Subterranean Fishes of the World

5282

2011

IUCN

Cambridge, UK and Gland, Switzerland

Central Africa supports an incredible biodiversity, and its inland waters are no exception. The Congo River has the highest species diversity of any freshwater system in Africa, and is second in species richness globally, after the Amazon. This diversity provides benefits to humans both directly, such as through livelihoods from fisheries, and indirectly through services such as the purification of water for drinking. Currently, central Africa is not heavily developed, but this is likely to change dramatically in the next few decades, in particular should long-term political stability come to the region. Development activities are, however, not always compatible with conservation objectives which are, in most cases, poorly represented within the development planning process. One of the main reasons cited for inadequate representation of biodiversity in the development processes is a lack of readily available information on inland water taxa. In response to this need for basic information on species, the IUCN Species Programme conducted a regional assessment of the status and distribution of 2,261 taxa of freshwater fishes, molluscs, odonates, crabs and selected families of aquatic plants from throughout central Africa. This study is based on the collation and analysis of existing information, and the knowledge of regional experts. All species are assessed through application of the IUCN Red List Categories and Criteria to assess species risk of extinction, and distribution ranges have been mapped for the majority of species, thereby providing a tool for application to the conservation and development planning processes. The full dataset, including all species distribution maps (GIS shapefiles), is freely available in the DVD accompanying the report and through the IUCN Red List of Threatened SpeciesTM website (www.iucnredlist.org). The richest area of species diversity is clearly defined by the channel of the Congo River and its tributaries the Ubangi River and the Kasai River. Another extremely diverse area is the highlands of south-western Cameroon. Particularly high numbers of species from all taxonomic groups are found in the Upper Congo Rapids, and at Malebo Pool, also on the mainstream Congo River. Approximately one half of all species are endemic to the region, including an exceptional 74% of all fish species. Fifteen per cent of the freshwater species of central Africa are threatened with extinction according to the IUCN Red List Categories and Criteria. If all Data Deficient species were also found to be threatened, this could rise to as much as 36%. This level of threat is predicted to increase dramatically in response to growing levels of development, unless the ecological requirements of freshwater species are given much greater consideration in future planning. By far the biggest threat in the region is habitat loss due to agriculture and deforestation, as well as infrastructure development, and water pollution (in particular by sedimentation). The highest concentrations of threatened species are found in the Lower Congo Rapids, just downstream from the two capitals of Brazzaville and Kinshasha, and in the highly vulnerable Western Equatorial Crater Lakes. A network of river and lake basins are identified as potential Key Biodiversity Areas (KBAs) most important for the protection of threatened and restricted range species. Future efforts in managing inland waters must take account of the upstream and downstream connectivity in freshwater ecosystems. For example, it is recommended that conservation efforts focus on the protection of upper catchment areas, provision of environmental flows, and the inclusion of rivers and lakes as specified conservation targets within protected areas rather than as boundary markers for protected areas. Integrated Water Resource Management is recommended along with the initiation of additional river/lake basin authorities, and increased capacity to manage protected areas. The results of this assessment are to be merged with similar studies that have been conducted for all other regions of Africa, in order to provide a baseline of the status and distribution of freshwater biodiversity throughout all of continental mainland Africa. This information source, which will be made freely and widely available, will provide essential information currently lacking in many places, to help conservation and development planning proceed in a manner that takes full account of the requirements of freshwater species. Finally, it is most important that the findings and the data compiled here, are made available to the relevant decision makers and stakeholders in a format that can be easily understood and readily integrated within the decision making process. The key messages from this assessment are: ■ The inland waters of central Africa support an exceptionally high diversity of aquatic species, with high levels of endemism. Many of these species provide direct (e.g. fisheries) or indirect (e.g. water purification) benefits to people. The conservation of these species is most important to the livelihoods and economies of the regions’ people. ■ More than 15% of species across the region are currently threatened and future levels of threat are expected to rise significantly due to increasing development throughout the region, and an associated higher demand for natural resources. ■ Data on the distribution, conservation status, and ecology of 1,207 species of fish, 166 molluscs, 458 odonates, 38 crabs and 392 selected aquatic plants are now freely available through this project and the IUCN Red List website (www.iucnredlist. org/initiatives/freshwater/centralafrica). ■ The data made available through this assessment must be integrated within the decision-making processes in planning for the conservation and development of inland water resources. Lack of available information should no longer be given as a reason for inadequate consideration for development impacts to freshwater species. ■ Species information remains very limited for many species within the region, with 21% of known species classified as Data Deficient. Regions in the Democratic Republic of Congo in particular are identified as a priority for future surveys. All taxonomic groups lack vital data on species distributions and threats, but spatial information on aquatic plants in particular needs to be greatly improved throughout the region.

2