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 C.A.P.E. Estuaries Management Programme; Gamtoos Estuary Management Plan: Situation Assessment 1 Enviro-Fish Africa (Pty) Ltd. 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. C.A.P.E. Estuaries Management Programme; Gamtoos Estuary Management Plan: Situation Assessment 2 Enviro-Fish Africa (Pty) Ltd. 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 bio- physical 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 C.A.P.E. Estuaries Management Programme; Gamtoos Estuary Management Plan: Situation Assessment 3 Enviro-Fish Africa (Pty) Ltd. 4.1 PHYSICAL DESCRIPTION The Gamtoos estuary (33º58’S; 25º04’E) is a medium/large, permanently open, shallow mud- dominated 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 km 2), 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 10 6 m3, which equates to 3 approximately half of the mean annual runoff of the catchment (495 to 501 x 10 6 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 m3 s -1 (Schumann and Pearce 1997). Agricultural pollution has been a cause for concern in the Gamtoos Estuary for some time. Marais (1983) noted high NO 2 levels 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 mouth. Outflow at the pipe has been measured at between 0.07 and 11 l s -1 (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.