Southern Africa has been shown here to support a high diversity of freshwater species of which a significant proportion is threatened. The level of threat to the associated habitats is further demonstrated through an assessment of South Africa’s rivers which found 82% threatened with 44% assessed as critically endangered. Without management intervention it is therefore expected that the overall status of southern Africa’s freshwater biodiversity will worsen as development pressures on natural resources increase. Indications from other more developed parts of the world are that the impact on freshwater ecosystems and their associated biodiversity will increase as development proceeds. In the Mediterranean basin, for example, the level of threat to freshwater species is extremely high (e.g. 59% of endemic freshwater fishes are assessed as globally threatened or extinct), mainly due to pressures induced by activities such as high levels of water extraction, pollution and alien species – all of which are associated with more developed countries.
As the southern Africa region moves forward and develops its water resources to improve access to potable drinking water and sanitation, and to provide greater production of food and power (hydropower), careful planning on the basis of reliable biodiversity information sets such as those provided here is essential if the impacts on freshwater biodiversity are to be minimised. Adequate account must be taken of the ecological requirements of freshwater species if we are to prevent their loss and the loss or degradation of the many benefits provided by wetland ecosystems. A major tool available for the protection of freshwater biodiversity is the Protected Area. However, it is clear that the current network of Protected Areas in southern Africa is in the large part not designed to target freshwater species such that any protection provided is largely incidental. The design of Protected Areas must move forward to take account of the high degree of connectivity within freshwater ecosystems. In particular, upper catchment areas should be protected to minimise downstream impacts of activities such as deforestation or excessive water withdrawal. The flow of water in wetland systems must be maintained at sufficient levels and cycles to maintain ecosystems functions in wetlands. Levels of water stress are already high in many parts of the region as shown by the map of Freshwater stress and scarcity in Africa by 2025.
Freshwater stress and scarcity in Africa by 2025. Downloadable from http://maps.grida.no/go/graphic/freshwater_stress_and_scarcity_in_africa_by_2025
A number of approaches for protective management of freshwater resources are now discussed.
It is generally accepted that the appropriate management unit for freshwater ecosystems is the river or lake catchment. Within catchments, or basins, the principles of IRBM should be adopted. The basic principles of IRBM are explained, along with a number of example case studies, at: : http://www.gwptoolbox.org/ .
In brief, IRBM is the process of integrating the work of conservation with other management actions focused on the development of water, land and related resources within a given river basin. It therefore requires communication, coordination and integration of actions across all related sectors. The aim is to maximise social benefits from the management, development and conservation of natural resources within the basin in a balanced way that also ensures the preservation and, where necessary, restoration of freshwater ecosystems. The setting up of River Basin Authorities, such as the Komati Basin Water Authority (KOBWA), a bi-national company formed in 1993 between the Kingdom of Swaziland and the Republic of South Africa, go a long way towards tackling these issues and are particularly important for bringing together the relevant management bodies from neighbouring countries in the cases of transboundary catchments. One of the key methodologies employed to ensure the use of water is managed in a way which provides for the continued functioning wetland ecosystems is through the provision of “Environmental Flows”. Environmental flow setting is conducted as part of the IRBM process.
An environmental flow is “the water regime provided within a river, wetland or coastal zone to maintain ecosystems and their benefits where there are competing water uses and where flows are regulated. Environmental flows provide critical contributions to river health, economic development and poverty alleviation. They ensure the continued availability of the many benefits that healthy river and groundwater systems bring to society.” (Dyson et al. 2003).
In order to calculate an appropriate environmental flow, information is required on the water requirements of all potential stakeholders in the system and this includes the environment. For the ecosystem to remain functional it is necessary to understand the water flow requirements of those freshwater species within the system. These species not only require a specific quantity and quality of water to flow but the timing of the flow cycle is also critical, for example, as a trigger for migration or spawning in some fish species. The biodiversity assessment conducted here aims to supply much of the species information required to initiate such a study of species flow requirements. The assessment provides baseline data sets of the species found within each catchment, and provides information on their basic ecological requirements and life histories. More detailed studies can then be focused on those species for which specific flow requirements are thought to be most critical.
Limitations on the available time and resources deny us the luxury of developing and implementing conservation actions for all water catchments throughout the southern Africa region. It is therefore useful to identify those areas where management intervention will provide the greatest rewards in terms of species conservation. The Key Biodiversity Areas identified as a result of this project provide an excellent starting point for such conservation focus as they identify those catchments containing species most at risk from global extinction on account of their vulnerability (e.g. threatened species) and / or irreplaceability (restricted range species found nowhere else). We would recommend as a priority that those candidate Key Biodiversity Areas identified through this assessment serve as an initial focus for conservation actions at the catchment scale across the region.
One of the most challenging parts of the process is presentation of the biodiversity assessment outputs in a format which is suitable and accessible to the widest range of stakeholders. In particular, the outputs need to be accessible to natural resource managers, developers and policy makers. This requires production of a range of products including, brief summaries of the issues and recommendations (policy briefs), more detailed technical reports, and comprehensive data sets. This report will serve as the detailed technical report of the assessment findings, and the full database including all species distribution shape files is attached as a CD Rom. Policy briefs will be forthcoming. All species global assessments and distribution maps (jpegs) will be directly accessible online through the IUCN website www.iucnredlist.org. Regional assessments will also be available online shortly. Ultimately, all species distribution shape files will be accessible online.
Identification of the primary end-users of this information is also a challenge given the multitude of different organisation with overlapping and sometime contradictory jurisdiction for the management of wetland ecosystems. Preliminary efforts have been taken to identify these stakeholders through an online survey of end-user data needs but more work needs to be done in this area. The preliminary results can be found on: http://www.unep-wcmc.org/freshwater_biodiversity/Africa/survey/ .
Having identified the stakeholders and packaged the outputs as required a process has to be established for ensuring that the information provided is now given the appropriate level of consideration within the decision making processes for development and conservation actions. Four case study demonstration sites have been set up as part of this project to determine the best process for integrating biodiversity information within these planning processes. The results of these case studies will be made available in the form of documents on “Best Practice” and “Lessons learned”. Descriptions of each case study are available from the project website (http://www.iucn.org/themes/ssc/our_work/freshwater/panafrican_sites.htm) and the results will be downloadable from December 2009.
Many areas in the southern Africa region are still not well surveyed such that the available information on freshwater species is insufficient for environmental and development planning. The areas where information is lacking can be identified most easily through mapping the locations of all species assessed for the IUCN Red List as Data Deficient (DD) (see below). From the information available on species ranges it is clear that the focus for future field survey should include the upper Zambezi, Rovuma and much of Angola. The additional areas highlighted in South Africa primarily reflect a number of species complexes that need to be resolved taxonomically. It is proposed that new funding be sourced to take the project to the next stage of implementing a programme of new field surveys and taxonomic work to complete the baseline information set assembled through this project.
Distribution of all species classified as Data Deficient. The map of course fails to show those many species which could not be mapped due to lack of information on their distribution ranges.
In conclusion, we hope that the information provided through this assessment will be taken up by the key stakeholders in freshwater ecosystems throughout southern Africa and will be integrated in the decision making processes for environmental and development planning in wetland ecosystems. In this way we hope that the future impacts of development actions affecting wetland ecosystems can be minimised and mitigated to the benefit of freshwater species and those people who rely on freshwater species for their livelihoods and pleasure.