Development and Social Betterment South Africa Initiatives to develop the skills of employees have been undertaken mainly by the large onshore mining companies who employ a significant staff complement of mainly low-skilled workers. Onshore human resource development initiatives by large companies include the establishment of trusts to fund training; sponsorship of community needs (such as clinics); conducting skills training at mining towns; and developing alternative land uses. Training on mines has been fragmented, however, and qualifications are not nationally standardised, leaving most employees with little improved chance of finding jobs.
DBCM, for instance, together with Anglo America, contribute to the Chairman’s Fund, which is the largest corporate contributor to educational and social development in South Africa. In 1997, the fund made donations
Overview of Diamond Mining in the BCLME 23 Anchor Environmental Consultants totalling over R56 million of which De Beers contributed R18.5 million. Most of the funding is invested in education.
To improve financial viability of mining, extend the life of the mines, and create jobs, some of the larger companies are investigating, or are already undertaking, alternative land use activities. Alexkor has mariculture and farming projects underway, and have further plans for mariculture expansion. The company, in conjunction with the Northern Cape Government, is also investigating tourism and other land use development options with a view to providing up to 700 jobs (if all plans reach fruition). DBNM are awaiting approval to start abalone cultivation and harvesting of Gracilaria and are considering other projects such as hemp cultivation and other agricultural projects. It appears that mariculture ventures undertaken by diamond mining companies in their processing dams would not otherwise be financially viable and can be considered a positive spin-off. It is not known whether these ventures would remain viable after mine closure, however. Unfortunately, the success of many of these projects will depend largely on the availability of fresh water - a scarce resource along the Namaqualand coast.
Namibia Namibia’s Minerals Act, 1992, requires holders of any mineral licence to: give preference to Namibian citizens with appropriate skills; carry out training programmes to promote the development of Namibian citizens; make use of products, equipment and services produced and available within Namibia, and co-operate with Namibians involved in the mining industry to promote skills development.
Namdeb took initiatives with Namibian small contractors in 1990 after pressure was exerted to expand shallow water operations in Namibia, similar to those that had been operating in Namaqualand since the 1980s. However, many small contractors operating from the beach south of Lüderitz failed to make a profit because of adverse working conditions and operational problems. Larger-sized “small contractors” operating from boats (e.g. Yam Diamonds) and others produced over 132 500 carats in 1994. Small contractors employ roughly 250 people, most of whom live in Lüderitz.
In line with government policy and to prolong the life of the mine by reducing overhead costs, Namdeb has privatised most non-mining activities in its mining town of Oranjemund, which are now run mainly by black entrepreneurs. The diamond industry has also benefited the local economy of Lüderitz (which houses its Elizabeth Bay mine) through the payment of wages (estimated at N$8 million), local sponsorship and direct business (N$3 million).
6.3 Socio-economic Environment – Negative Impacts
6.3.1 Shifting Emphasis from Onshore to Offshore Mining The intensity of onshore diamond mining in the coastal zone is in decline with a shifting emphasis to offshore operations. This is likely to have far reaching implication for aspects such as employment and skills training in both South Africa and Namibia.
Impact on Employment: The number of employees in South Africa’s onshore diamond mining industry as a whole has declined from over 19 500 in 1992 to less than 15 000 in 1997 (a rate of approximately 2.5-3% per annum). Alexkor and DBNM have been scaling down onshore operations and will continue to do so over the next 25 and 10 years respectively, as diamond reserves are depleted. Between the two companies, a minimum of 1800 jobs has been lost since 1992. The majority of employees in onshore diamond mines are from Namaqualand, about 80% of which are low-skilled workers. Mine retrenchments will therefore exacerbate the already dire unemployment situation in Namaqualand unless alternative employment sources are found. The unemployment rate in rural areas of Namaqualand has been estimated at 60% - a problem that has been compounded by the decline of the fishing industry, particularly the rock lobster industry.
Loss of jobs due to downscaling is not restricted to South Africa. Downscaling through natural attrition, facilitated by retirement and voluntary retrenchments, is ongoing in Namibia, and will continue over the next two decades exacerbating the already high unemployment rate in this region (estimated at about 34%).
The decline in onshore mining has occurred in parallel with a rapid growth in marine mining. Onshore mining companies are shifting the focus of their activities towards marine mining, and other companies have entered the diamond mining industry (e.g. Ocean Diamond Mining, Nautical Diamonds, BENCO). Marine mining is a highly specialised activity, requiring high capital inputs in the form of purchasing, maintaining and
Overview of Diamond Mining in the BCLME 24 Anchor Environmental Consultants equipping mining vessels with technical processing equipment. Relative to onshore mining, marine diamond mining requires lower inputs of low-skilled labour - up to 10% (in contrast to the 80% in onshore mines). With the present lack of alternative job sources in Namaqualand, the majority of workers retrenched from onshore mines in the next decade have little chance of finding work in the offshore industry. Furthermore, because a high level of skills are required for offshore mining, the majority of staff is recruited from urban centres overseas and in South Africa, particularly impacting Namibian employment. DeBeers Marine, for instance, employs qualified British Marine Officers because of the lack of qualified South Africans or Namibians. This is set to increase, as more mining vessels become operational – DeBeers Marine, ODM and Namco are all planning to augment their mining fleets by one vessel in the next two years.
In the absence of alternative employment in Namaqualand, many retrenched workers will, in all probability, relocate southwards to Cape Town or Saldanha (the centre of the West Coast Investment Initiative), attracted by the prospect of industrial expansion and job creation. For those that remain in Namaqualand, the loss of jobs and financial hardship that this will create may cause greater dependence on the natural resource base. This may include increased pastoralism and resultant overgrazing of sensitive coastal vegetation as well as increased collection (largely through poaching) of coastal shellfish resources (abalone, mussels and rock lobster).
Impact on Skills Training: With continued job losses due to downscaling of onshore mining activities, fewer training and skills enhancement opportunities will be available for unskilled workers thereby compounding the unemployment and poverty problem in rural mining areas. Migration of workseekers to other urban centres is likely to erode the economic support base of the former and compounds the unemployment problem in the latter. Offshore mining also provides fewer training opportunities for low-skilled employees, limited mainly to sponsorship of students to study engineering-related courses.
Mitigation: There is no direct mitigation that can be undertaken to stem the loss of jobs resulting from declining coastal reserves. Investment in training and investigation of future landuse options, however, are indirect means to provide opportunities for self-help.
Onshore and offshore mining companies are implementing training programmes that target upgrading of skills which will improve the chances of employees obtaining secure jobs in the post-mining environment. These companies should allocate a certain proportion of annual turnover to training and sponsorship for education. In line with the new Minerals Policy and Mine Health and Safety Act, which gives employees the right to education and training, the South African government has undertaken to promote Adult Basic Education and Training (ABET), and in particular, to ensure that people in the minerals and mining industry have access to quality education and training. The South African Qualifications Authority Act is also working towards standardising, at a national level, the qualifications achieved by training on mines.
6.3.2 Involvement of Small Scale Miners Impact: Limited involvement of small-scale miners in the diamond mining industry has created imbalances in the distribution of benefits of mining and has restricted the potential for these miners to secure a living. Small-scale mining has been hampered by factors including: 1) lack of access to finance by financiers unwilling to fund ventures which offer limited financial security and returns; 2) lack of appropriate structures to assist small scale mining development; 3) location of mining operations far from major markets; 4) lack of access to marketing channels; 5) lack of management and technical skills, and; 6) inability of small-scale entrepreneurs to provide adequate diamond security measures. Not only have these problems marginalised small-scale miners, but they have also led to the non-exploitation of marginal diamond deposits regarded by larger companies as unprofitable.
Mitigation: In line with the new Minerals Policy of South Africa and policies of the Ministry of Mines and Energy of Namibia, the respective governments have pledged to increase participation in the mining industry by those previously excluded. Measures that have been proposed to improve small miner involvement in the mining industry are: 1) to facilitate access to funding through appropriate institutions; 2) to ensure that information on technology and mineral development and exploitation is made available to the small-scale mining sector; 3) to encourage municipalities to support the emergence and development of small-scale miners, and; 4) to enhance the capacity of Department of Minerals and Energy to provide support to small-scale miners.
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6.3.3 Promotion of Joint Management Ventures with Employees Impact: Racial imbalances are prevalent within the mining industry (as in other industries) with the majority of middle and senior management positions still occupied by whites. Lack of joint management ventures or partnerships with mine employees has led to lack of advancement of “black” workers and professionals into senior positions or management levels. This has created a situation whereby black employees have become demoralised through lack of economic empowerment, which undermines the political and economic stability of the mining industry.
Mitigation: Training programmes to upgrade skills amongst the workforce have targeted this disparity (see above) but will still take many years to effect significant changes. To date, few mining companies have sought to involve employees in joint management ventures such as shareholder participation schemes. The policies of South Africa and Namibia (see above) seek to improve employee-employer relations within the workplace and promote black participation in ownership and management within the mining industry. Authorities have also undertaken to consider changes to tax administration and company law to reduce obstacles to mining companies introducing Employee Share Ownership Participation Schemes for low-income workers.
6.3.4 Reduced Revenue from Offshore Diamond Mining to Local Areas Impact: Onshore mining companies have devolved significant benefits to local areas. Most large companies have, or are in the process of, compiling and implementing company policy for the purchase of local goods and services and, where possible, from entrepreneurs from previously disadvantaged communities. In this way, these mining companies seek to devolve mining benefits to the local area and in so doing create a stable economic and political environment within which to conduct their activities.
Opportunities, however, for offshore mining companies to do likewise are limited by the fact that operations are conducted out of major urban centres, and most goods and services required to support offshore mining are high tech and not available from small scale enterprises. This is particularly the case in Namibia, where the use of Cape Town as a base for vessel servicing, repairs and victualling represents a loss of potential income for the Namibian economy. The shifting emphasis from onshore to offshore mining will lead to further losses to local economies.
Mitigation: No active mitigation measures have been implemented.
6.3.5 Allocation of Diamond Mining Revenues to Mining Areas Impact: The diamond mining industry and the governments of South Africa and Namibia have been criticised by communities and local authorities for the lack of investment in infrastructure and services in towns near diamond mining areas. This stems from the policy where diamond revenues are put into a central revenue fund that are allocated to various budgets by the Government, rather than direct re-investment in the local district. To date, initiatives to address the allocation of a portion of these revenues to local and/or provincial authorities have been rejected. The mining industry, as well as the fishing industry, has not been required to directly fund the maintenance of state or provincial roads and have placed strain on harbour facilities. This is a contentious issue amongst relevant local authorities. Despite the high income realised by diamond mining, areas surrounding diamond-mining exhibit retarded growth, lack of investment and in some places (e.g. Lüderitz) a growing population of unskilled workseekers. Elsewhere, where onshore diamond mining is in decline (e.g. Namaqualand), towns exhibit outmigration of the economically active age group to seek work elsewhere because of the lack of economic investment. Work seekers tend to move towards urban areas, such as Cape Town and Lüderitz, thereby compounding problems of crime, poverty, family separation and general demoralisation when jobs are not found.
Mitigation: No active mitigation measures have been implemented.
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6.3.6 Strain on Infrastructure and Services of Towns near Mining Areas Impact: Several towns along the South African and Namibian coasts are experiencing problems arising from the demand for infrastructure, services and resources to support the diamond mining industry. Many towns do not have the capacity to support the growing offshore mining industry – a problem compounded by the lack of direct financial inputs by Government. Infrastructure, services and resources which are often over-stretched include strain on harbour facilities, land fill sites, fresh water, and accommodation.
Mitigation: Facilities and the capacity of affected towns to support mining are being upgraded through redirection of financial and service inputs by Government and/or by creating incentives for mining companies to do so by working in conjunction with local authorities. This process needs to be expedited, however.
6.3.7 Conflict with the Fishing Industry Issue: Conflict exists between the rock lobster fishing and marine diamond mining industries. The rock lobster industry holds the diamond mining industry responsible for the killing of lobster and large-scale destruction of lobster habitat by stirring up sediments, cutting kelp, and poaching. Although research studies suggest there is no causal relationship between increased marine diamond mining and the decline in fish catch rates experienced in recent years, the issue remains a source of conflict between the two industries.
Mitigation: The formation of fora or committees on which all the major stakeholders are represented appears to be the current trend for pre-empting and resolving conflicts as they arise. The Marenpro Forum in Lüderitz, Namibia, in which representatives of the fishing and mining industry as well as government ministries participate, is one such active forum. A West Coast Liaison Committee is soon to be established and has similar objective to the Marenpro Forum. All the players in the diamond mining industry in each area along the coast e.g. Western Cape and Northern Cape and Namibia should be encouraged to participate and contribute to these fora.
6.3.8 Impacts on Future Land Use and Tourism Impact: Perhaps one of the most significant impacts of onshore and surf zone mining is the impact on future land use and tourism potential. Trenches, mining blocks, overburden dumps and an overabundance of roads scar the landscape, considerably altering the original topography. This constitute a significant aesthetic impact, which will have “knock on” effects on the tourist industry and may jeopardise the future land use potential of decommissioned mining land.
Mitigation : Currently, the issuance of mining licences requires proof of funds for rehabilitation. However, prior to 1980 rehabilitation was not enforced, and large areas have been left scarred and un-rehabilitated. Some of the damage was caused by companies who no longer operate and the present holders of mining licences for these areas cannot be held responsible. The ultimate responsibility for rehabilitating these areas now lies with the government of the respective countries. In South Africa, the Department of Mines and Energy (DME) and the Department of Water Affairs (DWAF) contribute to a fund for derelict and ownerless mines, which is used for rehabilitation, and health and safety reparations. However, limited funding as well as the inherent problems of rehabilitation in arid areas, are the biggest constraints to successful rehabilitation.
6.3.9 Loss of Cultural Resources Impact: The entire southern African coastal zone has a wealth of archaeological deposits, mainly found as surface shell middens, to a lesser extent cave deposits, and shipwrecks. Onshore, poorly planned access roads, camps and processing areas can inadvertently destroy middens constituting a significant loss to cultural heritage. Within the surf zone, shipwrecks are particularly vulnerable to mining disturbance. At least 2000 vessels are known to have sunk or run aground off South Africa’s shores since 1500 of which only a small fraction have been located. Surf zone mining, through displacement of obstacles such as boulders and suctioning of gravel, risks dispersing and breaking up shipwreck material. At present, the extent of damage to archaeological deposits has not been quantified.
Mitigation: Historically, mining companies have not had a responsible attitude towards protection of cultural resources. This is probably due mainly to the freedom the mining industry has enjoyed as South Africa’s and Namibia’s most important economic sector and the lack of environmental controls exerted on the industry until recently. In South Africa, negligence towards cultural resources has been partially encouraged by legislation that excludes diamond mining from the regulations under the Environmental Conservation Act on the use of off-road vehicles, and to portions of the National Monuments Act. This situation is changing, especially amongst the larger mining companies, who are demonstrating greater environmental responsibility in this regard by commissioning archaeological surveys prior to expanding their mining activities. Some companies, however, still have far to go in this regard.
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6.4 Biophysical Environment - Positive Impacts
6.4.1 Conservation of Flora and Fauna in Restricted Areas Impact: The most notable positive impact on the biophysical environment comes from the de facto nature reserve status of much of the terrestrial mining area. Access to most mining areas is highly restricted in order to minimise diamond theft, and as a consequence, human interference in many areas has been kept to a minimum. Many habitats have been left in pristine or near pristine condition, the scale of which is not insignificant - the Namibian ‘Sperrgebiet,’ for example, alone encompasses some 26 000 km2 of land.
The positive benefits from diamond mining are unequally shared between the marine and terrestrial environments, however. While access is restricted on land, large-scale offshore fishing enterprises continue uninterrupted along much of the diamond coast. Only shore-based forms of exploitation are effectively excluded.
6.5 Biophysical Environment - Negative Impacts Considered as a whole, marine diamond mining affects only a small fraction of the marine environment (Table 3). The overall aerial extent of mining activities encompasses less than 1% of the concession areas in South Africa and Namibia per annum, irrespective of the form of mining category. On the scale of the BCLME therefore, impacts of diamond mining are deemed to be of low to negligible significance. At local scales, however, their impact may be more severe. Due consideration must be given to the scale of operations when the impacts outlined below are evaluated.
Table 3. Relative extent of the various diamond mining activities in South Africa and Namibia. Type of Mining % of Concession Mined per Annum Beach Mining <0.5 % Shallow-water Mining – Shore Based <0.001 % Shallow-water Mining – Boat-based <0.01 % Mid-water Mining <0.5 % Deep-water Mining <0.01 %
6.5.1 Environmental Impacts of Terrestrial Mining Mining, Overburden and Tailing Dumps and Roads Impact: The impacts of terrestrial mining are caused individually or in synergy from 10 categories of mining activity: prospecting trenches; overburden dumps; tailings dumps; mining blocks; sediment plumes; roads and vehicle tracks; scarring and quarries; mining infrastructure; seaward disposal of fines tailings; and beach mining. Perhaps the three greatest impacts from terrestrial mining are due to the removal of overburden and diamondiferous gravel, the creation of overburden and tailings dumps, and the construction of roads. These activities impact soils and plant communities, in turn impacting the animal communities associated with them. The degree of impact depends on both the scale of the mining activity and the type of soil that is impacted. Actively forming soils harbour plant communities that are dynamic and resilient to even massive disturbances, whereas plant communities growing on older complex soils are dependent on the equilibrium of the soil, and usually fail to recover from disturbance if this equilibrium is not maintained. Stripping of overburden with a complex topsoil therefore has a relatively greater impact of longer duration than stripping an area of actively forming soils. Although some areas are back-filled, topsoils are generally not stored and the loss of topsoil means that recovery of plant comminutes to their former state depends on the formation of new soils – in the order of decades to centuries. Loss and recovery of animal fauna presumably follows the same route. Roads and heavy vehicle movement has the opposite effect to mining. These activities tend to compact the soil, thus rendering the area unsuitable for re-colonization by new plants. Additionally, it should be noted that numerous rare, threatened or endemic animal and plant species occur in the diamond areas, and are negatively affected by mining activities. Areas denuded of vegetation, such as trenches, mining blocks and tailings are inherently unstable, with the result that sand plumes frequently develop due to the strong winds and flat topography characteristic of the mining area. These sand plumes can be quite extensive, smothering vegetation and causing a significant secondary impact. It is believed that sediment plumes may have been a triggering force in the collapse of the saltmarsh ecosystems of the Orange River wetlands.
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Additional, lesser impacts are caused by mining infrastructure as buildings and equipment are often left on site following completion of mining, or if the equipment becomes derelict. Not only does this hinder recovery of the ecosystem, it also causes an aesthetic impact, in addition to the mine dumps and trenches that now dominate in a previously flat landscape.
Mitigation: Mitigation is principally through rehabilitation of the affected areas. The severe disturbance that results from mining in these arid terrestrial ecosystems, the dynamics of which are greatly retarded by the harsh environment, makes rehabilitation very difficult, however. Generally larger mining companies make the effort to stockpile topsoil and overburden separately and replace this material in appropriate positions in the refilled mining blocks. Little or no effort is made to rehabilitate prospecting trenches, however.
Seaward Disposal of Fine Tailings Impact: Discharging fine tailings to sea impacts the intertidal region, whether at a large scale such as the Elizabeth Bay Mine (Namibia) or at a smaller scale such as small contractors operating from the shore.
The sediment plume generated from the seaward disposal of fine tailings impacts intertidal rocky shores. The impact is localised to the extent of the sediment plume – a scale of 100 m in the case of large recovery plants, and a scale of 10 m for the smaller operations. The impact is caused by sand inundation that appears to impact particularly the grazers in the intertidal zone (e.g. Patella granatina, P. argenvillei), causing a decrease in the ability of these animals to adhere to the substrate. The resultant reduction in herbivory often leads to an increase in foliose algal cover, which causes shading and in turn decreases corralline algae cover below. A cascade effect is the loss of food to seabirds that forage on the intertidal. At small-scale contractor mining sites, full recovery takes less than two years after the cessation of mining activity.
Subtidal rocky shores do not appear to be adversely affected by light siltation by mine tailings, with the possible exception of sponges which are particularly sensitive to sand inundation. Should a beach prograde to cover the reef however, complete loss of habitat with the associated communities, will ensue.
The seaward pumping of fine tailings on sandy shores can have a profound effect on communities associated with these habitats. Fine fractions of tailings are suspended in the sea and advected offshore, whereas coarser fractions settle rapidly onto the beach. If large volumes of tailings are pumped seaward, this can lead to severe alterations of the physical state of the affected beach. For example, fine tailings at Elizabeth Bay have increased the size composition of sand across the entire beach. Prior to mining, Elizabeth Bay beach was composed of fine to very fine sands, with sand particles coarser than 100µm making up less than 10% of the total amount. With the advent of mining in 1991, mean particle size at the centre of the beach where tailings are disposed has increased from 110-160 µm to 600-900 µm, with a accompanying reduction of surf zone width by ~50% and an increase in the beach slope from 1:40 to 1:14. Beach macrofauna communities are almost entirely determined by the physical state of the beach, and this alteration to the physical state of the beach has led to a shift from a mussel dominated community to a community dominated by crustaceans with an accompanying loss of diversity. Following mine closure, recovery of the affected beaches to a pristine state will depend on the speed at which the beach returns to pre-mining physical conditions. This could take decades or even centuries.
Fish appear to benefit from the turbidity plume produced by the discharge of tailings spoil material from the Elizabeth Bay diamond mine, with increased species richness and abundance recorded within the plume relative to control sites on the same beach. It is believed that this is attributable to increased shelter from predators provided by the plume. Loss of potential food items (beach macrofauna discussed above), reduction of habitat through the narrowing of the surf zone, and the development of more turbulent waters associated with a narrower surf zone must have some, though unquantified, negative effects. Mitigation: Terrestrial slime dumps are an alternative to the seaward disposal of tailings, but this option is not without its own impact on the environment. No other mitigation or rehabilitation options are considered economically feasible.
6.5.2 Environmental Impacts of Beach Mining Seawalls Impact: The construction of seawalls has significant effects on the marine environment. Seawalls are constructed to push the shoreline between 200 and 500m into the sea, permitting access to diamond deposits of the subtidal. The seawalls require constant maintenance as rough seas typical of this coast continually erode the walls. Overburden alone is often insufficient for the construction and maintenance of these dams, and as a result, other sources of material are used for building material including the coastal dunes (in itself an impact
Overview of Diamond Mining in the BCLME 29 Anchor Environmental Consultants on the terrestrial environment). Following mining, maintenance of the seawalls ceases, the wall collapses, and the area is left to reform a new shoreline. Because the seawalls are constructed of a melee of fine sands to boulders not resembling the original beach material, the resulting shore is left physically altered. In some cases fine-grained beaches have been left as coarse-grained beaches while in other cases, rocky reefs have been converted to boulder fields. As discussed above, alterations to grain size can have profound effects on biological communities of sandy beach and rocky shore communities. Although such an impact has hitherto not been assessed in terms of field studies, the effects are roughly predictable. Pre-mining baseline data has been collected at one site, however, and the impact should be fully quantified once mining is underway in the next few years. Mitigation: Mitigation action includes the use of materials for seawall construction that are roughly equivalent to the sandy beaches that are stripped.
6.5.3 Environmental Impacts of Shallow-Water Mining Operations (<30m depth) Diver-assisted shallow-water mining activity targets gravel-filled gullies and potholes between reef ridges. Access to this gravel is either via the shore or through boat-based operations.
Access to Shore-based Mining Sites Impact: Access to nearshore diamondiferous gravel by shore-based operators often requires the construction of new roads, blasting rock cuts, moving of boulders and the construction of work camps in order to move machinery sufficiently close to the seashore. The act of mining leaves tailing dumps, most often left above the high water mark. The aesthetic and terrestrial impacts of these activities, albeit at a larger scale, have been discussed above.
Mitigation: It has been suggested that impacts of this nature could be mitigated if nearshore diamond pumping were undertaken exclusively from boats. Although possible, start-up costs associated with such a policy may be prohibitive for new entrants.
Kelp Cutting Impact: Kelp (primarily Laminaria spp.) is often cut by divers to provide unencumbered access to the mining site. This activity causes a localised impact, the severity and duration of which depends on the extent and frequency of kelp cutting and the age of the plants. Kelp sporelings settle most successfully at or near the holdfasts of adult kelp plants, and recovery of kelp beds proceeds from the fringe of the cut area. Therefore, the greater the area cut the slower the recovery. By the same argument, a clear-cut area or repeatedly cut area will recover relatively more slowly than an area where only adults are cut and small kelp plants are left behind. In the best case scenario, recovery can take less than two years, although in some areas recovery has not occurred, especially where high densities of sea urchins (Parechinus angulosus) occur. Sea urchins feed preferentially on kelp sporelings, and in sufficient densities can keep an area entirely denuded of kelp. Many animals utilise the kelp bed habitats during the juvenile stage of their lives, and the loss of this habitat could have a small but important cascade effect.
Mitigation: Mitigation action includes restricting the width of the lane of kelp cut, discouraging clear-cutting, and discouraging repeated cutting.
Benthic Communities Impact/Mitigation: Nearshore pumping of diamondiferous gravel by divers has a myriad of effects, such as the development of sediment plumes; uncovering of new reef where gravel is removed; the smothering of reef where tailings are discharged; the de-stabilising of reef where ‘cementing’ gravel is removed; physical disturbance of the suction pipe and diver abrading the reef; and the moving of boulders to access gravel beneath.
Concern has been expressed regarding the effect of sediment plumes on the primary productivity of phytoplankton and macroalgae. Compared with the naturally high levels of suspended sediment in this highly dynamic nearshore environment or the fine tailings deposited into the sea from land-based mining operations, this impact is thought to be negligible.
Nearshore mining putatively impacts the habitat of rock lobsters, rock lobsters themselves and their food source. A strong association of rock lobsters with reef- and boulder-dominated seabed has been established, as has the diversity of benthic organisms, most of which constitute the food source of the rock lobster. Diamond mining primarily targets sand and gravel areas, however, and the mining process does not directly threaten the
Overview of Diamond Mining in the BCLME 30 Anchor Environmental Consultants reef and boulder communities. By removing gravel, mining may in fact expose expanses of previously embedded rock and boulders. Although these are initially uninhabited, recolonisation by benthic communities is rapid and the area becomes statistically indistinguishable from unmined areas within six months, despite the bottom topography being considerably altered. Mining activity therefore can effectively convert gravel gullies into boulder beds, which are potentially suitable for habitation by rock lobsters.
The converse can also occur, however, if tailings are dumped onto reef- and boulder-dominated seabed, thereby smothering rock lobster habitat and/or food. Some dumping inevitably occurs on adjacent reef, but if this is restricted the impact is thought to be limited, as small quantities of tailings will be dispersed during subsequent storms. If the impact is cumulative, however, this can have the effect of converting preferred rock lobster habitat into sub-optimal small boulder or unsuitable gravel areas. These areas may be stabilised in time, although further research is needed before conclusive answers can be given concerning the impact of rock piles and tailings dumps. Mitigation measures should, however, include keeping the shifting of boulders to a minimum and dumping of tailings further offshore on non-reef areas.
Although diamond divers admit to pumping rock lobsters ‘for the pot’, the quantities involved are insignificant compared to the annual quota landed by the commercial rock lobster industry. To discourage poaching, however, mining vessels should be inspected occasionally for illegal catches, and mining licenses be confiscated if found guilty.
Seabirds and Seals Impact/Mitigation: Disturbance of seabirds and seals on the nearshore islands off the Namibian coast is a further issue of environmental concern. Nearshore subcontractors working the island concessions are forbidden to land on the islands except in emergency or if accompanied by personnel from the Ministry of Fisheries and Marine Resources (MFMR) in Lüderitz. All landings are recorded and reported to the MFMR.
Harder Fishing Impact/Mitigation: Allegations have also been made that the activity of diamond boats within the Olifants River estuary, and mining operations near the estuary mouth, have led to a reduction in gillnet catches of harders by local subsistence fishermen. Problems associated with waste disposal and maintenance operations which potentially release contaminants (e.g. oil, antifouling paints, sewage) into the estuarine environment have also raised concerns. Although the conclusions of the EIA were speculative only, reduced catches were attributed to overfishing and possible recruitment failure rather than boat traffic. It was, however, recommended that mining near or within the mouth and increased use of the estuary as a harbour for diamond vessels be discouraged.
6.5.4 Environmental Impacts of Mid-water and Deep-water Mining Operations (>30m) Tailings Plumes Impact: Fine tailings can remain in suspension for long periods forming plumes that are advected away from the mining vessel by ambient currents. Most of the silt sinks rapidly (minutes) during the initial convective descent phase; entrainment of seawater resulting in dilution of both the dissolved and particulate constituents of the discharge. Ultimately the density of the diluted discharge becomes neutrally buoyant, with the remaining particulate matter spreading and settling further through passive diffusion (hours). The potential impacts on water column processes of the temporary redistribution of slow sinking silts and clays originating from mining activities has received much attention in both Namibia and South Africa. A structured approach to the assessment of suspended sediment plumes, as recommended by the Environmental Protection Agency of the United States, has been adopted by the mining companies concerned. This includes desktop studies and predictive modeling in the pre-mining phase, followed by more intensive in situ biological and toxicological evaluations requiring field sampling, laboratory testing and rigorous data analysis.
Although the plumes may extend several kilometers, the potential impact on phytoplankton communities through reduction of light, nutrient enrichment, remobilization of contaminants, and deep oxygen consumption through decomposition of silt particles during descent, is generally very limited and localized. The extent of the impact of the plume depends largely on the proportions of silts and clays in the targeted sediment, and the sea surface conditions during disposal. Measurements of dissolved nutrient concentrations (NH4, PO4, NO3 and NO2) in the tailings discharge were within the specified limits set by the “Water Quality Guidelines for the South African Coastal Zone”. Rapid descent and dilution of dissolved nutrients and contaminants in the convective descent and passive dispersion phases resulted in ammonium concentrations declining to below detection levels within an hour of release. There was no evidence of the release of NO3 and NO2 from interstitial
Overview of Diamond Mining in the BCLME 31 Anchor Environmental Consultants waters as is to be expected from anoxic sediments. Due to their low solubility in seawater, elevated concentrations of trace elements (Cd, Co, Cr, Mn and Pb) have, however, been recorded in the tailings plumes; those of Cd, Cr, Cu and Zn breaching the recommended water quality guidelines. Evidence suggests that pesticide levels resulting from resuspended biogenic muds are unlikely to exceed recommended guideline levels. Remobilization and subsequent uptake of contaminants by marine organisms has important implications for bioaccumulation down the food chain. Assessments of the potential oxygen consumption through decomposition of silt particles during descent have indicated that rates are low and no measurable impacts on the typical bottom water concentrations are expected.
Ferrosilicon loss in the tailings has been reduced through the introduction of vertical impact crushers and sophisticated recovery systems, but an average of 127 t (in 1995) per vessel are still lost annually. In areas with iron deficiency, this could potentially increase primary productivity and alter the phytoplankton community structure.
Mitigation: No mitigation is warranted.
Impacts on Benthic Fauna Impact: The mining process removes unconsolidated sediments, resulting in the destruction of benthic fauna, and modification of the benthic habitat in the mining path and in adjacent areas where disturbed sediments are re-deposited. This causes direct mortality of organisms through the dredging and discharging process, potential smothering of organisms affected by the fallout, and possible aggravation of oligoxic conditions causing migration or even death. Consequently, a significant change in abundance and diversity of benthos has been observed in mined areas and their immediate vicinity. Substantial restratification of sediments occurs thereby influencing the rate of recolonisation as well as the structure of the developing benthic community. The recovery rate of a perturbed area has been estimated to take as long as eight years, but habitat modifications may be permanent resulting in a persistent environmental impact and change in the associated communities. This may potentially affect the food chain and have important implications for the distribution and abundance of other marine organisms such as rock lobsters and fish. However, without baseline data on the natural variability and patchiness in benthic community structure with sediment type, depth, and transient changes in water quality, it has not been possible to provide a cumulative assessment of mining damage. Furthermore, spatial heterogeneity of benthic communities has precluded the application of results across wider areas.
Mitigation: Leaving lanes of sediments undisturbed will facilitate the recovery of benthic communities.
Impacts on Fish and Fisheries The fish fauna of the west coast of South Africa and Namibia has a low diversity and contains few endemic species. Most species are widespread and to some extent migratory and are thus able to escape from oligoxic incursions as well as disturbance by mining tools. Although baseline knowledge exists of the abundance and distribution of the commercially important species in the areas of mining activity (hake, monkfish, sole, kingklip, and rock lobster), attempts to quantify these on a sufficiently fine scale to determine the impacts of offshore mining have not been attempted. Rock lobster and sole are the most restricted in their distributions and migratory capacity and thus the most likely to be at risk. The main spawning areas of the commercially important fish species are primarily north (<25°S) of current mining activities in Namibia, and south (St Helena Bay) of activities in South Africa. The shallow shelf region between St Helena Bay and the Olifants River appears to be utilized as recruitment grounds by most of these species. Desktop studies have identified the main potential impact of mining on fish to be on the breeding success rather than on the adult stocks themselves. The impact is thought to be greatest in the water column below the thermocline where the vulnerable early life-history stages may be negatively influenced by oligoxic conditions in the suspended sediment plumes. No quantitative data are available, however, and the coincidence between the sediment plume and fish egg and larval distributions needs to be investigated further.
The principle risk of offshore mining activities to rock lobster is the aggravation of oxygen poor conditions and the disruption of seasonal offshore migrations as part of their breeding and moulting cycles. Most of the rock lobster fishing activities occur within 5 nautical miles of the coast; overlap with offshore mining is thus limited. However, information on rock lobster behaviour in deeper water and the role of migrations is lacking and should be researched further before conclusions concerning the impact of mining can be made.
Impacts on Other Marine Fauna The primary sources of noise associated with mining operations are the sounds caused by equipment and machinery, and sonar and seismic equipment. The latter frequencies overlap with the spectrum of frequencies used by marine mammals to communicate and have the potential to cause injury and discomfort.
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Some crew changes involve aircraft flying low over wetlands, which has been found to cause disruption to the waterbirds. Reactions to fixed-wing aircraft and helicopters varies between bird species but foraging, roosting and breeding activities are generally negatively affected, potentially reducing reproductive success. Although no similar studies have been conducted on the effects of low flying helicopters on seabird and seal populations on offshore islands, short-term disturbances are to be expected.
6.5.5 Generic Impacts Numerous impacts are generic in nature, synonymous with virtually any shipping activity. These include waste disposal, sewage, paints, hydrocarbons, bunkering, freshwater, etc. Legislation is in place to deal with many of these impacts, and consequently these are not dealt with here.
Overview of Diamond Mining in the BCLME 33 Table 4. Summary of Socio-economic and biophysical impacts of marine diamond mining operations in the BCLME. Socio-Economics: Positive Aspects Impact Creation of Employment and Marine diamond mining industry provides considerable employment and tax revenue Revenue in RSA and Namibia. Human resource development and Some of the larger companies diamond companies in RSA and Namibia have started social betterment programs to develop skills and improve living conditions for low skilled workers (e.g. trust funds for training, sponsorship of community needs, development of alternative land uses). Namibian companies are required to preferentially employ Namibian citizens and purchase Namibian goods and services. Some companies have taken initiatives with small contractors to expand shallow water operations. Socio-Economics: Negative aspects Impact Mitigation Shifting emphasis from Onshore to An ongoing shift in emphasis from onshore to offshore mining is leading to escalating Alternative land-use options and training initiatives Offshore Mining unemployment in coastal towns in RSA and Namibia because of reduced low-skilled are being promoted and/or investigated. labour requirements. Revenue from offshore mining reaching local areas is much reduced compared with onshore mining as the larger vessels are supplied and serviced from a few large urban centres (e.g. Cape Town and Lüderitz). Involvement of small scale miners Opportunities for involvement of small scale miners in the diamond industry has been Mechanisms are being introduced to facilitate entry very limited owing to limited access to finance, technical skills and poor security. by small-scale miners (e.g. improved access to funding and technology).
Allocation of mining revenue to Tax revenue from mining concerns in RSA and Namibia is generally fed into a Financial and service inputs are being redirected by mining areas central revenue fund and is not necessarily re-invested in local districts. This has government and industry to upgrade facilities and resulted in diamond mining areas exhibiting retarded growth and poor infrastructure. capacities of affected towns. Conflict with the fishing industry Animosity exists between rock lobster fishermen in RSA and Namibia, and the Fora and committees are being established in RSA diamond mining industry whom they hold responsible for declining catches. and Namibia to resolve conflicts between major stakeholders. Foreclosure on future land use Mining activities tend to scar the landscape and can potentially impact future land use Laws in RSA and Namibia now require the options options long after mining ceases (e.g. tourism). rehabilitation of terrestrial mining areas.
Loss of cultural resources Mining operations have the potential to disturb both terrestrial and marine Archaeological surveys are now generally archaeological sites including shell middens and ship wrecks. commissioned before new areas are mined. Biophysical Environment: Positive Aspects Impact Defacto reserve status of mining Access to mining areas is highly restricted for security reasons with the result that areas human disturbance of terrestrial and nearshore areas by means other than mining is minimal. Biophysical Environment: Negative Aspects Impact Mitigation Terrestrial mining activities Terrestrial mining in the coastal zone has numerous impacts including scarring of the Mitigation is principally through rehabilitation of landscape, and the production of sediment plumes which can impact terrestrial and prospected and mined areas and through discharging aquatic communities. fine tailings into slimes dams. Beach mining activities Seawalls, constructed to permit ‘terrestrial’ access to diamond deposits in the subtidal, Using material for seawall construction that is result in physically altered shorelines and severe impacts on sandy and rocky shore equivalent to that which is stripped from the shore fauna. allows for a more rapid recovery of affected communities. Shallow water (<30 m) mining Access to the shore by shore-based operators requires roads, camps and often rock In-water mining needs to be limited to boat based cuts. operations only. Nearshore pumping has numerous impacts on benthic communities including the Tailings must be dumped away from rocky reef areas creation of sediment plumes, smothering of reef with discharged tailings, destabilising and boulder movements need to be kept to a gravel beds, physical disturbance by pipes, moving of boulders and kelp cutting by minimum. Restrictions have been placed on the divers to provide unencumbered access to mining sites. width of lanes cut, clear-cutting and/or repeated cutting. Mid-Water and Deep-Water Mining Fine tailings material remains in suspension for long periods and can impact No mitigation. (>30 m) phytoplankton, fish and marine mammals through light reduction, nutrient enrichment, remobilization of contaminants, clogging of fish gills and reducing oxygen levels. Mining process impacts benthic fauna by disturbing sediments, smothering and Suggested mitigation includes leaving lanes of aggravating oligoxic conditions on the sea floor. undisturbed sediments between mining areas.
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7. DIAMOND MINING IN THE BCLME – TOWARD INTEGRATED ENVIRONMENTAL MANAGEMENT
The Integrated Environmental Management philosophy, encompassing scoping, impact assessments and environmental management plans, is a large step toward the integrated environmental management of activities affecting the BCLME. Environmental concern, however, has had a recent birth, and the processes and mechanisms of environmental management are still evolving. The current model is good, but a few criticisms are warranted to take the environmental management of diamond mining in the BCLME into the future. Criticisms of socio-economic, biophysical and environmental management as a whole are discussed below.
7.1 Socio-economic Environmental Management EMPRs completed to date are deficient in their attention to socio-economic impacts, and in defining appropriate measures to mitigate or optimise these effects. In many instances, the discussion of socio- economic impacts focuses on the positive impacts of the mining venture only, such as employment creation, and a brief discussion of the economic spin-offs for the local economy (without expanding on predicted local expenditure). Management actions to address the negative socio-economic impacts of mining, such as problems associated with influx of job seekers and the infrastructural and service capacity of the affected towns and their capacity to support mining activities, are seldom considered in any detail. Furthermore, EMPRs rarely set management targets or goals for example, for implementing affirmative action, and the purchase of goods and expenditure in local communities from small micro- enterprises. Mining companies are reluctant to commit themselves to these kinds of policies, which can be audited.
Blame for shortcomings in environmental management cannot only be levelled at the companies concerned. There is a need for the governments of the respective countries to create incentives and to provide appropriate guiding legislation. Perhaps the most pressing requirement in this regard, is the need for the governments of Namibia and South Africa to redress their policies on the allocation of diamond mining revenues. Consideration should be given to investing a certain proportion of annual revenues to the areas which support diamond mining in order to upgrade infrastructure, stimulate development and create employment for local residents, especially in anticipation of continued downscaling of onshore diamond mining. Incentives such as tax breaks should be considered to encourage companies to purchase a greater proportion of goods and services from local entrepreneurs.
7.2 Biophysical Environmental Management Many environmental impact studies undertaken to date have been speculative desktop assessments, or conducted after-the-fact. In most cases, pre-mining baseline data were lacking or inadequate, which preclude detailed assessments of changes to the biophysical environment attributable to diamond mining. In an ecosystem where natural heterogeneity in the biophysical environment is commonplace, a great deal of uncertainty therefore remains concerning the extent and significance of the damage caused by mining activities. For example, despite considerable desktop effort devoted to rock lobsters, conflicts arise time and again because speculation is not defensible. Directed field studies that recently been completed are helping to clarify this issue, however.
A further shortcoming of many environmental impact studies is that most studies are addressed at either a high taxonomic level, or at the level of the community. For example, the effects of diamond mining have been examined with respect to benthic communities, sea birds, fish, mammals, etc. When considered as a group, more often than not the conclusions reached are that impacts are minimal. Some species, however, may be neglected through such an approach and there are cases where mining may in fact detrimentally impact specific components of the community. This is not insignificant, especially if the species in question are rare, endangered, or perhaps of commercial value. For example, beach communities as a whole are considered resilient to disturbance. However, there is considerable body of circumstantial evidence that suggests one component of beach communities is particularly susceptible to diamond mining: the semi-terrestrial isopod Tylos granulatus. Human impact on Tylos is so widespread, in fact, that it is being considered for inclusion as a Red Data Book species. This animal warrants further attention.
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7.3 Environmental Management as a Whole Cumulative impacts are an important, although a largely ignored issue both within and between the various users of the BCLME. Between industries, environmental management is most often conducted in isolation. That is to say that the EMPRs of diamond mining companies examine the effects of diamond mining, those for oil and gas exploration likewise only examine their own direct impacts, and so on. In an ecosystem such as the BCLME that has a myriad of users, isolated approaches may fail to uncover possible cumulative effects between industries that could ultimately lead to environmental catastrophe. With increasing pressure on the BCLME from fishing interests, oil and gas exploration, diamond mining, coastal shipping and recreational use, there is a dire need for an integrated and co-ordinated approach to the management of activities affecting this ecosystem.
On the other hand, cumulative impacts within the mining industry are also largely ignored. Impacts such as kelp cutting, disturbance to the benthic communities, and habitat modification, for example may act in synergy, although thus far these impacts have only been considered in isolation. Together, they may have chronic, acute or even beneficial impacts on the natural environment and these need to be further investigated through focused and scientifically valuable research and monitoring programmes. Such monitoring programmes will enable quantification of cumulative impacts in space and time, in relation to environmental and resource sustainability. The importance of cumulative impacts become all the more pervasive in an expanding and technologically advancing mining industry.
Environmental Management Programmes should be dynamic documents, being updating as mining methodologies or plans change, or as new environmental information becomes available. This is a side to EMPs that is not often seen. The plethora of monitoring activities have little value if the results of monitoring are not objectively evaluated and likewise incorporated within existing management programmes. Part of the problem is attributable to the insular approach to environmental management that has been adopted, which leads to considerable duplication in scoping, impact assessments, specialist studies and management plans. In addition to a waste of resources, information that is collected is rarely disseminated, with the result that mistakes can, and often are, repeated. As the problems faced by the mining industry are largely ubiquitous through the region, considerably more effort must be channeled into two activities: objective reviews of the information to date, and a means of consolidating directed research and monitoring.
The criticism levelled above becomes all the more pervasive when the future of marine diamond mining, and coastal and marine use as a whole, is considered. At present, the vast majority of diamond mining is terrestrial based, with marine mining enjoying only a small proportion of the effort. Numerous coastal mines are set to close over the next 10 to 20 years and future diamond mining effort is likely to expand into the offshore. Concomitantly, the stage is set to see an increase in effort in both fishing, and oil and gas exploration (see other documents in this series). Almost without question, this will lead to an increase in the number and severity of conflicts between these sectors, as the natural resource base is finite and shrinking, under pressure from an increasing number of users. This makes the need for co-ordinated efforts taking a holistic approach to environmental management all the more important.
7.4 Conclusions – The Way Forward Environmental management of the marine diamond mining industry in South Africa and Namibia, although very much in its infancy, has made major progress. A considerable volume of baseline information, albeit at a fairly coarse scale, has been collected and is available for use in the management of the system. Most of the major biophysical impacts of the mining activities on the environment have been addressed and, wherever feasible, appropriate mitigation measures have been implemented. The total area of the marine environment affected per annum by the diamond mining industry as a whole remains relatively small relative to what is available. Thus, whilst some of the impacts of mining may appear very severe in terms of the local environment, these must be placed into perspective on a larger geographical scale. In terms of the biophysical environment, several issues still require attention, with cumulative impacts of mining coupled with those of other users, as well as selected single species studies being the most pressing.
Perhaps the most significant step toward an integrated approach to the management of the environment is the establishment of fora as a means of fostering communication, education and securing funding. In Namibia, the Lüderitz Forum was established to tackle issues affecting all users of the marine environment and Lüderitz town. The Forum comprises representatives of local and national government (e.g. Ministry of Mines and Energy, the Ministry of Fisheries and Marine Resources), and the fishing and mining industry. A liaison committee is soon to be established for the West Coast region in the South Africa on which various industries
Overview of Diamond Mining in the BCLME 55 Anchor Environmental Consultants and other coastal users will be represented. Another positive initiative has been the formation of the South African and Namibian Marine Diamond Mining Associations. The former association has recently adopted a coordinated approach to environmental management through the development of a Generic Environmental Management Programme. A consolidated environmental baseline report on the environment of the South African west coast B, C and D concession areas was compiled in late 1997, and is to be followed shortly by a baseline report for the A concession areas and a generic EMPR for all four zones. Such initiatives must be commended.
In Angola, however, marine diamond mining is very much still in its infancy. Few, if any, serious initiatives have been undertaken towards sustainable exploitation of the mineral resources in this country. While it is good to think that much of the experience gained and many of the lessons learned in South Africa and Namibia will put this country in good stead for the future, several major stumbling blocks remain. Decades of civil war and continued political instability have stifled the development of local expertise and prevented access by foreign scientists. Consequently, there is little information available with regard to basic knowledge of biological and ecological functioning of systems in this country. Much of the country lies within subtropical and tropical areas and most of the information gathered regarding the consequences of mining in temperate ecosystems of South Africa and Namibia will be of little value. In this regard, desktop approaches will be all but meaningless, necessitating more costly field-based approaches in order to establish meaningful baselines on which comprehensive impact assessments can be based.
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8. BIBLIOGRAPHY
BARKAI, A. and M.O. BERGH, 1992. The effect of marine diamond pumping operations on the littoral and shallow sublittoral benthos along the South African west coast, Namaqualand region, with special attention to possible effects on the rock lobster resource: a pilot study. Report to Marine Diamond Mining Association (MDMA), pp 43. BARKAI, A. and M.O. BERGH, 1996. Marine diamond mining along the southern Namibian coastline: possible impacts on, and conflicts with, the local rock lobster fishery. Report for the Namibian Ministry of Fisheries and Marine Resources, pp 30. CARTER, R., LANE, S. and P. WICKENS, 1998. Towards responsible environmental management for marine diamond mining in South Africa. First Regional Workshop on the BCLME, Cape Town, South Africa, 22-24 July 1998. CENTRE FOR MARINE STUDIES, 1994. Desktop study considering potential impacts of bulk sampling and mining for diamonds by Arena Mining (Pty) Ltd. CENTRE FOR MARINE STUDIES, 1996. Monitoring of tailings plume for Arena Mining (Pty) Ltd in Licence Blocks 1946and 1950, Namibia. Clark, B.M., C.E. Smith & W.F. Meyer 1998. Ecological effects of fine tailings disposal and marine diamond pumping operations on surf zone fish assemblages near Lüderitz, Namibia. AEC Report # 1009/2, 45 pp. CORBETT, A. 1989. Diamond Beaches: A History of Oranjemund 1928-1989. A. Corbett, Cape Town. CSIR, 1988. Elizabeth Bay production facility: environmental impact study. Volume 2: Technical report. CSIR Report EMA-C 8887/2. CSIR, 1985. A preliminary report on the environmental implications of mining operations at Oranjemund. CSIR C/SEA 8501. CSIR, 1991. Elizabeth Bay monitoring project 1990 review. CSIR Report EMA-C 91126. CSIR, 1991. Environmental study: diamond mining activities – Olifants River estuary and surrounding areas. CSIR Report EMA-C 9184. CSIR, 1992. Inshore mining project review (1985-1990). CSIR Report EMAS-C 92018. CSIR, 1992. Elizabeth Bay monitoring project 1991 review. CSIR Report EMA-C 92039. CSIR, 1993. The composition and dynamics of turbid seawater at Elizabeth Bay. CSIR Report EMA-C 93004. CSIR, 1993. Elizabeth Bay monitoring project 1992 review. CSIR Report EMA-C 92004 CSIR, 1994. Elizabeth Bay monitoring project 1993 review. CSIR Report EMA-C 92059. CSIR, 1994. Alexkor environmental management programme. Vol. 1. Key Issue Scoping Report. CSIR Report EMAS-C94037(1). CSIR, 1994. Alexkor environmental management programme. Vol. 2. Specialist Studies Report. CSIR Report EMAS-C94037(2). CSIR, 1994. Alexkor environmental management programme. Vol. 3. Environmental Management Programme Report. EMAS-C94037(3). CSIR, 1995. Elizabeth Bay monitoring project 1994 review. CSIR Report EMA-C 92063. CSIR, 1995. Environmental impact assessment for the proposed mining of concession area M46/3/1607 off Lüderitz Bay: Namibia. CSIR Report EMAS-C95040b. CSIR, 1996. Elizabeth Bay monitoring project 1995 review. CSIR Report ENV/S-96066.
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CSIR, 1996. Environmental Impact Assessment for Marine Diamond Mining in the Namibian Islands Concession. CSIR Report EMAS-C96023. CSIR, 1997. Elizabeth Bay monitoring project 1996 review. CSIR Report ENV/S-97153. CSIR, 1997. Environmental Management programme report for marine diamond mining in the Namibian Island concession. CSIR Report ENV/S-C 97103. CSIR, 1998. Elizabeth Bay monitoring project 1991 review. CSIR Report ENV/S-98049. CSIR and SUE LANE & ASSOCIATES, 1997. Consolidated environmental baseline report: South African West Coast marine diamond B-D concession areas. CSIR/SLA Report MD-97/001. DAMARUPURSHAD, A.K. 1997. Review of Selected Commodities: Precious Metals and Minerals. Annual Report of MME 1997/8 DE BEERS MARINE 1998. Environmental Management Programme Report for De Beers Marine’s Deep-Sea Diamond Mining Operations in South African Concessions 2c, 3c, 4c, 5c, 7c, 8c, 9c, 10c, 12c & 8d. DEPARTMENT OF MINERALS AND ENERGY, 1992. Aide-Memoir for the Preparation of Environmental Management Programme Reports for Prospecting and Mining. DEPARTMENT OF MINERALS AND ENERGY, 1996. Standard environmental Management Programme for prospecting and/mining of precious stones in the (a) concession area and surf zone. Document A. General information, project description, description of the environment, environmental impact assessment and exemptions. DEPARTMENT OF MINERALS AND ENERGY, 1997. Guidelines for the preparation of an Environmental Management Programme Report (EMPR) for prospecting for and mining of offshore precious stones. CTD Book Printers, Parow. DEPARTMENT OF MINERALS AND ENERGY, 1997. Document B. Infrastructural requirements and operating procedures. ENVIRONMENTAL ADVISORY UNIT, 1993. A preliminary assessment of the effects of the diamond recovery boats on gill net catches of harders in the Olifants River estuary. EAU Report 01/93/01. ENVIRONMENTAL EVALUATION UNIT, 1992. Closure of De Beers Diamond Mines in Namaqualand. Report by S. F. Brownlie. ENVIRONMENTAL EVALUATION UNIT, 1994. Desktop study considering some potential impacts of diamond mining by De Beers Marine (Pty) Ltd. Report prepared for the EEU by the Centre for Marine Studies. ENVIRONMENTAL EVALUATION UNIT, 1996. Impacts of Deep-Sea Diamond Mining, in the Atlantic 1 Mining Licence Area in Namibia, on the Natural Systems of the Marine Environment. EEU Report No. 11/96/158, University of Cape Town. Prepared for De Beers Marine (Pty) Ltd. 370 pp. GRINDLEY, S. & A. MACKENZIE. 1993. An initial assessment of the Tormin Beach Mining Project on the Cape west coast. Environmental Evaluation Unit, University of Cape Town, 49 pp. LAIN, M. 1996. Prospecting and sampling: Namdeb’s lifeline into the future. EwiNamdeb 2nd Quarter 1996, Namdeb Diamond Corporation (Pty) Limited, Namibia. MCLACHLAN, A. and A.M.C. DE RUYCK. 1993. Survey of sandy beaches in diamond area 1. A report to Consolidated Diamond Mines, Oranjemund, Namibia. Unpubl. report. MCLACHLAN, A., R. NEL, A. BENTLEY, R. SIMMS and D. SCHOEMAN. 1994. Effects of diamond mine fine tailings on sandy beaches on the Elizabeth Bay Area, Namibia. Unpubl. contract report to CDM. MEYER, W.F., EWART-SMITH, C., NEL, R. and B. M. CLARK 1998. Ecological Impact of Beach Diamond Mining on Beach, Rocky Intertidal and Surf Zone Biological Communities in the Sperrgebiet,
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Namibia. Phase 1 – Baseline Surveys. AEC Contract Report #1011/2. 77 pp. MINING JOURNAL RESEARCH SERVICES. 1997. Namibia: Abundant Exploration Opportunities. Advertisement Supplement to Mining Journal 329 (8450): 16 pp. MURRAY, R. 1993. Mineral Investment in Namibia. Mining Research Services, London. 107 pp. NAMDEB DIAMOND CORPORATION (PTY) LTD. 1997. Environmental Management Programme Report. Vol. 6. Atlantic 1 Licence Area (Licence No. 47). NAMDEB DIAMOND CORPORATION (PTY) LTD. 1997. Mining Area 1 Licence Area: Environmental Management Programme Report. OPPENHEIMER, E. 1955. History of Namaqualand Diamond Fields 1925-1955. E. Oppenheimer & Son, Johannesburg. O’SHEA, D. O’C. 1971. An Outline of the Inshore Submarine Geology of Southern South West Africa and Namaqualand. M.Sc. Thesis, Geology Department, University of Cape Town. 94 pp. PALLET, J. 1995. The Sperrgebiet: Namibia’s Least Known Wilderness. DRFN & NAMDEB, Windhoek, Namibia PARKINS, C.A. and G.M. BRANCH, 1996. The effects of diamond mining on the shallow subtidal zone: An assessment of the Elizabeth Bay fine-tailings deposit, and contractor diamond divers, with special attention to the rock lobster, Jasus lalandii. Final Report to NAMDEB (Pty) Ltd. December 1996. PULFRICH, A and A. PENNEY, 1998. Assessment of the impact of diver-operated nearshore diamond mining on marine benthic communities in the Zweispitz area, Namibia. Report to NAMDEB Diamond Corporation (Pty) Ltd. SCHNEIDER, G.I.C., 1998. Diamond mining off the coast of Namibia and the marine environment. First Regional Workshop on the BCLME, Cape Town, South Africa, 22-24 July 1998. SCHNEIDER, G.I.C. & R. MILLER, 1998. Did nature compensate Namibia with diamonds? Namibia Review 7(3): 1-11. SUE LANE & ASSOCIATES, 1998. March 1998 review for DFI of CSIR Report EMAS-C95040b: Environmental impact assessment for the proposed mining of concession area M46/3/1607 off Lüderitz Bay: Namibia (Dated November 1995). SUE LANE & ASSOCIATES, 1996. Environmental assessment and management plan report for deep sea diamond mining in Namibia by Arena Mining (Pty) Ltd. October 1996. TOMIN, B.J. 1993. Migrations of spiny rock lobsters, Jasus lalandii, at Lüderitz : Environmental causes, and effects on the fishery and benthic ecology. M.Sc Thesis, University of Cape Town, pp. 1-99. WICKENS, P. & S. LANE. 1997. Deep sea investigations. Mining Environmental Management, December 1997, p7-10. WILLIAMS, R. 1996. King of Sea Diamonds. The Saga of Sam Collins. W.J. Flesch & Partners, Cape Town
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9. PEOPLE CONSULTED
South Africa Sue Lane: Sue Lane & Associates Lionel Philips, Alexkor, Alexander Bay Louis Luke, DMNM Human Resources Manager, Kleinsee Patti Wickens, De Beers Marine, Cape Town Andy Grills, De Beers, Namaqualand Jeremy Midgely and Romaine Kotze, Nautical Diamonds/Arena, Cape town Piet Slot-Nielsen, Transhex, Die Punt, W.Cape Mr Agenbag, Minerals Development, DME, Cape Town Mr A. Eager, Communications Dept., Minerals Bureau, Pretoria Ms.N. Botha, Statistics, Minerals Bureau, Johannesburg Mr A. Damarupurshad, Mineral Commodity Specialist, Minerals Bureau, Pretoria Ms. E. Swart, DME (Environmental Policy aspects), Pretoria Mr van Rensburg, N.Cape DME, Kimberley Mr. P. Schroeder, Ocean Diamond Mining South Africa Ltd West Coast District Council
Namibia Colleen Parkins, Environmental Officer, NAMDEB Mr JJ Dohogne, Directorate of Environmental Affairs, Windhoek Dr G. Schneicer, Director of Geological Survey, Ministry of Mines and Energy, Windhoek Mr G. McGregor, Commissioner of Mines, Ministry of Mines and Energy, Windhoek Mr W. Malango, Acting Director of Mines, Ministry of Mines and Energy, Windhoek Dr. AE Macuvele, Ministry of Mines, Windhoek
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BENGUELA CURRENT LARGE MARINE ECOSYSTEM
INTEGRATED OVERVIEW OF FISHERIES OF THE BENGUELA CURRENT REGION
November 1999
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BENGUELA CURRENT LARGE MARINE ECOSYSTEM
INTEGRATED OVERVIEW OF FISHERIES OF THE BENGUELA CURRENT REGION
A synthesis commissioned by the United Nations Development Programme (UNDP) as an information source for the Benguela Current Large Marine Ecosystem (BCLME) Programme
Authors I. Hampton 30 Jeffcoat Ave., Bergvliet 7945, South Africa
D. C. Boyer National Marine Information and Research Centre, Ministry of Fisheries and Marine Resources, P.O. Box 912, Swakopmund, Namibia
A.J. Penney 22 Forest Glade, Tokai 7945, South Africa A.F. Pereira c/o BENEFIT Secretariat, Ministry of Fisheries and Marine Resources, P.O.Box 912, Swakopmund, Namibia
M. Sardinha Institute de Investigação Pesqueira, Ministerio das Pescas, Ilha de Luanda, C.P. 83, Luanda, Angola
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EXECUTIVE SUMMARY
This Report gives an overview of the major living resources of the Benguela Current Ecosystem, and of the research which has been conducted on them by the three countries bordering the system (Angola, Namibia and South Africa) and foreign partners, as input to management of these resources. It treats the resources on a regional basis, and highlights trans-boundary problems which need to be addressed through a regional rather than a national approach. The report amplifies and updates recent summaries of scientific information on the resources, and adds material on the legal framework and structures under which they are managed in each of the three countries.
The distribution and habitats of the major species exploited by the purse seine, trawl, crustacean, linefish and artisanal fisheries of the region, and of the seal and main seabird populations, are briefly described and discussed with particular reference to questions of stock separation and the connection between apparently different populations. It is pointed out that a number of commercially- important species (e.g. hake, horse mackerel, deep-sea red crab, tuna and, probably to a lesser extent, sardine and anchovy) are distributed or move seasonally across national boundaries, requiring regional compatability in the research and management of these resources.
The life histories of the major exploited species are briefly outlined, with emphasis on temporal and spatial spawning patterns, the dispersal of the early- life stages, migration patterns of recruits and adults, and diet (particularly as it relates to potential competition between species). The broad picture to emerge is that the important offshore resources in the southern Benguela spawn over various parts of the Agulhas Bank, and depend to a greater or lesser extent on the equatorward jet current between Cape Point and Cape Columbine to transport the early life stages to the West Coast, where much of the recruitment takes place. Pelagic recruits return to the Agulhas Bank in the poleward counter current close to the coast. Species which become more demersal with age (e.g. hake and horse mackerel) tend to move into deeper water as they move south in the early stages, resulting in complex movements between the West and South Coasts and more widespread spawning areas. In the northern Benguela, spawning of many of the important species is concentrated in northern Namibia/southern Angola, and is probably influenced by movements of the Angola-Benguela front. Juveniles spawned in this area tend to move south close to the coast and to return northwards farther offshore when older.
The history and current status of the major fisheries of the region are discussed, concentrating on catch trends and changes in the nature of the fisheries. Over the past 30 to 40 years total catches in the south-east Atlantic have declined from a peak of more than 3 million tonnes in 1968 to levels of around 1 million tonnes per year in the 1990s. The most pronounced features in Namibia and South Africa have been the major decline in catches of South African and Namibian sardine in the mid- and late 1960s respectively (followed by a dramatic
3 Anchor Environmental Consultants further decline in Namibia in the mid-1970s), the major decline in the West Coast rock lobster resource (particularly off Namibia) to levels well below those in 1960, and the major reduction in hake and horse mackerel catches off Namibia in the 1990s, due largely to the withdrawal of foreign fishing fleets after Independence in 1990. Off Angola, the most notable feature is the sharp reduction in industrial catches of all the most important species (e.g. sardinellas, horse mackerel and deep-water prawns), due largely to the major reduction in foreign fishing effort from 1985 onwards.
Changes in the abundance and distribution of the major resources, including seals and seabirds, as revealed by acoustic, trawl and aerial surveys and catch- based analytical methods, are discussed. VPA estimates confirm the dramatic decline of Namibian sardine in the late 1960s and the subsequent further sharp decline in the mid-1970s. Acoustic surveys since 1990 show that the population dropped to its lowest ever level in 1995 (co-incident with a major Benguela Niño in the northern Benguela), but that it has recovered somewhat since then. Acoustic surveys of sardine and anchovy in South African waters indicate that there has been a gradual increase in sardine abundance since the mid-1980s (although probably not to pre-collapse levels), and show two cycles in anchovy spawner biomass, with peaks in 1986 and 1991. The distribution of Namibian sardine has moved northwards as the population has declined, an extreme being reached in 1994, when sardine were only found north of the Cunene River, in Angolan waters. Likewise, there has been a major shift in the distribution of sardine in South Africa since the 1960s; the core of the distribution of adults having shifted from the West Coast to the South Coast. Acoustic surveys off Angola indicate that, in the 1990s, the biomass of both sardinella and Cunene horse mackerel has roughly doubled compared to the 1980s. Recent swept-area estimates of hake abundance in both Namibia and South Africa indicate that these populations are relatively stable at present, and there is some evidence that they could be gradually increasing. An interesting trend has been the increase in the abundance of Merluccius paradoxus in Namibian waters since 1992, which may indicate recent expansion or northward displacement of the M. paradoxus population from the South African West Coast. Acoustic and trawl survey estimates of adult horse mackerel in Namibia and South Africa over the past decade do not reveal any pronounced trends apart from a roughly 3-fold increase in the biomass on the South African West Coast since 1991. It is evident from CPUE indices that the abundance of line-caught species in South Africa has declined over the past few decades, to almost zero in some cases. As a result, the distributional ranges of many of these species has contracted, and the magnitude and extent of their migrations has declined. Aerial censuses reveal that the Namibian seal population was roughly halved by the effects of the 1993-1994 extreme anoxia events in the northern Benguela, from which the population now appears to have almost recovered. Aerial censuses have also revealed long-term reductions in the numbers of Cape gannets and Cape cormorants on the West Coast of southern Africa since the 1960s, and continuing declines in numbers of African penguins.
A number of major effects of the environment on the distribution and abundance
4 Anchor Environmental Consultants of commercially important resources in recent years are discussed. The most dramatic of these was the wide-scale advection of low-oxygen water into the northern Benguela from Angola in 1993 and 1994, and the subsequent Benguela Niño of 1995, which appears to have severely affected the Namibian sardine population, and its major predators (particularly seals), and to have directly or indirectly increased mortality of juvenile hake on the Namibian shelf.
The present socio-economic value of the region’s fisheries to Angola, Namibia and South Africa is outlined. Their national importance and the balance between the various sectors (industrial, artisanal, recreational etc.) varies considerably between the three countries. The fisheries sectors in Angola and Namibia rank high in national importance, for local food production in the case of Angola, and in Namibia for exports from the industrial fishery, which are worth over 1,35 billion N$ (approx. 225 million US$) per year at present. In both countries the sector is an important source of employment, which is largely informal in the case of Angola, and formal in Namibia. In South Africa, while the fishing industry is relatively unimportant nationally, exports rival those of Namibia, and the industry is an important source of revenue, food and employment in coastal areas, particularly in the Western Cape Province, which yields 80 - 90% of the total South African marine fish catch. Artisanal fisheries are currently of relatively little importance in South Africa, but the recreational fishery for linefish is large and varied, and directly or indirectly generates revenue and employment opportunities which probably exceed those of the industrial fishery.
The broad national policies, legislation and formal structures for managing marine living resources in Angola, Namibia and South Africa are sketched, and the institutional capacity for research and management (including donor support) in each of the three countries is outlined. Current regional marine research programmes such as BENEFIT are briefly outlined, and other international and regional agreements pertaining to management of the region’s marine resources are listed. Recent and current methods used to assess the size of the major resources in each of the three countries are described in broad detail, and the methods used to manage them discussed.
Major gaps in current knowledge of the region’s resources and threats to their rational management are discussed, with particular attention to trans-boundary issues, which are seen to be notable for hake, horse mackerel, sardine, anchovy and crab stocks. The major general scientific problems are seen as inadequate understanding of stock definition (particularly for shared or migratory stocks), inaccurate or non-existent information on basic biological characteristics (particularly age structure) for many of the harvested species, inadequate absolute estimates of population size and of trends in biomass, the lack of Operational Management Procedures based on population models for many of the resources, and the inability to predict the effects of environmental perturbations on resource dynamics with sufficient confidence for this information to be used in national or regional management. In most cases these problems are particularly severe in Angola and, to a lesser extent, in Namibia. It is noted that the root cause of many of the trans-boundary management problems is the
5 Anchor Environmental Consultants lack of regional agreements and structures for research and management of shared resources, and the shortage of manpower and funds to undertake trans- boundary surveys and other related research activities.
Finally, particular scientific and operational problems in Angola, Namibia and South Africa are discussed on a national basis. In Angola, where resources and their environment have been significantly less studied than elsewhere in the region, there are limited data series for retrospective analyses, large deficiencies in the understanding of fundamental life history characteristics of commercially important species, and no population models on which to evaluate management options. Catch and effort statistics are unreliable, and fisheries regulations are difficult to enforce owing to the extended coastline and small corps of compliance officials. Research capacity is limited because of the small number of people involved and the lack of appropriate local educational facilities. Most importantly, the breakdown of basic services and infrastucture as a result of the protracted civil war, and the severe macroeconomic problems in the country at present seriously inhibit development of local capacity in all spheres. In Namibia, the chief scientific challenges are the development of population models and Operational Management Procedures which would enable alternative harvesting strategies for the major fisheries to be formally evaluated, and the finding of objective ways of including environmental information into management decisions. A major operational constraint is the severe shortage of scientific and particularly technical staff within the Ministry of Fisheries and Marine Resources for the large number of resources which have to be studied, a problem exacerbated by the need for local staff to spend extended periods abroad for further education. In South Africa, the nation’s strong capacity in marine science is being threatened by a reduction in research funding, which has led inter alia to difficulties in maintaining even essential resource-monitoring surveys, and strict curtailment of environmentally-orientated cruises. Loss of senior research and management staff as a result of moves to reduce the size of the Public Service has resulted in a loss of experience and a greater load on remaining staff, which is likely to be aggravated by added responsibilities under the new Marine Living Resources Act.
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CONTENTS
Executive Summary 3
1. Introduction 9
2. Occurence and Stock Identity 12
Small pelagic fish 12 Trawled fish 13 Crustaceans 16 Line-caught species 16 Seals and seabirds 18
3. Life History of Major Resources 19
3.1 Small pelagic fish 19 3.2 Trawled species 22 3.3 Crustaceans 26 3.4 Line-caught species 27 3.5 Seals and seabirds 28
History and Current Status of the Fisheries 29
Purse seine fisheries 30 Trawl fisheries 34 Crustacean fisheries 37 Commercial linefisheries 38 Artisanal/subsistence fisheries 40 Recreational fisheries 40
Changes in Abundance and Distribution of Major Resources 41
Pelagic resources 41 Trawled species 44 Crustaceans 48 Line-caught species 48 Seals and seabirds 49
Effects of the Environment on Distribution and Abundance 52
Pelagic resources 52 Trawled species 54 Crustaceans 55 Line-caught species 55 Seals and seabirds 55
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Socio-economic Importance 56
Management 61
Policy and legal framework 61 Research and management capacity 63 International and regional agreements and conventions 67 Management measures for major resources 68
Research Gaps and Threats to Management 75
Acknowledgements 80
11. References and Other Literature 81 12. Acronyms 91
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1. INTRODUCTION
The Benguela Current Ecosystem can be loosely considered as covering the continental shelf between the Angola-Benguela frontal zone in northern Namibia/southern Angola and the Agulhas retroflection area, typically between 36 and 37 oS (Shannon and O’Toole 1998). As such, it covers the West Coast of South Africa, the entire Namibian coast, and southern Angola (Fig. 1) to an extent depending on the position of the Angola-Benguela front, which moves seasonally typically between 14 and 17 oS.
Fig. 1 Southern Africa, showing the 200m isobath, considered here to delimit the continental shelf
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The Benguela Current is one of the world’s major eastern-boundary current systems, and is rich in pelagic and demersal fish populations, supported by plankton production driven by intense coastal upwelling. These populations have been heavily exploited by man, particularly since the Second World War. Total fish catches in the south-east Atlantic climbed rapidly during the 1950s and 1960s, with the development of hake, sardine, anchovy, horse mackerel and sardinella fisheries (Fig. 2), and a valuable fishery for rock lobster in both Namibia and South Africa. The total annual catch peaked at over 3 million tonnes in 1968, but it subsequently declined to a level of around 2 million tonnes in the 1970s. This was largely attributable to major declines in sardine catches off both Namibia and South Africa, which were only partly compensated by increased (largely foreign) catches of hake and horse mackerel off Namibia. Total annual catches in the region subsequently dropped further to around 1.2 million tonnes in the 1990s, with a further sharp decline in catches of Namibian sardine in the second half of the 1970s, and the cessation of foreign trawling for hake and horse mackerel off Namibia after her independence in 1990. Since the 1960s there has also been a dramatic decrease in rock lobster catches, particularly off Namibia, where catches are now some two orders of magnitude below their peak in the 1960s. It is believed that most of these declines have been due to overfishing, although some of the major fluctuations have probably been influenced to a greater or lesser extent by the large-scale environmental perturbations that have occurred periodically in the system during this period (Shannon and O’Toole 1998).
3 Total
2,5
Hakes 2
Chub mackerel 1,5 and snoek Horse mackerels
1 Round herring
0,5 Sardine Anchovy
Sardinella 1950 55 60 65 70 75 80 85 90 92 94 96 98
Fig. 2 Cumulative catches of the principal harvested species in the
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south-east Atlantic from 1950
This overview gives a brief description of the major living resources of the Benguela Current, and of the attempts that have been made, particularly in recent years, to manage them rationally and sustainably in each of the three countries bordering the system. It treats the fisheries regionally rather than nationally, and builds on material already presented in the regional Benguela Environment Fisheries Interaction and Training (BENEFIT) Programme Science Plan (Shannon and Hampton 1997), with particular emphasis on work carried out since the production of that document. References have largely been kept to recent key publications, and to a number of general articles from the region, wherein further references may be found.
For the purposes of this overview, the Benguela ecosystem has been defined somewhat more widely than its physical limits, to include the extremities of the warm water systems which bound it on both sides. This is necessary, because some of the major resources of the Benguela spend a significant part of their lives outside the system boundaries, and are strongly influenced by interactions between the cool waters of the Benguela and the warm water of the Angola and Agulhas Currents.
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2. OCCURENCE AND STOCK IDENTITY
2.1 Small pelagic fish
The major fisheries for small pelagic fish off the west coast of southern Africa are those for sardine Sardinops sagax (also known as pilchard), anchovy Engraulis capensis, juvenile Cape and Cunene horse mackerel (Trachurus trachurus capensis and T. trecae respectively), round herring Etrumeus whiteheadi, and the round and flat sardinella (Sardinella aurita and S. maderensis respectively), which are fished almost exclusively by Angola.
Sardine and anchovy live in temperate waters from southern Angola to KwaZulu- Natal in South Africa, with both species co-existing as quasi-discrete stocks off northern/central Namibia and off the Western Cape (i.e. between Cape Point and the Orange River). The degree of mixing between the southern and the northern populations of these species is unknown, but considering that the populations spawn in different, widely separated areas and are separated by a large, perennial area of cold, upwelled water off Lüderitz, it is probably not significant for management purposes, except in anomalous years. The round herring occurs over a similarly wide latitudinal range, but it appears to be most abundant east of Cape Point, particularly over the Central and Eastern Agulhas Bank. Most of the round herring caught in Namibian waters are juveniles, taken inshore as a small by-catch in the purse seine fishery. Although adults are occasionally taken farther offshore by bottom and midwater trawlers, the adult stock off Namibia is thought to be small compared to that farther south. Interaction between these stocks is probably of little consequence for management.
Juveniles of Cape horse mackerel (i.e. fish < about 20 cm) are most commonly found off the west and south-west coasts of South Africa, and off northern Namibia/southern Angola, south of the Angola/Benguela front. These fish are believed to originate from separate spawning stocks off South Africa's South Coast and northern Namibia respectively. Juvenile Cunene horse mackerel T. trecae are found in subtropical and tropical waters in Angola and (occasionally) off northern Namibia. Their distribution extends from north-west Africa to the Angola/Benguela front, which moves seasonally between about 14 and 17 oS, with an average position at 16 oS (Pereira 1988, Shannon et al. 1987). Because of the highly dynamic nature of the front, it is most likely that the juvenile Cunene horse mackerel found in southern Angola, and very occasionally in northern Namibia, are part of a single population.
Sardinella aurita and S. maderensis are found along the entire Angolan coastline, with the juveniles inshore, predominantly in the north. To the north their distribution extends apparently continuously along the coasts of Congo and Gabon, while to the south S. aurita can extend into northern Namibia in Benguela Niño years. In the north both species undertake extensive spawning migrations along the Angolan coast (S. aurita more so than S. maderensis), making it unlikely that distinctly separate stocks exist in this region. It has
12 Anchor Environmental Consultants however been suggested (Wysokiń ski 1986) that the Angolan stock of S. maderensis is independent of the stock off the coast of Gabon.
Sardine tend to live within about 50 km of the coast, and are often found close inshore, both in South African and Namibian waters. Anchovy have a similar coastal distribution, but are commonly found more than 100 km offshore on the Agulhas Bank off the Cape South Coast in the spawning season. Round herring are found widely distributed across the shelf both on the West Coast and the Cape South Coast, with a clear increase in size with distance offshore. Juvenile Cape horse mackerel off both South Africa and Namibia, and juvenile Cunene horse mackerel off Angola, are most abundant inshore, generally being found within the 100m isobath throughout the region. S. aurita inhabits the continental shelf and is generally found in calm saline waters (>35 ppt) at temperatures around 24 oC. In contrast, S. maderensis is a coastal, more euryhaline species, also generally found at temperatures above 24 oC, often in the vicinity of river mouths (Luyeye 1995). The two species appear to be roughly equal in abundance, except in the south where S. aurita predominates. Surveys indicate that sardinella density is generally higher in the central (Luanda-Benguela) region than to the north and south (Luyeye 1995).
2.2 Trawled fish The major species caught by trawl off Namibia and South Africa are the Cape hakes Merluccius capensis and M. paradoxus, which are caught in bottom trawls, and adult Cape horse mackerel, which are mostly caught in midwater trawls off Namibia and in bottom trawls off South Africa as a by-catch in the hake fishery. Other significant by-catch species in the hake fishery in both Namibia and South Africa are monkfish Lophius spp, kingklip Genypterus capensis, snoek Thyrsites atun and the West Coast sole Austroglossus microlepis. In recent years, the monk fishery in Namibia has become increasingly directed, with the West Coast sole as the most important by-catch. On the outer Namibian shelf there is also a valuable deep-water trawl fishery directed at orange roughy Hoplostethus atlanticus and, to a lesser extent, alphonsino Beryx splendens and other deep-water species. Off Angola there is a relatively small bottom trawl fishery for Benguela hake Merluccius polli and M. capensis (in the extreme south), and more important ones in central and northern Angola for demersal species such as Dentex spp. and red pandora Pagellus belloti. The large-eye dentex Dentex macrophthalmus is also taken off northern Namibia in midwater trawls, together with jacopever Helicolenus dactylopterus, another important by- catch species.
The distributions of the three species of hake in the Benguela region are shown in Figure 3. Merluccius polli occurs predominantly in Angolan waters, and is caught on the shelf slope as a by-catch in the prawn fishery and by deep water trawlers in the south, where its distribution overlaps with that of the shallow-water Cape hake M. capensis. The two species of Cape hake are found throughout Namibian and South African waters. M. paradoxus (deep-water hake) occurs in deeper water than M. capensis, although the two species co-occur at intermediate depths (Payne 1989). Typically the former is found in water 150 –
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800m deep, mostly at temperatures between 4 and 8oC, whereas the latter occurs from the coast to a water depth of about 380m, in temperatures between 4 and 12 oC. It has been suggested (Payne 1989) that, in South Africa, the relative abundance of the two species is related to the width of the shelf and the steepness of the slope, with M. capensis predominating where the shelf is broad and the slope steep, and vice versa for M. paradoxus. Larger individuals of both species are found at greater depths than smaller fish, and there is little overlap in the distribution of mature fish. M. capensis is the more common species off Namibia, especially in the central region, although M. paradoxus has been increasingly abundant and more widely distributed there in recent years (see following). M. paradoxus predominates off the west coast of South Africa. It is believed that this stock may be the origin of the Namibian M. paradoxus stock. A second population of M. capensis, which for management purposes is treated as a separate stock, exists in the extreme southern Benguela, chiefly over the Agulhas Bank.
In the 1970s and 1980s, ICSEAF treated Cape stocks off southern Angola/northern and central Namibia (15 - 25oS), southern Namibia (25 - 30oS), the South African West Coast (30oS - 20oE), and the South African South Coast as separate for management purposes. The species were considered together, as the catch records did not distinguish between them Fig. 3 suggests that the West Coast stocks of both species are probably shared between Namibia and South Africa, although catch patterns between Lüderitz and the Orange River indicate that there may be a measure of separation between the Namibian and South African M. capensis stocks. In contrast, there is some evidence from surveys (e.g. Strømme 1996) and commercial catches that, since 1990, there has been a gradual migration or expansion of M. paradoxus into southern Namibia and farther north, probably from South African waters. This is the only reported evidence of significant longshore movement of any of the three hake species, although it has previously been suggested that such shifts do occur in
14 Anchor Environmental Consultants response to environmental changes such as temperature fluctuations and the movement of de-oxygenated bottom water.
Fig. 3 Distribution of the three hake species in the Benguela ecosystem (from Payne1989)
At least two stocks of Cape horse mackerel exist off southern Africa, viz. off northern Namibia/southern Angola, and off the Western Cape. These stocks were once believed to be genetically separated by the environmental barrier of the Lüderitz upwelling cell, with only a limited interchange between them. However, the finding of large adults on the bottom across the shelf south of Walvis Bay in recent Namibian surveys (E. Klingelhoeffer, NatMIRC, pers. comm.) raises the question of a possible connection between this part of the population and that on the West Coast of South Africa. This is a regional question of major importance for managing this trans-boundary fishery. Opinion is divided on whether the horse mackerel on the Cape West and South Coasts form a single or separate stocks, with catch patterns suggesting the former and genetic studies the latter. There is little information regarding the stock structure of Cunene horse mackerel in Angolan waters, although Sardinha (1996) has suggested on the basis of biological data and distribution patterns that there are separate self-sustaining populations in the north and south of Angola. The hypothesis is currently being tested genetically (Sardinha and Nævdal, submitted). (CHECK WITH STAN/ROB LESLIE)
Orange roughy in Namibia are found mainly over the shelf between about 600m and 1000m depth at bottom temperatures of between 3 and 7 oC (A. Staby, NatMIRC, pers. comm.). The fish tend to be concentrated over hard substrata in a number of small areas, particularly during the spawning season. Alfonsino tend to be more widely distributed over the outer shelf, between about 400 and 700m. The degree to which the distribution of the two species extends into Angolan and South African waters, and the extent of any longshore migrations, is at present unknown.
The main commercial species of monkfish found in southern African waters are Lophius vomerinus (previously known as Lophius upsicephalus) and Lophius vaillanti. The former is found from northern Namibia to the East Coast of South Africa, but the latter only north of Walvis Bay. Both are demersal species, mainly found at depths of between 150 and 400m. Two separate recruitment areas for L. vomerinus have been located in Namibia: off Walvis Bay and near the Orange River. The relationship between these recruits and L. vomerinus to the south is unknown, as is the extent of any longshore migrations of adults. Nonetheless, it seems reasonable to assume that there is some interaction between the population(s) on the South African West Coast, and that found around the Orange River, in particular.
Demersal fish caught commercially by trawl in Angola can be grouped into species occurring below the thermocline along the continental shelf, and species
15 Anchor Environmental Consultants found above, below and in the thermocline. Sparids are the most important in the former group. particularly the large eye dentex Dentex macrophthalmus, which is fished between 60 and 300m depth between Lobito and as far south as Walvis Bay (Constança 1995). Other important species are the Angola dentex Dentex angolensis and the red pandora Pagellus belloti, which occur across the shelf to depths of around 300m (Bianchi 1986). These three species together usually make up more than half of the demersal catch. In the latter group the most important species is the bigeye grunt Brachideuterus auritus. A significant part of the demersal trawl catch consists of deep-water prawns and to a lesser extent, deep-water red crab, which are discussed in the following Section.
2.3 Crustaceans
The major crustacean fisheries along the west coast of southern Africa are those for the West Coast rock lobster Jasus lalandii off South Africa and Namibia, the red crab Chaceon maritae off northern Namibia and Angola, and for the deep- water rose prawn Parapenaeus longirostris and striped red prawn Aristeus varidens off northern and central Angola.
J. lalandii is a spiny lobster associated with the cool upwelled waters of the Benguela. It occurs in commercially exploitable densities from east of Cape Point to approximately 25oS, and at lower densities beyond its core distribution. Close inshore it is caught by hoopnets deployed from dinghies and by recreational divers, but in deeper waters is harvested by traps.
C. maritae occurs on the slope of the continental shelf from about 27 oS off Namibia, northwards to Angola, Congo and the Ivory Coast. Off Namibia it is found on soft mud substrata at depths of between about 300 and 900m, and is harvested solely by Japanese vessels using traps. Off Angola it is found within a similar depth range, particularly in the southernmost area, and is taken in traps and (occasionally) bottom trawls. It has recently been shown from tagging studies (Le Roux 1997) that adult females migrate from Namibia to Angola, suggesting a single stock in the region, which needs to be managed jointly by Namibia and Angola.
Parapenaeus longirostris is essentially an Atlantic Ocean prawn, found from Portugal to Angola in the east, and from Massachusetts, USA, to French Guiana in the west, whereas Aristeus varidens is an East Atlantic species, found from Rio de Oro (24 oN) to 18 oS (off Namibia). The depth disrtribution of the two species differ. P. longirostris is found on the continental shelf and upper slope, between 50 and 400m depth (López Abellán and de Cárdenas 1990) over sandy bottoms. A. varidens lives on the slope, mainly between 400 and 800m depth, and is strongly associated with muddy bottoms. The size of both species increases with depth, more so in the case of P. longirostris than A. varidens. Angolan-Spanish surveys have revealed that P. longirostris have a more homogeneous distribution than A. varidens, which tends to concentrate in several areas, mainly related to submarine canyons. Concentrations of P. longirostris tend to occur around recruitment areas.
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2.4 Line-caught species
The linefisheries of the Benguela Current and adjacent waters exploit a large number of species. They can be broadly classified into a) inshore reef fishes, which are mainly resident on shallow nearshore reefs and have a limited geographic distribution, b) migratory shoaling species, where the adults aggregate and migrate rapidly over large distances, usually as part of annual migratory cycles, and c) offshore large pelagic species such as tuna and billfish, which form large, highly-migratory straddling stocks that cross the borders of many countries, and even oceans.
In Angola, line-caught species belonging to the first two groups make up more than 40% of the total catch by the large inshore artisanal/subsistence fishery which extends along the entire coast. The most important groups caught by line are dentex, croakers (Sciaenidae) and groupers (Serranidae). Catches are highest in the provinces of Benguela, Namibe and Luanda (Anon. 1998a). The recreational fishery for linefish in Angola is underdeveloped and negligible compared to the artisanal/subsistence fishery.
The silver kob Argyrosomus inodorus is the most important of the linefish species caught commercially in Namibia, with roughly equal amounts being taken by commercial fishermen and recreational anglers. Other important angling species in Namibia are the steenbras Lithognathus aureti, the blacktail Diplodus sargus and the galjoen Coracinus capensis.
Off the South African West Coast, the dominant reef fish in the catches is the hottentot Pachymetopon blochii, which has been an important contributor to artisanal/subsistence linefish catches off the West Coast since the early part of the century. It is a highly resident species, which makes it susceptible to localised depletion in heavily fished areas. In contrast, the galjoen Coracinus capensis, which is a major shore-angling species off Namibia and the West Coast of South Africa, is highly migratory. Tagged galjoen have been found to have moved from northern Namibia to east of Cape Point.
Snoek is by far the most important migratory linefish species caught commercially on the West Coast of South Africa, and is important in Namibia as well. It is found along the entire southern African coast from southern Angola to Cape Agulhas, mainly in cool upwelled water, and is a major predator on pelagic fish in the region. Snoek were historically considered to form a single stock extending from Cape Agulhas to northern Namibia, and to migrate seasonally between these regions (e.g. Crawford et al. 1990). However, a recent study of all available evidence (Griffiths, in prep.) suggests that there may be two separate sub-populations – in Namibia and South Africa respectively - with medium-term (of the order of five years) exchange between them in response to environmental events and food availability.
Of the large pelagic species taken in the region, the most important in the
17 Anchor Environmental Consultants southern part is the albacore or longfin tuna Thunnus alalunga, which is currently caught by South African and Namibian pole and line vessels within territorial waters from south of Cape Point to Lüderitz. The species is also exploited by Asian high-seas longliners off both countries. The stock is believed to be part of a single southern Atlantic stock, separated from the southern Indian Ocean stock by the warm water of the Agulhas current. There is also a longline fishery for bigeye tuna Thunnus obesus along the edge of the shelf in both countries, mostly by Asian high-seas vessels. It is not known whether these fish form part of an Indian Ocean, Atlantic Ocean or circumglobal stock. In Angola the most important species taken by local baitboats is the yellowfin tuna Thunnus albacares, while bigeye tuna is the major constituent of the Japanese longline fishery. Yellowfin form part of an Atlantic population, which spawn off Brazil and the Gulf of Guinea, and are most abundant in southern Angola in summer.
Finally, mention must be made of the Cape hake Merluccius capensis, which although primarily a trawl-caught species, is also caught by lines off South Africa's South East Cape, and (to a lesser extent) Namibia, using both hand and hydraulically-hauled longlines. The South African fishery grew out of an experimental longline fishery for kingklip in the 1980s, which severely depleted that stock.
2.5 Seals and seabirds
The Cape fur seal Arctocephalus pusillus pusillus occurs along the southern African coast between Algoa Bay and southern Angola and is harvested in Namibia. Although the harvest is low compared to earlier times (the fishery is centuries old), seals have been included in this overview because they are major top-predators in the Benguela, whose dynamics have been strongly affected by fluctuations in a number of the major fish resources of the region, making them important visible indicators of environmental change. The same is true of resident seabirds such as the Cape gannet Morus capensis, the Cape cormorant Phalacocorax capensis and the African penguin Spheniscus demersus, which breed mainly on nearshore islands and guano platforms off Namibia and South Africa, and feed largely on pelagic fish such as sardine and anchovy. The dynamics of pelagic fish stocks is strongly reflected in changes in abundance, diet and breeding success of the seabirds, to the extent that in South Africa, consideration is being given to using this information directly in the management of the sardine and anchovy fisheries.
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3. LIFE HISTORY OF MAJOR RESOURCES
3.1 Small pelagic fish
Sardine and anchovy
Off Namibia, sardine spawn largely within 60 km of the coast in two main areas, one off Walvis Bay and the other farther north, in the mixing zone south of the confluence of the Benguela and the Angola Current systems. In the northern area, peak spawning (mainly by young adults) occurs near the 200m isobath in late summer/autumn in water temperatures between 19 and 21 oC, whereas spawning farther south (mainly by older fish) takes place in summer in cooler water close to upwelling zones. Since the collapse of the sardine stock in the 1970s (Section 4.1), spawning in the south has diminished in importance. The distribution and movement of anchovy off Namibia is similar to that of sardine there, but significant spawning only occurs north of Walvis Bay. The larvae of both species drift south close to the coast, recruiting as 0-group fish into the fishery in the cool upwelling areas near Walvis Bay. This is followed by a return northward migration of juveniles and young adults to the northern mixing area, where they first spawn. In the case of sardine, older fish subsequently return south again to spawn in the Walvis Bay region, although this migration is believed to have decreased in importance since the collapse of the fishery. The behaviour of sardine and anchovy off Namibia is analagous to that found in other upwelling systems, such as those off California, Peru and north-west Africa (Bakun 1995), where both spawning and recruitment occur downstream of the principal upwelling cell (Lüderitz in this case).
In the past, sardine in the southern Benguela have spawned in two areas, one of large adults in cool water west of Cape Columbine, and the other of younger fish in warmer water east of Cape Point, inshore of the Agulhas Current, analagous to the two sardine spawning areas off Namibia. However, since the major stock decline in the mid-1960s, there has been little evidence of spawning on the West Coast, and it seems that the stock is now perpetuated mainly by the younger adults spawning over the Agulhas Bank, particularly the Western Bank, between Cape Point and Cape Agulhas. Anchovy also spawn mainly over the Agulhas Bank, somewhat offshore of the sardine, in the upper mixed layer, in water temperatures ranging between 17 and 19 oC. Peak anchovy spawning is in early to mid-summer, whereas sardine spawn over an extended period, with weak maxima during late winter/early spring and late summer. In contrast to the northern Benguela, spawning occurs mainly upstream of the main upwelling centres of Cape Point and Cape Columbine. Eggs and larvae are transported from the Western Agulhas Bank to the West Coast (Fig. 4) between the 200m and 500m isobaths (Fowler and Boyd 1998), along the offshore boundaries of the upwelling cells by a perennial equatorward jet current, leading to recruitment downstream of the upwelling cells. Bakun (1995) has noted that this is a reversal of the normal spawning and recruitment pattern in other eastern-boundary
19 Anchor Environmental Consultants upwelling areas (e.g. the northern Benguela, California Current and Canary Current), the difference originating from the right-angular configuration of the
coastline in the southern Benguela. Fig. 4 Conceptual model of anchovy migration, constructed from acoustic survey data and trends in length in research midwater trawl catches (from Hampton 1992)
Sardine and anchovy larvae transported past Cape Columbine are either carried offshore and lost to the system, or are transported northwards and inshore (possibly assisted by active swimming as they develop), leading to recruitment of both sardine and anchovy inshore along the West Coast at least as far north as the Orange River (Fig. 4). There is evidence that in normal years, the northern limit of the dispersal is the southern edge of the Lüderitz upwelling cell, which causes the larvae either to be carried far offshore, or to be drawn inshore by compensatory flow and returned south by the inshore poleward counter-current. It has been suggested that in years when this cell is abnormally weak (as in 1987), pelagic larvae spawned in Cape waters may be carried past the Lüderitz “barrier” and recruit into the southern Namibian fishery, linking the South African and Namibian pelagic fisheries. This may have occurred in 1987, when an unexpectedly large number of anchovy recruits was caught in southern Namibia, resulting in catches roughly an order of magnitude higher than in the previous and following years.
Once inshore, the sardine and anchovy recruits off South Africa move south close inshore along the West Coast in autumn and winter, assisted by the poleward counter-current. They are possibly retained for a period in St Helena
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Bay before reaching the Agulhas Bank in early summer, towards the end of their first year of life. It is during this period that they are exploited by the purse-seine fleet, which mainly operates from ports on the West Coast. Adults tend to move eastward and (in the case of anchovy) offshore, with increasing age, although there is some return of older fish to the West Coast from the outer edge of the Agulhas Bank, probably assisted by the jet current off the Cape Peninsula.
A portion of the sardine population (mostly fish in their second year of life) undertakes a pronounced and well-documented inshore migration into the shelf waters of KwaZulu-Natal each winter (known locally as the “Sardine Run”), to at least as far up the coast as Durban. This is probably in response to the eastward retreat of warm subtropical water close inshore at that time of the year, and is assisted by equatorward counter-currents inshore of the Agulhas Current. The migration may be analagous to the movement of young Namibian sardine towards the subtropical system boundary in winter. It is most probable (though not yet demonstrated) that the surviving fish return rapidly to the Agulhas Bank later in the year in the strongly flowing Agulhas Current slightly farther offshore.
Analyses of stomach contents up to the end of the 1970s suggested that the diets of sardine and anchovy in the Benguela are similar, with phytoplankton as the main food source. However, laboratory and field studies since then have shown that zooplankton is more important in the diet of both species than was previously believed to be the case. Certainly, juvenile sardine and anchovy, and adult anchovy, feed primarily on zooplankton, although adult sardine appear to utilise more phytoplankton in areas of consistently high phytoplankton abundance. Little is known about the extent to which sardine and anchovy compete for habitat and food in the Benguela ecosystem, but a recent field study on feeding in mixed schools of juveniles, in which a clear size difference was found in the zooplankton taken by the two species (Louw et al. 1998), suggests that direct competition may be limited, at least in the younger stages.
Sardinellas
The main spawning area of S. aurita and S. madarensis is thought to be between 5 and 7 oS (Pointe Noire to south of the Congo River), with peak spawning in March-April. There appears to be a seasonal longshore migration pattern for both species, with an equatorward movement towards the spawning grounds during the first part of the year, and a return poleward migration of adults in the second half of the year to central and (in the case of S. aurita) southern Angola. Juvenile S. aurita are encountered over the whole littoral zone from Cape Lopez in Gabon to Baia dos Tigres in southern Angola. Upon reaching a length of 10 – 14 cm, the juveniles leave the littoral zone, and remain for some time in shallower shelf waters before joining the adult stock farther offshore (Troadec and Garcia 1980). Juvenile S. maderensis appear to be largely concentrated inshore north of the Congo River throughout the year (from data in Wysokiń ski 1986).
Little is known about the diet of sardinellas in Angola, although French studies in
21 Anchor Environmental Consultants the 1970s found that the diet of both S. madarensis and S. aurita in Congolese waters consisted almost entirely of the copepod Calanoides carinatus.
Round herring
Little is known about the seasonality of round herring spawning in the Benguela, although from ichthyoplankton surveys in the south, it appears that there at least, spawning probably occurs throughout the year, reaching a peak between late winter and early summer. The early life history of round herring spawned on the Agulhas Bank appears to be similar to that of sardine and anchovy spawned there, with the ichthyoplankton being transported to the West Coast by the same jet current, leading to recruitment along the West Coast at the same time of the year as sardine and anchovy recruitment, and movement onto the Agulhas Bank towards the end of the first year of life. The fish appear to move eastwards and offshore with increasing age, inhabiting the entire Agulhas Bank, at least as far east as Port Elizabeth (Roel and Armstrong 1991). As with sardine and anchovy, there is probably some return of older fish to the West Coast from the outer regions of the Bank.
Round herring is a particulate feeder, whose diet in South African waters consists exclusively of zooplankton (mainly copepods, euphausiids and decapods). Juveniles form pelagic shoals in the upper mixed layer, but adults perform pronounced diel vertical migrations, migrating from near the surface at night to near-bottom waters during the day, often passing through a temperature gradient of more than 10 oC.
3.2 Trawled species
Hakes
Cape hakes spawn in midwater throughout the year, with a peak in early summer for both M. capensis and M. paradoxus, and a secondary peak in late summer for M. paradoxus in the southern Benguela. Most M. paradoxus spawning is thought to take place along the edge of the Agulhas Bank, but spawning also occurs over the shelf-break west of St Helena Bay and off central Namibia. In the latter region, M. capensis spawn most frequently between 160 and 250m depth, spawning starting earliest in the shallower waters. The eggs of both species are concentrated around the depth of the thermocline, and the dispersal of M. paradoxus eggs and larvae produced on the South Coast could be similar to that of the pelagic fish spawning there, resulting in young M. paradoxus being plentiful between Cape Columbine and the Orange River. To the north, 0-group M. capensis are particularly abundant off Walvis Bay, which appears to be a nursery area. Juveniles of this species are also plentiful off the Orange River and south to about Cape Columbine, sometimes co-occuring with pelagic fish recruits in winter, on which they feed (particularly on anchovy). As with the pelagic recruits, juvenile hake in the Orange River area move south as
22 Anchor Environmental Consultants they grow older, but unlike them they tend to move offshore as they move south.
There is evidence that off the West Coast of South Africa, juvenile M. paradoxus move inshore in summer and offshore in winter, in response to changing feeding regimes. The adults, which tend to concentrate in depths greater than about 500m in summer and autumn, move inshore in spring to depths of around 300m, and then return offshore, movements which are probably related to both spawning and feeding. Off Namibia, M. capensis follows a similar inshore migration during the spawning season in early summer, followed by an offshore migration in late summer.
Cape hakes feed both close to the bottom and in midwater, and tend to be off the bottom at night, although no clear feeding periodicity in either M. capensis or M. paradoxus has been demonstrated, except in the case of juvenile M. capensis, which off the West Coast of South Africa have been observed to move off the bottom at night to feed on pelagic prey such as juvenile anchovy, and to return to the bottom before dawn (Pillar and Barange 1995). Recent studies (Pillar and Barange 1998) have indicated that M. capensis adults on the South African West Coast also move into midwater at night in response to the vertical migration of their prey, but that they only return to the bottom when satiated, regardless of time of day. This results in aperiodic, asynchronous vertical movements of individuals, depending on food availability and recent feeding activity. This lack of a distinct diel feeding rhythm has also recently been reported by Huse et al. (1998) from studies on the behaviour of M. capensis and M. paradoxus at a location on the central Namibian shelf, although they did find some evidence of increased feeding in the early evening, in common with earlier studies of M. capensis feeding in the same area.
Cape hakes are opportunistic feeders, resulting in considerable seasonal and spatial variability in their diet. On the South African West Coast, young M. capensis and M. paradoxus feed predominantly on planktonic crustaceans (particularly euphausiids), juvenile anchovy (by M. capensis), lightfish Maurolicus muelleri and lanternfish Lampanyctodes hectoris (by M. paradoxus), the diet of both species becoming increasingly piscivorous with age (Punt et al. 1992). Squid, epipelagic fish and, to a lesser extent, mesopelagic fish such as lightfish and lanternfish comprise a significant proportion of the diet of adult M. capensis, but in the larger fish the principal diet items are small M. paradoxus, small M. capensis (to a lesser extent) and other demersal species (Punt et al. 1992). With increasing age, M. paradoxus becomes increasingly cannibalistic on young M. paradoxus, which together with squid, crustaceans and mesopelagic fish constitutes most of the diet of the large mature adults on the Cape West Coast. In contrast, more than 90% of the diet of large M. capensis on the Agulhas Bank consists of pelagic fish (particularly anchovy), horse mackerel and young M. capensis, the size of prey increasing with hake size (Pillar and Wilkinson 1995). Cannibalism on M. capensis appears to be higher than on the West Coast, but the interspecific (hake-on-hake) predation somewhat lower.
The diet of hake in Namibia is similar to that in South Africa (see summary in
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Gordoa et al. 1995), the chief difference being the greater importance of myctophids (particularly for M. paradoxus), and the significant proportion of gobies Sufflogobius bibartus in the diet of both species. As in South Africa, both species become increasingly piscivorous with age, and hake-on-hake predation becomes increasingly important.
Because of their catholic feeding habits and abundance, hake are extremely important predators in the Benguela. For example, Punt et al. (1992) have estimated that Cape hakes in South African waters could consume as much as 6 million tonnes of food annually. Based on estimates of stock size in Namibia, it would appear that consumption there could be as high.
Horse mackerels
Cape horse mackerel T. trachurus capensis off the West Coast of southern Africa have broad spawning areas, with most intense spawning in warmer waters immediately west of the shelf-break in both regions. Egg and larva surveys in the 1970s (O’Toole 1977) showed that in Namibia the heaviest spawning occurs in the north between October and March in the mixing zone of warm oceanic water and cool coastal water, and that the timing of spawning is closely linked with the duration and intensity of mixing. Nursery areas exist in both the southern and the northern parts of the ecosystem, adjacent to the spawning grounds but closer inshore, and there are substantial longshore and cross-shelf migrations of both juveniles and adults.
Off Namibia, juvenile Cape horse mackerel live inshore, the smallest fish being found farthest north. Slightly larger individuals appear to migrate south towards Walvis Bay, especially in winter. Maturing fish move offshore and northwards to spawn, the adults generally occuring north of 21 oS.
Off the Western Cape, juveniles also occur inshore and the adults farther offshore. The movements of the fish with increasing age, and particularly the interchange between the West and South Coast populations, are particularly complex, as can be seen from a recent migration model postulated by Barange et al. (1998), reproduced here as Fig. 5. Note that the life history in the first year of life is similar to that of sardine and anchovy, with spawning on the South Coast leading to recruitment on the West Coast in the following year, probably driven by the same transport mechanisms. Recruitment occurs about three months earlier than that of sardine and anchovy, but overlaps with it to some extent, resulting in a by-catch of juvenile horse mackerel in the pelagic fishery. Thereafter the species diverge, with the horse mackerel becoming more demersal and moving offshore, probably ultimately leading to spawning over the shelf-break on the West Coast. Some of these fish however move onshore again in winter in their second year of life, and move onto the Western Agulhas Bank, assisted by the poleward counter-current on the inner shelf. These fish reach maturity at two years of age and move eastwards and offshore with increasing age, leading to spawning across the entire Agulhas Bank, which peaks at different times on the Western and Eastern Banks and which, on the Western
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Bank at least, appears to be closer inshore in winter than in summer. Barange et al.(1998) suggest that adults on the Eastern Bank move southward and westward to spawn on the Central Bank in spring, a movement which would favour transport of the ichthyoplankton to the West Coast. They also suggest that there is some secondary recruitment directly into the numerous bays of the South Coast from spawning farther offshore, probably aided by the inshore movement of spawners in winter. However, most of these hypotheses are still tentative and need rigorous testing.
Fig. 5 Conceptual model of Cape horse mackerel migration patterns in the southern Benguela, constructed from acoustic and research trawl information (from Barange et al. 1998)
According to Troadec and Garcia (1980), the core spawning area of the Cunene horse mackerel is off Mauritania and Senegal, where spawning peaks from February to June. Although spawning undoubtedly occurs farther south as well, including in Angolan waters, little has been reported about the locality and timing of any such spawning. Little is also known about the seasonal distributional patterns of the different life history stages of the species off Angola, although the fact that at the height of the fishery in the 1960s and 1970s, inshore catches used to show a sharp peak in October/November co-incident with a rise in water temperature, has led to suggestions that there is a seasonal inshore migration in response to changing environmental conditions. This is supported by survey data, which indicate that the proportion of the population in central Angola is
25 Anchor Environmental Consultants highest in summer (Sardinha 1996).
Cape horse mackerel up to the age of two years feed near the surface and are planktivorous. The diet, which consists mainly of copepods, is similar to that of sardine and anchovy, and juveniles up to about 10 cm in length can co-exist in schools with sardine and anchovy. Adults off the west coast of southern Africa are opportunistic feeders on euphausiids (which constitute 95% of their diet in Namibia), polychaete worms, chaetognaths, squid, various crustaceans and fish such as gobies Sufflogobius bibartus, lanternfish and lightfish. Older horse mackerel tend to feed in midwater, and their diet is similar to that of Cape hakes of similar size. Accordingly, there may be interspecific interaction between Cape horse mackerel and Cape hakes, with a decrease in the abundance of the one species benefiting the other, and vice versa. Pillar and Barange (1998) showed that adults on the Cape South Coast feed predominantly on copepods close to the bottom in late afternoon, migrate in synchrony into midwater at dusk, clearly for purposes other than for feeding, and return to near-bottom at dawn. Sardinha (1996) reports that in Angolan waters, horse mackerel of both species undergo a similar diel vertical migration. There have been no comparable studies in Namibian waters, but it would appear from the fact that adult horse mackerel there are caught by midwater trawl throughout the 24-hour period that their vertical migratory behaviour in this region may be different from that to the north and south.
Deep-water species
Orange roughy off Namibia have a short spawning period of about a month in July/August, when they spawn in dense concentrations close to the bottom in small areas typically no more than 10 - 100 km2 in extent. They are exceptionally long-lived and slow-growing, possibly only reaching sexual maturity at around 25 years off Namibia, and may have a maximum lifespan of over 100 years. The fish have a low reproductive rate, which together with their aggregating behaviour, makes them highly vulnerable to over-fishing. Alfonsino Berxy splendens are distributed over a wider area and are probably more productive. Little is known about their spawning behaviour or breeding habitat.
Dentex
Dentex macrophthalmus spawn throughout the year with a peak between October and April. The most intensive spawning occurs between Baia dos Tigres and the Cunene River at depths between 25 and 110m (Kuderskaya 1985). Little is known about migration patterns, except that according to Wysokiń ski (1986), the stock migrates shorewards in summer and offshore in winter. Even less has been reported on the life histories of the other commercially exploited demersal fish in Angolan waters.
3.3 Crustaceans
West Coast rock lobster
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J. lalandii has a well-defined moulting and spawning cycle. Adults moult once per year, the males in spring and the females in late autumn/winter, after which mating takes place. Egg-hatching peaks in October-November and the phyllosoma larvae remain planktonic for a long period, drifting in oceanic sub- gyres until they reach the puerulus (free-swimming) stage and settle. Females reach sexual maturity about five years after settlement, at a greater length in the south than in the north. Maturing males grow faster than females, resulting in the fishery being based largely on males. The adults are generally distributed offshore of the juveniles, except in the north, where the population is constrained close to the coast by low-oxygen water. J. lalandii feed largely on mussels, in particular the ribbed mussel Aulacomya ater, which is abundant in the rocky subtidal zone of the West Coast. In areas of low mussel abundance, the diet consists mainly of echinoderms (sea urchins and starfish), gastropods, bryozoans, polychaetes and seaweeds. The principal predators on J. lalandii are octopus, dogsharks, hagfish, whelks (on injured or weakened animals) and young seals. Cannibalism is known to be prevalent in overcrowded situations, particularly among juveniles.
Deep-sea red crab
Chaceon maritae in Namibia appear to spawn throughout the year, judging from the fact that no seasonal cycles in moulting and egg-bearing have been found there (Le Roux 1997). Adult females generally live in shallower water than males, and virtually all egg production and larval release takes place on the shallower part of the continental slope; a pattern which has also been found in Angola. The fact that the migration from Namibia to Angola is almost entirely by females suggests that this is a spawning migration.
Deep-sea prawns
Parapenaeus longirostris spawn throughout the year, with peaks in July and December. Sobrino and de Cardenas (1989) state that females reach sexual maturity at a carapace length of 21.6 mm. According to López Abellán and Garcia-Talavera (1992), there are nursery areas between 8 and 9 oS and between 10 and 11 oS. Eggs are demersal and the larvae planktonic. The larvae enter the post-larval phase at a length of 12 mm. Juveniles are concentrated between depths of 50 and 70m, where recruitment takes place. A sampling programme has shown that there is a major recruitment peak between January and March, and a lesser one in August-September (López Abellán et al. 1993).
Aristeus varidens appear to spawn throughout the year, with a peak in December and probably another in April-May. First maturity is reached at a carapace length of about 25 mm (Sobrino and de Cárdenas).
3.4 Line-caught species
Snoek spawn along the edge of the shelf off the West Coast of South Africa and
27 Anchor Environmental Consultants the western Agulhas Bank, and off southern Namibia, mainly from July to October. There is also some evidence of spawning farther north. It has been suggested that in South African waters the ichthyoplankton is transported by prevailing currents to a primary nursery ground north of Cape Columbine, and to a secondary one east of Danger Point on the South-West Coast (Griffiths, submitted). Juveniles tend to recruit inshore and remain as locally migratory shoals in nearshore nursery areas until they approach maturity, when they join the adult population. Their cross-shelf distribution on the inner shelf is determined by prey availability, and includes a seasonal inshore migration in autumn in response to pelagic fish migration patterns. Adult snoek are found throughout their distributional range, moving offshore and somewhat southwards to spawn. Other than this, there do not appear to be any seasonal trends in longshore movements of adults in South African waters (Griffiths, in prep.). Migrational patterns of juveniles and adults in Namibian waters have not been established with any certainty.
Albacore, the main contributor to the South African and Namibian large pelagic fisheries at present, are believed to migrate across the southern Atlantic to South America, and then northwards to spawn in the tropical central Atlantic. Juveniles occasionally recruit into waters off the Western Cape, but most of the fish caught are large reproductively inactive adults, following and feeding on the rich pelagic prey in the Benguela and Agulhas Current systems.
3.5 Seals and seabirds
The Cape fur seal breeds on small rocky nearshore islands and, most importantly, at six mainland colonies on the Namibian and northern Cape coasts where human access is restricted. Two of these colonies (Kleinsee in the northern Cape and Atlas Bay near Lüderitz) are believed to be the largest mainland seal colonies in the world. The breeding season, during which pupping is followed almost immediately by mating, lasts for 6 to 8 weeks in October/November. Pups are weaned at an age of 8 to 10 months, and thereafter forage widely. While attending their pups, adult cows feed within a few days range of the colonies, but the bulls appear to have separate feeding grounds, probably considerably further offshore. Much of the diet is made up of fish, of which commercial pelagic fish and hake are the most important on the South African West coast, and the bearded goby Sufflogobius bibartus (a non- commercial species), horse mackerel and juvenile hake the most important off Namibia. It has been estimated that seals in the Benguela consume about 1 million tonnes of fish annually, which is of the same order as the total annual fish catch in Namibia and South Africa.
The Cape gannet breeds on islands off southern Namibia and the West and South Coasts of South Africa, usually from September to November. The birds range widely during the non-breeding season, following their prey (largely sardine and anchovy), which they capture by plunge-diving. The Cape cormorant breeds mostly on nearshore islands and guano platforms, but also at islands within estuaries and lagoons, sewage works and on mainland cliffs. The
28 Anchor Environmental Consultants breeding distribution extends from northern Namibia to Algoa Bay. They are generally dependent on large surface schools of fish, which they capture by pursuit-diving, and do not forage as widely as gannets. Anchovy and sardine are the preferred prey species, with bearded goby an important prey in southern Namibia. The breeding range of African penguins extends from Algoa Bay to Sylvia Hill, south of Walvis Bay. They generally breed on islands, although there are a few small mainland rookeries in South Africa and Namibia. Pelagic shoaling fish, particularly sardine and anchovy, are the most important prey, which are caught by deep pursuit-diving. As with the Cape cormorant, the bearded goby has at times been an important prey off Namibia, particularly when sardine have been scarce.
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4. HISTORY AND CURRENT STATUS OF THE FISHERIES
Industrial catches of the major species in each country in 1997 are summarised in Table 1. Note that zeroes in parenthesis indicate an assumed zero catch in the absence of data to the contrary. A more general discussion of the history and current status of each sector of the fishery follows.
SPECIES ANGOLA SOUTH AFRICA TOTAL NAMIBIA
Pelagic fish Sardine (0) 27 892 116 992 144 884
Anchovy (0) 2 525 60 095 62 640
Juvenile Cape and 138 000 (1996) 88 295 12 727 239 022 Cunene horse (Mainly T. trecae) (T. t. capensis) (T. t. capensis) mackerel
Sardinellas 50 000 (1996) 0 0 50 000
Round herring (0) 5 084 92 209 97 293
Trawled fish Hakes 720 108 594 143 053 252 367 (Mainly M. polli) (M. capensis and M. (M. capensis and M. paradoxus) paradoxus)
Horse mackerels (0) 213 577 22 984 236 561 (all trawl methods) (T. t. capensis) (T. t. capensis)
Monkfish (0) 10 259 7 640 17 899
Other demersal 20 000 7 145 24 172 51 317 species (Mainly Dentex, (Kingklip, sole, etc.) (Kingklip, snoek, croakers and grunters) sole, etc.)
Deep-water species (0) 20 608 647 21 255 (Mainly orange roughy) Crustaceans West coast rock 0 307 1 726 2 033 lobster
Crabs 1 880 739 113 2 732
Deep-water prawns 5 600 (P. longirostris) 0 0 6 950 1 350 (A. varidens) Linefish
Tuna 910 (1995) 38 3 158 4 106
Other commercial unknown 8 671 12 132 20 803
218 460 493 754 497 648 1 209 862
Totals
Table 1. Industrial catches (in tonnes) of major species in each country in 1997, except where indicated otherwise. Assumed zero catches in parenthesis. Data for Angola from IIP. Data for Namibia and South Africa from Stuttaford (1998).
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4.1 Purse-seine fisheries
Annual landings of the major species exploited in the purse seine fisheries of the region from the 1950s to the present are shown in Figs. 6, 7 and 8 for Angola, Namibia and South Africa respectively. They are discussed by species below.
350
300
250 Horse mackerel Sardinella 200
150
100
50
1956 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995
Fig. 6 Purse-seine catches of sardinella (Sardinella maderensis and S. aurita combined) and (predominantly) juvenile Cunene horse mackerel off Angola since 1956
1 400 Sardine 1 200
1 000
800
600
400 Anchov y 200 Horse mackerel
1950 1953 1956 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998
Fig. 7 Purse-seine catches of sardine, anchovy and juvenile Cape horse mackerel off Namibia since 1950
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600 Anchov y 500
400 Sardine
300 Horse mackerel
200
100 Round herring
1950 1953 1956 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998
Fig. 8 Purse- seine catches of sardine, anchovy, round herring and Cape horse mackerel off South Africa since 1950
Sardine
Industrial catches of sardine in Angolan waters from the 1950s to the present, which are reduced to meal and oil, have fluctuated widely from almost zero to a maximum of 146 000 tonnes in 1957, depending on the state of the Namibian stock and the degree to which it has extended into Angolan waters. The fish were initially caught by a large local fleet of small vessels, but after Independence in 1975 were mainly taken by larger, foreign-owned purse-seiners which began fishing on sardine and sardinellas off Angola in 1976, processing their catches to a large extent at sea. Since 1994, when the adundance of sardine in Namibian waters has been particularly low, a number of Namibian vessels have fished under license for sardine in southern Angola, but only in 1995, when 47 000 tonnes were caught by such vessels, have these catches been significant.
In Namibia, annual catches of sardine (mainly adult fish, taken for both canning and reduction to meal and oil) rose rapidly from levels of around 200 000 tonnes to a maximum of nearly 1.4 million tonnes in 1968, whereafter there was a sharp decline to below 300 000 tonnes in 1971, followed by a slight increase in catches for a few years and a precipitous collapse in 1977 and 1978. Since then, annual catches have rarely exceeded 50 000 tonnes, reaching an all-time low of a little over 1 000 tonnes in 1996. It is most likely that these collapses were largely due to over-fishing (especially in the late 1960’s when in addition to the Walvis Bay fleet there were two factory vessels operating outside territorial waters), perhaps exacerbated by a number of years of poor recruitment as a result of adverse environmental conditions. A change from sardine nets to anchovy nets in the late 1960s, which would have placed greater pressure on the recruits, may also have been a contributing factor. With the decline of the stock in the 1970s the fishery
32 Anchor Environmental Consultants moved increasingly northwards, and the fleet changed from small, predominantly wooden-hulled vessels to larger steel-hulled refrigerated-seawater vessels capable of returning the fish from northern Namibia in a condition suitable for canning. South African catches of adult sardine for canning, and of both adults and juveniles for fishmeal and oil, rose from around 100 000 tonnes per annum in the early 1950s to a peak of around 400 000 tonnes per annum in the early 1960s. Thereafter, catches declined sharply to well below 100 000 tonnes per annum, a level which has only recently been regained with the steady growth of the stock since the mid-1980s. Prior to the collapse, the fishery was based on large adults off St Helena Bay, caught predominantly in winter. Thereafter it shifted to younger adults farther south, caught throughout most of the year, and recruits close inshore on the West Coast in autumn and winter as a by-catch in the anchovy fishery, a pattern which still persists. The fleet changed from 32-mm mesh sardine nets to 13 mm anchovy nets in the mid 1960s.
Anchovy
In the 1970s and 1980s, catches of South African and Namibian anchovy, which were not targeted in South Africa prior to 1964 and were hardly caught in Namibia before 1966, have been less variable than those of sardine, fluctuating under quota control around a level of around 300 000 tonnes in South Africa and 200 000 tonnes in Namibia. An exception was the pronounced peak in 1987 and 1988 in South Africa and in 1987 in Namibia, when catches were roughly double the average. The peak in South Africa is thought to have been due to exceptionally good recruitment, at least partly associated with enhanced transport of eggs and larvae to the West Coast in those years, while in Namibia, the peak was probably caused by an anomalous influx of anchovy recruits from the Cape stock, driven by the same environmental factors which caused the good recruitment in the south that year. Annual catches in South Africa in the 1990s have varied between 40 000 and 347 000 tonnes, but the Namibian catches have averaged less than 50 000 tonnes per annum during this period, with a decline to virtually zero in 1996 and 1997. Recent surveys confirm that the anchovy stock in Namibian waters is severely depleted at present.
Horse mackerels
The purse-seine fishery for predominantly juvenile T. trecae off Angola started in the 1950s. Catches rose in fluctating fashion from an average of slightly under 100 000 tonnes per annum between 1956 and 1965 to 261 000 tonnes in 1972. Yields then decreased with the cessation of Portuguese rule in Angola, but a record catch of at least 380 000 tonnes was recorded in 1978, by which time distant-water foreign midwater and bottom trawlers, targeting more on adults, had entered the fishery. In the early 1980s, the proportion of the catch taken by purse-seine varied between 15 and 47%, the remainder being taken by midwater (47 - 76%) and bottom (5 - 18%) trawl. Catches declined sharply during this period, and by 1984 only 55 000 tonnes of T. trecae in total were landed. Angolan catches since then have fluctuated between about 25 000 tonnes in
33 Anchor Environmental Consultants
1985 and 1991 and 130 000 tonnes in 1996. A small part of the catch (approximately 2 000 tonnes in 1997 – Anon. 1998a) is taken by small-scale purse-seiners operating close inshore in what is essentially an artisanal fishery.
In Namibia, horse mackerel were not recorded in purse-seine landings until 1971 when, following the first collapse of the sardine fishery, 140 000 tonnes were caught. Since then there have been sporadic catches in excess of 100 000 tonnes per year, with an average of 59 000 tonnes and a maximum of 116 000 tonnes in 1992. The fish are utilised entirely for meal and oil.
Purse-seine catches of horse mackerel in South Africa, which were once second only to sardine in the landings, peaked at 118 000 tonnes in 1954, and thereafter declined steadily to the early 1970s. Since then horse mackerel have only been a minor constituent of the pelagic fishery, with annual catches never having exceeded 10 000 tonnes. This decline is thought to have been due to a decline in the parent stock, probably aggravated by increased fishing pressure on the younger juveniles with the introduction of anchovy nets in the mid-1960s.
Sardinellas
Annual catches of the two sardinella species off Angola by the industrial fishery up to the mid-1970s fluctuated between about 50 000 and 150 000 tonnes. With the introduction of the large purse-seiners after Independence, annual catches rose to around 300 000 tonnes, followed by a steady decline from the mid-1980s to 1992 when catches stabilised at around 50 000 tonnes per year. In 1994 there were 36 vessels operating in this fishery, of which 26 were purse-seiners and 10 pelagic trawlers. The catch is used for fishmeal because the fish is too bony for canning. A small amount of sardinella (around 2 000 tonnes in 1997 – Anon. 1998a) is also caught by artisanal fishermen in small-scale purse- seine operations close inshore for local sale and consumption.
Round herring
Round herring have been a minor constituent of the South African purse-seine fishery since the late 1950s with annual catches in the 1980s and 1990s running at a level of about 50 000 tonnes, peaking at 76 000 tonnes in 1995. The juvenile fish are caught as a by-catch in the fishery for juvenile anchovy and sardine inshore on the West Coast, and the adults in targeted fishing between Cape Columbine and Cape Point, somewhat farther offshore, particularly during the first three months of the year. There have also been sporadic attempts to exploit the large adults in the Algoa Bay region by both purse-seine and midwater trawl. Some of the catch has been canned and the rest reduced to meal. The round herring resource in South African waters is believed to be under-utilised at present, and attempts at greater exploitation have been encouraged. In Namibia, around 1 000 tonnes of juvenile round herring are usually taken each year by the purse-seine fleet for reduction, although catches as high as 14 000 tonnes (in 1996) have been recorded. The potential for canning the larger fish has been investigated, but they have generally been
34 Anchor Environmental Consultants found to be too soft for this purpose.
4.2 Trawl fisheries
Hakes
Annual catches of Cape hakes (M. capensis and M. paradoxus combined) in Namibian and South African waters by local and foreign fleets since 1950 are shown in Fig. 9. Although the demersal fishery began around the turn of the century, catches prior to 1950 seldom exceeded 50 000 tonnes per annum, with most fishing effort being in South African waters. The Namibian fishery started in the late 1950s. In the early 1960s there was an explosive increase in effort and landings throughout the Benguela, with the arrival of foreign trawling fleets, and by 1972, the annual hake catch in the south-east Atlantic exceeded 1.1 million tonnes. Subsequently, catch rates and landings of hake declined sharply, and conservation measures were introduced, including the declaration of a 200-mile fishing zone by South Africa in 1977. Since then hake catches in South African waters have remained relatively stable at just over 140 000 tonnes per year. Off Namibia, hake catches between 1973 and Independence in 1990 averaged 500 – 600 000 tonnes annually, mainly taken by foreign fleets. At Independence, strict conservation measures were introduced, including the exclusion of foreign vessels. The hake catch is now taken exclusively by Namibian-registered vessels and the annual local catch has risen from 55 000 tonnes at Independence to around 120 000 tonnes over the period 1996 – 1998. Catches of M. capensis and M. polli in Angola are of a lower order, amounting to less
Namibia
800
600
400 Namibia
Foreign 200
South Af rica
600
400
200 Foreign
South Af rican
195052 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98
35 Anchor Environmental Consultants than 1 000 tons per year in recent years.s
Fig. 9 Catches of hakes off Namibia and South Africa by foreign and local fleets since 1950
Horse mackerels
Adult horse mackerel are the main target for midwater trawlers operating in Namibia and Angola, the Namibian fishery being the largest by volume in that country. Trawl catches of the two species rose from under 50 000 tonnes per annum in the early 1960s (when horse mackerel were only trawled in Namibia), to between 600 000 and 700 000 tonnes per annum from 1982 to 1984 (Fig. 10), by which time most of the catch was being taken by foreign (mainly former Soviet bloc) vessels. The fish were largely frozen and shipped back to Europe for human consumption. Trawl catches of horse mackerel (mainly T. trachurus capensis) in Namibia since Independence in 1990, when Namibia took control of the fishery, have fluctuated around 350 000 tonnes per annum, with a decline to between 200 000 and 250 000 tonnes per annum in recent years. The number of midwater trawlers in the fishery now is less than half that at Independence. The fleet is largely made up of ageing ex-Soviet bloc vessels, about half of which are now registered in Namibia, but which are mostly operated by foreign crew. The major part of the catch is frozen and transhipped to reefer vessels for export as a relatively low-value product to West Africa, but a small amount is now being smoked or dried-salted ashore for export to African countries.
Total 600
500
400 Midwater
300
200 Purse seine 100
1961 1964 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997
Fig. 10 Catches of (predominantly) Cape horse mackerel by midwater trawl and purse-seine off Namibia since 1961
Purse-seine and trawl catches of Cunene horse mackerel in Angola were summarised in Section 4.1. Compared to these catches, which have generally been between 50 000 and 100 00 tonnes per annum over the past decade,
36 Anchor Environmental Consultants catches of Cape horse mackerel in Angolan waters in the past decade have been insignificant.
The fishery for T. trachurus capensis in South Africa changed from a purse-seine operation for juveniles on the West Coast in the 1950s and early 1960s to a bottom-trawl fishery for adults on the South Coast thereafter, caught by both local and foreign (mainly Japanese) trawlers. Catches rose from about 10 000 tonnes in 1964 to a peak of nearly 100 000 tonnes in 1978 (Fig.11), and have averaged about 30 000 tonnes per annum over the past two decades. Between 1967 and 1975, horse mackerel contributed some 40% of the landings of the inshore demersal fishery on the South Coast, but since the gradual phasing out of the foreign fishery from 1982, this proportion has declined to around 20%. In the 1990s a targeted midwater trawl fishery for horse mackerel developed, mostly on the Eastern Agulhas Bank. Catches have been relatively low (average just under 8 000 tonnes per annum between 1990 and 1997) due to operational and marketing constraints, but there is concern that this fishery has the potential to threaten the resource. Horse mackerel catches in bottom trawls on the West Coast in the past decade have never exceeded 5 000 tonnes per year.
Trawl (south coast) 100 Purse-seine (west coast)
80
60
40
20
1950 1953 1956 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995
Fig. 11 Cape horse mackerel catches in the South African purse-seine (West coast) and trawl (South Coast) fisheries since 1950
Monkfish
The Namibian monkfish fishery was initially a by-catch fishery, but in recent years it has developed into a target fishery in response to increasing market demand. At Independence in 1990 the fishery changed from an international to a local fishery. Since then annual catches (mainly by small wetfish trawlers) have risen from 1 500 tonnes (the lowest value in the past decade) to around 10 000 tonnes, comparable to peak levels reached by the international fishery in the 1980s. The value of the product is high, making this fishery an important contributor to the Namibian economy (Olsen 1997). The by-catch of monkfish in
37 Anchor Environmental Consultants the South African demersal trawl fishery on the West and South Coasts has been relatively constant over the past two decades, at around 5 000 tonnes per year.
Other trawled species
In Angola, roughly 10 000 tons of demersal fish have been caught annually in trawls in recent years, mainly dentex spp., croakers (Scianidae), grunters (Pomadasydiae) and groupers (Serranidae). In Namibia the most important other species caught in bottom trawls are kingklip and sole, catches of which have averaged 1 275 and 340 tonnes respectively per year since 1990. The average combined catch of dentex and jacopever in midwater trawls in Namibia since 1990 is 3 750 tonnes (Boyer et al. 1998). In South Africa the two most important other trawled species are snoek and kingklip. Between 1990 and 1995 catches of these two species averaged 10 900 and 2 200 tonnes per year respectively.
Deep-water species
Exploratory fishing for deep-water trawl species, particularly orange roughy, began in Namibia in 1994. Small catches were made in 1995, but in the following season over 12 000 tonnes of roughy were caught (by bottom trawl) making this the second-largest roughy fishery in the world. The alfonsino catch during these two years was nearly 3 000 tonnes. Indications are that the 1997/98 catch of both species will be at the same level. At present only four roughy aggregations are being targeted, although there is some exploratory fishing for further aggregations. Five vessels are currently operating, in joint ventures between foreign and Namibian companies. The roughy and alfonsino catch is entirely exported, mainly in the form of high-value frozen fillets for the USA and Japanese markets respectively.
4.3 Crustacean fisheries
West Coast rock lobster
There has been a fishery for West Coast rock lobster since the early part of the century, and for a long period the fishery was the world’s largest for any Jasus species. During the 1940s and 1950s South African catches were relatively stable at around 9 000 tonnes (whole mass) per annum, but from the mid 1960s to the present catch levels have declined under quota control to around 1 500 tonnes per annum, with particularly sharp declines in the late 1960s, early 1980s and early 1990s, the most recent one being attributed at least in part to a sharp decline in the growth rate of individuals. In Namibia, where the resource was clearly over-exploited, annual catches have declined even more dramatically, from a peak of nearly 9 000 tonnes in 1966 to about 3 000 tonnes in the early 1970s, to half this level a decade later, and to a few hundred tonnes in recent years.
Deep-sea red crab
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The red crab fishery in Namibia started in 1973. Catches rose to a peak of about 10 000 tonnes in 1983, after which annual landings declined steadily to 2 676 tonnes in 1991, clearly as a result of over-fishing. Catches have fluctuated around this level since then. In only two of the years since the introduction of TACs in 1989 has the TAC been reached. The entire catch is taken by Japanese vessels fishing with traps. Off Angola, a few hundred tonnes of red crab are taken by trawl each year as a by-catch of the deep-water prawn fishery. Since 1986 there has also been a directed crab fishery by a single Japanese vessel, which has caught a few thousand tonnes per year on average. Deep-water Prawns
The deep-water prawn fishery off the west coast of southern Africa (mainly for rose and striped prawns) began in 1966, when a single Spanish trawler started operating off Angola. By 1972, a fleet of 54 foreign (mainly Spanish) trawlers was operating off Angola, and catches had risen from about 1 000 tonnes per annum to over 8 000 tonnes per annum. The catch peaked at over 12 000 tonnes in 1973, whereafter there was a sharp reduction in Spanish operations, ending in complete withdrawal from the fishery by 1977. The Spanish fleet was replaced by a Cuban fleet, which continued to fish until 1979, the total catch peaking at 11 400 tonnes in 1975. Since then catches have declined, with annual landings of the two species combined over the past decade fluctuating between about 3 500 and 7 000 tonnes per year (Fig. 12) peaking in 1997. In all but two of the years, landings of rose prawn have been higher than those of the striped prawn. At present, there are 44 vessels in the fishery, of which 22 are fishing under an agreement with the European Union, and the remainder are national.
Fig. 12 Annual landings of deep-water rose prawn and striped prawn in Angola since 1988 (from Sardinha) 1998)
39 Anchor Environmental Consultants
4.4 Commercial linefisheries
The total annual catch of tuna in Angolan waters between 1993 and 1995 reported to ICCAT varied between 291 and 910 tonnes, with yellowfin tuna (caught by local baitboats and longliners) and big-eye tuna (caught by foreign longliners) making up most of the catch .
Foreign longliners caught tuna in Namibian waters under South African licence prior to Independence in 1990. The Namibian-controlled tuna fishery started in 1991, and since then an average of 2 330 tonnes of tuna (predominantly southern albacore) have been taken per year by a fleet of about 30 local and foreign-owned pole or line vessels. The foreign longline tuna fishery, which targets bigeye tuna for the high-value sashimi market, started in 1993. Catches have varied between 52 tonnes in 1996 and 1 005 tonnes in 1994. Experimental catches of swordfish Xiphias gladius taken by surface longlining have been low (50 tonnes in three years), but are regarded as encouraging given the low level of effort. An average of 770 tonnes of snoek has been taken per year by commercial vessels since Independence, mostly by handline (Boyer et al. 1998). Catches of silver kob from commercial linefish vessels have fluctuated over the past three decades around an average of about 500 tonnes per year. It is estimated that at present the recreational catch of silver kob is roughly equal to the commercial catch (Kirchner 1998).
The commercial linefishery in South Africa developed rapidly after the Second World War, reaching its peak in the late 1960s, when about 20 000 tonnes on average were caught per year. Thereafter, catches declined despite increasing effort. The average annual catch of all species excluding tuna between 1993 and 1997 was 11 700 tonnes, of which just over half was caught west of Cape Point. Snoek have consistently contributed over half the catch since the start of the fishery. The average catch over the past five years was 6 650 tonnes, of which more than half was landed at St Helena Bay and Yzerfontein on the West Coast. The second-most important species in terms of landings was hake, with average landings of just under 1 000 tonnes per annum, caught mostly on the South Coast. Other important species include yellowtail Seriola lalandi, kob spp. (particularly Argyrosomus inordus) and geelbek Atractoscion aequidens, which together contribute almost as much as snoek to the annual landings.
There is a large and varied recreational fishery for linefish species in South African waters, particularly on the South and East Coasts. Off the West Coast, the species most commonly taken from boats are tuna, snoek and yellowtail, while galjoen, hottentot, silver kob and white stumpnose Rhabdosargus globiceps are the bony fish most commonly caught by shore-anglers.
The baitboat (pole) fishery for tuna in South African waters started in 1980, and by 1990 about 10 000 tonnes of tuna (predominantly southern albacore) were being caught per year. Catches subsequently declined to about half this (6 571 tonnes on average between 1993 and 1997), but reached about 8 000 tonnes again in 1998. For the past two decades there has also been a longline fishery
40 Anchor Environmental Consultants for large bigeye and yellowfin tuna by Japanese and Taiwanese vessels fishing under license, catches of the latter species being confined to the warmer waters east of Cape Point. In 1997, experimental pelagic longline permits were issued to South African fishermen, primarily to target high-grade tuna for fresh export. The vessels have made good tuna catches along the edge of the continental shelf, and have also caught substantial quantities of swordfish (probably nearly 1000 tonnes in 1998), which has a high market value and is likely to be exploited more heavily in the next few years.
4.5 Artisanal/subsistence fisheries
By far the most important artisanal fisheries in the region are in Angola, where they contribute some 30% of the total landings of fish and shellfish. Declared landings from this sector in 1997 amounted to nearly 30 000 tonnes (Anon. 1998a). In 1995 there were more than 23 000 registered artisanal fishermen, landing their catches at some 105 controlled landing places, predominantly in the central provinces of Luanda, Benguela and Kwanza Sul (Delgado and Kingombo 1998). The total number of boats in 1995 was estimated at 4 677, ranging in size and sophistication from unmotorised canoes (about 25% of the total) to small wooden boats 5 - 6.5 m long with or without motors (“chatas”), which make up about 70% of the total, to 8 – 12 m vessels (“catrongas”) with inboard motors and some preservation facilities (Delgado and Kingombo 1998). Larger “traineiras” (8 – 25m semi-industrial deckboats with inboard engines) are also involved in small-scale fisheries along the coast. The most common fishing gears are gillnets, longlines, and beach- and boat-operated seine nets and traps. The main species caught are pelagic fish such as sardine and sardinellas, horse mackerel, mullet, bigeye grunter and small tuna, and demersal fish such as bigeye dentex, croakers and groupers. Fresh fish is sold in urban areas close to the landing sites, or because of a lack of freezing facilities, is dried or smoked for sale in the rural areas.
Artisanal/subsistence fisheries off the West Coast of South Africa (particularly for mullet Liza richardsoni, which is now caught mainly by beach-seine and driftnets), have been in existence for centuries, but are of negligible value compared to the nation’s major industrial fisheries. In Namibia there is virtually no artisanal/subsistence fishing, because of the uninhabited desert coastline.
4.6 Recreational fisheries
Marine recreational fishing from skiboats and larger gamefishing boats, and by rock-and-surf anglers and spearfishermen is an important leisure activity in South Africa, and directly or indirectly generates a significant amount of employment and revenue (see Section 7). The sector has grown rapidly since the Second World War, to the extent that surveys indicate that approximately
41 Anchor Environmental Consultants
15% of coastal residents now fish in the sea on a regular basis. As the fishery has grown, there has been a tendency along the entire coast for catch rates to decline, and for endemic inshore reef species (such as galjoen and white stumpnose in the Western Cape) to be replaced by cartilaginous fish in the rock- and-surf catches.
Recreational fishing in Namibia is pursued by rock-and-surf anglers, who have access to about 20% of the coastline, and skiboat fishermen operating from Walvis Bay, Swakopmund and Lüderitz. The sector has grown rapidly in recent years, and now attracts many visitors to the coast, particularly from Namibia and South Africa, generating considerable employment and revenue in the coastal towns (see Section 7). With the recent increase in fishing pressure, the number of fish caught per angler has declined significantly.
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5. CHANGES IN ABUNDANCE AND DISTRIBUTION OF MAJOR RESOURCES
5.1 Pelagic resources
Sardine and anchovy
Virtual Population Analysis (VPA) estimates of sardine biomass in Namibia between 1952 and 1988 (Fig. 13) confirm the marked decline of the stock in the second half of the 1960s, and the collapse to well below 1 million tonnes in the mid 1970s. Catch patterns have clearly indicated a northward shift in the core distribution since the collapse of the fishery in the 1970s, possibly as a result of the depletion of the southern spawning population and the cessation of associated migrations. Acoustic survey estimates of sardine on the Namibian/southern Angolan shelf since 1990 (Fig. 14) indicate that the adult stock is still well below pre-collapse levels, with an all-time lowest estimate of only a few thousand tonnes in the summer of 1995/1996, co-incident with the Benguela Niño at that time (Section 6.1). The surveys also indicated a further northward shift in distribution in 1994, when the majority of the biomass was found off southern Angola. Survey estimates of anchovy and juvenile round herring combined (they are not distinguished in the surveys) have dropped from levels of around 200 000 tonnes between 1990 and 1993 to below 100 000 tonnes since then. The decline is reflected in the anchovy landings, which have
12
10
8
6
4
2
1945 50 55 60 65 70 75 80 85 90 95 been negligible since 1996.
Fig. 13 VPA estimates of sardine biomass in Namibian waters from 1952 to 1988 (from Boyer 1996)
43 Anchor Environmental Consultants
Angola 700 Namibia 600 * * 500 * * * 400 * * 300
200 * 100 * *
SURVEY YEAR (months)
Fig. 14 Estimates of sardine biomass in Namibia/southern Angola since 1990, obtained from acoustic surveys (updated from Boyer 1996). * = Angola not surveyed.
In South Africa, acoustic surveys of sardine over the past 14 years have revealed a gradual increase in spawner biomass from below 50 000 tonnes in 1984 to around 600 000 tonnes at present (Fig. 15). The same surveys (supported by concomitant egg-production surveys between 1983 and 1990) have revealed two major peaks in anchovy spawner biomass in South African waters during this period, with pronounced troughs in 1989/1990 and in 1996 (Fig. 15). Acoustic surveys of sardine and anchovy recruitment off South Africa show the same general pattern (Fig. 16), except in 1995, when strong anchovy recruitment was not matched by a high spawning biomass in that or the previous year. Of particular note is the high degree of correlation between the sardine and anchovy recruitment estimates throughout the time-series, which suggests that, in South Africa at least, recruitment of these two species is controlled largely by
1 500 Anchov y
1 000
500
Sardine
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997
44 Anchor Environmental Consultants common environmental influences on the early life history stages, and not primarily by spawning biomass.
Fig. 15 Acoustic estimates of anchovy and sardine spawner biomass off South Africa since 1984 (from Barange et al. in press) The South African surveys have also revealed significant shifts in sardine and anchovy distribution in the Southern Benguela since the early 1980s, the most prominent of which was a sudden large increase in the number of anchovy spawners on the West Coast in 1986, followed by a progressive reduction to the more normal low levels over the next three years (Hampton 1992). A significant eastward shift in both the anchovy and the sardine spawning populations has also been recorded in the past decade, from 1990 in the case of anchovy, and from 1988 onwards for sardine (Barange et al. in press).
120 Anchov y Recruits 100 500.000 Biomass 80 400.000
60 300.000
40 200.000
20 100.000
Sardine 30 Recruits 250.000
25 Biomass 200.000 20 150.000 15 100.000 10
5 50.000
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997
Fig. 16 Acoustic estimates of the number and biomass of anchovy and sardine recruits off South Africa since 1995 (from Barange et al. in press)
Sardinella
45 Anchor Environmental Consultants
Dr Fridtjof Nansen acoustic survey estimates of the biomass of sardinella (S. aurita and S. maderensis combined) in Angolan waters between 1984 and 1997 are shown in Fig. 17, which suggests that sardinella biomass has increased from
600
500 Sardinella 400
300
200
100
SURVEY levels of around 200 000 tonnes in the 1980s to more than double this in the 1990s. (This increase was probably at least partly due to the withdrawal of a major part of the distant-water foreign fleet in the late 1980s). It should be noted that at least some of the survey estimates are possibly negatively biased because of the difficulty in assessing sardinella acoustically when the fish are on or close to the surface, which frequently occurs.
Fig. 17 Estimates of sardinella (S. maderensis and S. aurita) biomass in Angola since 1985, from Dr Fridtjof Nansen acoustic surveys (Data from IIP)
Round herring
According to acoustic survey data, round herring spawner biomass in South Africa appears to have remained relatively constant at around 1 million tonnes since the first estimate was made in 1986. No pronounced shifts in the distribution of adults have been noted from the survey data, although since the surveys have not always encompassed the distributional range of the population, the possibility of such shifts cannot be excluded.
5.2 Trawled species
Hakes
Survey estimates of M. capensis and M. paradoxus abundance off South Africa
46 Anchor Environmental Consultants and Namibia over the past decade, derived from swept-area demersal surveys (supplemented by acoustic estimates of fish above the trawl in the Namibian surveys), are shown in Fig. 18. It is notable that there has been a marked increase in the abundance of M. paradoxus off Namibia since 1992, which is confirmed by a marked increase in the proportion of M. paradoxus in the Namibian hake catches in recent years (E. Voges, NatMIRC, pers. comm.). This increase may indicate northward displacement or expansion of the stock from South Africa, or alternatively, a shoreward displacement in response to changes in the oxygen content of bottom waters. Fig. 16 indicates that in Namibia, the component of the population targeted by the fishery (i.e. M. capensis >35 cm long) grew between Independence in 1990 and 1992, but thereafter declined for the next four years. The most recent survey results indicate exceptionally good recruitment in 1997 (Boyer et al. 1998), with a subsequent increase in fishable biomass to the highest level since Independence. Off South Africa, the survey results suggest an increase in M. paradoxus biomass on the West Coast over the past decade, but no clear trend in the biomass of M. capensis. The low estimate for M. paradoxus in 1992 supports the hypothesis of a longshore displacement of the Cape stock into Namibian waters in that year, but given the uncertainty in the estimates, this apparent connection should be viewed with caution.
1200 South Af rica Namibia
800
400
M. capensis M. paradoxus < 35 cm
Fig. 18 Research survey estimates of the biomass of Cape hakes (Merluccius capensis and M. paradoxus) off the West Coast of South Africa and off Namibia (data from M&CM and NatMIRC respectively)
Fig. 19 (from Anon. 1998b) shows trends in exploitable and total biomass of hake on the West Coast of South Africa from 1917 to the present, estimated from an age-structured production model. All indications are that the stock has been relatively stable over the past two decades, with signs of a gradual increase in recent years.
47 Anchor Environmental Consultants
2 000 Exploitable biomass Total biomass 1 600 Catch
1 200
800
400
1927 1937 1947 1957 1967 1977 1987
Fig. 19 Estimates of the exploitable and total biomass of Cape hakes in South African waters since 1917 from an age-structured production model (from Anon. 1998b)
Horse mackerel
Acoustic estimates of horse mackerel (mainly T. trecae) biomass in Angolan waters between 1985 and 1997, obtained from Dr Fridtjof Nansen surveys, are shown in Fig. 20. There appear to be two distinct periods: from 1985 to about 1995, when T. trecae biomass fluctuated around a level of about 200 000 tonnes and capensis biomass was occasionally of the same order, and from 1995 to the present, when T. trecae levels have been about twice as high, and T. t. capensis biomass very low. In all surveys the abundance was highest in central and southern Angola, except in 1996 (a year of anomalously warm conditions along the whole Angolan coast) when a third of the biomass was found in the north, between Luanda and Cabinda. The level of these estimates compared to the catches made at the height of the Angolan horse mackerel fishery (over 380 000 tonnes in 1978) is clear indication of the decline of the resource, which is supported by the more than 10-fold reduction in annual catches which has occurred since then (Section 4.1).
600 Cunene horse mackerel 500
400
300
200
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48 SURVEY Anchor Environmental Consultants
Fig. 20 Acoustic survey estimates of Cunene and Cape horse mackerel biomass in Angolan waters since 1985. Data from IIP (NB: check this Fig!)
Using a VPA of catch data from the former Soviet bloc fleet, Vaske et al. (1989) estimated that the biomass of Trachurus spp. in ICSEAF Divisions 1.3, 1.4 and 1.5 (i.e. between southern Angola and Cape Agulhas) between 1973 and 1987 fluctuated between about 1.5 and 2.3 million tonnes. This estimate must however be treated with caution because of, inter alia, the unreliability of the age-length keys used in ageing the fish. Since 1990, the biomass of adults and juveniles combined off Namibia and southern Angola has been estimated by annual acoustic surveys, predominantly from Dr Fridtjof Nansen (Fig. 21). The estimates generally fall between 1 and 2 million tonnes, with a maximum of 2.1 million tonnes in 1992. In an absolute sense, these estimates are questionable because of the lack of verification of the target strength expression used. For example, use of a target strength expression for T. trachurus capensis developed in South Africa (Barange and Hampton 1994) would lower the estimates by a factor of approximately 3. Furthermore, some of the differences between the surveys have been attributed to variations in the proportion of the population which is acoustically detectable rather than to fluctuations in the biomass (Anon. 1998c) – a problem which has also been experienced in acoustic surveys of horse mackerel in South Africa (see below).
2 000
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Fig. 21 Acoustic survey estimates of (predominantly) Cape horse mackerel biomass in Namibian waters since 1989. Data from NatMIRC
49 Anchor Environmental Consultants
Bottom trawl survey estimates of T. trachurus capensis biomass on the South African West Coast between 1985 and the present have increased from less than 10 000 tonnes in 1986 to between 50 000 and 300 000 tonnes since 1991. Equivalent estimates on the South Coast over this period for the 0-200m depth stratum have fluctuated between 100 000 and 580 000 tonnes, with an average of about 300 000 tonnes. There is however evidence from acoustic surveys and other acoustic observations that the South Coast trawl estimates are negatively biased because of the unavailability of part of the population to the bottom trawl at certain times and in certain areas (particularly on the outer shelf and over the shelf-break).
Deep-water fish
From a swept area analysis of commercial catches in 1996 and 1997, Branch (1996) and Branch and Roberts (1998) estimated the total abundance of orange roughy on the Namibian shelf at that time at over 200 000 tonnes. No biomass estimates considered reliable have yet been obtained for alfonsino. An acoustic survey of the three most important roughy grounds from Dr Fridtjof Nansen in 1997 gave an estimate of 147 000 tonnes after correction for the major sources of bias. A major difficulty in assessing the total roughy population by either trawl- based or acoustic methods is the lack of knowledge regarding the proportion of the population outside the known aggregations.
5.3 Crustaceans
West coast rock lobster
The Schaefer and Fox production models used to estimate the MSY for the Namibian rock lobster resource (Section 8.4) have given values of 4 300 and 3 100 tonnes respectively for the period 1958 - 1991. If the very variable data from the 1960s and the TAC-restricted data from the early 1990s are ignored, these estimates drop to 1 900 and 1 800 tonnes respectively. Recent modeling estimates put the stock at around 3 000 tonnes at present.
Assessments of the South African rock lobster resource based on conventional size-based analyses have shown it to be seriously depleted, estimates of recruitment in recent decades being only some 35% of pristine.
Deep-sea red crab
Photographic surveys of red crab within two approximately 50-km long sections of the northern Namibian shelf in the early 1980s indicated a biomass of approximately 5 000 tonnes in the one area and about 2 000 tonnes in the other. Recent estimates from analytical models (Section 8.4) indicate that the Namibian component of the stock has declined from about 40 000 tonnes at that time to around 10 000 tonnes in the 1990s, which is reflected in the decline in the catch rate during this period (Section 4.3). In Angola, estimates of 47 6000 tonnes, 91 000 tonnes and 18 000 tonnes have been reported for 1977, 1982 and 1996
50 Anchor Environmental Consultants respectively (Neto 1997), perhaps indicating a decline of the Angolan stock as well, which might be expected in view of the fact that this appears to be a single shared stock, with considerable trans-boundary migrations.
Deep-sea prawns
Estimates of rose prawn and striped prawn abundance off Angola have been made from Dr Fridtjof Nansen trawl surveys between 1985 and 1997. The estimates for the two species combined vary between 1 770 tonnes in 1996 and 5 850 tonnes in 1986, divided almost equally between the two species. There does not appear to have been any major shift in distribution during the survey period.
5.4 Line-caught species
Judging from commercial handline catches, the abundance of snoek in Namibia increased some three-fold between 1970 and 1980, probably in response to an increase in the abundance of prey in the form of juvenile horse mackerel, which was then the dominant pelagic fish species in the region. This increase was also reflected in catches of snoek by the international midwater trawl fleet operating off Namibia at the time, which rose sharply during this period to levels of over 20 000 tonnes per year. Relatively constant catches by commercial linefishermen and in trawls since Independence suggest that the population is relatively stable at present, although the trawl catches are now an order of magnitude lower than in the 1970s and 80s. It is not clear whether the latter reflects a major reduction in biomass, or is due to a change in distribution and/or fishing strategy.
Commercial catches of other linefish species in Namibia have also not fluctuated widely since Independence. Kirchner (1998) has recently estimated that the current exploitable biomass of the most important of these (silver kob) is in the region of 11 000 tonnes. The estimate was obtained from a Thompson and Bell yield-per-recruit model, using catch-at-age data for two years. She estimates that the stock is currently at between 29 and 46 % of its virgin biomass and that the current fishing mortality is between 0.12 and 0.22 yr-1.
Fluctuations in the abundance of line-caught species in South Africa are evident from catch-per-unit-effort (CPUE) indices, which for practically all species have declined over the past few decades, to almost zero in some cases. This is the case for both resident reef fish and migratory shoaling species. For many of the latter it has been estimated that spawner biomass/recruit ratios are now below the recommended critical threshold level of 25% (Penney et al. 1997), with ratios for important species such as the silver kob being only 3 – 12% of pristine. As a result of stock declines, the distributional ranges of many of these species appear to have contracted towards the centre of their past distributions, and the magnitude and extent of their migrations has declined. Of the migratory shoaling species, snoek and yellowtail are perhaps the only ones considered not to be overexploited in South African waters, although there have been substantial fluctuations in abundance and distribution of both species in the past, probably in
51 Anchor Environmental Consultants response to changes in the abundance and distribution of their pelagic prey.
Seals and seabirds
The Southern African seal population was heavily overexploited in past centuries and the breeding colonies around the Cape Peninsula were exterminated soon after the arrival of European settlers in the 17th century. Subsequently, as a result of conservation measures applied over many years, and probably the establishment of new mainland colonies in areas of restricted human access, the population increased from around 100 000 animals in 1900 to 1.5 to 2 million animals in the early 1990s, as deduced from aerial surveys of pups and tag- recapture studies. The Namibian population subsequently declined (probably by almost a factor of 2) as a result of breeding failure and high pup and adult mortalities brought about by the effects of the 1994-95 intrusion of warm, low- oxygen water into northern Namibia (Anon. 1997a). In 1994 and 1995 there was also a northward shift in distribution, with Cape fur seals being found as far north as Luanda, feeding on sardinella. Recent information suggests that the distribution has now returned to normal, and that the population has almost recovered to previous levels (Geromont et al. in press).
Aerial censuses have shown that between 1956 and 1986, the population of Cape gannets at the Namibian colonies declined from around 200 000 adults to only about 50 000, which was probably due to the decline and subsequent collapse of the Namibian sardine resource during this period. Over the same period the adult populations at the two colonies off the Westen Cape remained relatively constant at around 30 000 birds, whereas numbers at Bird island, Algoa Bay, increased from around 20 000 to approximately 60 000 birds. The surveys also revealed a substantial decline in the numbers of Cape cormorant, from more than a million birds in the early 1970s to about 277 000 pairs in the late 1970s, and only about 120 000 pairs in the mid 1980s. The decline was most severe in the north. As with the gannet, the population on the South Coast increased as the West Coast population declined, by a factor of five between 1956 and 1978. The African penguin population in Southern Africa has been reduced to very low levels during the last few centuries through prolonged and excessive egg collection and disruption of their breeding habitats during the guano rush in the 1840s. The most recent estimate of the total population, from an aerial census in 1995, is about 150 000 birds, of which about 40% were found on islands off the South African West Coast. Even allowing for underestimation owing to inadequacies of the aerial survey technique, this population is probably at least an order of magnitude below pre-exploitation levels.5 2525252525252525252525252525252525252525252525252525252525 2525252525252525252525252525252525252525252525252525252525 2525252525252525252525252525252525252525252525252525252525 2525252525252525252525252525252525252525252525252525252525 2525252525252525252525252525252525252525252525252525252525
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54 Anchor Environmental Consultants
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55 Anchor Environmental Consultants
perhaps to have been displaced.
In the southern Benguela, the exceptionally good anchovy recruitment in 1986 and 1987 is thought to have been at least partly associated with enhanced leakage of Agulhas Bank shelf water onto the West Coast, and the increased influence of westerly winds, which would have resulted in favourable transport and entrainment of eggs and larvae with minimum offshore advective loss. The weak anchovy recruitment in 1989 was associated with poor feeding conditions during the latter part of 1988 in the spawning area over the western Agulhas Bank, and with less favourable transport to the nursery grounds on the West Coast. In general, it appears from extensive studies of transport mechanisms, food availability, wind stress, primary production and other environmental influences, that in the southern Benguela there is an optimum environmental window for good anchovy (and probably sardine) recruitment, with too much or too little wind stress, primary production etc. being detrimental to recruitment (e.g. Hutchings et al. 1998). Variations in these conditions may explain much of the observed variation in recruitment (Fig. 16), and hence in spawning biomass, although there is evidence that other factors such as temperature and feeding conditions on the spawning ground, the location and duration of the spawning, and the condition of spawners can also have an effect on recruitment (e.g. Hutchings et al. 1998, Painting and Korrûbel 1998, Korrûbel et al. 1998, Shannon 1998). The balance of the evidence does however suggest that offshore advective loss of ichthyoplankton, which is present to some extent in all years, is probably a major controlling factor in both anchovy and sardine recruitment. Isolating and ultimately quantifying the most important environmental factors affecting the recruitment of pelagic fish in the Benguela region is a major research thrust, both in national research programmes and in regional/international programmes such as BENEFIT, ENVIFISH and VIBES (see Section 8.3).
On a larger scale, the meridional distribution of sardine and anchovy in the Benguela Current may be affected by shifts in the major wind belts across the African continent. Their distribution might therefore be expected to be connected to that of sardine and anchovy in the Canary Current, which would also be affected by such shifts. In contrast, there is some evidence that regime shifts in the Benguela, and switches between sardine and anchovy dominance (which according to scale-deposit studies have a characteristic periodicity of around 50 years), tend to be out of phase with those in the Pacific. It is also notable from a comparison between Figs 7 and 8 that, over the past two decades, there has not been a close correspondence between abundance trends in the northern and southern Benguela for either sardine or anchovy. This could possibly be due to the major differences in the geographical relation between the spawning and upwelling areas in the northern and southern Benguela noted in Section 3.1, and consequent differences in the effect of wind stress on recruitment processes.
6.2 Trawled species
Relatively little is known about the behaviour of Cape hakes in the Benguela
56 Anchor Environmental Consultants ecosystem, and of their responses to environmental variability and change. Adult hake are good swimmers, undergo vertical migrations, can tolerate a range of temperatures, and are particularly well-adapted to low oxygen conditions, the adults being able to tolerate levels as low as 0.25 ml l-1 . They are therefore well able to react to unfavourable environments, and being opportunistic feeders, long-lived and inhabiting a wide area, should be robust to all but major environmental perturbations. There is some evidence to suggest that low surface temperatures favour hake recruitment, or at least that the recruits are more abundant and at higher densities during cool periods, e.g. in 1992 in the case of M. capensis in Namibia, and in 1987 for M. paradoxus in the southern Benguela. Also, there has been a clear positive correlation between monthly catch rates and SST in Namibia in certain years (e.g. 1994 through 1996), although in other years (e.g. 1993 and 1997) the correlation has been as clearly negative (Boyer et al. 1998). The reasons for these apparent connections are not understood. The response of hake to hypoxic conditions is of particular interest in Namibia, where levels over a large part of the shelf can become intolerable even to hake, possibly causing major shifts in distribution, affecting recruitment strength (Woodhead et al.1996), and causing increased mortality of juveniles and older fish if extensive and persistent enough. For example, Hamukuaya et al. (1998) found that persistent and pronounced hypoxic conditions off central and northern Namibia in 1994 displaced M. capensis offshore, subjecting them to heavy mortality from predation by larger hake and trawling. Improving understanding of the effects of temperature and oxygen fluctuations on the distribution, abundance and behaviour of hake in the Benguela region is the focus of a number of local, regional and international research efforts.
Little is known about the reaction of adult horse mackerel to environmental perturbations in the Benguela, although it is believed that in Namibia, warm- water intrusions can cause the fish to move closer inshore (Klingelhoeffer 1996). This is supported by the fact that in Namibia over the past five years, there has been a clear positive correlation between seasonal trends in CPUE and surface temperature along the 200m isobath (Boyer et al. 1998), and by historical catch data, which show that there was a large-scale southward shift in the distribution of both T. trachurus capensis and T. trecae in the northern Benguela in the late 1950s/early 1960s, coinciding with the intrusion of warm, highly saline water from the north. This was followed by a northward movement from the mid 1970s, following a period of cooling. The effect of the environment on the distribution and migration of horse mackerel in the Benguela as a whole is an important trans-boundary question, inter alia for interpreting and comparing survey results in neighbouring countries.
The possible effect of environmental changes on the deep-water resources of the region is totally unknown, but it could be substantial. For example, the fact that orange roughy off Namibia concentrate within a narrow temperature range and spawn on very specific sites suggests that any significant change in the near-bottom temperature could have a major impact on the distribution and perhaps the spawning process, which could severely disrupt the fishery targeting these sites.
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6.3 Crustaceans
There is evidence that the declines in J. lalandii lobster production in Namibia and South Africa which occurred towards the end of the 1980s were at least partly environmentally induced. In the southern Benguela, the decline resulted from reduced growth rates, whereas off Namibia it was attributed to changes in availability related to oxygen fluctuations in bottom waters, aggravated by over- fishing. Since there is relatively little longshore migration of rock lobster, and it is improbable that fishing impacted all areas simultaneously, it seems most likely that the resource responded to some large-scale change in the environment. In the south, the decline in growth rates may have been caused by a reduced biomass of ribbed mussels, or by changes in primary production and a regime shift in the benthic foodweb.
6.4 Line-caught species
Relationships between linefish species and the environment in the Benguela have not been formally studied or quantified in any way. As most linefish species are predators, the effects of environmental perturbations on their distribution and abundance is likely to be secondary, through more direct effects on the abundance and distribution of their prey.
6.5 Seals and seabirds
The high mortality and breeding failure of Cape fur seals at all the Namibian colonies in 1994 and 1995 was accompanied by a drastic deterioration in the condition of both pups and adults, and was clearly the result of low food availability over most of their habitat. This is confirmed by the estimates of low sardine abundance in the period between 1994 and 1996 (Fig. 14). Likewise, the major reduction in the number of Cape gannets in southern Namibia (particularly at Ichaboe Island) in the 1960s and 1970s would appear to be related to the decline of the Namibian sardine stock during this period, the sharpest decline occurring in the mid-1970s, coincident with the collapse of the fishery. The decline of the sardine stock appears to have had a similar, but somewhat less pronounced, effect on the Cape cormorant population off Namibia.
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7. SOCIO-ECONOMIC IMPORTANCE
Summary data on the economic value of Namibian and South African commercial fisheries in 1996 and 1997 respectively are set out in Table 2. (The information available for Angola is less detailed, and cannot be given in this form).
FISHERY NAMIBIA (1996) SOUTH AFRICA (1997)
Landed value Wholesale Landed value Wholesale (Million N$) (processed) value (Million R) (processed) value (Million N$) (Million R)
Pelagic Canned fish 28.3 291.0 Fish meal & oil 45.8 66.6 Bait 3.4 8.4
Total 26.0 93.9 77.5 366.0
Demersal Bottom 593.3 * 718.1 406.1 ** 1 000.5 ** Midwater 275.1 293.0 Deep-water 94.2 171.1 Longline 22.2 40.0
Total 962.6 1 182.2 428.3 1 040.5
Crustacea Rock lobster 13.0 20.2 50.9 102.2 Red crab 17.7 17.7
Total 30.7 37.9 50.9 102.2
Line Tuna 10.3 12.9 Snoek 24.9 48.5 Other 32.7 44.7
Total 13.3 44.7 67.9 106.1
Total 1 032.6 1 358.7 624.7 1 614.7
Table 2. Value of major industrial fisheries in Namibia and South Africa in 1996 and 1997 respectively. Namibian data from MFMR. South African data from Stuttaford (1998). Note: N$1 = R1. * Includes longline catches ** Includes midwater trawl catches The following is a more general description of the socio-economic value of the
59 Anchor Environmental Consultants major fisheries in each of the three countries
Angola
The fisheries sector is very important in Angola, being the third-most important industry after oil and diamond mining. It provides nearly half of the animal protein of the country, and is an important source of employment and food to populations of the coastal regions, where it is often the only source of livelihood for the poorer population groups. Domestic consumption of fish, which was estimated at 11.1 kg per person per annum in 1994, is the highest in the region.
According to the results of a survey conducted in 1992, there were at that time around 30 000 workers directly involved in activities of the fisheries sector, of which some 18 000 were involved in artisanal fisheries. The remainder were involved in industrial fisheries and public administration. In addition, it was estimated that some 5 000 persons (mainly women) were involved in informal fish trade activities. A more recent report (Delgado and Kingombo 1998) puts the number of artisanal fishermen a few years later at over 23 000, and the number of people involved in informal fish trading at between 20 000 and 30 000. Many artisanal fishermen are not able to make a living solely from fishing, and supplement their incomes by, for example, agricultural and commercial activities.
At present, roughly half of the revenue from fish and fish products in Angola comes from exports, which varied in value between US$ 27 million in 1993 and US$ 46 million in 1995. Prawns are the most important product, making up 48% of the total revenue from the fishery sector in 1995, for example. The main export markets are Europe for prawns and demersal fish, African countries for small pelagic fish including horse mackerel, and Japan for tuna and crab.
Although some of the resources have clearly been overexploited, others are probably still under-utilised, evidenced by the fact that, in some of the fisheries, TAC limits have often not been reached, and that total industrial catches before Independence were typically some three times higher than they are now. This is partly due to operational constraints stemming from a breakdown in infrastructure during the civil war, and the socio-political and security situation in the county at present. With greater political and economic stability, some of these resources could well contribute more to the Angolan economy than they do at present.
Namibia
Fisheries is the third-largest sector of the Namibian economy, behind agriculture and mining, The industrial fishery has generated more than 10% of the GDP in recent years, producing products to the value of N$ 1 374 million in 1996. Exports were valued at N$ 1 048 million in that year, making the sector the second-largest export earner behind mining. It is the second-fastest growing industry in the Namibian economy (behind tourism) with the value of production and exports now being some six times greater than at Independence.
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The fisheries sector is extremely important in the social economy of Namibia, particularly in Walvis Bay, which is the major fishing port and where most of the processing plants are situated. Local employment in the sector grew rapidly after Independence, with an estimated 6 000 jobs having been created between 1991 and 1994. The integration of Walvis Bay into Namibia in 1994, and the removal of the uncertainty regarding the port’s future, stimulated an influx of investment in the fishing industry and subsidiary service industries with a further growth in employment. The number of people directly employed in the fisheries sector in 1996 was about 15 000, of which some 7 500 were fishermen. Of these 43% were foreigners, mainly in the horse mackerel and tuna fisheries, a proportion that has decreased from around 66% in 1993. It has been projected that by the year 2 000, the total number of people employed in the fisheries sector will have risen to above 20 000, exceeding the original target of 15 000 set in 1992.
The demersal fishery is the most valuable fishery in Namibia. In 1996 the catch had a landed value of N$ 593 million, and a final value after product beneficiation of N$ 718 million. About 90% of the catch is either sea-frozen or wetfish hake. Monkfish make up most of the remainder, with the average landed value of the catch in recent years amounting to some N$ 70 million per year (Olsen 1997). Almost the entire demersal catch is exported.
The pelagic fishery is second in importance, canned sardine being the most valuable product. In recent years the total export earnings from the pelagic fishery have been around N$ 400 million per annum, except in 1996 when no fish were canned, causing exports to drop to N$ 91 million. In more normal years, canned fish, almost all of which is exported to South Africa, make up more than 90% of the export earnings of the fishery, with fishmeal contributing almost all of the remainder.
The midwater trawl fishery for horse mackerel has contributed some N$ 250 million per year in exports in recent years, mostly in the form of relatively low- value frozen fish, with minor contributions from fishmeal (around 10% ) and dried-salted fish (approx. 3 % in 1996). There is little product beneficiation, the export value of the catch being typically only about 10% above the landed value. Only about 3 % of the production is consumed domestically.
The deep-water fishery has made a significant contibution to the fisheries sector in recent years, with exports to the value of N$ 171 million in 1996. Orange roughy contributes more than 90% by value, and alfonsino most of the remainder. Processing (mainly the production of high-quality fillets for the USA and Japanese markets) approximately doubles the value of the catch, and is labour-intensive, providing much-needed employment in Walvis Bay.
The above four industries contribute more than 90 % by product value of all of Namibia’s industrial fish production. Of the remainder, only the tuna (3%), crab (1.5%) and rock lobster fisheries (1.5%) contribute more than 1% in most years. To these must be added the recreational linefishery. Kirchner, Sakko and Barnes
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(in press) have estimated that between October 1997 and September 1998, some 8 800 anglers spent 173 000 days angling, and had direct expenditures of N$ 29.7 million. Value added to gross national income within the shore-angling fishery during that period was estimated at N$ 14 million. The expenditures ultimately resulted in gross national income of some N$ 3 000 per angler, or N$ 27 million in aggregate.
South Africa
The living marine resources of the Benguela Current form the basis of a fishing industry which supports some 26 000 people (mostly in the Western Cape), and supplies food for the whole Southern African subregion. In 1997 the South African fishing industry caught a total of 445 000 tonnes of fish, shellfish and seaweed nationwide, of which more than 90% was taken from the Benguela. The wholesale value of the total processed output in this year was estimated at R 1 953 million, with an export value of R 873 million, on a par with Namibia. Fishing is particularly important in the social economy of the Western Cape, where some entire coastal communities depend directly or indirectly on fishing for their livelihood. However, the fishing industry yields less than 1% of South Africa’s GDP.
In terms of volume, the purse-seine fishery for pelagic species is the most important sector. In 1997 (a comparatively poor year), landings of pelagic fish totalled 286 000 tonnes, of which about a third was canned. Practically all of the remainder was reduced to meal. Because of the high local demand for fishmeal, and the comparatively small output of canned fish, the pelagic sector exports relatively little (export value R 31 million in 1996). The sector is entirely industrialised, the smaller vessels (some of which are privately owned) concentrating on anchovy and juvenile sardine for meal, and the larger, factory- owned vessels on adult sardine for canning.
Economically, the trawl fishery is the most important sector of the South African fishing industry. Catches of hake, which amounted to 147 000 tonnes in 1997, usually contribute about 70% of the trawl catch and about 80% of its value. Horse mackerel, snoek, monkfish and kingklip are the most valuable other trawled species, together accounting on average for about 20% by landing and value of the catch. In 1997 the landed value of processed products from a total demersal trawl catch of 200 000 tonnes was R 428 million. The value of hake exports in 1997 exceeded R 300 million; about a third of the total revenue from all South African fish and shellfish exports. The fish are largely caught by trawlers operating under quotas held by a number of large companies, although in recent years a number of smaller companies and private boat-owners have entered the trawl fishery. A longline fishery from smaller vessels has also been developing, accounting for about 3% of the hake catch in 1997.
The West Coast rock lobster fishery is a major export fishery in South Africa, about 75% of the catch being exported. In the 1997 season, 1 726 tonnes of rock lobster were landed from the West Coast, with a wholesale processed
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(mainly frozen tails) value of R 102 million. The rock lobster fishery is labour- intensive, and is an important source of employment and income in many fishing villages on the Cape West Coast.
The wholesale processed value of all commercial landings of linefish in South African waters in 1997 was estimated at R 106 million, of which about half was contributed by snoek. Contributions from tuna catches in this year made up 12% of the remainder. These figures do not represent the substantial direct and indirect contribution which recreational and subsistence fishing on linefish species makes to the South African economy. A recent nationwide survey conducted between 1994 and 1996 (Brouwer et al. 1997, McGrath et al. 1997) showed that over that period there were some 3 000 registered commercial linefish boats and about 7 900 skiboats operating off the South African coastline. About 18 100 crew were employed on the commercial boats, while nearly 14 000 recreational fishermen went to sea on skiboats. They estimated furthermore that roughly 412 000 people participated in shore-based angling, and about 7 000 each in beach-seining/gill- netting (largely a subsistence fishery) and recreational spearfishing. In all, they estimated that South Africa’s linefisheries and direct support industries provide employment to over 130 000 people, and that some 20 000 households living in poverty depend on linefish catches for about 9% of their household income. They put the total contribution of linefisheries to the gross geographic product (GGP) of South African coastal provinces (Western and Northern Cape, Eastern Cape and KwaZulu-Natal) at nearly R2 200 million, which amounts to 1.3% of the GGP of those provinces. Although a significant proportion of this was caught on the South and East Coasts, it is clear that the value of the South African linefisheries in the Benguela system is out of all proportion to the product value of the catch.
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8. MANAGEMENT
8.1 Policy and legal framework
In all three countries of the region it is the national policy to utilise living marine resources on a sustainable basis for the benefit of the nation, and to manage them according to scientific information and principles. Ultimate responsiblity for control measures rests with the State in all three countries. Most of the primary research on fisheries resources has been done by state-run research institutes operating within Government Departments (viz. the Ministry of Fisheries in Angola, the Ministry of Fisheries and Marine Resources in Namibia, and the Department of Environmental Affairs and Tourism in South Africa).
Angola
The nation’s marine and inland fisheries are managed and developed in terms of the Fisheries Act, which was developed with the assistance of the FAO and promulgated in 1992. The Act covers such aspects as fisheries management (which is implemented through various Executive Decrees governing different sectors of the fishery), planning and licensing, the control of the quality and export of fish products, and surveillance and enforcement. In recent years, with the move to a market economy in Angola, and the privatisation of large State- owned companies, the State has limited its activities to the management of the resources, surveillance, support of development and the creation of infrastructure.
The broad national policy regarding fisheries development centres around the stengthening of regulatory and management capabilities of the Government, the development of small-scale fisheries, developing and increasing the participation of the national fleet in industrial fisheries, the rehabilitation of land-based industries with an emphasis on frozen, salted and canned products, and the improvement of the quality and distribution of fish for domestic and export markets. In terms of this Policy, the State is encouraging conversion of present licencing agreements for foreign fishing into joint ventures involving local vessels and Angolan entrepeneurs.
Research is carried out by IIP, the Instituto de Investigação Pesqueira (Institute of Fisheries Research), and IPA, the Instituto de Desenvolvimento Pesca Artesanal (Institute for Development of Artisanal Fisheries), both of which fall under the Ministry of Fisheries and have headquarters in Luanda, with smaller regional laboratories along the coast. IIP annually submits a document on the current state of the fisheries resources in the Angolan EEZ and recommendations on TACs and other control measures to the Ministry of Fisheries, and maintains a corps of some 120 observers for monitoring catches. As part of the national surveillance system, Angola is already implementing a VMS for fishing vessels, which is one of the more advanced in the region. (CHECK_FONTES) The Ministry of Fisheries receives support for research and development from
64 Anchor Environmental Consultants donor agencies such as the Swedish International Development Agency (SIDA) and the Norwegian Agency for Development Co-operation (NORAD), and from fishing agreements with the European Union (EU). Cooperation with international bodies (such as the FAO) and various donor agencies and overseas laboratories (such as the Institute for Marine Research in Bergen and the Portuguese Institute of Marine Research in Lisbon) in the development and management of Angola’s fisheries is seen as very important. The development of links with other countries in the region (particularly Namibia) is also regarded as important, as is participation in regional marine science programmes such as BENEFIT (see Section 8.3), whose training and infrastructure-building goals are seen as being particularly pertinent to the needs of the country.
Namibia
In Namibia, a 200 nautical mile Exclusive Economic Zone was declared on Independence in 1990, followed by the promulgation of a new Sea Fisheries Act in 1992, and the introduction of a new national policy on exploitation rights and quota allocation in 1993. A major emphasis has been placed on Namibianization of all sectors of the fishing industry and the building up of local research and management capacity. Fisheries research is conducted within the Directorate of Resource Management of the Ministry of Fisheries and Marine Resources (MFMR), by the National Marine Information and Research Centre (NatMIRC) in Swakopmund and the Lüderitz Research Centre. Scientific recommendations for the harvesting of all resources except seals are presented to the Namibian Sea Fishery Advisory Council, which makes recommendations to the Minister of Fisheries and Marine Resources after considering socio-economic factors and the industry’s perception of the state of the resource. The Council also advises on the allocation of a research fund derived from levies on catches. The Minister, after consultation with a Fisheries Management Committee within the Ministry, submits TAC recommendations to Cabinet for final endorsement. Legislation is effectively implemented. All fish must be off-loaded under inspection at either Walvis Bay or Lüderitz, and a fisheries observer trained in basic biological sampling accompanies all vessels large enough to carry extra personnel. Surveillance is carried out by patrol vessels and aircraft, and a satellite vessel- monitoring system is being investigated. In addition to her national responsibilities, Namibia has established a SADC Sector Coordinating Unit within the MFMR to discharge her responsibility as Sector Coordinator for Marine Fisheries and Resources for the SADC.
South Africa
Until very recently, management of South Africa’s living marine resources was carried out in terms of the Sea Fisheries Act of 1988. TACs and other control measures were decided upon by the responsible Minister (most recently the Minister of Environmental Affairs and Tourism), acting on advice from his Department and a Sea Fisheries Advisory Committee (SFAC), which received input inter alia from the Department’s Chief Directorate of Sea Fisheries. The SFAC also made recommendations on the allocation of the Sea Fishery Fund, a
65 Anchor Environmental Consultants fund derived from levies on fish catches that was used to support research and development activities. Quotas were awarded by an independent Quota Board.
A new Act (the Marine Living Resources Act of 1998) has recently been promulgated. It includes in its objectives the achievement of broad and accountable participation in decision-making processes, and the restructuring of the fishing industry to redress historical imbalances and achieve equity within the industry. The SFAC has been replaced by a Consultative Advisory Forum (CAF), which is responsible for advising the Minister of Environmental Affairs and Tourism on management and development of the fishing industry (including the setting of TACs), research direction and allocation of a Marine Living Resources Fund, which replaces the former Sea Fishery Fund. The new Fund receives income from levies, licences, penalties and other sources, which permits its disbursement to spheres of fisheries management (e.g. administration, compliance) other than only research and development. The Minister is ultimately responsible for deciding upon TACs and other control measures, and for allocating quotas on advice from his Department. Implementation of fisheries regulations is still carried out by the Department, with assistance where necessary from the South African Navy and the Police Unit for Coastal Patrols. A VMS system to assist in monitoring the movements and activities of fishing vessels is currently being tested.
8.2 Research and management capacity
Local institutions
In Angola, accommodation available for marine science and technology is generally adequate, particularly at IIP headquarters in Luanda. However, the laboratories are not well equipped, and the support infrastructure (technical services, communications systems, computing and library facilities etc.) is inadequate to service the needs of the Institute. The Institute’s research vessel Goa is poorly equipped and is at present not operational, making the Institute totally reliant on foreign research vessels (particularly Dr Fridtjof Nansen) for research cruises in Angolan waters. Although the Institute employs a number of research staff with post-graduate degrees in marine science from overseas universities, most are graduates of the Agostino Neto University in Luanda, where no courses in marine science subjects are provided. Consequently there is an acute shortage of professional knowledge, both in terms of numbers and skills, which is only being partly overcome by post-graduate training within the Institute and abroad. The same is true of technical support personnel.
NatMIRC in Swakopmund, Namibia, currently employs a research staff of some 42 scientists, technicians and assistants, and the Lüderitz Research Centre, which is responsible for research on local resources in southern Namibia, about 10. NatMIRC’s office, laboratory, library and meeting facilities are new and excellent, and the Lüderitz facilities are even newer. NatMIRC possesses a range of reasonably modern equipment, and there is a public aquarium within the building to increase public awareness of marine issues. The Ministry
66 Anchor Environmental Consultants operates a 47 - m research stern trawler R. V. Welwitschia (scientific capacity 9) which is relatively new and well-equipped for resource and environmental surveys in local waters. All acoustic surveys on pelagic fish are now done on this vessel, but trawl surveys are still done on Dr Fridtjof Nansen and commercial trawlers because of limitations in Welwitschia’s bottom-trawling capability. The Ministry’s scientific staff are generally well qualified, but have limited experience. On appointment few have specific training as marine scientists, and most undergo further training through studying for post-graduate degrees at South African or overseas universities and the attendance of courses and specialist workshops locally or abroad. Training and research support is also received from donors and from foreign consultants attached to or engaged by the Ministry for varying periods. Nonetheless, there are staff limitations, a particular practical one being the shortage of qualified technicians to maintain and develop the specialised equipment needed for research.
Namibian institutions which are involved in marine science education, or which have the potential to become involved, are the University of Namibia (UNAM) in Windhoek, through a new course in natural resources which includes marine science subjects, and the Polytechnic of Namibia, through its nature conservation diploma. Through the BENEFIT Training Programme, inter alia, ways are being sought to strengthen the ties between NatMIRC and these institutions and other tertiary education bodies in the region.
In South Africa, statutory responsibility for advising on the state and management of marine living resources, and for carrying out the necessary research in order to do so, resides with the Department of Environmental Affairs and Tourism. Research was until very recently carried out by the Sea Fisheries Research Institute (SFRI) in Cape Town, which resorted under the Department’s Chief Directorate of Sea Fisheries. The Institute had an establishment of some 150 scientific and technical staff, who conducted research on all aspects of marine science, including resource assessment, physical, chemical and biological oceanography and equipment and gear development (including electronics). The Institute itself, as well as the Chief Directorate it served, has now been restructured to meet new challenges in resource management in the country. The scientific component is now split among three resource-orientated directorates within a new Chief Directorate of Marine and Coastal Management (M&CM), the scientific establishment becoming more involved in resource management issues in an attempt to strengthen the whole Chief Directorate where it is needed most. Scientists will still however have leading roles in the new structure, within a matrix-like system which is being developed to ensure continuation of the strong scientific ethic already in place.
M&CM has a number of research vessels, the largest of which are the two research stern-trawlers, R. S. Africana (78m, with a capacity for 19 scientists) and the 52m-long R. S. Algoa, which has a capacity for 13 scientists. Both vessels are excellent platforms for multi-disciplinary research, and are relatively well equipped, although some of the equipment requires updating or replacement. In recent years the vessels have been underutilised due to staffing
67 Anchor Environmental Consultants and funding problems, and maintenance problems are increasing. M&CM has good workshop and library facilities, and possesses a wide range of oceanographic and survey equipment (some of which was developed in-house), as well as a newly-built research aquarium of world-class standard. The Department also publishes the prestigious South African Journal of Marine Science, edited by M&CM staff, which has a high current ranking in the international Science Citation Index, and in which much of the research work in the Benguela has been published. To date 20 volumes have been published, dating back to 1983.
Other South African institutions actively involved in research in the Benguela are the University of Cape Town (Departments of Oceanography, Zoology, Applied Mathematics and Statistical Sciences), the University of the Western Cape (Departments of Zoology and Botany), and to a lesser extent, the South African Museum in Cape Town (Taxonomy), the University of Port Elizabeth (Departments of Zoology and Oceanography), Rhodes University in Grahamstown (Department of Ichthyology and Fisheries Science), the Port Elizabeth Museum and the J.L.B. Smith Institute of Ichthyology in Grahamstown, a national facility of the National Research Foundation. Technical training in oceanography is offered by the Cape Technikon in Cape Town, which runs a 3- year diploma in oceanography, with practical training and lecturing by M&CM staff. These institutions have been an important source of professional and technical staff for South African marine research institutions, and strong links have been developed between them and the State, for example through the Benguela Ecology Programme (BEP); a highly successful collaborative research venture between the former SFRI and several of the universities (particularly UCT) which was started in 1981 and is still running (see assessment by Field, 1996).
In South Africa, a national oceanographic data base for physical and chemical data is maintained by the CSIR’s (Council for Scientific and Industrial Research) South African Data Centre for Oceanography (SADCO) in Stellenbosch. High- resolution raw and partly-processed thermal and ocean colour imagery can be purchased from the CSIR’s Satellite Applications Centre (SAC) in Haartebeeshoek, which maintains an archive of NOAA AVHRR imagery dating back to 1984. These Centres are capable of serving the needs of much of the region, although there are inadequacies such as incomplete satellite cover of northern Angola and the lack of biological information within SADCO.
Donor assistance
Marine research in the Benguela has been, and continues to be, supported by donations and other assistance from foreign governments such as Norway, Germany, Iceland, Sweden, Denmark, France, the United Kingdom, Spain and Japan, plus the European Union. Assistance is also being received from international organisations such as the FAO.
Through the Nansen Programme, sponsored by the Norwegian Agency for
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Development Co-operation (NORAD), the research vessel Dr Fridtjof Nansen has been active in the South-East Atlantic since her commissioning in 1994, and is to remain in the region until at least 2002 to assist in the national programmes of Namibia and Angola, and the regional BENEFIT Programme. Dr Fridtjof Nansen is a 57-m multi-purpose vessel excellently equipped for stock assessment surveys and studies on fishing gear performance and fish behaviour. She replaces her predecessor of the same name which carried out stock assessment and environmental surveys in Namibian waters from Independence in 1990, and off Angola since 1985, in terms of an earlier phase of the Programme. The new phase, which was launched in 1993, places greater emphasis on training and capacity-building in fisheries research and management, and has recently been expanded to include the strengthening of local fisheries institutions, particularly in Namibia and Angola. With the transition to democratic rule in South Africa in 1994, the Nansen Programme established links with marine research institutions there (particularly Sea Fisheries, now M&CM), and has endeavoured to strengthen regional co-operation in fisheries research in the Benguela. In line with this, the Nansen Programme has actively supported the BENEFIT initiative since its conception, and is now a major provider of financial and material support to BENEFIT, the latter in the form of ship’s time on Dr Fridtjof Nansen and assistance from Norwegian scientists on the staff of the Institute for Marine Research (IMR), Bergen.
The German government, through GTZ, the Deutsche Gesellschaft für Technische Zusammenarbeit (German Organisation for Technical Co-operation) has supported marine environmental research and monitoring and training in Namibia since 1993, and has also been an active supporter of the BENEFIT Programme throughout its development stages. It has recently committed funds to support BENEFIT in a number of ways over the next three years, including the funding of a number of regional environmental research activities aimed at improving understanding of the impact of the environment on the major resources of the region. In addition, the German government has funded a combined research and training cruise to the region on a chartered vessel (Petyr Kottsov) as a contribution to BENEFIT, and has promoted collaboration between regional and German scientists, mainly from the Institüt für Ostseeforschung, Warnemunde (IOW) and the Centre for Tropical Marine Ecology (ZMT), Bremen; collaboration which is expected to continue under the umbrella of BENEFIT.
In Angola, the Swedish and Danish International Development Agencies (SIDA and DANIDA) have in the past given considerable assistance in building infrastructure for fisheries research and development, with a particular recent emphasis on artisanal fisheries, while in Namibia, the Icelandic International Development Agency (ICEIDA) has provided assistance to the Ministry of Fisheries and Marine Resources (MFMR), mainly in the operation of Namibian research vessels and the training of officers and crew. ICEIDA has also supported the SADC Fisheries Sector Co-ordinating Unit in Windhoek. DIFD, the Department for International Development of the United Kingdom (formerly ODA, the Overseas Development Agency), has developed a fisheries information system for MFMR, and is currently investigating ways of improving the collection
69 Anchor Environmental Consultants of fisheries statistics in the whole of the Southern African region. The Japanese government built and donated R. V. Welwitschia to the Namibian government, and made a small vessel (R. V. Matsuyama Maru) and researchers available for specific research projects for a two-year period. Namibia has also received training assistance from a number of countries and donor agencies and the FAO, the latter in the form of stock assessment courses and advice by expert consultants. The FAO has also actively supported courses in South Africa.
The French government is currently supporting a bilateral study with South Africa, aimed at providing new tools and information for the regional assessment of pelagic fish resources in the Benguela. The project, code-named VIBES (Variability of exploited pelagic fish resources in the Benguela ecosystem in relation to Environment and Spatial aspects) involves collaboration between the French Research Institute for Development Co-operation (formerly ORSTOM, now IRD), M&CM, UCT and other universities and research institutes in South Africa and France. It is to be extended and expanded into the region through affiliation with the BENEFIT Programme.
The region as a whole is also to receive assistance through a three-year European Union – funded international collaborative project on environmentlal conditions and fluctuations in the distribution of small pelagic fish in the Benguela (code-named ENVIFISH). The partners are Angola, Namibia, South Africa, Germany, Norway, Portugal, the United Kingdom, the European Union Joint Research Centre in Ispra, Italy, and the FAO. ENVIFISH will be closely linked to both BENEFIT and VIBES.
8.3 International and regional agreements and conventions
FAO Code of Conduct for Responsible Fishing
Angola and Namibia are signatories to this Agreement. South Africa is yet to sign, but has agreed in the interim to abide by its provisions.
United Nations Convention on the Law of the Sea (UNCLOS) - South East Atlantic Fisheries Organisation (SEAFO)
Angola, Namibia and South Africa have all ratified UNCLOS and have voted in favour of its Convention on Transboundary and Highly Migratory Stocks, and the United Nations Implementing Agreement (UIA) relating thereto. Subject to that Agreement, Angola, Namibia and South Africa, along with the United Kingdom (acting on behalf of its Dependencies; Ascension Island, St. Helena and Tristan da Cunha), have formulated the South East Atlantic Fisheries Organisation (SEAFO) for the conservation and management of straddling and High Seas stocks in the South-east Atlantic. Other parties which have expressed interest in SEAFO are the European Union, Japan, Norway, Russia, Ukraine and the USA. Negotiations on this Agreement are far advanced, and will ultimately lead to regional arrangements for the management of straddling and High Seas stocks in the region. This is likely to be the first Agreement concluded under the UIA.
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International Commission for the Conservation of Atlantic tunas (ICCAT)
Angola and South Africa are both long-standing members of ICCAT and Namibia is about to join the organisation.
The BENguela Environment Fisheries Interaction and Training (BENEFIT) Programme
BENEFIT is a regional marine research and training programme involving Angola, Namibia and South Africa, with financial and other assistance from a number of Northern Hemisphere countries which have recently been active in marine research and training in the Benguela region, such as Norway and Germany, and the African Development Bank. The Programme is aimed at improving knowledge and understanding of the dynamics of key commercial stocks in the Benguela (primarily hakes, horse mackerels, small pelagic fish and crustaceans) and of linkages between environmental processes and stock dynamics, with the broad objective of improving management of these resources. BENEFIT has the full support of the Angolan, Namibian and South African governments, and of SADC, all of which are represented on a Policy Committee which guides the Programme through a network of Committees and Working Groups, on each of which all three countries are represented. International scientific guidance is provided by a Scientific Advisory Panel, on which France, Germany, Norway, South Africa, USA and the United Kingdom are represented.
BENEFIT has been conceived as a ten-year programme, and will operate in terms of a locally-developed Science Plan (Shannon and Hampton 1997) which inter alia identifies the broad scientific and training problems of the participating countries, and stresses the need for a regional approach to their solution. The Programme is now underway, and the first research projects (all of which will be regional in nature) started in 1999 with assistance from the Norwegian and German governments (through NORAD and GTZ respectively). The specific training needs of the region are being identified, and contacts between local fisheries research organisations and tertiary education establishments are being strengthened with a view to developing an integrated regional training programme for BENEFIT. In addition, in mid-1999 the African Development Bank sponsored a 40-day BENEFIT training cruise in the region on R. S. Africana, which provided training in marine science to other African countries in addition to the BENEFIT partners.
It is envisaged that there will be close links between the BENEFIT and BCLME Programmes which, although differing in emphasis and scope, will be mutually complementary.
8.4 Management measures for major resources
Pelagic fisheries
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In Angola, sardinellas, horse mackerels and sardine have been assessed acoustically since 1985 from first the original, and then the new Dr Fridtjof Nansen (see estimates in Figs. 14, 17 and 20). In the absence of reliable catch statistics for these species, IIP has based management recommendations solely on trends in the survey estimates. The fisheries are managed by TAC, with no distinction between the two sardinella or two horse mackerel species. At a recent international workshop on the management of small pelagic fish in Angola, Congo and Gabon, attempts were made to estimate MSY for the region’s sardinella and T. trecae stocks using surplus production models for the former and an age-structured model for the latter. CPUE indices needed in these models were derived indirectly from the acoustic survey data and information on total catches. The sardinella models (which were considered to be more reliable than the horse mackerel model) placed the MSY at more than double the catch in recent years (around 60 000 tonnes) suggesting that these species are curently underexploited. In contrast, the horse mackerel model suggested that the current level of catch of around 60 000 tonnes per annum is approaching the species’ sustainable level. The Workshop emphasised, inter alia, the need for reliable direct CPUE indices for all the species considered, the collection of fleet and country-specific length frequency data, and the need for an effective monitoring, control and surveillance system in Angola and its northern neighbours.
Prior to Independence in 1990, the management of pelagic fish in Namibia (primarily sardine and anchovy), was based on stock assessments by South African scientists, derived from CPUE indices, aerial and acoustic surveys and VPA of commercial catch data, supported by trends in the diets and breeding success of predators, and in guano production. Since Independence there have only been TAC restrictions on sardine and, in recent years, juvenile horse mackerel. Anchovy catches are however restricted somewhat by a closed season and limits on the by-catch of sardine. Recommendations on the sardine TAC have been based on acoustic/midwater trawl surveys conducted by first the old, then the new Dr Fridtjof Nansen, and the MFMR research vessels Benguela and Welwitschia. Extensive use is made of fishing vessels as scouts to find shoal groups and check that fish have not been missed close inshore or outside the surveyed area. Attempts have also been made by NatMIRC to deduce population trends in sardine from VPA and length-based cohort analysis of commercial data, but this work has been severely hampered by the unreliability of the ageing techniques used and insufficient information on population parameters. Consequently, the results have not yet been considered in management recommendations. At present, the recommended TAC for the forthcoming season is taken as 18 % of the survey estimate at the end of the previous fishing season, with subsequent adjustments if surveys during the season indicate unusually high or low recruitment, growth or mortality. This procedure has enabled management authorities to react to major resource fluctuations but, as has been emphasised at a recent international workshop on research and management of the Namibian sardine (Anon. 1997b), there is a pressing need for more rigorous stock assessment modelling, using all
72 Anchor Environmental Consultants appropriate data, as the foundation for management decisions.
In South Africa, the most important pelagic resources (i.e sardine, anchovy and round herring) have been routinely surveyed acoustically since the mid 1980s, with surveys of recruitment in winter and spawning biomass in summer (e.g. Hampton 1992, 1996). Between 1984 and 1993, the anchovy spawning biomass was also estimated annually by egg surveys, using the daily egg- production method; a method which is now being considered for sardine. The survey estimates of sardine and anchovy spawning biomass and recruitment strength, and of the precision of these estimates, are used together with (in the case of sardine) estimates of the population age structure from commercial data, to model the risk to the stocks of various harvesting strategies, and hence to recommend TACs for sardine and anchovy. This process is carried out through a Pelagic Working Group, with input from Sea Fisheries survey personnel, modellers from the Department of Applied Mathematics, UCT and M&CM, environmentalists and, on occasion, the pelagic fishing industry. The current strategy is to manage the sardine and anchovy fisheries together and interactively in such a way as to optimise the sardine catches, while heeding the needs of the anchovy fishermen, who frequently catch juvenile sardine as a by- catch. There are at present no direct restrictions on the round herring fishery, because the resource is not thought to be threatened by the comparatively low levels of catch (typically less than 50 000 tonnes per year from a stock which has consistently been estimated acoustically at about 1 million tonnes).
Trawl fisheries
Hake off Angola (Merluccius polli and, in the extreme south, M. capensis), have been investigated in the course of various bottom-trawl surveys conducted by R. V. Goa between 1970 and 1992, the old and new Dr Fridtjof Nansen between 1984 and the present, and recently, by chartered fishing vessels. As a part of these studies, the other major groups of demersal species in Angolan waters (dentex, croakers and groupers) have also been investigated. In the absence of reliable fisheries statistics for any of these species in Angolan waters, stock assessments and TAC recommendations have been based on trends in the survey estimates using holistic models. With improvement of commercial catch information, it will be possible to incorporate CPUE data into the analysis. Separate TACs are set for the two hake species and for different groups of other demersal fish. Other forms of control include effort limitation, the prohibition of trawling close to the coast, and minimum size limits.
Between 1975 and 1989, the assessment and management of Namibian hake stocks was carried out under the auspices of ICSEAF. Various surplus production models based on catch and effort data from the Soviet and Spanish fleets were used in the assessments. The fishery was managed by mesh regulations and limits on the TAC, which was apportioned between nations according to their historic interest and performance in the fishery. Since Namibia’s declaration of an EEZ in 1990, and the subsequent withdrawal of foreign fleets, the hake TAC has been based on biomass estimates obtained
73 Anchor Environmental Consultants from Dr Fridtjof Nansen bottom trawl surveys, in which Norwegian and Namibian staff participate. To these estimates are added acoustic estimates of hake off the bottom. The surveys produce estimates of the fishable (> 35 cm) and non- fishable (<35 cm) components of the population for both M. capensis and M. paradoxus. Trends in the survey estimates of the adult stock and of recruitment strength are combined with CPUE indices of trends in the adult stock to recommend annual adjustments in the TAC. Previously, the recommendation was set at 20% of the estimated fishable stock, but a new Operational Management Procedure, in which the TAC is adjusted according to the average change in the survey and CPUE indices for the previous 5 years (Butterworth and Geromont 1997), has recently been recommended as an interim measure until the question of whether the survey estimates can be treated as absolute has been resolved. (Treating them as absolute indicates that the resource is currently heavily depleted, in conflict with a number of different production models, which indicate the opposite – Anon. 1997c. The discrepancy is resolved if the survey estimates are treated as relative rather than absolute).
M. capensis and M. paradoxus in South African waters are assessed as one for management purposes, using commercial data in a locally-developed dynamic Schaefer-form production model, which since 1989 has included multiple CPUE series, and is tuned by data from research swept-area surveys using bottom trawls. Recently, the Fox form of production model has been applied, and advances made in incorporating age structure for the hake stock on the South Coast, where the trawl and linefisheries select different age components of the population (Geromont et al. 1999). The assessments are carried out by M&CM, with modelling assistance from the Department of Applied Mathematics, UCT. The group together makes annual TAC recommendations through a Demersal Working Group, which liaises with the demersal industry when and where appropriate. The survey estimates used in the assessments are obtained from annual swept-area bottom trawl surveys of the West and South Coasts from R. S. Africana, using pseudo-random depth-stratified sampling. The estimates are treated as relative because of difficulty in quantifying catchability coefficients. Research is currently directed at refining the assessments by using Generalised Linear Models to improve the validity of the CPUE time series, investigating the effect of wind stress on commercial catch rates, and disaggregating the commercial catch by species so that a species-specific VPA can be performed.
Since 1984, assessment of Cape and Cunene horse mackerel in Angolan waters has mainly been done from acoustic surveys conducted by the old and the new Dr Fridtjof Nansen, most of them as extensions to Namibian surveys. Information relevant to stock assessment has also been collected during R. V. Goa cruises between 1972 and 1992, as well as from collaborative resource studies with the Atlantic Research Institute for Fisheries and Oceanography (ATLANTNIRO) of the former USSR. As with other commercial species in Angola, catch statistics on the horse mackerel fishery are inadequate for assessment and management of the fishery, and TACs (for the two species combined) are based on trends in the survey estimates .
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In Namibia, adult horse mackerel were assessed and managed from 1980 to 1989 according to TACs set by ICSEAF agreements, based on Schaefer and Fox surplus production models applied to catch data from the international midwater trawl fishery. No distinction was made between Cape and Cunene horse mackerel, although the former dominated in the catches. TACs were allocated between interested nations by ICSEAF in a similar manner to the hake TACs. Since 1990, when the fishery came under Namibian control, TACs for the midwater trawl fishery have been based on MFMR recommendations, made according to trends in acoustic survey estimates, recently supported by length- based and age-based VPA estimates, obtained using commercial catch data. The reliability of horse mackerel ageing techniques needs to be substantially improved before the age-based VPA estimates can be used with greater confidence.
In South Africa, the lack of a reliable age-structured catch and CPUE data series has hampered attempts at producing reliable stock assessments of T. trachurus capensis. A surplus production model, based on CPUE indices, egg-density data and abundance indices from direct surveys, was used to assess the resource on the South Coast between 1989 and 1991 and recommend TACs through the Demersal Working Group. The first TAC (30 000 tonnes) was set in 1990. These assessments were discontinued in 1991 when withdrawal of the Japanese vessels terminated the CPUE time series. Since 1993 a Beddington and Cooke- type yield-per-recruit model, based primarily on bottom-trawl survey estimates has been used to set a precautionary catch limit. The estimates are obtained from surveys on Africana which are biased to a highly variable degree because of spatial and temporal variations in the availability of horse mackerel to bottom trawls. To reduce this bias, acoustic techniques are now being introduced to estimate the portion of the population on the South Coast which is inaccesible to the bottom trawl (Barange et al. 1998).
Management of the deep-water fisheries off Namibia is based on TAC recommendations from the Namibian Deep Water Fisheries Working Group to the Namibian Sea Fishery Advisory Council. The Working Group consists of MFMR scientists and industry representatives, and receives input from a number of foreign scientific and industry consultants. For orange roughy, management is based on a population model which uses acoustic and swept-area survey estimates of abundance on the three main grounds, and swept-area estimates of abundance on these grounds from commercial catches throughout the season, to recommend TACs for each of the grounds. The current policy for the fishery is to have a fishing-down period at a constant catch, followed by a gradual reduction in catches to a level likely to provide MSY. No TACs have been recommended for the Alfonsino fishery because of the low level of catch. This situation will be reviewed should the annual catch rise above 2 000 tonnes.
The monkfish fishery in Namibia is at present managed by effort control, mesh- size limits and by-catch penalties on catches of monkfish by hake trawlers, which in recent years have made up more than 30% of the monkfish catch. Recently there has been pressure to move to a catch-limited control system.
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Crustacean fisheries
West Coast rock lobster resources in Namibia and South Africa are assessed and managed according to various population models. In Namibia, a Schaefer surplus production model based on annual catch and effort data is used to recommend TACs and minimum size limits, with the assumption that the stock at the start of the time series (1958) was 40% of pristine. Fishing is controlled by limits on the TAC per area, a prohibited area and closed season, minimum size and bag limits, and various restrictions on catch methods. Stock assessment- related research being conducted by MFMR staff in Lüderitz includes investigation into the effects of migrations on sex ratios, the estimation of growth rates through tagging studies, and studies on the effect of environmental conditions (particularly oxygen levels) on CPUE indices.
In South Africa, the J. lalandii resource has been assessed and managed since 1992/93 through a size-based population model which uses data on growth rates, size structure and sex ratios in catches, CPUE and total landings. Results from a Fisheries-Independent Monitoring Survey have also been used. The model, which has been modified and updated a number of times since its inception, is used to make recommendations on TACs for the commercial fishery, and on a minimum size limit. The catch is also controlled by a closed season, prohibited areas, a bag limit and other restrictions on recreational fishermen. Very recently, a new Operational Management Procedure has been introduced to facilitate TAC recommendations. The input data required are the TAC from the previous year, and three of the indices of resource status (averaged over the three previous seasons), which were used previously in the size-based model (Anon. 1998b).
The management of deep-sea red crab in Namibia is based on length-based cohort analysis and prediction models, adapted to fit the growth dynamics of the species, using growth rates established by tagging (Le Roux 1997). The models are used to project future stock size as a function of catch, from which TACs are recommended. The catch is also controlled by limits on minimum size and the prohibition of fishing inside the 400m isobath. Management of the resource in Angola is based on CPUE trends and estimates of MSY, using estimates of natural mortality from a number of different sources. Catches are controlled by TAC, effort control, prohibition of fishing inside 500m to protect juveniles and immature females, a minimum size limit and limitation of the crab by-catch in the prawn fishery.
The deep-water prawn fishery off Angola is managed on the basis of trawl survey estimates and CPUE trends, which are used in a simplified Beverton and Holt model to recommend TACs for rose prawn and striped red prawn. Other forms of control include the prohibition of fishing within certain inshore areas to protect juveniles, a closed season and effort limitation /reduction.
Linefisheries
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There are effectively no restrictions on catches in the large artisanal fishery in Angola, partly because of the difficulty in enforcing regulations. Consideration has however been given to protecting the interests of small-scale fishermen by prohibiting trawling close to the coast, which can severely disrupt small-scale fishing operations. The issue has not been resolved and remains a source of conflict between industrial, semi-industrial and artisanal fishermen in Angola.
Management of the tuna fisheries in Angola and South Africa is carried out in line with ICCAT regulations. Although not yet a member of ICCAT, Namibia is also following these regulations, and implements effort control over both national and foreign vessels. The commercial line fishery for snoek and angling species in Namibia is at present unrestricted, but recreational catches of angling species are controlled by closed areas and bag limits.
In South Africa there is a comprehensive suite of linefish management regulations developed by the National Marine Linefish Committee, which was set up in 1984. These include regulations on the licensing and number of permits for commercial fishing boats, bag limits by species category for all recreational and part-time commercial fishermen, closed seasons for certain species, and minimum size limits for the most important ones. After 1985 the Committee was superseded by an independent body; the South African Marine Linefish Management Association (SAMLMA), which has provided advice on modifications of the original measures. The new Marine Living Resources Act of 1998 retains most of the past measures, with some changes in the commercial permit system and the institution of a “Subsistence” fishing category, in which fishermen are subject to bag limits but permitted to sell their catches. Recreational fishermen are also now obliged for the first time to obtain an angling permit, although as before, will not be permitted to sell their catches. Continuing reduction in the abundance of most linefish species has led to the development of a holistic mangement protocol for linefish, which is currently being taken forward.
Seals
The Namibian seal harvest is primarily controlled through limitations on the annual TAC, with separate allowances for pups and bulls and for the different colonies. TAC recommendations are based on aerial censuses and estimates of biological parameters for the population (fecundity rate, mortality of pups and adults, sex ratios etc.), which are used in a deterministic, age-structured model of the female component of the population to predict ideal harvesting levels for maintaining sustainable yields. The total seal harvest in recent years (which has not always reached the TAC) has varied between 17 000 animals in 1991 and 38 000 animals in 1994, with pups contributing about 80% of the harvest in all years.
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9. RESEARCH GAPS AND THREATS TO MANAGEMENT
There are a number of broad gaps in scientific understanding of the dynamics of the Benguela Current’s marine resources which inhibit rational, optimal management of these resources in all three countries. The major problems have been identified in the Draft BENEFIT Science and Implementation Plan (Shannon and Hampton 1996), and are the focus of a recently-developed framework for resources research within the Programme (Anon. 1998d). Briefly, they can be summarised as:
Inadequate definition of stocks and understanding of factors affecting the separation and/or interchange between them, especially for stocks which are shared between countries or move between them, such as hake, horse mackerel, red crab and, to some degree, certain pelagic fish species. Lack of this information makes it difficult to manage these resources on a national basis and is likely to complicate any attempts at regional management.
Inaccurate or non-existent information on basic biological characteristics such as growth and natural mortality rates, reproductive characteristics, recruitment variability and population age structure for most of the harvested species. These are important input parameters for population dynamics models used in the region (which are themselves often inadequate). A particular problem for most species is the inadequacy and lack of validation of ageing techniques.
Inadequate absolute estimates of population size and questionable indices of population trends for most of the exploited species, due to deficiencies in the methods used to obtain these estimates. Furthermore, few attempts have been made to assess the accuracy or precision of the estimates, making it difficult to assess their value.
The lack of Operational Management Procedures based on population models for many of the major resources is seen locally as a serious problem, precluding any meaningful form of risk analysis or quantitative evaluation of harvesting strategies for these resources. This is a particular problem in Angola, and to a lesser extent, Namibia.
Inability to predict the effect of environmental perturbations on resource dynamics for any species with sufficient confidence for the predictions to be used quantitatively in resource management.
Those of the above which are trans-boundary problems in resource management are summarised in Table 3. Included in the Table is an indication of the immediate and root cause of each of the problems listed. It will be noted that the root cause of many of the problems is the lack of regional agreements and structures for research and management of shared resources, and the shortage of manpower and funds to undertake trans-boundary surveys and other trans- boundary research activities.
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Issue Immediate cause Root cause Problem Management of Inadequate information Lack of trans-boundary Lack of regional agreement(s) and hakes (South on identity of M. surveys structures under which trans-boundary Africa/ Namibia) capensis and M. surveys could be organised. Shortage of paradoxus stocks in funds and manpower for surveys southern Benguela
Inadequate Lack of ichthyoplankton Shortage of funds and manpower for understanding of life surveys and migration surveys and data analysis. Low priority history (spawning areas, studies in both Namibia given to ichthyoplankton work. Lack of larval dispersal patterns, and South Africa structures for organising trans-boundary migration of juveniles surveys and collaborative migration and adults etc.) studies
Questionable Different survey Inadequate intercalibration and comparability of stock techniques, sampling gear comparison of techniques. Lack of estimates in Namibia and ageing methods. regional structures for standardising and South Africa Different interpretations of methods commercial catch data
No unified Operational Different approaches to Different national exploitation policies Management Procedure management and exploit- and constraints. Lack of structures for or common exploitation ation control in the two regional resource management. Shortage control methods countries, and different of modellers, particularly within level of modelling skills NatMIRC
Inadequate under- Lack of studies on Shortage of funds, vessels and staff for standing of effects of interaction between hake appropriate monitoring and dedicated trans-boundary environ- and their environment on behavioural studies mental perturbations on appropriate scales abundance, distribution, behaviour and production
Management of Inadequate knowledge of Shortage of trans- Lack of regional agreement(s) and horse mackerels integrity of T. trachurus boundary surveys, structures for joint surveys. Shortage of (Angola/Namibia/ capensis stock(s) off particularly in southern funds and staff for surveys. Shortage of South Africa) west coast of southern Benguela. Limitations of skills in genetics and other stock Africa stock characterisation characterisation techniques studies Inadequate understand- Lack of ichthyoplankton Lack of regional agreement(s) and ing of spawning and surveys and migration structures for trans-boundary larval dispersal patterns, studies throughout the ichthyoplankton surveys. Shortage of particularly in southern region funds and manpower for data collection Namibia, and of adult and analysis migration in this region
Questionable Different survey Inadequate intercalibration and comparability of stock techniques, sampling gear comparison of techniques. Lack of estimates in South and ageing methods. regional agreement(s) for standardising Africa and Differences in methods of methods, and of funds and manpower for Namibia/Angola collecting and interpreting data collection and analysis commercial catch data
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Issue Immediate cause Root cause Problem Management of Inadequate understanding Lack of studies on Shortage of funds, vessels and manpower horse mackerels of effects of large-scale interaction between for appropriate monitoring and dedicated (cont). environmental horse mackerel and their behavioural studies perturbations on environment on abundance, distribution, appropriate scales behaviour and production
Management of Inadequate information on Shortage of surveys Lack of regional agreement(s) and sardine (Angola/ the degree of mixing across national structures under which trans-boundary Namibia/South between Namibian and boundaries at different surveys could be organised. Shortage of Africa) and South African sardine and times of the year funds and manpower for surveys anchovy ( South anchovy stocks, and on the Africa/Namibia) extent to which the Namibian sardine stock extends into Angola.
Inadequate understanding Lack of ichthyoplankton Lack of funds and manpower for data of spawning and larval surveys in southern collection and analysis dispersal patterns of Angola and northern sardine in Namibia and Namibia (in recent southern Angola times), and lack of studies on sardine migration in the northern Benguela
Inadequate understanding Lack of integrated Lack of regional agreement(s) and of physical and biological surveys and structures for setting up such studies. factors affecting the environmental studies on Shortage of funds and manpower for penetration of the South pelagic fish in vicinity of surveys and data analysis African anchovy stock into national boundary Namibia and the Namibian sardine stock into Angola
Management of Inadequate knowledge of Lack of trans-boundary Lack of regional agreement(s) and Deep-sea red crab migration of stock between surveys at different times structures for setting up trans-boundary (Angola/Namibia) Namibia and Angola of the year. Limited surveys. Shortage of funds and tagging and other manpower for surveys and tagging studies migration studies Questionable compara- Different survey and Inadequate comparison and standard- bility of stock estimates in assessment techniques isation of techniques. Lack of regional Angola and Namibia agreement(s) and structures for promoting standardisation
Different management and Lack of common Lack of regional agreement(s) for joint exploitation control management and management and exploitation control methods in Angola and harvesting strategy Namibia
Table 3. Immediate and root causes of major trans-boundary problems in the manage- ment of the region’s marine living resources In addition to these general scientific problems (which are not unique to the
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Benguela), there are particular scientific and operational problems and threats to management in each country, which differ according to the nature of the fisheries and the economic realities and research and management capacity in each country.
In Angola, the resources and their environment have been significantly less studied than elsewhere in the Benguela, and the history of fisheries research is too short to have provided a long time-series of observations and a strong scientific foundation for the proper analysis of trends in population size (Neto 1998). There are limited national data for long-term retrospective analyses of major fluctuations in the marine ecosystem, large deficiencies in the understanding of fundamental life history characteristics (e.g. stock delineation, location of spawning grounds, distribution of ichthyoplankton, nursery grounds, migration patterns) of commercially important stocks, and no population models which can be used to evaluate management options. Partly because of the large number of remote landing points, and a small corps of compliance officials, catch and effort statistics for many of Angola’s fisheries tend to be unreliable, making it difficult to implement even basic management measures. Research capacity is limited because of the small number of people involved, the lack of appropriate tertiary education in fisheries science in the country, and the severe macroeconomic problems in the country resulting from the protracted civil war and resultant breakdown of services. There is clearly a desperate need in Angola for education and training in fisheries science and resource management at all levels, but this can only proceed if there is stability, and basic services and infrastucture are in place.
In Namibia, there are fairly reliable catch statistics for all of the exploited species, and control measures are effectively implemented. The greatest general scientific problem is the development of rigorous methods of assessing sardine, hake and horse mackerel biomass from survey and other information, and the building of these assessments into formal, testable management procedures which take assessment errors into account. In view of the dramatic effects which the major environmental perturbations of the mid 1990s had on the abundance and distribution of Namibian resources (particularly sardine and their predators), a strong need has been perceived to improve understanding of the effects of the environment on the country’s marine resources, particularly with a view to predicting recruitment and anticipating changes in distribution. The major operational constraint is a severe shortage of scientific and technical staff within the Ministry of Fisheries and Marine Resources for the large number of resources that have to be studied, and the amount of effort necessary merely to maintain the current level of resource monitoring. The often prolonged absence of staff attending training courses and studying outside Namibia for higher degrees places an additional load on remaining research staff, further reducing the amount of time available for detailed analysis of results, innovative research and the publishing of results in the primary literature. Although the opportunities for local tertiary education in marine science may improve in due course, lessening the need for distance-education, this problem is likely to persist for some time.
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In South Africa, there are long and generally reliable time-series of catch statistics for the major exploited species, and effective exploitation control measures for most of them. The major exception is the linefishery, where attempts to limit effort have so far been ineffective. The problem is being exacerbated by technological improvements and increased capitalisation in the sector, and increasing demands on already over-exploited coastal linefish resources by a rapidly expanding subsistence sector.
Although the scientific basis for fisheries management in South Africa is very much stronger than elsewhere in the region, there have been a number of developments which in recent years have weakened national capacity in marine science, and which threaten to weaken it further. State funding for marine research, both within statutory organisations and at universities is shrinking, with a consequent shortage of funds for equipment, running expenses travel and education. There is a shortage of funds to maintain, man and operate ageing research vessels, and at present little provision for replacing them. Because of these factors, increased difficulty is being experienced in maintaining even routine resource-monitoring cruises essential for recommending TACs, and there is almost no ships’ time available for developmental work and supporting (e.g. environmental) research. This jeopardises the substantial progress which has been made in the past two decades in understanding the effect of the environment on fish resources in the southern Benguela, at a time when the use of such understanding in fisheries management is being pioneered in the region.
Also, in recent years there has been a weakening of scientific and research management capacity within the Department of Environment Affairs and Tourism due to loss of senior staff brought about largely by moves to reduce the size of the Public Service. The loss of expertise, and in many cases, posts, has added to the routine commitments of remaining staff, further limiting their opportunities for undertaking innovative work and otherwise pursuing their scientific careers. The weakening of state-funded capacity in marine reseach, unless compensated for by an increase in the marine research done by non- statutory bodies and through regional and international co-operative programmes, could well lead to a decline in the quantity and quality of marine science in South Africa.
With the broadening of participation in the fisheries sector under the new Act, and the increased number of landing sites, monitoring is becoming increasingly difficult, which is likely to result in a decline in the reliability of data. The pressure on already hard-pressed staff within the M&CM Chief Directorate brought about by growing demands on the MCS Unit and new responsibilities to advise on quota allocation (previously the function of the Quota Board) is likely to add to staffing problems in the years ahead.
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10. ACKNOWLEDGEMENTS
We acknowledge generous assistance given by staff at IIP Luanda, NatMIRC, Swakopmund and M&CM, Cape Town in providing data needed for this Report. We also thank the Reprographics Section, M&CM, Cape Town for the use of figures and other artwork from their files. Drs A.I.L.Payne and P. de Barros are thanked for extensive and helpful comments on an earlier draft of the manuscript, which led to a number of improvements, and generally tightening of the text.
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11. REFERENCES AND OTHER LITERATURE
During the past decade several thousand scientific publications on the Benguela ecosystem and its resources have been published in the primary scientific literature, the majority of them dealing with the southern Benguela. A listing of these is beyond the scope of this document. Instead, readers are referred to Crawford et al. (1987) and references therein for a comprehensive summary of the published work on the major fish and inverterbrate resources of the Benguela up to that date, and to the book Oceans of Life off Southern Africa (Eds. A.I.L. Payne and R.J.M. Crawford, 1989, revised in 1995), which gives a popular but authoritative account of the same body of work. Much of the more recent work has been published in the South African Journal of Marine Science, particularly in the three “symposium volumes” viz. Vol. 5: The Benguela and Comparable Ecosystems (Payne et al. 1987), Vol.12: Benguela Trophic Functioning (Payne et al. 1992) and Vol. 19: Benguela Dynamics: Impacts of Variability on Shelf-Sea Environments and their Living Resources (Pillar et al. 1998). A wealth of information on the Namibian and South African fishing industries, fisheries, catches, etc. may be found in the Fishing Industry Handbook series, edited by M. Stuttaford and published annually by Marine Information CC. The references listed below give details on these publications, a short selection of other useful works, and the articles cited in the text, which have largely been restricted to work which has appeared since publication of the BENEFIT Science Plan (Shannon and Hampton 1996, 1997).
ANON 1997a – Proceedings of International Workshop on Research and Management of Cape Fur Seals in Namibia, Swakopmund, June 1997: 60 pp.
ANON 1997b – Proceedings of International Workshop on Research and Management of Pilchard in Namibia, Swakopmund, February 1997: 130pp.
ANON 1997c – Proceedings of International Workshop on Research and Management of Hake in Namibian Waters, Swakopmund, October 1997: 233pp.
ANON 1998a – Dados estatisticos sobre as capturas da pesca artesanal, 1997. Instituto de Desenvolvimento da Pesca Artesanal, Ministério das Pescas, Luanda, Angola: 54pp.
ANON 1998b - Research Highlights, 1997-1998. Sea Fisheries Research Institute, Cape Town, South Africa: 67pp
ANON 1998c – Cruise Report of Dr Fridtjof Nansen horse mackerel survey, June 1998. National Marine Information and Research Centre,
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Swakopmund.
ANON 1998d – Framework BENEFIT Resources Research Programme. July 1998. BENEFIT Secretariat, Windhoek: 8pp.
ARMSTRONG, M. J. and R. M. THOMAS 1989 - Clupeoids. In Oceans of Life off Southern Africa. Payne, A.I. L. and R. J. M. Crawford (Eds). Cape Town; Vlaeberg: 105-121. BAKUN, A. 1995 – Patterns in the Ocean: Ocean Processes and Marine Population Dynamics. Published jointly by Centro de Investigaciones Biologices di Nord Ovest, La Paz, Mexico and University of California Sea Grant, San Diego, USA: 320pp.
BARANGE, M. and I. HAMPTON 1994 – Influence of trawling on in situ estimates of Cape horse mackerel Trachurus trachurus capensis target strength. ICES J.mar.Sci. 51: 121-126.
BARANGE, M., PILLAR, S.C. and I. HAMPTON 1998 – Distribution patterns, stock size and life-history strategies of Cape horse mackerel Trachurus trachurus capensis, based on bottom trawl and acoustic surveys. In Benguela Dynamics:Impacts of Variability on Shelf-Sea Environments and their Living Resources. Pillar S.C., Moloney, C.L., Payne, A.I.L. and F.A.Shillington (Eds). S.Afr.J.mar.Sci. 19: 433-449.
BARANGE, M., HAMPTON, I. and B.A. ROEL (in press) – Trends in the abundance and distribution of anchovy and sardine on the South African continental shelf in the 1990s, deduced from acoustic surveys. S.Afr.J.mar.Sci. 21: 367-391.
BIANCHI, G. 1992 – Demersal assemblages of the continental shelf and upper slope of Angola. Mar. Ecol. Prog. Ser. 81: 101-120.
BOYER, D. 1996 – Stock dynamics and ecology of pilchard in the northern Benguela. In Proceedings of the Seminar and Workshop The Benguela Current and Comparable Eastern Boundary Upwelling Systems, Swakopmund, Namibia, May 1995: 79-82.
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consumption of food by Cape hake Merluccius capensis and M.paradoxus off the South African west coast. In Benguela Trophic Functioning. Payne, A.I.L., Brink, K.H., Mann, K.H. and R.Hilborn (Eds). S.Afr.J.mar.Sci. 12: 611- 634.
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12. ACRONYMS
ATLANTNIRO Atlantic Research Institute for Fisheries and Oceanography (Kaliningrad, former USSR) AVHRR Advanced Very High Resolution Radiometer BCLME Benguela Current Large Marine Ecosystem (Programme) BENEFIT BENguela Environment Fisheries Interaction & Training (Programme) BEP Benguela Ecology Programme CPUE Catch Per Unit Effort CAF Consultative Advisory Forum (South Africa) CSIR Council for Scientific and Industrial Research (South Africa) DANIDA Danish International Development Agency DIFD Department for International Development (United Kingdom) EEZ Exclusive Economic Zone ENVIFISH Environmental Conditions and Fluctuations in Distribution of Small Pelagic Fish Stocks (Programme) EU European Union FAO (United Nations) Food and Agriculture Organisation GTZ Deutsche Gesellschaft für Technische Zusammenarbeit ICCAT International Commission for Conservation of Atlantic Tunas ICEIDA Icelandic International Development Agency ICSEAF International Commission for the South-East Atlantic Fisheries IIP Instituto de Investigação Pesqueira (Angola) IPA Instituto de Desenvolvimento da Pesca Artesanal (Angola) IMR Institute of Marine Research (Bergen, Norway) IOW Institüt für Ostseeforschung (Warnemunde, Germany) IRD (French) Research Institute for Development M&CM (Chief Directorate) Marine and Coastal Management (Department of Environmental Affairs and Tourism, South Africa) MFMR Ministry of Fisheries and Marine Resources (Namibia) MSC Monitoring, Surveillance and Control NatMIRC National Marine Information and Research Centre (Namibia) NORAD Norwegian Agency for Development Co-operation ODA Overseas Development Agency (United Kingdom) ORSTOM French Research Institute for Development through Co-operation SADC Southern African Development Community SADCO South African Data Centre for Oceanography SAC Satellite Applications Centre (CSIR, South Africa) SAMLMA South African Marine Linefish Management Association SEAFO South East Atlantic Fisheries Organisation SFAC Sea Fisheries Advisory Committee (South Africa) SFRI Sea Fisheries Research Institute (South Africa) SIDA Swedish International Development Agency SST Sea surface temperature TAC Total Allowable Catch UCT University of Cape Town UIA United Nations Implementing Agreement
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UNAM University of Namibia UNCLOS United Nations Convention on the Law of the Sea VPA Virtual-population Analysis VIBES Variability of exploited pelagic resources in the Benguela ecosystem in relation to Environmental and Spatial aspects (Programme) VMS Vessel monitoring system ZMT Centre for Tropical Marine Ecology, Bremen
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SYNTHESIS AND ASSESSMENT OF INFORMATION ON THE BENGUELA CURRENT LARGE MARINE ECOSYSTEM (BCLME)
THEMATIC REPORT NO.2
INTEGRATED OVERVIEW OF THE OCEANOGRAPHY AND ENVIRONMENTAL VARIABILITY OF THE BENGUELA CURRENT REGION
By
L.V. SHANNON and M.J. O’TOOLE
Windhoek, Namibia November 1999
1. INTRODUCTION
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The Benguela is one of four major current systems which exist at the eastern boundaries of the world oceans, and the oceanography of the region is in many respects similar to that of the Humboldt Current off Peru and Chile, the California Current off the west coast of the U.S.A. and the Canary Current off north-west Africa. These eastern boundary currents are characterized by upwelling along the coast of cold nutrient-rich water, and are important centres of plankton production which support a global reservoir of biodiversity and biomass of fish such as sardine (pilchard), anchovy and horse- mackerel and also sea birds and marine mammals.
The coastal upwelling area of the Benguela Current ecosystem extends from southern Angola along the west coast of Namibia and South Africa around the southernmost part of the continent. While the area shares many of the generic characteristics of other eastern boundary currents, it is unique in that it is bordered at both northern and southern ends by warm water systems viz. the Angola Current and Agulhas Current respectively. These equatorward and poleward boundaries are not fixed in space and in time, but are highly dynamic, and their pulsing impacts on the ecosystem as a whole and on its harvested resources. With a western boundary approximating to the 0° meridian, the Benguela thus encompasses the coastal upwelling regime, the eastern part of the South Atlantic gyre and a complex system of fronts and transition zones. In terms of the Benguela Current Large Marine Ecosystem (BCLME) Programme, the Benguela is viewed in a broader context than is customarily defined, and includes the full extent of Angola’s Exclusive Economic Zone (EEZ), with a northern boundary at 5°S at the Angola Front. (The latter is the boundary between the BCLME and the equatorial current system.)
The earliest physical observations in the South Atlantic and Indian Oceans were those necessary for the safe and efficient passage of sailing ships along the trade routes between Europe and the East. The early Portuguese, Dutch and other navigators accordingly compiled comprehensive records of winds and currents – records which display a remarkable amount of information about the underlying physical oceanography of the region. The first published work of scientific merit was, as may be expected, of currents around the Cape of Good Hope and was compiled by James Rennel in the 18th century (Rennel 1778). It was, however, the cruise of the H.M.S. Challenger in the 1870s which initiated the global science of oceanography, and pioneering studies were conducted on that expedition in the Benguela region during 1873. The next half-century witnessed the age of the great oceanographic expeditions inter alia those of the Valdivia, the Gauss, the Planet and the Möwe. It was, however, work undertaken during the expedition of the German Meteor in the South Atlantic between 1925 and 1927 that resulted in a quantum jump in human understanding of the oceanography of the Benguela and adjacent regions.
The scene for development of regional oceanography was set by the arrival in Cape Town of Professor J. D. F. Gilchrist in 1896. Gilchrist is regarded as the father of southern African oceanography, and he undertook a host of marine studies in Angola, Namibia, South Africa and Moçambique. During the second half of the twentieth century it was oceanographers such as Drs T. J. Hart, R. I.Currie, A. J. Clowes, A. H. B. De Decker, N. D. Bang, J. R. E. Lutjeharms and L. Hutchings who contributed so much to the understanding of the complex physics, chemistry and biology of the Benguela.
This overview is a brief summary the oceanography and environmental variability of the Benguela Current Large Marine Ecosystem. As such it draws principally on the published scientific literature which now comprises several thousand authoritative articles. In preparing this overview, we have synthesised available information and ideas and have attempted, where possible and where appropriate, to simplify and to explain concepts in
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such a way that they will be intelligible to non-oceanographers, yet still useful to marine scientists with an interest in the Benguela system. It is not, however, a Benguela science review per se: There are a number of authoritative reviews in the international scientific literature, and these are referred to in the text, together with other key publications.
The overview commences with a discussion of the main physical features and processes in the Benguela - the bathymetry, windfield, temperature, upwelling, currents, fronts and boundaries. Key aspects of the chemistry and chemical processes follow, including major and minor elements and all-important dissolved oxygen. The next section deals with plankton, primary and secondary production and the foodweb and carbon budget. We have also devoted several paragraphs to a discussion of environmental variability and the ecosystem consequences thereof. Finally we have provided a perspective on the various issues, problems and threats facing the Benguela, and have identified what we believe are the major gaps in knowledge and understanding. It is hoped that the various sections collectively will provide a useful introduction to, or at least background information for, those overviews dealing with more specific aspects of Benguela resources.
PHYSICAL FEATURES AND PROCESSES
2.1 Bathymetry
The continental shelf along the west coast of southern Africa is variable in width and depth. It is narrow off southern Angola (20km), south of Lüderitz (75km) and off the Cape Peninsula (40km) and widest off the Orange River (180km) and in the extreme south where the Agulhas Bank extends over 200km polewards from Cape Agulhas, the southernmost tip of Africa. The edge of the continental shelf, or shelf break as it is generally termed, lies at depths between about 200m and 500m. The position of the 200m depth contour (isobath) is shown in Fig. 1. By global standards the Benguela continental shelf is relatively deep, and the slope and configuration of the shelf is by no means uniform. Indeed, double shelf breaks are common off the west coast of Southern Africa: for example near Walvis Bay (23°S latitude) there are inner and outer breaks beginning at depths of about 140m and 400m respectively. This is illustrated graphically in Fig. 6, which also shows a similar feature at 32°S off South Africa. Between about 31°S and 35°S several convoluted submarine canyons intersect the shelf, the best known of which is the Cape Canyon which lies approximately 80 north-west of Cape Town. The variable topography of the Benguela shelf is of particular significance for near shore circulation and for fisheries.
The continental shelf is covered by layers of sediments primarily of biological origin (biogenic) and large areas of shelf sediments contain more than 75% calcium carbonate. Significant features of the Benguela shelf are two extensive mud belts, each about 500km long. The southern belt extends from the Orange River southwards, up to 40km wide with an average thickness of 15m, and is mainly of river origin. The northern belt which lies over the middle shelf off Namibia comprises organically rich diatomaceous oozes (originating from planktonic plants). In places the organic carbon content of these diatomaceous muds exceeds 15%!
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West of the shelf break is a steep continental slope area which descends to a depth of about 5000m where it meets the abyssal plain of the South-east Atlantic Ocean. This plain comprises two large ocean basins, the Cape Basin and the Angola Basin, separated by a submarine mountain chain, the Walvis Ridge which runs from its abutment with the continental shelf at latitude 20°S (northern Namibia) in a south-westerly direction for more than 2500km towards the Mid-Atlantic Ridge. The steep continental slope and a cross- section of the Walvis Ridge is illustrated in Fig.6. As may be expected, the latter feature forms a barrier to deep circulation in the South-east Atlantic. Other prominent bathymetric features are the Agulhas Ridge which forms the southern boundary of the Cape Basin, and the Agulhas Plateau – both shown in Fig. 1, and numerous seamounts of volcanic origin, of which Vema is perhaps the best known.
2.2 Winds
Winds significantly influence the oceanography of the Benguela region on various time and space scales, ranging from basin-wide seasonal and longer period processes to local inshore events of only a few hours duration. The prevailing winds along the west coast of southern Africa are controlled by anticlockwise (anticyclonic) motion around the South Atlantic High pressure system, the seasonal low pressure field over the land and eastward-moving cyclones which cross the southern part of the subcontinent. The South Atlantic High (Anticyclone) is part of a discontinuous belt of high pressure which encircles the southern hemisphere and is maintained throughout the year. Small seasonal differences occur. On average the anticyclone is centred at about 28°S: 8°E, and undergoes seasonal shifts, being at a more northerly and easterly position in winter than in summer. The pressure over the subcontinent alternates between a well-developed low during summer and a weak high in summer, and consequently the atmospheric pressure gradient – and hence wind – is seasonably variable. The coastal plain, much of which is arid, acts as a thermal barrier to cross-flow, and hence winds tend to be predominantly southerly (longshore) over most of the Benguela region, being “topographically steered” along the coast. These longshore winds produce coastal upwelling which gives much of the Benguela its cool surface water characteristics (discussed in the next subsection).
The essential seasonal differences in the intensity of the upwelling-producing longshore winds is best illustrated in Fig.2. From this diagram it is evident that the principal perennial area of strong southerly winds lies near Lüderitz (27°S) with a secondary area near Cape Frio (18°S). In winter the northward shift in the atmospheric pressure systems has a strongest influence south of 31°S, where there is a relaxation of the southerly winds and a greater frequency of westerlies. Off central Namibia wind speeds are generally lower on average, and display less seasonality. Off northern Namibia, the longshore wind is strongest during autumn and spring. North of about 15°S, the latitude of Namibe in southern Angola, the winds are much weaker than off Namibia and South Africa, although they remain longshore on average and reach maximum intensity during winter.
A common feature of the wind field during autumn and winter are “Berg” winds. These catabatic winds occur when there is a pronounced high pressure over the subcontinent, and they blow down from the central plateau across the escarpment and over the coastal plain and then seawards. They are hot, dry winds, often laden with fine particles of dust which is
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visible in some satellite pictures. They exert little direct physical effect on the sea, however, as being warm, they tend to blow above the cool marine atmosphere layer.
Apart from seasonal changes in the windfield, coastal winds are modulated in the southern Benguela during summer by the passage of the easterly-moving cyclones (low pressure cells) which move past the tip of the subcontinent. These result in periodic changes in winds from northerly – initially with an easterly component, before blowing from the northwest – to southerly (southwesterly to southeasterly). The latter can be quite intense and are often characterised by a “tablecloth” of cloud over Table Mountain at Cape Town. These wind relaxation-reversal-strengthening events typically occur on periods of 3 to 10 days.
Diurnal changes in coastal wind intensity and direction are common throughout most of the Benguela region north of St Helena Bay (near 33°S). These are associated with the differential heating and cooling of the sea and the adjacent land mass, typical of the classical land-sea breeze effect. Off much of Namibia coastal fog is often associated with the night time and early morning slacker winds, and tends to dissipate around noon when the southerly wind intensifies.
Readers wishing to know more about the climatology of southern Africa are referred to a definitive book on the subject by Tyson (1986), while comprehensive accounts of the winds over the ocean are contained in Nelson and Hutchings (1983), Shannon (1985), and Shannon and Nelson (1996). For comparisons of the winds and oceanography between the Benguela and the other three eastern boundary current systems, Parrish et al (1983) and Bakun and Nelson (1991) are recommended texts.
2.3 Upwelling and surface temperature
Coastal upwelling is the process whereby cold water is brought to the surface near the coast under the influence of longshore equatorwards winds. The essential process is illustrated in Fig. 3. In simple terms, the longshore wind can be viewed as displacing warm surface water northwards and, as a consequence of the earth’s rotation, offshore. This results in a drop in sea level against the coast, which serves as a non-permeable boundary. To balance the displaced water, the deeper water wells up inshore, and compensatory circulations and longshore currents over and adjacent to the continental shelf are set up. In a simple one cell system, the thermocline (layer where there is a strong vertical temperature gradient) is displaced vertically upwards, and may result in a front between the warm oceanic water and the cool upwelled water, with water moving at depth over the shelf and upwards, and sinking at the front. This is in reality an over-simplification – two or three fronts may develop with rather complex circulations in between, while the actual extent of upwelling and the intensity and direction of shelf currents will be influenced by “coastal trapped waves” – a type of internal wave within the ocean. The existence of these coastal trapped waves can result in enhanced or reduced upwelling and larger sea level changes than might simply be inferred from the wind. Nevertheless, as a general rule, the areas along the west coast of southern Africa where the southerly winds are consistently strongest are also the areas where upwelling is most pronounced. It follows, therefore, that coastal upwelling in the Benguela is neither uniform in time or in space.
The wind field, topographic features (bathemetry and land features) and orientation of the coast result in the formation of a number of areas where upwelling is more intense. The principal upwelling centre or cell is in the central Benguela in the vicinity of Lüderitz
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(27°S). Strong upwelling occurs there throughout the year (Stander, 1964), with some slackening during autumn, and the extensive zone characterised by cold surface water, weak stratification and high turbulence which results there appears to be an important determinant of the biology of the system – effectively dividing the Benguela into two quasi- independent subsystems (Fig. 7). There are several secondary upwelling cells viz Cunene, northern Namibian and central Namibian cells (at approximately 18°, 20° and 24°S) and the Namaqua, Columbine and Cape Peninsula cells (at about 31°, 33° and 34°S). The last two are seasonal, with maximum upwelling occurring between September and March, whereas off northern and central Namibia upwelling is more perennial, but with a late winter maximum. Several smaller ephemeral upwelling cells develop to the west of headlands along the south coast. Although upwelling does occur along the coast of Angola at times, it is not pronounced, and the water column remains stratified throughout the year.
In the northern Benguela peak upwelling and insolation (solar heating) are out of phase, and sea surface temperatures over the shelf follow a distinct seasonal cycle. In the south off the Cape Peninsula, maximum insolation and the upwelling season coincide, and average sea temperatures inshore vary seasonally by little more than 1°C. Viewing the Benguela in terms of a heat budget, the central zone is a major heat sink, with negative climatological sea surface temperature anomalies of 5° - 6°C in the Lüderitz vicinity. South of Africa in the area influenced by the Agulhas Current positive climatological sea surface temperature anomalies of 2°-4°C exist and the area is a major heat source for the atmosphere.
Off Angola, north of about 14°S, there is a positive offshore climatological sea surface temperature anomaly during summer. The dramatic temperature differences between surface waters of the Angolan and Agulhas Currents and those associated with upwelling off Namibia and South Africa are illustrated in Figs 4 and 8.
2.4 Water masses and general circulation
Like temperature, salinity is an important physical property of sea water, and also affects density, and density and pressure (which is approximately proportional to depth) are key parameters in terms of ocean dynamics – just as they are in the atmosphere, the only difference being that sea water is less compressible than air. Salinity is measured in “practical salinity units” (psu) and one psu corresponds to one part per thousand or one tenth of one percent. The salinity of sea water is typically about 3.5% or 35 psu, but like temperature can vary. Salinity is influenced inter alia by fresh water input from rivers, by evaporation, precipitation, freezing of sea water and melting of sea ice.
Water masses are defined by specific temperature-salinity properties. There are a number of different water masses present off the west and south coasts of southern Africa, and their distribution and essential characteristics have been described by various authors and reviewed by Shannon (1985), Chapman and Shannon (1985) and Shannon and Nelson (1996).
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The principal water masses in the Southeast Atlantic are Tropical and Subtropical Surface Waters, Thermocline Waters (comprising South Atlantic and Indian Ocean Central Water), Antarctic Intermediate Water (AAIW), North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW). The “core” characteristics of these are annotated in Fig. 5 which shows the typical temperature-salinity curves (relationships) for the water masses present in the South-east Atlantic. The linear part of the curve (approximately 6°C, 34.5 psu - 16°C, 35.5 psu) spans the Thermocline Water layer, and this is the water which upwells along the coast, and which constitutes, often in highly modified form, the waters present over the continental shelf in the Benguela system. From this figure it can be seen that there are quite marked differences between the Thermocline Water present in the northern and southern parts of the Benguela and true South Atlantic Thermocline Water. At the core of the layer, however, i.e. at 10° - 12°C, it is impossible to distinguish between the Thermocline Waters of different origins on the basis of temperature and salinity only. The flow of the Thermocline Water tends to be similar to that of the overlying surface water, which is discussed a little later. In a recent paper Poole and Tomczak (1999) using optimum multiparameter analysis show a clear separation between Thermocline Water in the Benguela Current system south of about 25 °S and that further north, the latter being >80% Western South Atlantic Central Water.
Thermocline Water overlies Antarctic Intermediate Water, which is formed in the Southern Ocean and which is characterised by the salinity minimum in the temperature-salinity curve. The core of the AAIW in the Benguela has a salinity in the range of 34.2 – 34.5 psu and a temperature of 4° - 5°C, and is present in the region at an average depth of 700 – 800m. In terms of volume, AAIW accounts for about 50% of the water present in the upper 1500m. The AAIW in the southern Benguela is generally much fresher (younger and less mixed) than that present off Angola and Namibia, and is also fresher than that from the Indian Ocean. The differences in “freshness” of AAIW at three areas in the Benguela is illustrated in Fig. 6. While there is some northward movement evident in the south of mixed South Atlantic and South Indian AAIW, the greater part of this water mass in the Benguela region (at least in the area adjacent to the continental shelf) evidently moves southwards from the tropical South Atlantic, having reached the area by a somewhat circuitous route. Further offshore, the AAIW flows in a north-westerly direction. AAIW does not upwell to the surface anywhere in the Benguela.
North Atlantic Deep Water corresponds to the deep salinity maximum (see Fig. 5) and has a salinity typically >34.8 psu, and lies below the AAIW stratum. As its name suggests it is formed in the North Atlantic. It then sinks and spreads southwards. At the equator it comprises a thick layer between 1000m and 3500m of relatively warm (for its depth) and saline water. West of the Benguela continental shelf it flows generally polewards, becoming diluted en route south. Volumetrically, NADW is the main water mass present in the South-east Atlantic.
Underlying NADW in the Cape Basin is Antarctic Bottom Water. AABW forms near the edge of the Antarctic continent in the Weddel Sea area, and spreads throughout the Southern Ocean. Unless prevented by topography, it also tends to spread northwards in the South Atlantic, Indian and Pacific Oceans. In the Cape Basin it flows slowly clockwise, moving southwards at depths greater than 4000m west of the Benguela continental shelf. The Walvis Ridge forms a virtually non-penetrable barrier to the northward flow of the
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AABW, which as a consequence is not significantly present in the Angola Basin. The effect of the Walvis Ridge on the distribution of AABW is dramatically illustrated in Fig. 6.
Whereas the general movement of deeper water masses viz. AAIW, NADW and AABW in the Southeast Atlantic is polewards, the flow of the Subtropical Surface Water (STSW) tends to be more closely aligned to the direction of the prevailing wind – at least in the area south of 15°S latitude where the flow is generally in a north-westerly direction with speeds typically in the range 10 – 15 cm/s. with an average of around 17 cm/s. As a consequence of seasonal warming and cooling of surface water, the temperature – salinity characteristics of STSW can be quite variable, and can range from 15° to 23°C and 35.4 psu to 36.0 psu. (see Fig. 5). The surface water present off Angola is mainly of tropical/equatorial origin. Temperatures in excess of 25°C are common, reaching 28° - 29°C in summer and there is usually a very strong and shallow thermocline present. (This and the contrast with the area further south is highlighted in Fig. 6.) Surface salinity in the area is highly variable, ranging from very low values close to the mouths of major rivers such as the Congo, to levels in excess of 36psu further offshore. The influence of the Congo River at the surface can be substantial, and water from this source can be traced as far south as Namibia. (Dr M. E. L. Buys, pers. comm.) It is generally observed as a thin surface layer, lens-like in places overlying a strongly stratified surface sea water layer.
The principal features of the flow of surface water, and away from the coast also of Thermocline Water, is illustrated schematically in Fig. 7. The broad arrows between 15° and 35°S represent the Benguela Current, which can best be defined as the integrated equatorward flow of the upper layers in the South Atlantic east of the 0° meridian. The circulation has been described in some detail by Stramma and Peterson (1989) and summarised by Shannon and Nelson (1996), and readers are referred to these papers for further particulars. In terms of absolute volume, the total equatorial flow of the Benguela Current, including that of surface, Thermocline and AAIW is thought to be about 15 – 25 Sv (one Sv is 106 m3/s). North of 15°S, which encompasses the Angola system, the main features of the currents within the surface, Thermocline and AAIW layers are (a) a large cyclonic gyre centred around 12°S, 4°E viz. the Angola Dome (b) the Angola Current which flows southwards along the edge of the continental shelf and (c) the Equatorial Undercurrent and South Equatorial Current which feed the Angola Current from the north- west. The oceanography of the Angola system (including the Angola Dome) and the offshore northern Benguela area was well documented by Moroshkin et al (1970). The existence of the Angola Dome and cyclonic flow around it was confirmed by Gordon and Bosley (1991). The volume transport around the Angola Dome is of the order of 3 Sv. The major dynamics affecting the eastern tropical Atlantic Ocean were summarised Voitureiz and Herbland (1982) and by Picaut (1985).
Of the 15 – 25 Sv equatorward flow in the main Benguela Current (as defined earlier), some 7 Sv is of Indian Ocean origin (Van Ballegooyen et al 1994). The latter comes from the Agulhas Current which flows southwards and westwards along the east coast of South Africa. The Agulhas Current is the major western boundary current in the Indian Ocean (75 Sv), and is rather analogous to the Gulf Stream and the Brazil Current. The Agulhas tends to follow the edge of the continental shelf and on reaching the Agulhas Bank turns southwards and then eastwards, flowing back into the Indian Ocean. This turning back is
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termed “retroflection”. Small periodic meanders termed the Natal Pulse, may develop in the main body of the Agulhas Current off Natal and these grow downstream, resulting in the Current becoming unstable and the shedding of large eddies or rings. About six or eight Agulhas rings are shed each year, and these fast spinning rings move slowly (typically 5 –8 cm/s) in a west-north-westerly direction into the South Atlantic, transporting about 7 SV of Indian Ocean water on average. At the surface shallow filaments of Agulhas Current water also may round the Cape of Good Hope, just outside the upwelling area, but the mass of water associated with these filaments is usually fairly small although occasionally the southern Benguela is flooded by warm water of Agulhas origin. The retroflection of the Agulhas Current and the leakage of warm Indian Ocean water into the South Atlantic is well illustrated in Fig. 4, and shown diagrammatically in Fig. 7. In summary the main features of the surface currents are:
Offshore: flow of about 15 – 20 cm/s (i.e. about 1/3 knot in a northwesterly direction over most of the region between 15°S and 35°S (viz. the Benguela Current)
Cyclonic circulation around the Angola Dome and periodic intrusion of tropical water from the north and north west into the northern Benguela
Leakage of Agulhas Current water into the South Atlantic, mainly via rings and to a lesser extent via shallow filaments
Shelf circulation
Circulation over the continental shelf and in the oceanic area adjacent to the shelf has been the subject of intensive investigation during the past twenty years, although most of the effort has been focussed on the southern Benguela. The various observations were summarised by Shannon and Nelson (1996) and again recently by Shillington (1998).
Surface currents over much of the Benguela shelf are largely influenced by the prevailing winds. In the south there is a general convergent flow of surface water from the Agulhas Bank westwards and northwards around the Cape of Good Hope which funnels into a frontal jet west of the Cape Peninsula (discussed later). Typical speeds are in the range of 25 –75 cm/s. Near Cape Columbine (33°S) the surface current divides into an offshore flow and a northward alongshore flow, partially into St Helena Bay. A southward moving current often occurs near the surface close inshore over the entire region, particularly during winter and also periodically during the rest of the year when reversals take place on a time scale of several days. Over the Namibian shelf, the surface currents are generally in a northerly direction, closely aligned to the wind. However, periodic and episodic reversals in the surface currents can occur, the most pronounced and extended reversals occurring during Benguela Niños (discussed in Section 5). The most prominent circulation feature off the coast of Angola in the southward flowing Angola Current. Whether this current is a permanent or seasonal feature is not clear as most of the more comprehensive investigations appear to have been undertaken during the autumn and winter months.
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Certainly the existence of the Angola Current was well documented by Moroshkin et al (1970). It is a coastal current, generally present as a poleward flow over the upper part of the continental slope (i.e. west of the shelf break), detectable between the surface and a depth of about 200m. Literature on the current is sparse, but there is some evidence of seasonality, with the most intense flow occurring during late summer (March), when surface speeds as high as 70cm/s have been reported, and subsurface speeds of up to 88 cm/s (Dias 1983). The dynamics of the Angola Dome and Angola Current are linked with those of the system of equatorial currents and the Benguela Current and upwelling processes. However, to what extent the Angola Current contributes to the Benguela system off Namibia is uncertain – at the surface and subsurface at least. In this respect Dias (1983) showed that most of the southward flow of the current at a depth of 100m turned between 16°and 17°S latitude to flow westwards just north of the Angola-Benguela front. At greater depths e.g. 400m, the poleward flow from Angola into the northern Benguela does however seem to be more continuous, and this has been the focus of recent cooperative research between German, Norwegian, Angolan, Namibian and South African scientists.
In the southern Benguela, in particular off the Cape Peninsula, but also in the vicinity of Cape Columbine there exists a strong equatorward flowing jet. First predicted and discovered by Bang and Andrews (1974) the existence of this jet has subsequently been confirmed as a semi-permanent feature of the upwelling system. Current velocities are highest at subsurface depths, being typically in the range 25 – 75 cm/s. The jet is important biologically in that it is known to transport eggs and larvae of various fish species from the spawning grounds on the Agulhas Bank to the nursery areas inshore north of Cape Columbine. To what extent the jet is continuous throughout the Benguela, or indeed even if it exists in the central and northern Benguela, is not known, although there is a suggestion in the work of Gordon et al. (1995) that a jet like feature is present in the upper 100m over the mid-shelf near Lüderitz.
Apart from the shelf-edge jet, the most significant discovery during the past two and a half decades has been of a poleward undercurrent. The idea of a poleward flow in upwelling regions seems to have originated from ideas put forward by Hart and Currie (1960) in their classic text on the Benguela Current viz. as some form of compensation for the water displaced from the inner shelf by upwelling. Nelson (1989) showed that, as in the case of in other upwelling systems, a poleward undercurrent does exist in the Benguela, but which is much more extensive than that required as compensation for coastal upwelling, stretching from the coast, across the shelf and out into the Cape Basin. Current meters have revealed that subtidal currents on the shelf are dominated by the presence of coastal trapped waves (previously commented on), which have periods of 3 to 8 days. These result in a net polewards flow of about 5km/d or 5.8 cm/s (Nelson 1989). On occasions this southwards- moving current may reach the surface inshore, resulting in episodes of poleward flow at the surface. In St Helena Bay, such events result in episodic flushing of the Bay. Aspects of the poleward current will be discussed further in Section 3.1 which addresses dissolved oxygen.
The shelf-circulation can thus be briefly summarised as follows:
Wind driven surface currents over the shelf
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Poleward subsurface flow over shelf and in deeper water adjacent to shelf throughout the region (4-5 km./d)
Poleward flowing Angola Current in extreme northern part of the Benguela region i.e. along coast of Angola
Jets associated with the upwelling system and located near the edge of the continental shelf in the southern Benguela
Coastal trapped waves are characteristic of the shelf area throughout the Benguela (periods typically 3-8 days).
System boundaries, fronts and filaments
Whereas a thermocline refers to a layer where there is a rapid change in temperature with depth, a halocline and a pycnaocline are vertical discontinuities of salinity and density respectively. Fronts refer to areas where there is a sharp change in temperature, salinity (or some other parameter such as colour) horizontally. Reference back to Fig 3 which illustrated a simplified concept of upwelling, it can be seen that where the thermocline intersects with the sea surface, the vertical discontinuity is translated into a horizontal discontinuity viz. a front. Physical boundaries of, and within, the Benguela are usually associated with fronts of one form or another, and these fronts tend to form barriers to horizontal movement of water and small particles such as plankton. They may be less important as barriers for highly motile animals such as fish and marine mammals.
Northern boundary
The physical northern boundary of coastal upwelling is marked by the Angola-Benguela frontal zone. The temperature and salinity front (series of fronts) is a permanent feature at the surface, identifiable to a depth of at least 200m, and is maintained throughout the year within a narrow band of latitudes, characteristically between 14°S and 17°S (i.e. close to the Angola-Namibia border). The front generally has a west-to-east orientation, and appears to be maintained by a combination of factors, including bathymetry, coastal orientation, stratification, wind stress and opposing flows of the Benguela and Angola Currents. The southwards migration of the front is most pronounced during late summer when longshore winds in the northern Benguela are weaker and upwelling is reduced. The situation in northern Namibia/southern Angola is in some respects analogous to the seasonal cycle off Peru in the Pacific during some years, when anomalously warm water appears (El Niño). There is a South Atlantic equivalent of the Pacific El Niño and it manifests itself as an episodic extreme warming in the tropical eastern Atlantic and the movement of tropical water southwards and eastwards along the Namibian coast. These Benguela Niños (Shannon et al. 1986) occur on average every ten years and are not necessarily in phase with the El Niño- Southern Oscillation (ENSO) – although some links with the latter are evident. Benguela Niños occurred in 1934, 1949, 1963, 1984 and 1995 and probably also in 1910, in the mid-1920s and in 1972-1974. Although not as frequent or intense as El Niños, like the Pacific counterpart, their impact on the ecosystem and harvested resources in the northern Benguela is enormous.
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The characteristic location of the Angola-Benguela frontal zone is shown in Fig. 7. This is a much simplified diagram, as the “front” is often a combination of fronts with convoluted characteristics. (For example see Fig. 8 – which illustrates the surface expression of the Angola-Benguela frontal zone in April 1997).
While the Angola-Benguela Front (more correctly a series of fronts) comprises the northern extent of the main coastal upwelling zone, upwelling can occur seasonally along the entire coast of Angola. There are, in any event, strong linkages between the behaviour of the Angola-Benguela front (and the oceanography of the area to the south of it) and processes occurring off Angola, especially the Angola Dome and the Angola Current. Unless these are considered as an integral part of the BCLME, it will not be feasible to evolve a sustainable integrated management approach for the Benguela. Moreover, there is a well- defined front at about 5°S, viz the Angola Front which is apparent at sub-surface depths. It is this front which is the true boundary between the Benguela part of the South Atlantic and the tropical/equatorial Gulf of Guinea system. A northern boundary at 5°S would thus encompass the Angola Dome, the coastal Angola Current and the area in which the main oxygen minimum forms and the full extent of the upwelling system in the South-east Atlantic. A pragmatic northern boundary is thus at 5°S latitude (see Fig 7) which is in the vicinity of the northern boundary of Angola (Cabinda) and the southern extent of the Gulf of Guinea Large Marine Ecosystem (GOGLME).
Southern boundary
The southern boundary of the Benguela system can be considered as the Agulhas retroflection area, typically between 36° and 37°S. Like the northern boundary, this warm southern boundary pulsates on a spectrum of time and space scales, and about 10% of the warm tropical Agulhas Current “leaks” into the South Atlantic. As previously explained most of this leakage is in the form of rings (eddies) which are shed from the Agulhas Current as it retroflects. The main trajectory of these shed rings is west-north-west, although departures from this have been recorded, and there exists a well documented case of ring interacting with the Benguela upwelling system and drawing upwelled water off the shelf in the form of a large curved upwelling filament. In addition to rings, there is a small regular leakage of filaments of Agulhas water around the Cape of Good Hope just west of the edge of the shelf and thermal front (which is associated with the upwelling). On occasions there are substantial intrusions of Agulhas Current water into the southern Benguela, of which the best documented case occurred in 1986 and coincided with that year being among the warmest this century in the South-east Atlantic Ocean. Another large intrusion occurred during the summer of 1997/8. Like its counterpart in the north, these Agulhas intrusions appear to affect the living resources in the southern Benguela.
The location of the southern boundary is shown schematically in Fig.7, while the typical extreme complexity of this boundary and retroflection of the Agulhas Current and “leakage” is illustrated in Fig. 4.
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Western boundary
The western (offshore) boundary of the Benguela is fairly open ended, but is generally taken as approximately the 0° meridian. As such the Benguela sensu lato includes the coastal upwelling area, the longshore fronts (see below) and the eastern portion of the South Atlantic gyre. By definition then the Benguela Current comprises the total area of equatorward flow in the upper part of the South-east Atlantic Ocean.
Longshore fronts
There exists over much of the area between Cape Frio (18°S) and Cape Point (34°S) a well-developed longshore temperature front or fronts, which extends seasonally (in summer) eastwards around the Cape of Good Hope. The oceanic thermal front approximates to the seaward boundary of the general area influenced by coastal upwelling. South of Lüderitz a single front is usually well defined, and although spatially and temporally variable, coincides approximately with the run of the shelf break (edge of the continental shelf). Further north the surface manifestation of the front is more diffuse and multiple fronts are evident on occasions. The meandering nature of the front is evident in satellite imagery (see Figs 4 and 8). Upwelling filaments which have a life span of days to several weeks and which are generally orientated perpendicular to the coast cause the front to become highly convoluted. Opinion as to whether these filaments are randomly distributed or site specific are divided, although most recent evidence points to the latter (which can be explained in terms of bathymetry and system dynamics).
CHEMISTRY AND RELATED PROCESSES
Prior to 1925 very little was known about the chemistry of the South-east Atlantic Ocean and adjacent areas, and it was not until data collected by the German Meteor Expedition of 1925 – 1927 were analysed and interpreted that a picture of the large-scale distribution of elements of importance such as oxygen, phosphorous and silica began to emerge. In the Benguela region, although the role of upwelling in the supply of nutrients (the dissolved fertilisers in the sea) was appreciated as early as the 1930s, it was not until the publication of the definitive work of Hart and Currie (1960) that the nutrient chemistry was placed in a proper physical and biological perspective. Subsequent investigations by inter alia authors such as De Dekker (1970), Calvert and Price (1971) and Andrews and Hutchings (1980) resulted in a greatly improved understanding of the chemical-biological processes of importance in the Benguela. The available information on the Benguela chemistry and related processes was reviewed by Chapman and Shannon (1985) while recently Bailey and Rogers (1997) have provided a useful overview of chemical oceanography within the context of marine geoscience in southern Africa.
Before discussing the essential features of processes associated with the chemistry of the Benguela system it is perhaps appropriate to explain some basic concepts so that readers who are not oceanographers or chemists will more easily be able to follow the subsequent discussions. Viewed very simply, macro-nutrients such as ammonia, nitrate, phosphate and
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silicate are present in sea water at low but significant concentrations. Near the sea surface these nutrients are consumed by microscopic plants (phytoplankton). Photosynthesis takes place, and the phytoplankton multiplies or blooms, absorbing carbon dioxide and releasing oxygen into the water. The phytoplankton is then either consumed by small planktonic animals (zooplankton) and some fish species or otherwise sinks slowly to the bottom. In this process bacteria play an important role, and as the phytoplankton and also faeces and organic material from zooplankton and higher consumers sinks, these decay. During the decay, oxygen dissolved in the deeper sea water layers and sediments is consumed and nutrients are released back into the water column. The overall process results in a lowering of nutrient concentrations in the surface layers and an increase at depth, with the opposite situation applying to dissolved oxygen. Within the context of a system such as the Benguela, it is the upwelling that is thus so important in bringing the nutrient-rich deeper water to the surface where photosynthesis can occur, and this explains why eastern boundary currents are so rich biologically. In the Benguela there is an imbalance between phytoplankton and zooplankton and fish production, and much of the decaying phytoplankton is deposited on the seabed, forming the organically rich diatomaceous sediments which are characteristic of the larger part of the Benguela shelf. In turn, processes which take place at the interface between the sediments and the overlying water and in the water in the sediments (interstitial water) are chemically also very important, in particular for the “regeneration” of nutrients.
Although what has been described is perhaps somewhat of an oversimplification of the complex physical-chemical-biological interactions which occur, it does help to explain the cycle.
3.1 Dissolved oxygen
One of the major features of the Benguela region is the occurrence of large areas where very low concentrations of dissolved oxygen are found. Thermocline Water (Central Water) in the South-east Atlantic Ocean, which is the upwelling source water, commonly contains between 4.8 and 5.2 ml/l dissolved oxygen and is about 80 – 85% saturated. In contrast, the shelf waters in the Benguela system frequently contain much lower concentrations, and on occasions at sites such as Walvis Bay the sea can become anoxic at times, particularly at depth, while near the surface during phytoplankton blooms photosynthesis can result in the surface layer becoming supersaturated with oxygen. The occurrence of low-oxygen water is not only important in terms of the chemistry, but plays a key role in controlling the distribution and abundance of several marine species – not only bottom-dwelling (benthos) like rock lobster, but also fish such as hake. To avoid confusion, in the following paragraphs, we shall refer to water having an oxygen content of less than 2 ml/l as “oxygen-deficient” and above 2 but less than 5 ml/l as “oxygen-depleted”.
The first comprehensive account of the large scale distribution of dissolved oxygen in the South Atlantic was provided by Wattenberg (1938), and was based on measurements made during the expedition of the Meteor a decade earlier. His work showed the existence of a wedge-shaped tongue of oxygen-deficient water with its core lying at a depth of 300 – 400m, and extending from its base between the equator and 20°S at the African continent, across the South Atlantic. Concentrations lower than 0.5ml/l were recorded in the
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Benguela region near 15°S. The permanence of this major low oxygen feature in the South Atlantic has been confirmed by all subsequent large-scale investigations.
Hart and Currie (1960) and others have demonstrated the existence of an oxygen-deficient layer overlying the continental shelf north of Walvis Bay, and it is clear that oxygen- depleted subsurface water is a characteristic feature of much of the northern and central Benguela shelf. Subsequent studies have shown that low oxygen conditions can exist at times on the shelf further south, for example near the Orange River, in St Helena Bay and even at some sites on the Agulhas Bank. Hart and Currie (1960) suggested that the oxygen-depleted shelf water might be transported southwards from the tropical South-east Atlantic along the edge of the shelf in a deep compensation current, a view supported by De Dekker (1970) and Andrews and Hutchings (1980) who put forward convincing arguments in favour of this, and suggested that the oxygen-deficient water which occurs as far south as the Cape Peninsula at times, originates from Namibia.
The most comprehensive study of dissolved oxygen off Angola and Namibia was that undertaken by Bubnov (1972), and he suggested that the main oxygen minimum in the South Atlantic forms in a broad area off Angola, and is reinforced by processes associated with the Angola Dome. This is shown schematically in Fig. 9. Bubnov, however, calculated that the level of primary production over the Namibian shelf was sufficient to provide the concentrations of oxygen observed in the water column there in the absence of any advection (horizontal movement) from the north, a view supported subsequently by a number of authors. Interestingly, Poole and Tomczak (1999) show that the pseudo age of this oxygen poor water off Angola is 50 years or greater, in contrast to the younger more recently ventilated water south of 30°S which is less than 10 years “old”.
Thus, while southward advection of oxygen-deficient and oxygen-depleted water from the Angola Basin via a poleward undercurrent may be an important mechanism controlling the distribution of low oxygen water on and adjacent to the shelf, local processes over the Namibian shelf are probably more important on average as determinants of oxygen dynamics in the Benguela region per se. This view is reinforced by the properties and distribution of the main oxygen minimum layer off Angola which are different to those of the oxygen-depleted/deficient shelf waters off Namibia. Indeed two distinct maxima cores have been observed on occasions, one over the shelf (locally produced) and a deeper one (probably part of the main minimum layer) west of the shelf break. It does seem, however, that the high primary production off Namibia is an important contributor to the main oxygen minimum layer, the latter at times spilling onto the shelf and reinforcing the depletion processes in Benguela shelf waters. There is also evidence that there is a slow southward advection of oxygen-deficient water throughout the Benguela at least as far south as the Cape Peninsula with lowest oxygen concentrations occurring during late summer/autumn in the southern Benguela. The fact is that oxygen-deficient water dynamics which plays a pivotal role in the ecosystem are not well understood. What is known is that substantial interannual variability in the oxygen concentrations does occur (discussed later) and that this is important for fisheries.
A conceptual model of areas where the low oxygen water forms and its movement is given in Fig. 9. Readers are referred to Chapman and Shannon (1987) and Bailey and Rogers (1997) for further information.
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3.2 Nutrients
The general features of the distribution of nutrients in the Benguela resemble closely those of other upwelling regions. The upwelling water is enriched in nutrients relative to the surface layers and during active upwelling this water reaches the euphotic zone (the biologically productive surface layer which sunlight penetrates) near the shore. Following the establishment of the thermocline, phytoplankton production consumes nutrients in the upper layers, leaving them much depleted, while nutrient re-enrichment occurs below the thermocline as the phytoplankton decay. Chapman and Shannon (1985) pointed out the difficulty in discussing the nutrient status of the whole Benguela because the chemistry is very much site specific, and it is therefore not easy to generalise.
The shelf waters of the Benguela are, however, characterised by elevated concentrations of nutrients in comparison with those in the surface mixed layer of the adjacent oceanic waters, and also in comparison with concentrations in source waters. For example, South Atlantic Thermocline Water contains about 0.8 – 1.5 µM (micro-moles) phosphate, but shelf waters have phosphate concentrations typically between 1.5 and 2.5 µM, with values as high as 8µM having been recorded off Namibia. Local regeneration processes are important throughout the Benguela, but particularly off Namibia. In comparison with the eastern boundary of the Pacific, source waters in the Benguela have lower levels of inorganic nutrients, and consequently a lower potential for new production. (The term “new production” is commonly used by marine chemists and biological oceanographers and can be viewed simply as that based on outside sources of “fertilisers” such as nitrates, unlike “ regenerated production” which results from the locally produced waste material – ammonia and urea based.). Typical concentrations of macronutrients in the Benguela system are summarised in Table 1.
Table 1: Nutrient concentrations (µM) in (a) offshore upwelling (b) shelf and (c) oceanic surface waters in three areas of the Benguela, based on published work.
Area Phosphate Silicate Nitrate Cape Peninsula (a) 20 1.5 16 23 1.5 19 (b) <1 0.5 5 (c) St Helena Bay – Orange River (a) 25 2 10-20 25 2.5-3 20-40 (b) <1 0.5-1 8 (c) Namibia 15-25 1.5-2.5 5-20 (a)
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10-30 2-3 20-50 (b) <5 <2 <1 (c)
One generalisation which can be made is that the importance of nutrient regeneration in the supply processes increases northwards in the Benguela system.
Whereas Thermocline (Central) Water of South Atlantic origin contains fairly similar concentrations of nitrate and phosphate as South Indian Ocean Thermocline Water, the silicate content of the latter is only about half of the former. This is significant for the nutrient chemistry of the Agulhas Bank region, which can according to Lutjeharms et al. (1996) be divided into distinct nutrient “provinces,” the eastern off shore part of the Bank being dominated by nutrient-poor Subtropical Surface Water and the western and inshore areas influenced by nutrient-rich South Atlantic Thermocline Water. Although upwelling occurs inshore in the lee of prominent capes, the Agulhas Bank system is strongly stratified in summer, particularly so in the eastern part. As a consequence nutrient concentrations tend to be higher in winter over the Bank as a whole in winter when the shallow seasonal thermocline breaks down. Readers requiring further information are referred to an excellent overview of the nutrient dynamics of the Agulhas Bank in Bailey and Rogers (1997). Published work suggests that silicate is the limiting nutrient at times in the northern Benguela, while nitrate is on occasions limiting in the southern part of the system. This is perhaps counter intuitive when it is considered that the Namibian shelf sediments are rich in biogenic silica and Agulhas Current/Bank water (which leaks into the southern Benguela) relatively poor in silica. Considerable advances have been made during the past decade with respect to the assimilation of ammonia and nitrate by phytoplankton using stable-isotope nitrogen fifteen (N 15) incubation techniques by authors such as Probyn et al. (1990), Probyn (1992) and Waldron and Probyn (1992).
A significant contribution to the understanding of nutrient dynamics and production was made during the second phase of the Benguela Ecology Programme (1987-1992) with the recognition of the importance of the microbial loop and the application of N 15 labelling techniques to distinguish between newly incorporated nitrogen (NO3-N or N2) and metabolically recycled nitrogen (NH4-N or dissolved organic-N, i.e. urea).
Using satellite-derived sea surface temperature imagery, Waldron and Probyn (1992) estimated the potential new production in the Benguela system, and the first of these authors subsequently went on to calculate new production during the 1980s using sea level as a proxy for upwelling. Following on from work on carbon pathways in the southern Benguela upwelling system (Waldron et al. 1998), Dr Waldron has kindly generated a nitrate-nitrogen driven pathway for the Benguela as a whole for the purpose of this overview. This is given in Fig. 10 and illustrates simply and dramatically the import and export fluxes in shelf waters, in particular the nitrate-driven new production and the role of the shelf sediments as a sink. This will be discussed further in the section dealing with the foodweb and carbon budget.
Sulphur
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Perhaps one of the most obvious features of the marine chemistry of the northern Benguela is the odour of hydrogen sulphide gas which is associated with “sulphur eruptions”. These periodic eruptions are common in the general vicinity of Walvis Bay, usually during late summer when upwelling is at a minimum i. e. under quiescent conditions.
Sulphide formation results when anaerobic biological breakdown of organic substances and bacterial reduction of sulphate which is present in sea water and in the interstitial water in the marine sediments occur. As biological reduction of sulphate is an anoxic process, sulphide formation can occur where there is above average oxygen consumption or poor circulation - circumstances which may be associated with the decay following a major bloom of phytoplankton in an embayment or even along an open coast under quiescent conditions. These suboxic or anoxic conditions are common in the northern Benguela shelf waters and underlying organically rich sediments, and this provides suitable environmental conditions for the formation of sulphides by sulphate reducing and anaerobic bacteria.
As hydrogen sulphide which may be formed in the process can be extremely toxic, even at very low concentrations, mass mortalities of marine organisms are often associated with the “sulphur eruptions”’ compounding the effect of the already depleted oxygen content of the sea water. Records of fish kills in the Benguela resulting from sulphide production go back at least as far as 1928, but the occurrence of sulphide was not positively identified until later (Copenhagen 1934). Sulphurous fumes are often present in the atmosphere at coastal sites in central Namibia and may penetrate 60km or more inland. Their corrosive effect on iron and steel and tarnishing of paintwork, brass and silver is visibly evident in Walvis Bay and Swakopmund. During the sulphide events, mud islands may appear and disappear, the smell of rotten eggs pervades the air, and the sea takes on an appearance of boiling – hence the term “sulphur eruptions”. The most recent widescale sulphur eruption occurred in the Walvis Bay/Swakopmund area during March/April 1998 and was characterised by a strong odour of hydrogen-sulphide. The sea along the coast turned a milky-turquoise colour for as far as the eye could see.
The main area within which the sulphur eruptions occur is the so-called “azoic zone”, and free sulphur can be present in sediments from this area. Even 100km further south, concentrations of sulphide as high as 65mg/l may occur in interstitial water in sediments (Bailey 1979). Hydrogen sulphide concentrations of about 1ml/l have been measured in the northern Benguela. In the southern Benguela, eg. St Helena Bay, even though sediments may smell of sulphide, there are very few published measurements of free hydrogen sulphide. However, during the autumns of 1994 and 1998 a strong odour of hydrogen sulphide persisted for about a week in the atmosphere around Cape Town, as a consequence of decaying phytoplankton blooms in the St Helena Bay area, suggesting that sulphide events may be more common in the southern Benguela than hitherto appreciated.
In spite of the occurrence of sulphide in Benguela sediments and shelf waters, surprising little research has been conducted on the subject. Apart from the relevance of such studies to investigation and prediction of mass mortalities of marine life, public awareness and interest is high. Moreover, what is perhaps not well known, but may be extremely important in terms of industrial development along parts of the west coast, relates to the solubilization of heavy metals. For example mercury sulphide which is insoluble in normal
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oxygenated (oxic) water and sediments and is generally regarded as environmentally harmless, can be transformed to polysulphides of mercury in the presence of low concentrations of sulphide, and goes into solution – thereby becoming a serious environmental hazard.
Other aspects of marine chemistry
In their comprehensive review of the chemical oceanography of the Benguela system, Chapman and Shannon (1985) also discussed other aspects of the redox chemistry, including that of iodine and biomine, in addition to nitrate/nitrite and sulphate/sulphide as couples. (An important reference work on the subject is Price and Calvert 1977 which complements an earlier publication by these authors viz. Calvert and Price 1971). Chapman and Shannon also reviewed published work on the minor elements, which in contrast to the oxygen and nutrient distributions and dynamics have received very little attention in the Benguela. Minor elements include inter alia the alkali elements (potassium, rubidium and lithium), barium, and heavy metals. Many of the pioneering measurements of metals such as copper, iron and manganese, which are trace nutrients, were made by Orren (1969, 1971). As part of a South African marine pollution study, these and trace metals such as cadmium, nickel, lead and zinc were measured in water and sediments along the coast during the 1970s and 1980s eg. Eagle et al. (1982). Their results were summarised by Shannon and Chapman (1985) as was the work of authors such as Chester and Stoner (1975) on the concentrations of metals in dust and surface water particles collected in the Benguela region. Excluding urban environments, most of the measurements on metals in sediments have been from the organically rich Namibian shelf region, and it would appear from the available data that the concentrations of metals in these sediments are higher than observed in many other marine sediments.
Man-made chemicals such as chloro-fluoro-carbons (“CFCs”) have been detected in the deeper water masses present in the South-east Atlantic. CFCs such as CFM-11 and CFM- 12 are useful tracers of water mass age and movement, and in the southern African context of the exchange of waters between the South-east Atlantic, North Atlantic and Indian Oceans.What the results also show is that even the deep bottom waters in the Southern Hemisphere have potential to be contaminated by activities of industrial Northern Hemisphere countries and can no longer be considered as pristine.
In conclusion it must be noted that chemical oceanography has for the past two decades been very much a “Cinderella discipline” in southern African countries, and in spite of the importance of chemical processes in regulating the biology of the Benguela ecosystem, this has apparently not been adequately recognised by the fisheries and environmental agencies.
PLANKTON AND THE FOODWEB
The literal translation of the word “plankton” is “wanderer”, and the term applies to a spectrum small neutrally buoyant (“free floating”) organisms in the sea which have little or no power of locomotion, and which drift with the currents. These small microscopic plants and animals provide the primary food sources for a host of marine species and constitute
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the early building blocks in the marine food chain or, more correctly, the foodweb. The microscopic unicellular plants which occur in surface layers of the ocean are known collectively as phytoplankton, while their animal counterparts are referred to as zooplankton. Although the most common components of zooplankton are only a few millimeters in size, zooplankton includes much larger floating animals such as jellyfish. Useful reviews of plankton in the Benguela system are those of Shannon and Pillar (1986) – now a bit dated – and Hutchings and Field (1997). Perhaps the most readable introduction to the zooplankton of the Benguela Current region is Gibbons (1999).
Phytoplankton and primary production
Like all plants, phytoplankton require sunlight in order to photosynthesise, and accordingly most of the organic productivity associated with these floating algae takes place near to the sea surface. Phytoplankton can for all practical purposes be divided into two categories viz. diatoms, which have no power of self propulsion and which have an outer skeleton of silica, and those which have small hairs or flagella which enable some weak motion viz. flagellates. The latter are generally more fragile than diatoms and are associated with less- turbulent and more stratified waters. Diatoms are characteristic of turbulent, nutrient-rich upwelled water. In upwelling systems the biomass of diatoms is generally much higher than the biomass of flagellates.
The Benguela is generally regarded as a diatom-dominated system. This perception is to some extent an artifact of past sampling, which has tended to miss the very small cells or nanoplankton. (The productivity of nanoplankton is regulated by regenerated nitrogen – see Section 3.2 – and historically nanoplankton have been undersampled in the Benguela). Both the northern and southern Benguela share many similar species assemblages, with Chaetoceros, Nitzschia, Thalassiosira, Rhizosolenia being endemic throughout the region. There are, however, essential differences between the north and the south, some of which are linked to the atmosphere/ocean dynamics (e.g. nutrient supply, turbulence and stratification). The diatom Delphineis karstenii (Fragilaria karstenii) is restricted to the north, while Skeletonema costatum is found predominantly in the southern Benguela, evidently having been most abundant in the early-mid 1960s and mid 1980s (both warm periods in the system). The large cell Coscinodicus spp. commonly occurs in areas of high turbulence. Over the Agulhas bank, the species assemblages are more cosmoplitan than along the west coast. Microflagellates are common in the central area of the northern Benguela e.g. Gymnodinium and Peridinium spp.
Phytoplankton abundance both from net and bottle sampling and chlorophyll a measurements highlights the dichotomy between the northern and southern parts of the system, with low values around 27-28°S (the base of the Lüderitz upwelling cell), and high values downstream of the cell, and also further south associated with downstream areas of the other upwelling cells (Namaqua, Columbine, Cape Peninsula). Off Namibia during periods of active upwelling, highest concentrations of phytoplankton occur offshore (50km), and during quiescent periods in a narrow band close to the coast. A characteristic difference between the northern and southern Benguela is that concentrations of chlorophyll a are generally higher off Namibia than off South Africa, being more uniformly distributed in the former with less well defined chlorophyll fronts at the oceanic boundary.
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The advent of ocean colour satellite imagery in the late 1970s provided new insights into the distribution and large scale dynamics of phytoplankton blooms. The Coastal Zone Colour Scanner (CZCS) on the Nimbus-7 satellite in fact resulted in a quantum leap in knowledge and understanding of the global distribution of phytoplankton, and southern African oceanographers played an important role in the early validation of CZCS data and application of satellite-derived ocean colour imagery in the study of upwelling ecosystems and fisheries. After about ten years (which is a very long time for a satellite sensor to function) the CZCS eventually failed, and it wasn’t until very recently that a new and much more sophisticated generation of colour satellites were launched and became operational. Of these, the Sea-viewing Wide-imaging Field-of-View Sensor (SeaWiFS) launched in August 1997 is the best-known and most user-friendly. Fig. 11 is a snapshot of the distribution of plant pigments in the Benguela between 16° and 32° S from SeaWiFS.
In the southern Benguela chlorophyll is determined by wind cycles and displays significant seasonality. Maximum concentrations tend to occur 20-80km offshore. (Blooms following periods of active upwelling can extend 100km or more offshore). Chlorophyll a concentrations in recently upwelled water, maturing upwelled water and aged upwelled water are about 1, 1-20 and 5-30 mg/m3 respectively. Over the Agulhas Bank phytoplankton production is largely controlled by thermocline/nutricline dynamics and the area is characterised by a deep chlorophyll maximum layer, at a depth of about 40m.
The total primary production in the Benguela system is approximately the same as that in the Peruvian system, but substantially greater than off California. Brown et al. (1991) provided an authoritative review of phytoplankton primary production and biomass in the Benguela. Average values are given in Table 2.
Table 2. Average values of phytoplankton biomass and production.
Primary production (C14 uptake) Phytoplankton Biomass g C/m2/d tons C/y Tons C Northern Benguela (15°S-28°S) 2.6x106 1.2 77x106 Southern Benguela (28°S-34°S) 0.7x106 2.0 76x106 South-west Coast (34°S-30°E) 0.5x106 1.9 79x106
Bacterial biomass and production estimates range from a conservative 2-7% and 3-5% of that of phytoplankton to 8-27% and 26-44% respectively in the least conservative case.
Substantial advances have been made with respect to the dynamics of phytoplankton- blooms and plankton-ecology in general in the southern Benguela by drogue studies (following patches of freshly upwelled water as it ages) and anchor station experiments. (The latter were also done in the northern Benguela.) During the past decade a good
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understanding of community structure and variability has been gained in the southern Benguela which has showed systematic trends in dominant patterns of diatoms, dinoflagellates and microflagellates in relation to upwelling, pulsing, turbulence and stratification. The importance of phytoplankton seed populations in determining the composition and time required for bloom development has been established and insights have been gained into maintenance and life-survival strategies. In this respect, diatoms tend to form spores which sink rapidly, and this enables them to remain in the nearshore and nutrient-rich environments closer to upwelling centres (Pitcher 1990). Studies on rate dynamics have enabled the quantification of the phytoplankton loss process to be made. The knowledge gained in the south, if applied in the north, should facilitate a quantum jump in the understanding of the dynamics of the Benguela – at least in respect of plankton processes.
Red tides and harmful algal blooms.
Outbreaks of red tide occur both in the northern and southern Benguela. They tend to be observed most frequently close inshore, where their visual and at times harmful effects are most apparent. Red tides are most frequent during quiescent conditions which follow upwelling, or during periods of light onshore winds and downwelling which commonly occur in the southern Benguela during times of Pacific El Niño events. The red tide causing organisms in the Benguela are generally dinoflagellates and sometimes ciliates, and contrary to popular belief, most of the red tide species are non-toxic (Horstman 1981).
That red tides occur regularly in the Benguela is not unexpected. Diatoms, which dominate the phytoplankton in the Benguela, have high nutrient requirements and are adapted to turbulent conditions. The diatom blooms which are associated with upwelling events quickly strip the nutrients from the upwelled water, and as the water column stabilises and stratifies, this provides a suitable environment for dinoflagellates, which being tolerant of low nutrient conditions, and favouring stable high light conditions, can then outcompete the diatoms and “bloom”. The dynamics of red tide blooms in the Benguela have been studied in some detail, in particular in the south, during the past two decades by Dr G. Pitcher and his coworkers. In a recent article Pitcher and Boyd (1998) have described from an examination of the distribution of dinoflagellates across the continental shelf and of currents the physical mechanisms responsible for red tide outbreaks, and for the maintenance of motile populations within the system.
The most common red tide organism in the southern Benguela is Noctiluca scintilans, a non-toxic dinoflagellate. It also occurs off Namibia. This organism has been associated with fish mortalities, however, not through any toxin, but by depleting the dissolved oxygen in the water during major blooms, and also evidently by clogging the gills of fish. Noctiluca blooms have a characteristic bright orange colour – almost luminous (see Fig. 12). The most common red tide species off Namibia appears to be Heterocapsa triquentra, and like species of Gymnodinium, Gongaulex and Scrippsiella, it has been linked to mortalities in fish. Most reported mortalities of marine life in the Benguela which have been associated with harmful algal blooms (HABs), in particular mortalities of sand mussels and benthos have been due to a few species of Gongaulex and to Mesodinium rubrum. The latter species is also known to occur off Angola. Red tide outbreaks off Angola were first reported in the scientific literature of the 1940s. A major bloom of Prorocentrum balticum
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occurred between Namibe and Luanda in August-September 1951, and was associated with high fish mortality (Silva, 1953) – see also a comprehensive account of red water on the coast by Paredes (1962). Pitcher (1999) recently reviewed the pertinent information on HABs in the Benguela system. His report is an excellent overview of the subject and introduction to the published literature.
Whether or not the frequency of red tides and HABs in the Benguela is increasing, is not clear. What is known is that there are interannual fluctuatations in occurrences, probably associated with changes in weather patterns. Moreover, in the late 1980s, “green tides” occurred in the area east of Cape Point, in particular in False Bay. These outbreaks caused large mortalities of sedentary organisms such as abalone and also led to respiratory problems in humans swimming in, or in close contact with, affected areas of sea water. The species responsible was Gymnodinium nagasakiensis and is though to have been imported via ballast water discharges. However, relatively little is known about the extent of exotic species introduced into the system from such discharges.
Zooplankton and secondary plankton
Zooplankton in the Benguela ecosystem is dominated by small crustaceans (tiny shrimp-like animals), the most important groups being copepods and euphausiids. Of these copepods are numerically the most abundant and diverse group. Species diversity is highest near the warm water boundaries of the ecosystem i.e. in the vicinity of the confluence between the Angola and Benguela Currents, west of the oceanic front and shelf break, and in the extreme south over the Agulhas Bank and adjacent Agulhas retroflection area. Over the shelf, within the main upwelling system copepod diversity is lower, and biomass higher, being dominated by a mixture of small (Paracalanus, Ctenocalanus, Oithona, Clausocalanus), medium (Centropages, Metridia) and large (Calanoides, Rhincalanus) copepods. Among the most common species are Centropages brachiatus, Calanoides carinatus and Metridia lucens. On the Agulhas Bank the zooplankton biomass is dominated by a single species, the large copepod Calanus agulhensis which has a centre of distribution in the central-eastern part of the Bank – over the endemic ridge of cool water. Copepods play an important role in the trophic functioning of the Benguela ecosystem. They are the principal food of anchovies and as a consequence they are the most studied zooplankton group – in the southern Benguela at least.
There are more than 40 species of euphausiids in the Benguela ecosystem. Of these Euphausia lucens is the dominant euphasiid in the southern Benguela and Nyctiphanes capensis in the north. Except in the central Benguela i.e. near Lüderitz, these two species generally do not occur together. The latter species also occurs, however, east of Cape Agulhas. Overall abundance of euphasiids appears to decrease towards the boundaries of the Benguela ecosystem. Studies on the life history of euphausiids in relation to the physical environment have led to an improved understanding of the role of euphausiids in the ecosystem and also to a better understanding of the dynamics of the various fronts and associated upwelling and sinking processes. Studies of the vertical distribution and daily movement of euphausiids in the Benguela have shown that the younger stages to occur near the surface and migrate little, while older stages occur deeper and display significant
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migration. Euphausiids are important prey items for anchovy and hakes, and conversely E.lucens is capable of capturing and consuming small fish larvae.
Thaliaceans (salps and doliolids – gelatinous zooplankton) are common throughout the Benguela. They are often indicators of intrusions of warm water, particularly in the southern Benguela. Analyses of gut content suggest that thaliaceans feed mainly on phytoplankton in inshore waters and on zooplankton offshore. The impact of thaliaceans on zooplankton and ichthyoplankton (fish eggs and larvae) has not been quantified, but it could be significant at times. Likewise the abundance and impact of other gelatinous zooplankton, which is periodically abundant in the Benguela, in particular off Namibia (“jelly invasions”), has not been quantified.
In the northern Benguela peak abundances of zooplankton appear to coincide with periods of maximum phytoplankton abundance viz. November – December and March – May, the former following the main upwelling season and the latter during moderate upwelling when summer stratification weakens. In both cases the spatial distribution of zooplankton differs from that of phytoplankton in that zooplankton tend to be more abundant offshore of the (coastal) phytoplankton maxima (beltlike distribution parallel with the coastline). This is probably an oversimplification. However, as there is a general lack of proper quantitative estimates of zooplankton abundance and production in the northern Benguela, coupled with the fishery-centred sampling bias.
In contrast, in the southern Benguela there are relatively good estimates of zooplankton distribution, abundance and production. Zooplankton standing stock estimates in the upwelling area off the Cape Peninsula display distinct seasonality, associated with the upwelling cycle, with a winter minimum and a summer maximum. Superimposed on the seasonal cycle is substantial shorter period variability (determined by upwelling pulsing, the dynamics of the phytoplankton blooms and the life histories of the various zooplankton groups). The series of drogue studies in the 1980s which followed an upwelling pulse and tracked the processes as the freshly upwelled water parcels aged, have contributed substantially to the understanding of plankton dynamics. In the southern Benguela the best estimates of zooplankton production suggests that it is of the order of 80gC/m2/y.
Hutchings et al. (1995) have reviewed inter alia zooplankton grazing in upwelling systems and highlighted a number of generally applicable principles which follow: Although copepods and euphausiids have rapid responses to increased food in terms of egg production, their response in terms of growth of juvenile stages to adulthood are much slower. Behavioural adaptations promote maintenance in the upwelling circulation. Juvenile stages remain near the surface; older stages migrate more extensively and are advected back into inshore water again, allowing grazers to prolong contact with phytoplankton blooms. Wind reversals/calms which allow phytoplankton to return shorewards or be entrained in eddies as they develop may increase the phasing effiencing between phytoplankton and zooplankton. Because of their limited mobility power, zooplankters need to adapt behavioural responses to maximise contact with food items and also minimise predation mortality. The recirculation of zooplankton may be favoured by undercurrents, eddy structures – such as exist near upwelling centres – and inshore counter currents. Like upwelling systems in general, in the Benguela zooplankton biomass maxima tend to exist downstream from upwelling centres and it is these areas which are preferred habitats of
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developing juveniles of fish species such as anchovy and sardine. Examples of these areas are St Helena Bay, Orange River bight, near Walvis Bay and off northern Namibia.
During the past decade Cape Town-based planktologists have focussed much of their attention on copepod and euphausiid ecology, reinforcing field studies with experiments using animals reared in the laboratory. This has led to a greatly improved understanding of feeding requirements, growth rates and how zooplankton adapt to environmental variability in the southern Benguela. Combined field-laboratory experiments have shown that anchovy are size-selective feeders (“biters”) rather than filter feeders and derive most of their energy requirements from large copepods and euphausiids. Conversely sardine (pilchard) feed predominantly by filtering – even filtering relatively large zooplankton such as euphausiids. Only when the density of large food organisms is very low does biting become more important for sardine than filtering (Van der Lingen 1994). Whereas the energy costs of filter feeding for anchovy are high (higher swimming speeds result in high respiration), for sardine the opposite applies i.e. the costs for filter feeding remain much lower than for anchovy even at high swimming speeds, while more energy has to be expended to orientate on prey in a biting mode (Van der Lingen 1995). This food partitioning is illustrated diagrammatically in Fig. 13. The consequence of the different feeding behaviour between anchovy and sardine is that sardine do better when small food particles dominate as in stratified waters, whereas anchovy should do better when the sea is dominated by larger particles, such as during turbulent upwelling conditions and might explain why sardine and anchovy appear to undergo alternative phases of dominance in upwelling regions over periods of 30-60 years (Hutchings and Field 1997). It might also explain some of the observed differences between the southern (rapidly pulsed) and northern (more uniform) parts of the Benguela ecosystem.
The past decade has also witnessed close collaboration between biological oceanographers, physical oceanographers and fishery scientists fostered through joint participation in hydroacoustic fish survey cruises, and this enabled the application of oceanographic knowledge about mechanisms of upwelling and plankton dynamics to be applied directly to solving fishery problems. Apart from obvious increased relevance of research, it also resulted in a greatly improved fundamental understanding of biological oceanographic processes and the role of these as a determinant of fish recruitment. Suites of papers which have appeared in the South African Journal of Marine Science Volumes 5, 12 and 19 and other mainstream international journals document these developments, while progress in various aspects of biological oceanography in the Benguela ecosystem have been very adequately reviewed in a recent article by Hutchings and Field (1997).
Perhaps the most significant finding during recent years is that of Verhehe et al (1998) who observed that crustacean zooplankton abundance, expressed in terms of number of animals, increased by two orders of magnitude in the southern Benguela between 1951 and 1996,suggesting that a major change in the ecosystem has occurred. (This is discussed in Section 5.)
Readers interested in the zooplankton of the Benguela ecosystem within the context of the physics and chemistry and general biology of the South Atlantic Ocean are referred to a recent review article by Boltovskoy et al (1999).
Foodweb and carbon budget
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As Hutchings and Field (1997) have pointed out, grazing by copepods and euphausiids and the sedimentation of organic material within the Benguela cannot account for the decline in phytoplankton blooms after upwelled water has stabilised, so considerable recycling of organic material must take place in the water column in the southern part of the ecosystem. This has been confirmed by the application of stable isotope techniques (N15 uptake methodology) by Probyn (1992), Waldron et al (1998) and others that the f-ratio (a relative index of new production) in the Benguela is relatively low (0.2 – 0.3) - only about one half or one third of the value in the Humboldt and California Current systems (Refer also back to Fig. 10). Thus, despite the high rate of new nitrogen input to the shelf waters via upwelling, much of the shelf water is dominated by the microbial foodweb fuelled by recycled nutrients (Hutchings et al 1995). Following the argument further, as it is new production which determines the productivity at higher tropic levels (fish), and as the food chain in the Benguela has been found to be much more complex (and less efficient) than the classical 20% applicable in a simple short-food chain (phytoplankton→ zooplankton→ fish), this to some extent explains why the Benguela yields considerably less fish than 100 million tons which simplistic estimates might indicate. Perhaps the most realistic model of the trophic functioning of the Benguela was that developed by Moloney (1992), by incorporating the microbial foodweb. Her model is illustrated diagrammatically in Fig. 14. The fundamental concepts embodied in this simple sketch have major implications for understanding the functioning of upwelling systems and their evident resilience! The understanding of the complexities of the foodweb and underlying processes is an imperative for the management and sustainable utilisation of the living marine resources of the Benguela ecosystem.
In a comprehensive examination of the mechanisms which drive the carbon flux in the Benguela, Monteiro (1996) concluded that upwelling source water moves on to the shelf at three principle sites which are determined by topography (the most important of these being at 27°S near Lüderitz, the others being at 18°S at Cape Frio and at 32°S), and that it is modified on the shelf, becoming enriched in nitrogen and carbon before eventually outcropping at the main upwelling centres (of which there are six). Monterio (1996) hypothesised that the three source sites act as “gates” or barriers to the southward movement of water on the shelf. He developed a model which suggested that the water which upwells at sites north of Lüderitz resulted in outgassing of carbon dioxide, while at Lüderitz and further south, the “carbon pump” and biological activity result in that part of the system being a carbon dioxide sink. Based on certain assumptions about dissolved organic carbon, Monterio calculated that the Benguela system as a whole was a small carbon dioxide sink of 0.34 – 1.5 million tons C/y. The better quantification of upwelling systems such as the Benguela as sources or sinks of carbon dioxide has important implications for the global carbon budget. The Achilles heel remains inadequate knowledge about fluxes of dissolved organic carbon.
ENVIRONMENTAL VARIABILITY
A complex array of processes affect the Benguela over a broad spectrum of space and time scales, ranging from the molecular level and fractions of a second to those which span
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several thousands of kilometers (basin-wide and global) and take place over several months, years, decades or even longer.
There are a number of physical factors which are important determinants of the structure and functioning of the ecosystem, and of these the wind – and in particular the periodicity in the longshore upwelling producing wind – is of over-riding importance. The wind field and wind frequency significantly influence coastal trapped shelf waters (these are internal waves in the sea, referred to earlier), upwelling, formation of fronts, production of filaments, surface and near-surface currents and the depth of the thermocline inter alia, and a host of dependant chemical and biological processes. The large-scale wind field is also an important determinant of basin-wide circulation, and consequently changes in winds even thousands of kilometers away can impact on the movement of water at the boundaries of the Benguela and within the system.
Apart from winds, seasonal change in insolation (solar heating) is important, influencing the temperature of the surface layer, its thickness and thermocline formation, while variations in light intensity likewise are important in terms of photosynthesis and primary production. What should be recognised is that over one third of the Benguela upwelling area and all of Angola’s coastal oceanic waters lie within the tropics, and consequently receive high levels of thermal radiation and light. Tides and tidal currents are important in the near-shore environments, especially in semi-enclosed bays, although in comparison with coastal areas in those parts of the world which experience large tidal ranges, their effects within the Benguela are relatively minor. (The tidal range in the Benguela is typically 1-2m.) There are a number of similarities between the variability in the Benguela and other upwelling systems, but there are also some important differences. What distinguishes the system from other eastern boundary regions is the existence and variations in the northern and southern boundaries viz. the Angola- Benguela front and the Agulhas retroflection area. In addition, the variability in the southern Benguela caused by the free passage of westerly winds and low pressure systems south of the sub-continent make this area quite unique.
However, like in other upwelling systems which are pulsed, the biota in the Benguela ecosystem are generally well adapted to the inherent variability in physical forcing on seasonal and shorter time scales. The biota are, however, less well adapted to sustained major events or changes which occur less frequently i.e. every several years or even over decades. Accordingly, we provide only abridged comments on aspects of small-scale and seasonal variability, and focus most of the discussion on the “catastrophic” occurences which have system-wide impacts. We also highlight some long-term and decadal changes which have been observed in the system.
Small-scale variability
Processes which occur on time scales of hours to several days and space scales of meters to tens of kilometers are characteristic of upwelling events. These “event scale” processes attracted considerable research attention in the 1970s and 1980s in the southern Benguela, and much of this work has been reviewed by Shannon (1985), Chapman and Shannon (1985) and Shannon and Pillar (1986). The application of remote sensing using aircraft and satellites during wind events in combination with in situ measurements using ships, provided knowledge about the initiation of upwelling, the growth and decay of upwelling plumes off the Cape Peninsula and Cape Columbine following the onset, intensification and
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subsequent reversal of the upwelling causing winds. Measurements in situ over hours and days provided a good understanding of biochemical processes and plankton dynamics. For example, by following patches of water and frequent sampling of these during upwelling events, the supply and depletion of nutrients, effects of light and light limitation, development of plankton “blooms”, species successions, decay processes etc were observed and quantified (e.g. Barlow 1982, Brown and Hutchings 1985). Although most of this research was conducted in the southern Benguela, scientists from the former German Democratic Republic undertook off central Namibia in 1976 one of the most intensive studies of the system over a period of a few weeks, using a combination of repeated surveys along a line of stations and quasi-continuous sampling at a fixed station. (e.g. Postel 1982). Their work showed vividly how the chemistry and biology of the water column changes in response to changes in its physical structure. A somewhat similar experiment was conducted in St Helena Bay a decade later and the findings were published in a special issue of Progress in Oceanography (Volume 28).
There is so much information contained in the hundreds of scientific publications which resulted from the era of event-type process studies in the southern Benguela, that it is just not possible to condense it adequately and explain it simply. What is apparent, however, is that there exists as superb body of information on the dynamics of upwelling and its consequences in the southern Benguela. Volumes 5 and 12 of the South African Journal of Marine Science published in 1987 and 1992 respectively contain many of the relevant papers. The small and mesoscale processes in the northern Benguela and in Angolan waters have, however, with few exceptions, received less attention. As the systems there function differently from that in the south, simple extrapolation of results and application of some of the concepts developed in the south to the Namibian and Angolan systems may be inappropriate and misleading.
Seasonal changes and intra-annual variability
The large scale atmospheric weather systems over the south Atlantic display a seasonal pattern of northward and southward migration, and the effect of this seasonal cycle together with changes in insolation, manifests itself in the upper layer. The seasonal changes in longshore upwelling wind stress have already been commented on in Section 2.2 (refer also to Fig. 2). Stratification also plays an important role in seasonal behaviour, for example in the generation of internal tides and in the transport of water. Stratification in the surface layer is intensified by the inflow of fresh warm water from the Congo River, which drains much of central Africa. It seems probable that the Congo River exerts a significant influence on the surface waters off Angola, as the presence of Congo River water can be detected over distances of 1000km or more from its mouth (Dr M. E. L. Buys, pers comm). Information about the seasonal and interannual nature and impact of this water along the coast of Angola may be provided by an examination of the 30 year long record from the monitoring station at Lobito and from other records.
Off Namibia and Angola, there is a distinct seasonal cycle in surface and upper layer temperature, with a maximum in March and a minimum in August/September. The range in seasonal average sea surface temperature is about 4° - 6°C . In the southern Benguela the upwelling season coincides with the period of maximum insolation, and accordingly the range in seasonal average temperature is only 1°-2°C. At the boundaries of the upwelling
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system, the water column becomes strongly stratified during the austral summer, particularly so over the eastern Agulhas Bank and off Angola, north of the Angola- Benguela front (see Fig 6). The Angola-Benguela front migrates seasonally between its northernmost location near 14°30’S in August and its southernmost position at 17°S in March, the latter being associated with a poleward push of saline Angolan Current water. In the south, the boundary at the Agulhas retroflection likewise displays apparent seasonality, being furthest south in autumn (Dr C. A. Villacastin-Herrero, personal communication). The Agulhas retroflection area is one of the global “hot spots” in terms of variability of temperature and water movements. Apart from the impact of this variability on the South-east Atlantic and the Benguela, it is also important for global climate, as the area south of Africa acts as a veritable “choke point” or “valve” for the movement of heat and salt between the Indo-Pacific and the Atlantic Oceans. (Most of this heat is transported via the six or so rings which are shed each year from the Agulhas Current, so changes in the frequency of ring formation can have major implications for climate)
Although the seasonal changes evident in the upper layer correspond to the seasonal shifts in the weather patterns and insolation, there are no obvious comparable changes in currents. Indeed, the currents near the bottom over the shelf display much less seasonal variability than that which occurs during “events” on 3 to 10 day time scales. There is, however, some suggestion of seasonality in the southward extent of the oxygen depleted shelf water, which reaches a maximum in summer/autumn.
The abundance of phytoplankton throughout the Benguela tends to be higher in summer and autumn, and zones of highest concentration usually lie further offshore during the season of upwelling. Taking the Benguela as a whole, the productive area appears to be larger during summer and autumn than in winter and spring. Subsurface chlorophyll maxima are common throughout the Benguela, particularly marked during summer and autumn when water over the Agulhas Bank is strongly stratified. Storm mixing in areas such as the Agulhas Bank and other shallow parts of the shelf can deepen and erode the thermocline to such an extent that during some winters there is a complete destruction of the thermocline, and the water column becomes well mixed from top to bottom. When this happens higher concentrations of nutrients and consequently higher concentrations of phytoplankton biomass and production can result.
Seasonal trends in zooplankton abundance tend to follow the phytoplankton cycle. Perhaps the most comprehensive record which exists was that provided by Andrews and Hutchings (1980). These authors monitored several parameters in the water column along a line of stations off the Cape Peninsula monthly over three years, and showed that there was about a twofold increase in zooplankton biomass during the upwelling season in the southern Benguela compared with winter (typically 3g dry wt/m2 in January and 1.5g/m2 in August). Further north in the Benguela, there appears to be less seasonality in zooplankton abundance. What is also clear is that consumption of zooplankton by some fish species can significantly reduce zooplankton abundance – even result in “holes” in the distribution on occasions, providing clear evidence that at times food in the form of zooplankton can be a limiting factor for fish.
Interannual variability and episodic events
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There are few reliable and long-term data series from the Benguela region. The longest of these is for sea surface temperature (SST) and it dates from the early part of the 20th century. The majority of the records of other physical, chemical and biological oceanographic parameters are either shorter or are otherwise fragmented in space and in time. A consequence of this is that much of our present understanding of interannual variability in the Benguela has been deduced from case studies of extreme or episodic environmental events, in particular those which significantly impacted on fish abundance and distribution. The most obvious of the extreme events which have occurred in the Benguela are Benguela Niños (manifest by major incursions of warm tropical water from Angola and from the west into the northern Benguela which occur on an average every ten years), large scale hypoxia in subsurface and bottom water on the continental shelf, anomalous large scale flooding of the southern Benguela by warm Agulhas Current water, major intrusions of cold Sub-Antarctic Water in the south, and sustained anomalous upwelling (or the absence thereof) caused by changes in regional winds. These major environmental “perturbations” will be discussed presently.
A substantial amount of year-to-year environmental variability has been observed in the Benguela ecosystem during the past two decades. The principal changes and fluctuations which have been documented since 1980 can be summarised as follows:
∗ Below average sea surface temperature in the shelf area of the northern and southern Benguela during 1982 and 1983
∗ A short-lived warm event in the extreme southern Benguela during early 1983, associated with the large El Niño which occurred in the Pacific that year, and the commencement then of an extended period of weaker than normal equatorward winds near Cape Columbine (33°S). The period 1982-1983 saw an abrupt change of 30° in the wind direction on the south coast which served to redress long-term changes in the wind direction preceding the event
The 1984 Benguela Niño that followed the cool period in the northern Benguela (but which had little impact on the southern region).This resulted in reduced upwelling off Namibia, the intrusion of warm, saline tropical water from Angola and offshore, deepening of the thermocline and changes in plankton and fish
A warm anomaly in the south in 1986, which coincided with the intrusion of Aghulhas Current water into the South-east Atlantic, especially during the winter. This resulted in favourable environmental conditions (short lived) for pelagic fish
An onset of cooling in 1987, i.e. a reversal of the warming trend with the influx of Sub- Antarctic water into the southern Benguela in early 1987
A period of warming in the southern Benguela in late 1988 and early 1989, evidently associated with changes in the Agulhas retroflection, and a short-lived intrusion of warm water
Sustained cooling of shelf waters in the southern Benguela from autumn 1989, and the termination of the negative equatorward wind anomaly (at 33°S) which commenced in
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1983. Period of two months of below average reversal of flow at a current meter site at 33°S, completely uncharacteristic of the record, occurred during winter 1989. The abundance off the west coast of the copepod Calanus agulhensis (endemic to the Agulhas Bank) decreased between 1988 and 1991
An extended period of below-average trade winds in the extreme south that commenced in the latter part of 1990
An eighteen month long cool period commenced in the extreme northern Benguela in mid- 1991, with pronounced upwelling off northern Namibia and Angola
Intrusion of an Agulhas ring during November and December 1992 adjacent to the coast near Cape Point
Anomalously strong south-easterly winds in the southern Benguela during the summer of 1993/1994 which resulted in strong upwelling along the west and south coasts, and coinciding with a widespread negative SST anomaly in the South Atlantic
Development and poleward propagation of major hypoxia on the shelf over the full extent of the Benguela region and the occurrence of “black tides” during 1994
Benguela Niño during 1995 in the northern and central Benguela, characterised by poleward flow and widespread warming and altered fish distribution and abundance
Return to more normal environmental conditions in the northern Benguela in 1996 and 1997
A large intrusion of Agulhas water into the southern Benguela during the summer of 1997/1998, followed by a large bloom of red tide organisms in the St Helena Bay area, localised hypoxia, and an odour of hydrogen sulphide along the coast as far south as Cape Town
The term “Benguela Niño” was coined by Shannon et al. (1986) and refers to large scale episodic warm events that occur along the coast of southern Angola and Namibia every ten years on average, and which have a character not unlike the El Niño in the Pacific Ocean. Every few years the tropical eastern Atlantic becomes anomalously warm as a consequence of relaxation in the trade winds and the deepening of the thermocline and reduced loss of heat from the ocean to the atmosphere. Occasionally, every ten years on average, this warming is even more extreme, evidently as a consequence of a sudden relaxation of the winds off Brazil, and when this happens the warm water anomaly in the tropical Atlantic travels eastwards and southwards, trapped (guided) by the coast of Africa. The result is a large southward displacement of the Angola-Benguela front, and a flooding of the Namibian shelf by warm tropical water – sometimes very saline (1984), at other times low surface salinity (1995) – depending on the orientation of the flow and the amount of fresh water from the Congo River present. Benguela Niños are accompanied by increased oxygenation of subsurface and bottom shelf waters either as a consequence of reduced deep flow of water southwards from Angola, or (more likely) reduced primary production and decay on the Namibian shelf. Benguela Niños are less frequent than Pacific El Niños. Just like in the Pacific they are superimposed on the seasonal cycle, but unlike the Pacific
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the seasonal changes in the Atlantic much larger, and the Atlantic or Benguela Niños, have a smaller signal. Benguela Niños occurred in 1934, 1949, 1963, 1984, 1995 and probably around 1910, in the mid-1920s and in 1972-74. The most recent event and its biological impact has been well documented by Gammelsrφd et al (1998). Benguela Niños are not necessarily in phase with Pacific El Niños, but they do appear to be a regional response to changes in the global atmosphere-ocean system.
Just as Benguela Niños are associated with extreme disturbance of the Angola –Benguela front, extreme disturbances in the retroflection (turning back) of the Agulhas Current at the southern boundary of the Benguela can be manifest as a major incursion of Agulhas water moving into the Benguela system around the Cape of Good Hope. These intrusions may be in the form of shallow surface filaments of warm water (the more usual case), but on occasions warm rings shed from the Agulhas Current can take a more northerly path than usual and impact on subsurface and deeper currents along the edge of the continental shelf – as was the case in 1989. A well documented Agulhas intrusion occurred in 1986 (Shannon et al 1990). Previous large-scale intrusions may have occurred in 1957 and 1964. The most recent event took place during the post austal summer (1997-1998).
Whereas Agulhas intrusions result in the input of anomalously warm water into the Benguela, incursions of cold Sub-Antarctic water do occur, and occasionally the effect of these can be felt as far north as 33°S (north of Cape Town), as was the case early in 1987. It seems that these rather unusual events are associated with the shedding of rings at the Agulhas retroflection, and they have an appearance of a compensatory northward flow from the Sub-tropical Convergence following the formation of a ring. Their biological consequences in the Benguela are unknown.
Changes in the strength and direction of longshore winds can, if prolonged over several months or longer, result in periods of anomalously low temperatures along the coast (increased upwelling) or warmer conditions associated with more quiescent conditions and downwelling. For example, the abnormally cool shelf waters present in the northern Benguela in the early 1980s were associated with a prolonged period of stronger than normal longshore winds. Cool conditions were again characteristic of the early 1990s off Namibia, while in the southern Benguela in 1993/94 the enhanced upwelling was a consequence of stronger south-easterly winds that summer. Perhaps the most dramatic changes occur on the south coast where surface temperatures lower than 10°C can result on occasions following periods of anomalous easterly (longshore) winds. These conditions tend to occur during times of Pacific La Niñas, while during El Niños, westerly winds tend to dominate the Agulhas Bank system and result in downwelling at the coast.
During some years, the most recent being 1993-1994, the oxygen depletion of shelf waters in the Benguela is unusually severe, and this results in widespread anoxia and hypoxia in the system. Although most pronounced in the northern Benguela, episodic depletion of oxygen does occur in the southern Benguela (e.g. in autumn of 1994). These large scale hypoxic and anoxic conditions appear to coincide with quiescent conditions which follow periods of sustained and enhanced upwelling – as a consequence of increased primary production and subsequent decay of phytoplankton blooms (e.g. red tides). It also appears likely that changes in the composition and flow of subsurface waters, in particular the concentrations of dissolved oxygen in/and the southward moving undercurrent along the west coast may
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be contributing factors, and this suggests that processes taking place off Angola may exert an important influence on the Benguela ecosystem via advection (currents). Irrespective of the causative mechanisms, large scale hypoxia and anoxia result in massive mortalities of marine organisms and changes in distribution and abundance of fish such as hakes (e.g. Hamakuaya et al 1998). The spectacular impact of such events on non-swimming benthic animals e.g. rock lobsters, is shown in Fig. 16. In the northern Benguela the widespread occurrence of oxygen depleted/deficient water does not coincide with Benguela Niño events, but appear to precede these.
Decadal changes and regime shifts
There is a growing body of evidence which suggests that marine ecosystems undergo decadal-scale fluctuations driven by variability in climate. This is most apparent at the higher trophic levels (fish). For example in the Humboldt Current system decadal period switches in dominance between sardine and anchovetta have occurred this century, and it is also apparent from the sediment record (from analysis of fish scale deposits) that species alternations have occurred during past centuries i.e. prior to the advent of fishing and other anthropogenic impacts. Moreover it has been demonstrated that populations of sardine in different parts of the Pacific (off Chile/Peru, California/Mexico and Japan) have undergone synchronous fluctuations this century. In the Benguela ecosystem there have been corresponding fluctuations in sardine abundance, although these appear to be out of phase with those in the Pacific. Also, there is evidence in the southern Benguela, at least, of species alternations-regime shifts- between anchovy and sardine, and in the northern Benguela the sediment record suggests that both species undergo decadal-scale fluctuations, at times alternating species dominating, at others the two species fluctuating synchronously (e.g. Shackleton 1986). What is also apparent from the sediment record is that there can be long periods (several decades) where both species are absent or only present at a low biomass.
As previously indicated, there are few long-term data series of environmental parameters for the Benguela region. The available indices do, nevertheless, show that changes and fluctuations on decadal or longer time scales have occurred in the Benguela this century, and superimposed on this variability a progressive warming of surface waters of about 0.7°C from 1920 is apparent throughout the Benguela and South-east Atlantic (This value has been corrected for changes in measuring instruments). The analysis of Taunton-Clark and Shannon (1988) showed that the 1920s and 1930s were cool years in the region and that a change to warmer conditions took place during the 1940s, followed by a gradual strengthening of the south-easterly trade winds over the next few decades. A system-wide change occurred in the late 1960s, to be followed by an extended warm period. The warming trend accelerated during the 1980s and this decade was the warmest this century in the South-east Atlantic. Longshore wind stress in the Benguela increased sharply after 1974 and the shelf waters along the west coast of South Africa and Namibia were abnormally cold in the early 1980s. In the southern Benguela (at least), wind record displays a sharp change in 1982/1983, with significantly lighter winds blowing for the remainder of the decade (Shannon et al 1992). It is perhaps significant that there is substantial decadal-scale variability evident in the post 1960 winds off Brazil (Carton and Huang 1994). The Gulf of Guinea temperature records also suggest an apparent periodicity between large sustained warm events of about 10 years.
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While the physical mechanisms linking decadal variability observed in the South-east Atlantic with that of the Indo-Pacific and North Atlantic is not understood, it is likely that the Benguela is influenced by external changes, and must be viewed within the context of the global ocean-atmosphere system. Generally, warming/cooling in the tropical Atlantic appears to be out of phase with that in the Pacific. What is also quite conceivable is that changes in the formation of Deep Water in the North Atlantic – such as occurred in the late 1960s during the “great salinity anomaly” will alter the northward movement of heat through the Atlantic and the flux of water and heat south of Africa. (Note that the South Atlantic is the only ocean where the net movement of heat is towards the equator, and much of this comes from the Indo-Pacific.)
While decadal-scale changes are evident from some of the physical parameters and in fish populations, these are not so apparent in the chemistry and plankton because of the fragmented nature of the available records. The available information does however point to the likelihood that comparable changes in the plankton has taken place, and by extrapolation from the biology and physics, that changes in nutrient supply have also occurred. Brown and Cochrane (1991) analysed chlorophyll a (a proxy for phytoplankton biomass) data available for the southern Benguela between 1971 and 1989. Although there appears to be a decreasing trend during the two decades from about 3.5 mg/m3 to 2.0 mg/m3, it is not statistically significant because the data are highly patchy. In what is perhaps the most important paper on zooplankton in the Benguela during recent years, Verheye et al. (1998) found that the abundance of animals in all main toxonomic groups in the St Helena Bay area increased by at least ten fold between 1951 and 1996 (These measurements applied to the main pelagic fish recruitment season viz March-June). Total zooplankton abundance expressed in numbers of animals increased by more than one hundred fold. The increase was accompanied by a significant shift in the community structure of near shore zooplankton, with a trend towards smaller size organisms. Whether the observed change is a consequence of reduced predation pressure by anchovy and sardine (“top down control”) or climatologically induced viz – upwelling, primary production and entrainment (“bottom up control”), is not clear at this stage. Other changes in zooplankton include the decrease in abundance on the west coast of the copepod Calanus agulhensis between 1988 and 1991 (previously mentioned) and the relative scarsity of the euphausiid Nyctiphanes capensis now in comparison with the 1950s (E. lucens is currently dominant).
Recent developments
In March/April 1998 environmental variability in the South-east Atlantic was the focus of an important International Symposium and Workshop, held in Swakopmund, Namibia. Hosted by the Namibian Ministry of Fisheries and Marine Resources and sponsored by The World Bank, BENEFIT, the German Agency for Technical Cooperation (GTZ), the Royal Norwegian Consulate General in Windhoek (Office for Development Cooperation) and the Scientific Committee for Oceanic Research (SCOR) of the International Council for Science (ICSU) provided a showcase of current knowledge and ideas about environmental variability in the Benguela, possible linkages/teleconnections with variability elsewhere in the Atlantic Ocean and with the global system, the time and space scales of the variability and ecosystem implications. Ninety leading scientists participated in the Symposium/Workshop. Of these 30 were from overseas and another 5 were international experts seconded to-or resident in- the SADC region, making this meeting among the most
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international of any oceanographic conference held in southern Africa. Comprehensive proceedings are available (Shannon and O’Toole 1998).
ISSUES, PROBLEMS, THREATS AND GAPS IN KNOWLEDGE
The different, but complementary, processes associated with the development of BENEFIT and the BCLME, as well as national strategic planning initiatives have generated a wealth of information about the main environmental issues, problems and threats in the Benguela region and gaps in knowledge and understanding. Various reports e. g. Anon (1997), Hempel and Haslund (1997), Shannon and O’Toole (1998) and Croll (1998) document these fairly comprehensively. Accordingly, the following sub-sections draw on the available literature, although obviously we have had to synthesise and provide a degree of re- interpretation of the various views and perceptions.
6.1 Fundamental issues
As pointed out earlier in this Overview, the Benguela differs from other upwelling ecosystems in several respects, e. g. it is bounded on northern and southern ends by warm- water regimes and strong fronts are associated with these boundaries; in the southern Benguela upwelling is strongly pulsed on a time scale of 3 – 10 days due to the free passage of low pressure systems moving past the African continent; the Agulhas retroflection results in a high degree of complexity and variability which does not have an equivalent in any other upwelling area, and results in a net movement of heat in the South- east Atlantic towards the equator and conduit linking the Benguela with the Indo-Pacific; the continental shelf is very variable in depth and width; a key fish spawning area exists upstream of two important upwelling centres and planktonic fish and larvae utilise a strong jet current to move to the recruitment area; the northern, central and southern parts of the Benguela function very differently, with the peak upwelling seasons in the north and south being distinctly out of phase, either in synchrony with , or opposing, the annual solar- heating cycle. The complex and unique character of the Benguela thus necessitates special attention. Ideas and principals developed elsewhere will not necessarily be simply transferable and applicable to the Benguela.
To date little attention has been given to transboundary environmental issues and the management of these. This is largely due to the nature and location of the external and internal system boundaries. The northern boundary of the main upwelling system viz the Angola –Benguela front lies close to the country boundary between Angola and Namibia, while the major “internal boundary” feature viz the Lüderitz upwelling cell which effectively divides the Benguela into northern and southern parts is not far from the Namibia-South Africa border. The colonial past, coupled with the distinct distributions of the principal harvested living marine resources has resulted in the countries in the region focussing activities within their own EEZs. Moreover the civil war in Angola and political problems in the region during the 1970s and 1980s resulted in scant attention being given to cross-system boundary environmental issues. A question which needs to be addressed within the context of the BCLME is definition of the northern boundary of the Benguela Current large marine ecosystem per se. Perhaps the term Greater Benguela Current System might be appropriate as this would clearly include the Angolan region and the Agulhas retroflection?
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Management of Benguela living and non-living resources has in the past not been integrated adequately either within countries or within the region. There has also been a general lack of an ecosystem approach to the management of living marine resources, although attempts have been made to take environmental considerations into account, for example, in setting catch levels in the different countries. The real challenge for the BCLME initiative is the development of viable integrative environmental mechanisms for the region as a whole i.e. at the ecosystem level.
Environmental variability
Although the Benguela environment displays a high degree of variability across a wide range of time and space scales, there is a growing realisation and consensus that it is the major sustained events and changes which seem to impact on the ecosystem as a whole. From a management point of view, there is a need to predict these large environmental events and changes, and the impacts of these on the system. There is evidence that the Benguela responds to basin-scale processes, in particular changes in the physical environment in the tropical Atlantic (e.g. changes in windstress off Brazil) and in the North Atlantic (e.g. North Atlantic Oscillation), changes in the Southern Ocean (e.g. Antarctic Circumpolar “Wave”) and to those in the Indian Ocean (variations in winds, the flow and leakage of the Agulhas Current). These changes are in turn are linked to global ocean- atmosphere processes. In other words, the Benguela must be viewed within the context of the global environment, not in regional isolation. However, the problem is that the teleconnections and linkage processes are not properly understood. Nevertheless, documented changes in the state of the ecosystem and regime shifts are congruent with decadal scale changes which have taken place in other ecosystems, but again it is difficult to distinguish between a natural environmentally driven cause (bottom up) and that caused by humans (top down). At the First Regional BCLME Workshop, the changing environment was a key issue raised within all three working groups. What is very clear, however, is that predicting environmental variability and change and the impacts is likely to be extremely difficult - yet so important. It will necessitate comprehensive monitoring, process studies and modelling at the very least.
While it is apparent that major environmental events such as system-wide hypoxia/anoxia and Benguela Niños as well as changes in primary and secondary production, occurrences of harmful algal blooms (red tides), changes in currents etc are important determinants or indicators of ecosystem variability and change, the present level of environmental monitoring within the Benguela region is totally inadequate to document these – let alone to use the information for any predicting or forecasting. The issue of environmental monitoring in the Benguela was addressed in some detail at an International Workshop held in Swakopmund in April 1998, and a monitoring framework was developed (mainly for Namibia). Implementation of a cost-effective regional monitoring strategy and system along these lines is seen as an important component of the BCLME programme. However, environmental monitoring will be expensive and is not readily automated. Although obviously satellite remote sensing will comprise an essential element of the environmental monitoring, it will require appropriate in situ measurements (“ground truthing” or validating) to be useful.
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Some of the more obvious features/issues re environmental variability in the Benguela e.g. harmful algal blooms and the role of sulphur in the ecosystem (cf sulphur “eruptions”) will be addressed at specialist international workshops which are scheduled to take place in Namibia within the next six months. The possible expansion of a monitoring buoy network from the tropical Atlantic to the Benguela (PIRATA array) is being examined.
The introduction into the ecosystem of exotic species of marine organisms accidentally e. g. via ballast water discharges from ships entering ports, or deliberately e.g. unauthorised mariculture ventures, is a potential threat, but remains unquantified. Perhaps the biggest threat to the Benguela is from the cumulative effect of small changes, some of which may be imperceptible, as a consequence of human activity in the region (fishing, mining etc) and as a consequence of global climate change.
6.3 The Benguela and global environmental (climate) change.
There are two issues here, viz the role of the greater Benguela ecosystem in global climate change processes, and the impact of climate change on the Benguela. With respect to the first issue, there is some uncertainty as to whether the Benguela is a net source or sink of atmospheric carbon dioxide (see Section 4) with the “physical pump” supplying CO2 through outgassing from upwelling opposing the “biological pump” which will remove CO2 from the atmosphere through primary production and the marine food web. Work of Monteiro (1996) indicates that the southern Benguela may be a net sink and the northern Benguela a net source, with the Benguela as a whole being a small sink. However, if the Angola region and Angola Dome were to be included, the picture may alter radically. Similarly changes in primary production and the marine food web could further alter the balance in future. Thus knowledge of what happens in the Benguela and other upwelling systems is important for global models predicting future climate change. A problem is that very few studies have been made in the Benguela on the flux of carbon, and this is exacerbated by the dearth of marine chemists in southern Africa and the low priority given by regional funding agencies to marine chemistry.
The importance of ocean processes in climate studies and prediction is highlighted by the fact that the top 1 metre of the sea contains as much heat as the entire 50km overlying column of atmosphere! More-over, the South Atlantic is the only ocean in which there is a net movement of heat from the south to the equator. This is in part due to the “leakage” of warm Agulhas Current water into the South Atlantic via the Agulhas retroflection “choke point” or “valve”. This area is part of a global ocean heat “conveyer belt” linking the Pacific, Indian and Atlantic Oceans which has a return cold conveyer arm deeper down. This is illustrated schematically in Fig 17. When global climate warms the conveyer speeds up, when it cools it slows down. Thus the marine environmental processes which take place in the southern part of the greater Benguela system viz in the Agulhas retroflection may area have an enormous impact on world climate. This is recognised internationally, and highlights the global importance of the Benguela environment – the conduit for the heat, a veritable global climate valve.
Global climate has warmed by about 0.8°C this century, and the balance of evidence suggests a discernable human influence on global climate. If it is accepted that significant change will occur in global climate in the next century, this is likely to impact on the Benguela – not so much through small increases in ocean temperature and sea level
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(expected to increase by about 50cm by the end of the 21st century) but through changes in wind over the South Atlantic and Indian Oceans. Coastal winds are likely to strengthen and if this happens, upwelling will intensify and the present upwelling area may expand. This in turn would have consequences for primary production and the food web and also for global climate. In addition there may well be impacts from increased levels of ultraviolet radiation resulting from the destruction of stratospheric ozone by CFCs. (In this respect the “ozone hole” is still expanding). There remains so much uncertainty about the likely changes and interactions, that any scenarios developed at this stage would be purely speculative. Nevertheless it would be reasonable to anticipate that ecosystem changes and regime shifts will occur during the 21st century and that these changes are likely to impact on the economies of Angola, Namibia and South Africa. This again highlights the need for appropriate environmental monitoring, studies of cause and effect and modelling with the view to improving predictability. However, the impact of changes in the Benguela marine environment may be dwarfed by the likely impact of climate change on rainfall in southern Africa and of this on the economy of SADC countries.
6.4 Gaps in knowledge and understanding
Some of the more obvious shortcomings or gaps are listed below in point form. (These are not in any particular order)
Teleconnections between the Benguela and the tropical Atlantic, North Atlantic, Southern Ocean and Indo-Pacific and the linkage mechanisms (cf global weather patterns)
Predictability of environmental change and ecosystem response
Dynamics of formation, advection and impact of oxygen deficient/depleted water in the greater Benguela system (hypoxia/anoxia phenomena)
Dynamics of the Angola Current, its variability, and associated processes
Role of the Walvis Ridge – physical, chemical and biological
Various atmosphere-water-sediment chemical processes
Angola – Benguela front dynamics and stability and biological impact thereof
The Benguela undercurrent and spatial continuity
Changes in system wide plankton abundance and species composition, during the past 50 years. (Samples exist, but require analysis and interpretation)
The Benguela sulphur cycle/system and its biological consequences
Plankton production in Angola’s EEZ and in the Angola Dome, and associated biochemical processes
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Harmful algal blooms (red tides) – distribution, frequency, species,impacts
Extent and impact of exotic species of marine flora and fauna introduced from ballast water discharges (control measures?)
Seasonal and interannual variability of the Agulhas Current and Agulhas retroflection
Extent of marine pollution in the Benguela and its impact
Impact of climate change on the Benguela ecosystem
Quantification of the greater Benguela as a net source or sink of carbon dioxide
Environmental (ecosystem) impact of offshore mining activities and oil/gas exploration/extraction
Transboundary environmental policy/management
Human-environment-resource interactions : quantification of natural environmental variability vs human impact on the ecosystem
Infrastructure and human capacity
Comprehensive information about human capacity and infrastructure available in Angola, Namibia and South Africa and shortcomings is provided in Appendix I. The principal constraints and problems are briefly as follows:
∗ There is a steep gradient from south to north in terms of both expertise and infrastructure. In the case of Angola, while laboratory and office accommodation is good, there is a general lack of laboratory equipment and instruments and the necessary support infrastructure. There are few scientists dedicated to environmental studies in Angola, with a lack of chemical and biological oceanographers. Namibia has excellent facilities but few posts are allocated to environmental research and monitoring.
Except in South Africa, there is a general lack of trained and experienced technicians to operate and support (service/maintain) high technology equipment and to provide the necessary technical support to research staff. This shortcoming has serious implications for environmental monitoring programmes, and results in inefficient use of oceanographers with interpretive skills
There are relatively few scientists in the region with broad-based interpretive skills i.e. who can integrate and synthesise across disciplines. There is also a shortage of modellers, although this is being addressed by South Africa
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There are very few marine chemists and chemical technicians in the region – including in South Africa. Marine chemistry is de facto the “Cinderella” activity in the Benguela
While there is a need throughout the region to develop oceanographic expertise, in particular in Angola but to a lesser extent also in Namibia and South Africa, there is a shortage of tenured posts available for new graduates from universities and technikons i.e. there are needs, but few available jobs
Angola does not have a viable research ship, and relies on assistance from Norway. The situation in Namibia and South Africa is more satisfactory, although funding and manpower constraints in the last mentioned country are making it difficult to operate research ships such as F.R.S Africana (which is now 17 years old)
Funding
Funding for marine science and technology throughout the region is limited, and is decreasing every year in real terms, because of other more pressing national priorities. In Angola salaries of qualified scientists at IIP are very poor and staff are obliged to seek alternative means to supplement incomes. Environmental research and monitoring is seen in all countries as a lower priority than e.g. resource based work as it has a longer “pay back” period (cf pure research vs applied research). As a consequence funding for marine environmental research and monitoring in the Benguela is inadequate – even in South Africa. Unless the funding problem can be addressed adequately, and also flexibility to utilise funds improved, there will be little prospect of a viable environmental component within the BCLME
ACKNOWLEDGEMENTS
The authors are most appreciative of the help and encouragement provided by the various experts consulted during the preparation of this overview. In particular we wish to acknowledge with sincere thanks support from staff of the governmental lead agencies in the three countries participating in the Benguela Current Large Marine Ecosystem Programme viz. Ministry of Fisheries and Marine Resources (Namibia), Instituto de Investigaçao Pesqueira (Angola) and Sea Fisheries Research Institute of the Department of Environmental Affairs and Tourism (South Africa).
This Overview was funded by The World Bank via a Block B grant from The Global Environmental Facility (GEF) with The United Nations Development Programme (UNDP) as implementing agency. Assistance provided by UNDP staff, both in New York and Windhoek, is acknowledged with appreciation. The work was guided by the BCLME Management Committee, the Members of which provided useful comments and helpful advice.
The Benguela-Environment-Fisheries-Interaction-Training Programme (BENEFIT), a regional initiative of Angola, Namibia and South Africa which was launched in 1997 was a catalyst for the development of the BCLME Programme. This Overview draws on
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information and ideas generated by the embryonic BENEFIT, and from the regional and international oceanographic experts who have participated in the initiation of BENEFIT.
Valuable information on the Angolan component of the Benguela environment was provided by Messrs. V. L. L. Filipe and F. Pereira, of the IIP in Luanda, while a recent report prepared by Drs G. Hempel and O. H. Haslund on the status of marine science in Angola was an important source of information about Angolan institutional capacity. Dr H. Marques, Advisor at IIP, Luanda, provided many useful comments and suggestions on the draft text which has been revised accordingly.
Satellite images of the Benguela were kindly provided courtesy of Ms S. Weeks (OceanSpace CC) and her assistance in this respect is gratefully acknowledged. The majority of the diagrams were generated by Mr A. P. van Dalsen (SFRI) whose considerable cartographic skills are apparent in the illustrations.
REFERENCES
During the past decade several thousand scientific publications on the Benguela ecosystem and its harvested resources have appeared in the primary scientific literature, the majority of which dealt with the southern Benguela. A full listing of these is beyond the scope of this document. The key references have, however, been cited in the text and details of these follow. In addition readers are referred to suites of papers in volumes 5,12 and 19 of the South African Journal of Marine Science, (1987, 1992 and 1998 respectively) and in Progress in Oceanography, Vol 28 (1991).
ANDREWS, W. R. H. and L. HUTCHINGS 1980 – Upwelling in the southern Benguela Current. Prog.Oceanogr. 9:81 pp
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BAILEY, G. W. 1979 – Physical and chemical aspects of the Benguela Current in the Lüderitz region. MSc thesis Univ. Cape Town:225 pp
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STANDER, G. H. and A. H. B. DE DECKER 1969 – Some physical and biological aspects of an oceanographic anomaly off South Wets Africa in 1963. Ivestl. Rep. Div. Sea Fish. S. Afr. 81: 46 pp.
STRAMMA, L. and R. G. PETERSON 1989 – Geostrophic transport in the Benguela Current region : J. Phys. Oceanogr. 19: 1440-1448.
TAUNTON-CLARK, J. and L. V. SHANNON 1988 – Annual and interannual variability in the South-east Atlantic during the 20th century. S. Afr. J. mar. Sci. 6: 97-106.
TYSON, P. D. 1986 – Climate Change and Variability in Southern Africa, Oxford univ. press, Cape Town: 220 pp.
VAN BALLEGOOYEN, R. C., GRUNDLINGH M. L. and J. R. E. LUTJEHARMS 1994 – Eddy fluxes of heat and salt from the south west Indian Ocean into the south east Atlantic Ocean : a case study. J. Geophys. Res. 99 (C7) : 14053-14070.
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VOITUREIZ, B. and A. HERBLAND 1982 – Comparison des systemes productifs de l’Atlantique Tropical Est.: dômes thermiques, upwellings côtiers et upwelling équatorial. Rapp P.V. Reun Con. int. Explor. Mer. 180: 114-130.
WALDRON, H. N. and T. A. PROBYN 1992 – Nitrate supply and potential production in the Benguela upwelling system. In Benguela Trophic Functioning, Payne, A. I. L., Brink, K. H., Mann, K. H. and R. Hilborn (Eds). S. Afr. J. mar. Sci. 12 : 865-871.
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WALDRON, H. N., PROBYN, T. A. and G. B. BRUNDRIT 1998 – Carbon pathways and export associated with the southern Benguela upwelling system : A re-appraised. S. Afr. J. mar. Sci. 19 (in press)
WATTENBERG, H. 1938 – Die Verteilung des Sauerstoffs im Atlantischen Ozean. Wiss. Ergeb. Dt. Atlant. Exped. “Meteor” 1925-1927 9: 132 pp.
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APPENDICES
APPENDIX I
INSTITUTIONAL INFRASTRUCTURE AND CAPACITY
Human capacity
Hempel and Haslund (1997) have provided a comprehensive assessment of the state of marine science and science capacity in Angola. The Instituto de Investigacao Pesqueira (IIP) is the central institute for basic marine environmental and fisheries research. With a total staff of about 220, of which approximately 40 are university trained, IIP’s primary focus is on the monitoring, research and assessment of the fish resources per se. The environmental (oceanography) component of IIP comprises 14 staff members, engaged in various aspects of fisheries oceanography, environmental monitoring and pollution control. The policy of IIP is to increase the skill level of staff, and considerable success has been achieved through close collaboration with the Agostinho Neto University in Luanda and other SADC universities (e.g. University of Cape Town) as well as with universities in Europe, principally in Russia, Germany and Norway. Participation in IOC- sponsored and BENEFIT training initiatives is likewise proving to be beneficial. In spite of difficult operating conditions, with severe limitations in terms of equipment and infrastructure, IIP staff do not lack initiative and enthusiasm, and this bodes well for the future. Donor support from countries such as Norway, Germany and Sweden to strengthen human capacity has been and continues to be vital.
Namibia has a long tradition in marine science and technology, and following independence in 1990, the government has placed a strong emphasis on the training of Namibians and the development of local expertise. The Ministry of Fisheries and Marine Resources (MFMR) is the agency responsible for monitoring, research, assessment, management and control of living marine resources within Namibia’s EEZ. The monitoring, research and assessment component, which will be referred to loosely as “research” is headed by a Director based in Windhoek and with most research staff located in Swakopmund at the National Marine Information and Research Centre (NatMIRC). A smaller research group is based in Lüderitz. MFMR has a research and support staff complement of about 100 persons of whom approximately 40 have four-year or higher university qualifications. On paper the “environmental research” component comprises 9 research posts and two technical positions. Recent restructuring within the Ministry in order to strengthen capacity to address pressing fishery monitoring and assessment problems, has de facto resulted in a substantial shrinkage of the oceanography group, although the Ministry is evidently taking steps to redress this. The environmental group, although small, has since independence embarked on a comprehensive monitoring programme, and through close collaboration with, and with strong support from Norwegian and German scientists developed a high degree of competence. (This is reflected in the large number of reports and publications which have been produced by the oceanographers during recent years). Several of MFMR staff have post-graduate qualifications gained at overseas and SADC universities, and like IIP, MFMR has a strong education and training policy. The advent of BENEFIT is enabling
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further development of Namibian marine science capacity. The Ministry has wisely decided to make maximum use of remotely sensed marine environmental data, and is currently developing appropriate skills to utilise and interpret these. There remains, however, a shortage of technical posts and trained oceanographic technicians. The University of Namibia (UNAM) has a close association with MFMR and is keen to develop collaboration training courses in oceanography and fisheries science. UNAM does not yet offer post- graduate degree courses in marine science.
South African marine science celebrated its centenary in 1995, and can generally be considered as world class. The Marine and Coastal Management (MCM) of the Department of Environmental Affairs and Tourism, based in Cape Town has a total research staff complement of about 150, of whom approximately 50 are university graduates. The support staff comprise highly skilled engineers, technicians and technical assistants. All of the technicians possess formal technical qualifications (NDT oceanography) or similar – equivalent to a three year university degree). The majority of t14 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314 314314314314314314314314314314314314314314314314314314314314314314314314
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South Africa: F. R. S. Africana (78m). Modern all weather multi-purpose fisheries and oceanography research stern trawler built in 1981. Excellent laboratories. Carries 17 scientists. F. R. V. Algoa (53m). Converted commercial stern trawler, with similar capabilities, but on a lesser scale, to Africana . Carries 12 scientists. F. R. V. Sardinops (37m). Old (1958) research side trawler. Limited capability. Carries 4 scientists. The manning arrangements for South African research vessels are problematic.
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Norway: R. V. Dr Fridtjof Nansen (78m). Modern multi-purpose fisheries stern trawler. Excellent. Carries 17 scientists. The vessel built in 1992 replaced the previous one of same name which had been operating in the South-east Atlantic since the late 1980s. This is probably the most versatile and useful vessel in the region and the cornerstone of fisheries research (surveys) off Namibia and Angola.
Germany: Although there is no German research ship dedicated to the region, Germany chartered a vessel in 1997 for the investigation of the Angola/Benguela front, and plans to charter vessels for work in the Benguela ecosystem again in the future.
(c) Equipment/Instrumentation
Except R. V. Goa, R. V. Kuiseb and F. R. V. Sardinops, the research ships are well equipped and possess modern instrumentation and gear. In the case of South Africa much of the instrumentation has been locally developed (a result of sanctions) and has during the past five years become run-down as a consequence of shrinking budgets and increased operating costs. Shore-based laboratory facilities in terms of instrumentation and equipment in South Africa and Namibia range from adequate to excellent. The Angolan laboratories are generally poorly equipped, with very limited instrumentation. The supporting infrastructure is likewise totally inadequate. A satellite communication link with IIP in Luanda has recently been established.
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APPENDIX II
OCEANOGRAPHIC AND FISHERIES DATA AND INFORMATION SYSTEMS
Angola
There are four separate fisheries data processing systems in operation in Angola: one system is based at the Fisheries Research Institute (IIP), one is in the Directorate of the National Fisheries (DNP), one is at the Directorate of Surveillance (DNF), and there is a system used by the Planning Office in the Ministry of Fisheries (GEP).
The DNP system has been developed through Swedish support and is based on the Swedish Baltic Sea fisheries data system. It is used for commercial fisheries statistics. The version in use in the DNP has been modified to meet local needs, but is as yet incomplete. The system enables the registration of fishing companies, catch discharges, gear and species data, registration of gear in use in the fishery. These data are available for both national, joint venture and foreign fishing vessels and companies. The system also facilitates the registration of fishing enterprises, taxes, contracts, export data and transhipment details. The analysis output is limited at present but the intention is to access and output details on quotas and TACs. Exchange rate updating will be included so that values can reflect local currency fluctuations. The DNP has three MS-Dos Windows based PCs which are as yet unlinked. A small dedicated computer network has recently been purchased. created to deal specifically with the database, with its own personnel and resources.
Angola has recognised that there needs to be a unified data system and has proposed modifying the DNP system so that more detailed analysis for stock and catch assessment can be achieved. A programme to unify the systems has been devised, and this will be done in conjunction with an upgrading of the data collection system. IIP is developing its own database for fisheries and oceanographic scientific data. A new section in IIP has been created to deal specifically with the database, with its own personnel and resources. The oceanographic data still need to be incorporated in the database. A major task will be to recover and include the historic records which span nearly 30 years.
Apart from oceanographic data collected by Angola e. g. a 30 year time series of sea surface temperature, salinity and oxygen at Lobito and other pre- and post-independence records, IIP has a comprehensive set of data from the monitoring and research programme. IIP also holds Russian data sets on the oceanography of the Angola/Benguela front and Angola Dome, while more data sets rest in Kaliningrad.
Namibia
The Ministry of Fisheries and Marine Resources has developed and implemented an integrated Fisheries Information Management System that provides a data capture, information management and reporting system for all core information on the fisheries sector. The FIMS provides for the following modules; Species, Vessels, Factories, Fisheries, Exploitation Rights, Quotas, Payments, Landings, Logsheets and a Management Information System (MIS). This core system is designed to manage all information from and to the fishing industry. Work is also well advanced in the development of two further sub-systems: the Biological, Oceanographic and Supporting Research Module (BOSRM) and the Surveillance and Enforcement Module (SEM). The overall system will thus provide access to the full range of information available tot the Ministry, including all available historical data and international databases. The BOSRM will provide access to, and be integrated with, fisheries sector information to enable accurate and meaningful analysis and interpretation of catch information against fishery and environmental dynamics. However, delays in the implementation of BOSRM mean that there is no viable oceanographic data base available to MFMR scientists, and data are currently stored on disk and hard copy.
It is planned that all information, subject to confidentiality and security, will be made available for research and general use by government, industry, international collaborating partners and agencies
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through a variety of systems of access.
The system was developed using S-Designer and Powerbuilder and is implemented using Microsoft NT and SQL Server in a Windows 3.1 and 95 environment. There are four sites each with their own server networks at Windhoek (Ministry of Fisheries and Marine Resources HQ), Swakopmund (National Marine Information and Research Center), Walvis Bay (Inspectorate and Operations Centre) and Lüderitz (Inspectorate and Research). These four LANs are connected by a WAN through a leased line system on fibre-optic cables and all network management is from the Information Systems Division in Windhoek. The majority of hardware has been specifically purchased for the designed task (Olivetti servers and work stations) but with a view to appropriate expansion – particularly of storage and processing power.
Namibian oceanographic data holdings, pre-and post-independence, including extensive data collected during cruises of the Dr Fridtjof Nansen during the 1980s and 1990s and during cruises of R. V. Welwitschia and R. V. Matsuyama Maru (Japanese Overseas Fisheries Cooperation Foundation), are extensive and generally of a high quality. Cruise data are augmented by data from coastal monitoring stations (Swakopmund and Lüderitz) and satellite imagery.
South Africa
MCM has been using the Data General range of mini computer since 1979 for the processing of data relating to commercial catches, research samples and environmental parameters. The applications were developed in Cobol and the data stored in an Infos hierarchical database. These systems are currently being converted in order to make use of the advanced features offered by new hardware and software technology. These applications will be run on a local area network using Novel NetWare. The data are being converted to a relational database which will support the integration of common entities, such as grids, vessels and species codes, and provide better facilities for ad hoc management and research queries. The software is being developed using Borland Delphi, a fourth generation language which runs on PCs using Windows 95. The bulk of the systems relate to commercial catches from the following sectors: Demersal, Pelagic, Rock Lobster, (West Coast, South Coast and Natal), Abalone, Linefish and Netfish. Some data sets cover catches from 1978 to date. The environmental parameters (physical and chemical0 and stored in the Oceanographic Database. The issuing of vessel licences and fishing permits is handled by the Boat Registration System.
The University of Cape Town is well connected in the academic and research environments in Southern Africa. Not only does the University have a wide range of computers available, from Macs to PCs to Workstations, but it has expertise that is of world class quality. All of the University computers are connected to the Internet as well as on several local area networks on campus. The University is constantly seeking to upgrade and improve the quality of this interconnectivity so as to increase the flow of information. Through the Centre of Marine Studies and the various Departments at the University, expertise is readily available in the fields of data processing and statistics, resource assessment, management and conservation as well as environmental evaluations and oceanographic remote sensing. These skills can be applied to the problems of data and information management as well as in the interpretation, presentation and publication of the necessary data.
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South Africa possesses an extremely comprehensive collection of oceanographic data; discrete, profile and time series. Most of these are available from SADCO (see below) and/or MCM. South Africa also has extensive holdings of NOAA satellite sea surface temperature data.
South African Data Centre for Oceanography (SADCO)
SADCO was established as a national oceanographic data bank in the 1970s to service South Africa’s marine science community. It has subsequently developed into a regional facility. SADCO archives, extracts and manipulates oceanographic data from the southern African marine environment and provides a spectrum of professional cost-efficient and user-friendly services. It also promotes the scientific and commercial application of oceanographic data.
SADCO receives data for the area 0°-70°S and 30°W-70°E from a variety of sources including various southern African marine agencies, and World Data Center, and other international data sources by exchange or purchase.
The SADCO data base contains observations since 1850 which include inter alia the following: Oceanographic station data for surface and serial depths, giving values of temperature, salinity, sound velocity, oxygen, nutrients etc.
Digital bathythermograph and XBT data
Surface data from voluntary observing ships (VOS) including waves, wind and weather, comprising some 3 million readings
SADCO also has access to various document information systems which enable literature searches for published oceanographic data
SADCO is guided by a Steering Committee and managed by CSIR on behalf of its sponsors which include the South African Department of Environmental Affairs and Tourism, the South African Navy, CSIR, Foundation for research Development and the Namibian Ministry of Fisheries and Marine resources. Service charges are modest. SADCO could play an important role in BCLME.
Data Confidentiality/Restrictions
Most oceanographic data collected by regional scientists/research institutions is generally available to other bona fide scientists subject to certain conditions. These conditions include inter alia appropriate acknowledgement of data ownership, a time clause to give the owner a reasonable period to analyse the data and publish research results. Oceanographic collected in international waters around southern Africa by overseas oceanographic institutes is likewise generally readily available to scientists and technicians in southern African states. Again the principals and ethics of international science and/or intellectual property rights apply. For example, SADCO receives and archives various forms of oceanographic data but can put a limited-period hold on data if requested by the collector of the data to do so. These data would then not be released to a third party during
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the embargo period unless authorised by the data owner, but the data could be used with other data in the data-base for averaging purposes. The present system works well.
Resource-based data are, however, in a different category and fisheries data may not be readily available outside of the organisation responsible for its collection. This practice is not peculiar to southern Africa and applies almost universally. There are two main reasons for this viz. (a) commercially sourced fisheries data contains information which may give the supplier (fisherman or fishing company) a competitive edge over rivals and (b) raw fisheries data may be regarded as strategic information by management agencies and national governments. Fisheries data are, however, generally readily available in processed form. Nevertheless the fact remains that most fisheries and oceanographic data are collected by, or at the behest of, organisations funded by national tax payers and there is a universal movement towards increased transparency and accountability of governments.
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APPENDIX III
LIST OF PERSONS CONSULTED
The major part of this Overview was prepared at the University of Cape Town. It draws on input from a large number of individuals, by way of written documents (reports, publications), or from presentations at symposia and workshops (e. g. International Symposium and Workshop on Environmental Variability in the South-east Atlantic, Swakopmund, March/April 1998; First Regional Workshop on BCLME, Cape Town, July,1998) and from discussions with key role players. The persons consulted specifically for the Overview were as follows:
Dr J. Augustyn (Acting Director, MCM) Dr L. Hutchings (Chief Specialist Scientist, MCM and Member: BCLME Management Committee) Dr M. J. O’Toole (MFMR, and BCLME Project Coordinator) Mr G. W. Bailey (MCM) Dr R. G. Barlow (MCM) Dr A. Cockcroft (MCM) Dr R. J. M. Crawford (MCM) Dr J. David (MCM) Prof. J. Field (Zoology Department, UCT) Dr V. Filipe (IIP) Mrs P. Krohn, (Oceanography Department, UCT) Prof. J. R. E. Lutjeharms (Oceanography Department, UCT) Dr V. de Barros Neto (IIP) Dr A. Pereiro (IIP/BENEFIT) Dr S. Pillar (MCM) Dr G. Pitcher (MCM) Dr M. de Lourdes Sardinha (IIP) Ms L. J. Shannon (MCM) Prof. F. Shillington (Oceanography Department, UCT) Mr A. P. van Dalsen (MCM) Dr H. Verheye (MCM) Dr H. Waldron (Oceanography Department, UCT) Mr B. Wessels (MCM) Drs P. Freon, P. Curie and C. Roy (ORSTOM, seconded by the French Government to work in the Benguela region 1998-2000)
In addition to the above, discussions were held with key staff of MFMR in Namibia as part of a separate contract in 1997/1998 funded by The World Bank with the purpose of developing an environmental strategy for MFMR. The principal individuals consulted during this exercise were: Dr B. Oelofsen (Director: Resource Management MFMR) Dr. B. van Zyl (Deputy Director: Applied Research MFMR) Ms J. Botha (MFMR) Mr C. Bartholomae (MFMR) Ms A. Risser (MFMR) Ms K. Noli-Peard (MFMR) Mrs B. Currie (MFMR) Mr C. Beyers (MFMR) Mr A. Kemp (MFMR)
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Dr G. Ohe (GTZ) Dr M. F. Tejedor (seconded to MFMR by Spanish Government)
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APPENDIX IV
ACRONYMS
AABWAntarctic Bottom Water AAIW Antarctic Intermediate Water BCLME Benguela Current Large Marine Ecosystem BENEFIT Benguela-Environment-Fisheries-Interaction-Training (Programme) BEP Benguela Ecology Programme CZCS Coastal Zone Colour Scanner EEZ Exclusive Economic Zone ENSO El Niño – Southern Oscillation EU European Union FRD Foundation for Research Development (South Africa) GDP Gross domestic Product GEF Global Environmental Facility (World Bank) GLOBEC Global Ocean Ecosystem Dynamics GTZ Deutsche Gesellschaft fur Technische Zusammenarbeit ICEIDA Icelandic International Development Agency IGBP International Geosphere-Biosphere Programme IHDP International Human Dimensions Programme IIP Instituto de Investigaçao Pesqueira (Angola) IOC Intergovernmental Oceanographic Commission MCM Marine and Coastal Management (South Africa) MFMRMinistry of Fisheries and Marine Resources (Namibia) NatMIRC National Marine Information and Research Centre (Namibia) NORAD Norwegian Agency for Development Cooperation PDF Programme Development Fund (of GEF) RV/S Research Vessel/Ship SADC Southern African Development Community SADCO South African Data Centre for Oceanography SANCOR South African Network for Coastal and Oceanic Research SAP Strategic Action Plan SeaWiFS Sea-viewing Wide Field-of-View Sensor SFRI Sea Fisheries Research Institute (South Africa) SIDA Swedish International Development Agency SPACC Small Pelagic Fish and Climate Change Programme (of GLOBEC) SST Sea Surface Temperature STSW Subtropical Surface Water TAC Total Allowable Catch TW Thermocline Water UNAM University of Namibia UCT University of Cape Town UNESCO United Nations Education, Scientific and Cultural Organisation UWC University of the Western Cape WCRP World Climate Research Programme
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APPENDIX V
NOTES ON ANGOLAN OCEANOGRAPHIC CRUISE AND DATA REPORTS AND PUBLICATIONS
MR A. F. PEREIRA, A MEMBER OF THE SCIENTIFIC STAFF OF IIP WHO IS CURRENTLY ON SECONDMENT TO THE BENEFIT SECRETARIAT, WAS COMMISSIONED TO COMPILE INFORMATION ABOUT OCEANOGRAPHIC CRUISES UNDERTAKEN IN ANGOLA’S EEZ AND TO EXTRACT PERTINENT INFORMATION FROM THE VARIOUS CRUISE AND DATA REPORTS AND PUBLICATIONS. IN COLLABORATION WITH IIP STAFF, IN PARTICULAR MR V. L. L. FILIPE, MR PEREIRA PRODUCED A COMPREHENSIVE DRAFT DOCUMENT WHICH CONTAINS A WEALTH OF INFORMATION RELEVANT TO BCLME, AND WHICH WILL BE EXTREMELY USEFUL FOR PLANNING PURPOSES. THE FOLLOWING IS A SHORT COMMENT ON THE AVAILABLE INFORMATION AND ITS POTENTIAL UTILITY.
Since 1985, the R. V. Dr Fridtjof Nansen has undertaken numerous surveys of Angola’s fish resources in collaboration with IIP. During these cruises environmental measurements (e.g. temperature, salinity, dissolved oxygen, plankton, currents etc) were made. Some 18 cruise reports spanning the period 1985-1998 are now available, and these contain information about the various parameters measured, and useful comments on the state of the environment by the compiler, key extracts of which are contained in Mr Pereira’s report (“pertinent comment by compiler”). Apart from the R. V. Dr Fridtjof Nansen, cruises were also undertaken by Angola’s R. V. Goa and various other research vessels – Russian, Portuguese, Cuban etc. Eleven cruise reports emanating from the R. V. Goa and nine from other vessels are available.
Since Independence, IIP scientists have authored 17 environmental scientific papers. These are mostly in Portuguese, but a number of recent articles are in English. Although it has not been possible in view of time limitations to undertake a comprehensive assessment of these publications, it is clear from the information provided by Mr Pereira that as a set they do provide a valuable addition to the literature on the Benguela ecosystem. What is also apparent is that IIP scientists, drawing on this material and their knowledge of the Angolan marine environment, will be able to make a substantial contribution to the execution of the BCLME during the implementation phase.
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CONTENTS
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1 Introduction 1
2 Physical features and processes 2
2.1 Bathymetry 2 2.2 Winds 3 2.3 Upwelling and surface temperature 4 2.4 Water masses and general circulation 6 2.5 Shelf circulation 9 2.6 System boundaries, fronts and filaments 10
3 Chemistry and related processes 13
3.1 Dissolved oxygen 14 3.2 Nutrients 15 3.3 Sulphur 17 3.4 Other aspects of marine chemistry 18
4 Plankton and the foodweb 19
4.1 Phytoplankton and primary production 19 4.2 Red tides and harmful algal blooms 21 4.3 Zooplankton and secondary production 23 4.4 Foodweb and carbon budget 25
5 Environmental variability 26
5.1 Small-scale variability 27 5.2 Seasonal changes and intra-annual variability 28 5.3 Interannual variability and episodic events 29 5.4 Decadal changes and regime shifts 33 5.5 Recent developments 34
6 Issues, problems, threats and gaps in knowledge 35
6.1 Fundamental issues 35 6.2 Environmental variability 36 6.3 The Benguela and global environmental(climate) change 37 6.4 Gaps in knowledge and understanding 38 6.5 Infrastructure and human capacity 39 6.6 Funding 40
7 Acknowledgements 41
8 References 41
Appendix I Institutional infrastructure and capacity 49 ∗ Human capacity 49
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∗ Infrastructure 50
Appendix II Oceanographic and fisheries data and information systems 53 ∗ Angola 53 ∗ Namibia 53 ∗ South Africa 54 ∗ South African Data Centre for Oceanography (SADCO) 55 ∗ Data confidentiality/restrictions 56
Appendix III List of persons consulted 57
Appendix IV Acronyms 59
Appendix V Notes on Angolan oceanographic cruise and data reports 60 and publications
FIGURE CAPTIONS
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Fig. 1 Locator map and principal bathymetric features of the Benguela region
Fig. 2 Monthly windstress along the west coast of southern Africa, 75km offshore (modified from Boyd 1987). Note the windy areas near Lüderitz and Cape Frio and the pronounced seasonality in the south
Fig. 3 Conceptual picture of wind-induced coastal upwelling (modified from Shannon 1989)
Fig. 4 Satellite-derived sea surface temperature distribution in the southern Benguela, 9 October 1997
Fig. 5 Characteristic temperature-salinity relationships for the South-east Atlantic Ocean and Benguela region
Fig. 6 Vertical east-west sections at three locations in the Benguela, illustrating the depths of principal water masses, viz Tropical Surface Water (TSW), Subtropical Surface Water (STSW), Thermocline Water (TW), Antarctic Intermediate Water (AAIW), North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW). Note the absence of AABW in the area north of the Walvis Ridge, and the strongly stratified surface layer off Angola
. Fig. 7 Physical boundaries of the Benguela and surface (upper layer) currents
Fig. 8 Satellite-derived sea surface temperature distribution in the northern Benguela, 10 April 1997
Fig. 9 Conceptual diagram showing location of zones of formation of oxygen poor water in the South-east Atlantic
Fig.10 A two-dimensional network of nitrate (and hence carbon) pathways between ocean, shelf and sediments. Numbers are grams carbon x 1013 . (Courtesy Dr H. Waldron, Oceanography Department, University of Cape Town)
Fig. 11 Ocean colour image showing chlorophyll distribution in the Benguela obtained by SeaWiFS satellite, 9 March,1998 – Courtesy NASA and Ocean Space CC
Fig. 12 Bloom of red tide organism Noctiluca scintilans in the southern Benguela
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(Courtesy D. Horstman, SFRI)
Fig. 13 Diagram showing partitioning of planktonic food between sardine and anchovy (from Van der Lingen 1994)
Fig.14 Southern Benguela upwelling foodweb models (a) Rythers (1969) model and (b) a revised more appropriate model incorporating the microbial foodweb (from Moloney 1992)
Fig.15 Distribution of sea surface temperature in the northern Benguela, early in 1984, showing the southward penetration of warm water during a Benguela Niño (NOAA image generated by and reproduced courtesy of Ms Scarla Weeks, Oceanography Department, University of Cape Town)
Fig.16 Mass mortality of rocklobsters at Elands Bay in the southern Benguela as a consequence of the appearance of oxygen deficient water (Courtesy Dr A. Cockcroft, SFRI)
Fig.17 The “Great Ocean Climate Conveyor Belt” (modified from Broecker, 1991)
160 AN OVERVIEW OF THE SOCIO-ECONOMICS OF SOME KEY MARITIME INDUSTRIES IN THE BENGUELA CURRENT REGION
Chris Tapscott
A Report Prepared on Behalf of the Benguela Current Large Marine Ecosystem Project
Windhoek, October 1999 162 Table of Contents
Page
1.0 Background...... 1
2.0 Objectives of the Study...... 1
3.0 Terms of Reference...... 1
4.0 Methodology...... 2
5.0 The Social Economy of the Benguela Current Region - An Overview...... 2
6.0 Angola...... 4 6.1 Demography and Settlement Patterns...... 4 6.2 Social Services...... 6 6.3 Physical Infrastructure...... 7 6.4 Fisheries...... 8 6.5 Diamond Mining...... 9 6.6 Oil and Gas...... 10 6.7 Other Economic Activity...... 10 6.8 Development Potential...... 11
7.0 Namibia...... 13 7.1 Demography and Settlement Patterns...... 13 7.2 Social Services...... 18 7.3 Physical Infrastructure...... 18 7.4 Fisheries...... 19 7.5 Diamond Mining...... 21 7.6 Oil and Gas...... 23 7.7 Other Economic Activity...... 23 7.8 Development Potential...... 24
8.0 South Africa...... 25 8.1 Demography and Settlement Patterns...... 25 8.2 Social Services...... 27 8.3 Physical Infrastructure...... 28 8.4 Fisheries...... 29 8.5 Diamond Mining...... 31 8.6 Oil and Gas...... 33 8.7 Other Economic Activity...... 33 8.8 Development Potential...... 34
9.0 Threats to the BCLME – Policy Issues...... 34
Individuals Interviewed...... 39
11.0 Bibliography...... 40
Maps
Map 1. The BCLME Study Area ...... 3 Map 2. The Coastline of Angola Indicating Provincial Boundaries...... 5
162 163 Map 3. The Coastline of Namibia Indicating Regional Boundaries...... 14 Map 4 The West Coast of South Africa from Alexander Bay to Lamberts Bay...... 26 Map 5. The West Coast of South Africa from Lamberts Bay to Cape Agulhas...... 27
163 164 ANNEX N
BENGUELA CURRENT LARGE MARINE ECOSYSTEM STAKEHOLDERS
GROUP 1 Sustainable Management and Utilization of Resources
Ministeries Responsible for :-
Fisheries Environment Tourism Transport Mining Energy Finance
Private Sectors:-
Fishing Companies Mining Companies Oil and Gas (Offshore Exploration and Production) Companies Tourism Companies
Others:-
International Donor Agencies Relevant NGO’s Research Institutions and Universities Coastal Communities Interested Individuals
GROUP 2 Environmental Variability
Ministries Responsible for :-
Fisheries Environment Tourism and Health Finance Mining Energy Works, Transport and Communication
Private Sectors:-
Fishing Companies Mining Companies Oil and Gas (Offshore Exploration and Production) Companies Tourism Companies
Others:-
International Donor Agencies Relevant NGO’s Research Institutions and Universities Coastal Communities Municipalities Port Authorities
164 165 Meteorological Services Interested Individuals
GROUP 3 Ecosystem Health and Pollution
Ministeries Responsible for:-
Fisheries Environment Energy Mining Health Tourism Finance Defence Immigration Police Transport and Communication Trade
Private Sectors :-
Fishing Companies Mining Companies Oil and Gas (Offshore Exploration and Production) Companies Tourism Companies Shipping Companies
Others:-
International Donor Agencies Relevant NGO’s Research Institutions and Universities Port Authorities Municipalities Meteorological Services Coastal Communities Interested Individuals
Brief Description of PDF-B Involvement The seed for the BCLME Program was sown at a workshop/seminar held in Swakopmund, Namibia in mid- 1995. This paved the way for the development of a PDF Block B Grant Proposal to GEF, and its subsequent approval and implementation in 1998. In July 1998 the First Regional BCLME Workshop, attended by approximately 100 stakeholders and regional and international experts, was held in Cape Town, followed by a formal meeting of key stakeholders. The attendance and proceedings of this workshop are attached to this document as Annex 9.
Stakeholders have and will continue to include the ministries in Angola, Namibia and South Africa responsible for the environment, marine resources, mines, energy, tourism, science and technology, transport, ports and harbours, etc.; representatives of relevant industry sectors such as diamond mining, fishing (including artaisanal fishers), oil and gas (e.g. SONANGOL from Angola); education and training establishments - universities and technikons; regional and local authorities and NGOs. The lead stakeholders are: Ministry of Fisheries and Marine Resources, Namibia; Ministries of Fisheries and Environment, Angola; Department of Environmental Affairs and Tourism, South Africa.
165 166 The First Regional Workshop identified the issues and problems/constraints in the BCLME and possible solutions. As a follow-up, six comprehensive syntheses and assessments of information on the BCLME (thematic reports) were produced, viz: fisheries, oceanography and environmental variability, diamond mining, coastal environments, off-shore oil and gas exploration/production, socio-economics. These reports were reviewed at the Second Regional BCLME Workshop held in Namibia in April 1999, and used as a basis together with input from the First Workshop and participants for drafting the TDA and setting the SAP framework. Actions subsequently have led to the finalisation of the TDA, SAP, Project Brief and of the BCLME Program.
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