Gamtoos Estuary Management Plan Volume I Situation Assessment

Enviro-Fish Africa (Pty) Ltd.

C.A.P.E. ESTUARIES MANAGEMENT PROGRAMME

GAMTOOS ESTUARY MANAGEMENT PLAN
VOLUME I
SITUATION ASSESSMENT
(STATE OF PLAY REPORT)

Produced by:

Enviro-Fish Africa (Pty) Ltd.
P.O. Box 94 Grahamstown
6140

Produced for:

Cape Nature December 2007

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C.A.P.E. Estuaries Management Programme; Gamtoos Estuary Management Plan: Situation Assessment

1. INTRODUCTION

Estuarine ecosystems are not isolated systems. They form an interface between marine and freshwater systems and are part of regional, national and global ecosystems either directly via water flows or indirectly through the movement of fauna. In addition to the biota that these estuaries support, they provide a range of goods and services (uses) to the inhabitants of the various regions. Disturbances in one estuary can influence a wide variety of habitats and organisms in the broader freshwater or marine ecosystem. Thus, the interaction between the systems and users creates a delicate balance, the sustainability of which needs to be addressed by some form of management plan.

In order to address this balance in a consistent manner in the Cape Floristic Region (CFR), the Cape Action for People and the Environment (C.A.P.E.) Estuaries Management Programme has developed a holistic and inclusive management process representative of all stakeholders. The programme is governed by a Task Team comprising of officials from C.A.P.E., CapeNature, Marine and Coastal Management (MCM), the Department of Water Affairs and Forestry (DWAF), the Eastern Cape Parks Board (ECPB) and the Council for Scientific and Industrial Research (CSIR), which heads the technical support group.

The urgent need for Estuary Management Plans (EMPs) became apparent during the development of the new Integrated Coastal Management Bill. Estuaries and the management thereof have not been adequately addressed by past marine, freshwater and biodiversity conservation Acts. Estuaries and estuaries management have been marginalized due to the fact that they do not fit the ambit of any one government Department. Estuaries and the management thereof now form an integral part of the new Integrated Coastal Management Bill which outlines a National Estuarine Management Protocol. The protocol identifies the need for the development of EMPs, as these would help to align and coordinate estuaries management at a local level.

Approximately 62 estuaries exist within the CFR. These vary from small relatively simple systems to large complex systems. In order to create a focal area within which the programme can be initiated, six priority estuaries were identified at a stakeholder workshop (proceedings available on request). These priority estuaries are located on the following six rivers: the Olifants, Breede, Heuningsnes, Klein, Knysna and Gamtoos.

Enviro-Fish Africa (Pty) Ltd. has been contracted by Cape Nature to address the development and implementation of an (EMP) for the Gamtoos estuary. This report fulfills the requirements of Objective 1, namely a Situation Assessment, and is presented in the form of a State of Play or SOP Report.

2. TERMS OF REFERENCE

OBJECTIVE 1: SITUATION ASSESSMENT

The consultant is expected to review all existing local information in the form of local research reports and management processes. This information can be obtained from Local Authorities and forums. A map of the estuary should be developed identifying different habitats and potential and existing management zones. The map should identify and record all developments in at least a 500m zone surrounding the estuary. The possible direct impacts of these and other local developments should be noted.

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The description of the current situation should include information on:

••

Legal requirements relevant to the specific estuary Requirements stipulated under existing institutional Management Strategies such as Catchment Management Strategies, IDP (including SDF and Water Development Services Plan), Ramsar & National Heritage Site Strategies, Protected Area & Conservation Plans (C.A.P.E. Estuaries) relevant to the specific estuary the Biophysical environment (present Ecological Health & Important physical processes) the Socio-Economic environment (e.g. demographics & economic profile, land-use and planning provisions, cultural & heritage resources, water supply & demand, waste management etc.)

••

•••••

Conservation Planning The Exploitation of living resources Mariculture activities Resource Directed Measures, e.g. Classification, Reserve and RQO Current institutional structures governing estuarine issues

The estuary should be represented spatially in the form of a GIS Map indicating the following:

••••••••••••

Important biophysical features All protected/conservation areas Areas earmarked for rehabilitation Land-use and planning provisions of surrounding lands Infrastructure Cultural & heritage sites Recreational activities Living resource exploitation Mariculture activities Wastewater discharges Stormwater drains Solid waste dump sites.

Finally, an assessment of the opportunities and constraints (e.g. legal obligations, constraints of tenure, prior usage, health and safety, natural hazards) should be done to guide the development of the EMP.

3. PROJECT TEAM

Overall responsibility for the project lies with Enviro-Fish Africa (Pty) Ltd. The project and team will be managed by Dr Tim Andrew of EFA; Dr Aidan Wood from Gleneagles Environmental Consulting CC is the project coordinator and will provide specialist input where required; Dr Warren Potts, a post-doctoral student in Ichthyology at Rhodes University, will provide specialist input with regards living resource exploitation and the biophysical aspects of the estuary; Dr Rob Palmer from Nepid Consultants will provide specialist input with regards the catchment, water use and water requirements; and Dr Albrecht Goetz from the South African Environmental Observation Network will be responsible for all mapping and GIS work.

4. BIO-PHYSICAL DESCRIPTION

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4.1 PHYSICAL DESCRIPTION

The Gamtoos estuary (33º58’S; 25º04’E) is a medium/large, permanently open, shallow muddominated turbid system, entering the sea through a dynamic coastal dunefield, with a shallow (< 1.5 m) tidal inlet when the estuary is not in flood. Historically however, the estuary has not always been open to the sea. During the drought in the late 1950s up until 1960, the mouth was closed. A flood in 1961 opened the mouth on the eastern shore (Salme 1994) but by 1969 the mouth of the estuary had closed again. However during the1971 floods, there were five mouth openings of which the biggest was 4.2 km west of the position in the early 1960’s. The previous opening eventually closed forming a tidal inlet or lagoon on the eastern shore (Marais 1983). Since the early 1980s, the mouth position has remained relatively stable and at the time of this survey (5 – 9 November 2007) was to the right of the abandoned tidal inlet referred to as "Gamtoos Lagoon", which is shallow (< 1.8 m), navigable only on a fuller tide, with a maximum width of ∼ 200 m (Heinecken 1981; Reddering and

Scarr 1990). The mouth itself is narrow (< 50 m) at its closest point to the sea, but widens to ~250 m for the first 1.5 km upstream where there is an extensive flood tide delta. This area hosts a variety of wading and other sea birds, including a large number of the endangered Oyster Catcher. The estuary remains relatively wide in the middle reaches and the main channel deepens to ~4 m. From 7 km upstream (approximately opposite the Ferry Hotel) the estuary is channeled and narrows to < 100 m with steep banks and a narrow intertidal region dominated by Phragmites reed beds. The channel at this point is shallow (< 2.5 m), and the depth gradually gets less until it measures < 1.0 m deep at the tidal head some 20 km upstream (Schlacher and Wooldridge 1996). The exact position of this tidal head is also transitory and its distance from the mouth depends on the degree of river scouring and the amount of freshwater input into the system.

The catchment area that drains into the tributaries of the Gamtoos is extensive (±34 500 km²), and extends far into the interior. An average of <600 mm of rain falls in the catchment annually, and dams are required to conserve freshwater for agricultural, industrial and private requirements (Schumann and Pearce 1997). There are three major dams on the catchment, including the Kouga Dam, that have reduced the supply of freshwater to the estuary. The total storage capacity of the main reservoirs is between 249 and 255 x 10⁶m³, which equates to

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approximately half of the mean annual runoff of the catchment (495 to 501 x 10 m

Jezewski and Roberts 1986; Midgley et al. 1994; van Niekerk and Huizinga 2003). Evaporation and abstraction of river water further reduce freshwater flow to the estuary, and in 1997, mean freshwater flow into the Gamtoos was estimated at <1 m³s^-1(Schumann and Pearce 1997).

Agricultural pollution has been a cause for concern in the Gamtoos Estuary for some time. Marais (1983) noted high NO₂levels in the upper catchment and attributed it to intensive farming in the Patensie floodplain. Van Niekerk and Huizinga (2003) noted that an extensive surface and subsurface agricultural drainage system directs runoff from the low-lying Loerie Flats region into an agricultural drainage pipe that empties into the estuary 16.5 km from the
-1 mouth. Outflow at the pipe has been measured at between 0.07 and 11 l s (Schumann and

Pearce 1997). The contribution of water to the estuary was considered insignificant, but nutrient concentrations, particularly in the upper estuary, were significant. The agricultural drainage pipe which discharges runoff from an area of approximately 50 ha and throughflow from the upper 1.2 m of soil into the estuary, gives an indication of the contribution of nutrients from surface runoff of the agricultural fields to the estuary. Pearce (1996) estimated that on an annual basis, approximately 75 kg of phosphorous, 129 kg of nitrate and 16 kg of

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nitrite entered the estuary from the surface agricultural drainage system alone. A mixing zone exists around the discharge point resulting in a dilution of the pollutants entering the estuary. Such dilution increases with distance from the discharge point and thus brought the concentration of nutrients measured at certain times in the estuary to within recommended limits. Total groundwater discharge also contributes significant levels of nutrients to the Gamtoos. Pearce (1996) estimated that between 10 and 2 700 kg of nitrate-N, 1 and 89 kg of nitrite-N and 10 and 400 kg of phosphorous-P were contributed by total groundwater discharge to the estuary per annum. These estimates were regarded as 'conservative' and only represented inputs from an area that comprises less than 20 % of the total area bordering the estuary.

4.2 BIOLOGICAL DESCRIPTION

4.2.1 Fish

Van Wyk (see Heinecken 1981) conducted one of the first ichthyological studies on the Gamtoos Estuary. He identified dusky kob (Argyrosomus japonicus), spotted grunter

(Pomadasys commersonni), white steenbras (Lithognathus lithognathus), mullet species

(Family: Migulidae) and seabarbel (Galeichthys feliceps). In a more comprehensive study, Marias (1983) conducted extensive gillnet surveys and concluded that the estuary had a rich large-fish fauna dominated by dusky kob, spotted grunter, white sea-barbel, white steenbras and leervis. The estuary is particularly well known for the large dusky kob that utilize the system as a resting and feeding area and as such the protection of the estuary is of paramount importance to the survival of this national resource. Angler reports suggest that the large dusky kob and white steenbras are predominantly found in the lower reaches of the estuary, while the spotted grunter, seabarbel, leervis (Lichia amia), and mullet species are found throughout the system. Bok (1984) observed the mullets, Myxus capensis and Mugil cephalus 120 km upstream of the estuary mouth. Recently, members of the competitive light tackle boat angling fraternity indicated that a large number of elasmobranch species are frequently captured near the mouth of the estuary. Angling records showed that these include the diamond ray (Gymnura natalensis), eagleray (Myliobatus aquila), blackspotted electric ray

(Torpedo fuscomaculata), ragged tooth shark (Eugomphodus taurus) and lesser sank shark

(Rhinobatos annulatus). Strydom (1998) studied the larval fishes in the estuary and identified the larvae of a total of 28 species belonging to 15 families. The most dominant families were the Clupeidae (with one species, the estuarine round herring, Gilchristella aestuaria being by far the most abundant) followed by Gobiidae and Sparidae.

4.2.2 Birds

Bird counts by the St. Francis Bay Bird Club on the middle and lower reaches of the Gamtoos estuary since summer 2001 have revealed a total of 67 species from 39 families. Amongst these are the endangered African Black Oystercatcher and the rare (in South Africa) European Oystercatcher. The adjacent Gamtoos Coastal Reserve is known to be an important area for oystercatchers and as many as 200 individuals have been observed in a single day (Chuck Cook, St. Francis Bay Bird Club, Pers. Comm.). Data collected by the club are forwarded to the Avian Demography Unit in Cape Town and are considered to be reliable. The mouth region of the estuary including the blind lagoon and extensive adjacent wetlands are considered to be of primary importance to a range of species.

4.2.3 Invertebrates

Gaigher (in Heinecken 1981) surveyed the bait organisms in the Gamtoos River system in

1980 and indicated that sand prawn Callianassa kraussii and mud prawn Upogebia africana

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were abundant wherever suitable substrate occurred in the lower part of the estuary. Upogebia were generally not found higher than the Ferry Hotel (approximately 7 km upriver), while Callianassa were found right to the confluence of the Gamtoos and the Loerie Rivers. He observed scattered populations of pencil bait (Solen capensis), but made no mention of bloodworm (Arenicola loveni) although they are known to be present and exploited for bait by anglers.

5. LEGISLATION PERTAINING TO ESTUARINE MANAGEMENT

The purpose of this section is to review all forms of legislation that may have an impact on the management of the Gamtoos estuary. This review incorporates international agreements and strategies as well as all forms of national, regional and local legislation.

5.1 INTERNATIONAL OBLIGATIONS (Table 5.1)

Table 5.1 Summary of International obligations and their relevance to estuarine management.

International Obligations

Short Description

Convention on Wetlands of International The broad aims of this Convention are to Importance especially as Waterfowl Habitat (1971) (Ramsar Convention) Agenda 21 (1992) as reaffirmed at the United Nations World Summit on Sustainable Development - Johannesburg Summit (2002) stem the loss and to promote wise use of all wetlands (including estuaries). This is not a legally binding document, but Agenda 21 is an internationally accepted strategy for sustainable development; the principles of sustainable development are easily applied to the estuarine scenario.
United Nations Convention on Biological The objectives of convention include the

Diversity (1992)

conservation of biological diversity; the

sustainable use of biological resources; and the fair and equitable sharing of benefits arising from the use of genetic resources. This framework sets an "ultimate objective" of stabilizing greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic
United Nations Framework Convention on Climate Change (1992)

interference with the climate system. This has particular relevance to estuaries when considering changes in rainfall, storm severity and flood levels and frequencies. The GPA is designed to assist states in taking action to prevent, reduce, control or
Global Programme of Action for the Protection of the Marine Environment from Land-based Activities (GPA) (1995) elimination the degradation of the marine environment (including estuaries), and to assist in its recovery or rehabilitation from the impacts of land-based activities.

5.2 NATIONAL LEGISLATION (Table 5.2) AND POLICY (Table 5.3)

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Table 5.2 Summary of national legislation and its relevance to estuarine management in general and the Gamtoos in particular. OBJ = Setting Resource Objectives; L&D = Land-use and Infrastructure Development; WQQ = Water Quantity and quality; ELR = Exploitation of Living Resources (from Taljaard 2007).

National Legislation

Lead Agent

Relevance to the Gamtoos

Estuary

OBJ

L&D

WQQ

ELR

National

DEAT

This Act provides for the conservation of biological

diversity, regulates the sustainable use of biological resources and ensures a fair and equitable sharing of the benefits arising from the use of genetic resources.

X

Environmental Management: Biodiversity Act (Act 10 of 2004)

National Health Act Delegated to

Delegated to Provincial and Local authorities from

Department of Health
XX

(No. 61 of 2004)

Provincial and

Local authorities from Department of Health

National

DEAT

This Act provides for the protection and conservation of

ecologically viable areas representative of South Africa’s biological diversity and its natural landscapes and seascapes; for the establishment of a national register of all national, provincial and local protected areas; for the management of those areas in accordance with national norms and standards; for intergovernmental co-operation and public consultation in matters concerning protected areas.

X

Environmental Management: Protected Areas Act (Act 57 of 2003)

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Table 5.2 continued

National Legislation

Lead Agent

Relevance to the Gamtoos

Estuary

OBJ

L&D

WQQ ELR

Disaster

Act is

To provide for an integrated and coordinated disaster

X

Management Act (No. 57 of 2002) administered by a management policy that focuses on preventing or reducing Cabinet member the risk of disasters, mitigating the severity of disasters, designated by the emergency preparedness, rapid and effective response to

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disasters and post-disaster recovery; the establishment of

national, provincial and municipal disaster management centres; disaster management volunteers; and matters incidental thereto

Local Government: Department of

This Act deals with Integrated Development Planning

(IDP), which is intended to encompass and harmonise planning over a range of sectors such as water, transport, land use and environmental management.

X

X
XX
Municipal Systems Act (Act 32 of

2000)

Provincial and Local Government

Development

Same

This Act requires the setting of Land Development Objectives and the principles of this Act have also been incorporated into the Municipal Systems Act. This Act requires that all municipalities, local and district councils, draw up IDPs for the integrated development and management of their areas of jurisdiction.
X