New freshwater ecosystem atlas shows which rivers and wetlands to keep in a natural condition

Publication Date: 
Monday, November 14, 2011 - 00:00

Maps to support sustainable development of water resources

A new atlas that contains mapped river, wetland and estuary priorities for South Africa was launched by the Deputy Minister of Water and Environmental Affairs, Ms Rejoice Mabudafhasi, today.

Maps to support sustainable development of water resources

A new atlas that contains mapped river, wetland and estuary priorities for South Africa was launched by the Deputy Minister of Water and Environmental Affairs, Ms Rejoice Mabudafhasi, today.

The atlas is the result of a project that started three years ago to answer the question: How many and which rivers and wetlands do we have to maintain in a natural condition to sustain economic and social development, while still conserving our freshwater biodiversity? The project partners included the South African National Biodiversity Institute (SANBI), the Council for Scientific and Industrial Research (CSIR), the Water Research Commission (WRC), the World Wide Fund for Nature - South Africa (WWF), the Department of Water Affairs and the Department of Environmental Affairs, the South African Institute for Aquatic Biodiversity (SAIAB) and the South African National Parks (SANParks).

Project leader and CSIR principal scientist, Dr Jeanne Nel, says water influences the well-being of a country’s people; water shortages or a decline in water quality will hamper economic development. Ultimately, she adds, the quantity, quality and timing of water flow are determined by the health of the ecosystems through which the water flows.

Mandy Driver, Director: Biodiversity Policy at SANBI, says the 2004 National Biodiversity Assessment highlighted the shocking state of river ecosystems in South Africa, with 84% of ecosystems associated with South Africa’s large rivers being critically endangered, endangered or vulnerable. While this study explored main rivers, the 2011 National Biodiversity Assessment took smaller tributaries into account. This assessment was less pessimistic but still found that over half of South Africa’s river ecosystems are threatened. “The National Freshwater Priority Areas project has its roots in these findings. We needed a strategic intervention to help sustain and conserve the country’s freshwater ecosystems,” she says.

The starting point for the work was agreeing on criteria for priority areas. These criteria heeded the following aspects: maintaining some natural examples of the full variety of South Africa’s freshwater ecosystems; areas that are considered high water yield or high groundwater recharge areas; free-flowing rivers, which are long stretches of rivers without dams; areas where populations of threatened or near-threatened freshwater fish occurred; and connectedness, as ecosystems that are connected are more likely to support biodiversity.

The project used data from the national river health programme as well as from a multitude of river surveys and assessments, some of which were coordinated by the then Department of Water Affairs and Forestry.  The research team also sourced data from the different provincial structures in the various water management areas. These data sets were then put into a spatial format and were once again taken to freshwater ecologists and biodiversity experts at regional review workshops. “The atlas content summarises the data and on-the-ground knowledge of the freshwater ecological community in South Africa, representing over 1 000 person years of collective experience. The collaborative spirit of the freshwater scientific community in South Africa has been one of the biggest success factors of the project,” says Driver. Dr Harry Biggs, Program Integrator: Adaptive Biodiversity Outcomes at SANParks says: “The evaluation of an expert who has been in the field for years, is incredibly important.”

Dr Ernst Swartz, senior scientist at SAIAB, believes the project will make a difference in the conservation of freshwater fishes in South Africa. “For the first time, freshwater fish experts around the country prioritised threatened fish species and their surviving populations on a national scale. The maps we produced are a benchmark for future conservation planning and represent a significant step towards prioritising our efforts to prevent extinction of our unique freshwater fish fauna.”

Refinements were made and the priorities were then determined by using a conservation planning tool that seeks to find the most spatially efficient solution to achieving the criteria. “The configuration of priority areas is based on sound science and is designed to be spatially efficient, in other words, it is designed to meet biodiversity targets in the smallest area possible and to avoid conflict with other land and water resource activities,” explains Dr Nel.

Some of the key findings that emerged once the data had been collected and processed, include:

  • Overall, tributaries are in a far better state than mainstem rivers and they offer excellent conservation opportunities. They also support the sustainability of hard-working rivers further downstream by diluting poor water quality and ‘flushing’ pollutants. Only 35% of the length of South Africa’s mainstem rivers is in a good condition, compared to 57% of the tributaries.
  • Some 57% of river ecosystems and 65% of wetland ecosystems are threatened. The high levels of threat result particularly from intense land pressures, especially around cities.
  • By treating less than a quarter (22%) of our rivers as priority areas, South Africa will be able to conserve natural examples of its diverse freshwater ecosystems while contributing to sustainable development of water resources in the country.
  • South Africa has only 62 free-flowing rivers, which constitute only 4% of our river length. Free-flowing rivers have become a very rare feature in the South African landscape and the few representative examples must be kept free-flowing.
  • The priority areas identified in the atlas protect over 50 threatened fish species.  Many of these fishes are on the brink of extinction,  but by managing a very small proportion of our rivers, this can be avoided.

The atlas contains 19 priority area maps: one for each water management area in South Africa. The maps show river priority areas and the associated land that drains into that particular river reach, called the sub-catchment. It also shows wetlands, or clusters of wetlands that are priorities. It has different colour fish symbols to indicate the presence of a fish sanctuary for critically endangered and endangered and other threatened indigenous freshwater fish. Upstream management areas are also indicated: in these areas development can go ahead, but must not impact on the condition of the downstream priority areas.

The atlas is also available on DVD with a GIS viewer. The project team has compiled an implementation manual to provide guidance on how the freshwater ecosystem priority areas should be implemented.

Dr Mao Amis, Manager: Catchment Stewardship Progamme at the WWF says effective water conservation cannot be achieved without partnering: “A single entity cannot hope to achieve all the goals relating to water conservation. Different role players are involved, including decision-makers in government and the environmental agencies that are concerned about freshwater ecosystems. This project is an excellent example of how we need to work together.” Dr Stanley Liphadzi, Director: Water-linked Ecosystems at the WRC, agrees: “South Africa’s challenge is to involve all the implementers from the start, as this project has done, so that we can improve on implementation and thereby improve our aquatic ecological conditions.”

Mandy Driver of SANBI says: “For me, the highlight of this project has been that we’ve managed to produce maps that feed directly into both water and biodiversity policy and legislation.” The Department of Water Affairs says the maps are useful for water resource classification, ecological reserve determination (the quality and quantity of water prescribed by law to meet basic human needs and keep the river sustainable) and the issuing of water-use licences. The Department of Environmental Affairs in turn says the project is contributing to the listing of threatened ecosystems and the implementation of the national protected areas expansion strategy.

The atlas will be housed at www.sanbi.org.

Issued on behalf of the project partners by CSIR Communications.

Water Research Commission: Media enquiries: Hlengiwe Cele, hlengiwec@wrc.org.za, cell 083 2669781 or Dr Stanley Liphadzi, Director: Water-Linked Ecosystems, stanleyl@wrc.org.za

World Wide Fund for Nature: Dr Mao Amis, Manager: Integrated Catchment Management: 
WWF South Africa, mamis@wwf.org.za, tel 021 657 6694

South African Institute for Aquatic Biodiversity: Media enquiries: Penny Haworth, tel 046 603 5800, p.haworth@saiab.ac.za or  Dr Ernst Swartz, senior scientist, tel 046 603 5800 e.swartz@saiab.ac.za

Department of Environmental Affairs: Media enquiries: Reyhana Mahomed, tel 012 395 1795, rmahomed@environment.gov.za

South African National Parks: Dr Dirk Roux, dirkr@sanparks.org, cell 082 496 2144 or Dr Harry Biggs, harry.biggs@sanparks.org, cell 082 905 4664

South African National Biodiversity Institute: Media enquiries: Pontso Pakkies, tel 012 843 5200 P.Pakkies@sanbi.org.za or Mandy Driver, Director: Biodiversity Policy, M.Driver@sanbi.org.za, tel 021 799 8838

Council for Scientific and Industrial Research: Media enquiries: Tendani Tsedu, mtsedu@csir.co.za, cell 082 945 1980 or Dr Jeanne Nel, principal scientist, jnel@csir.co.za, tel 021 888 2484 or cell 072 120 6442