Significant declines in African freshwater species, pose major threat to availability of resources
In a report published today by the IUCN, it was found that 21% of African freshwater species are threatened with extinction.
©Neil Cumberlidge Over the last 5 years, a network of over 200 scientists have been working to document the extinction risk of African species, and the threat this poses to freshwater resource availability across the continent. In a report published today by the IUCN (International Union for the Conservation of Nature), it was found that 21% of African freshwater species are threatened with extinction. The study was based on regional conservation assessments of 5,167 species of freshwater fish, molluscs, crabs, dragonflies and damselflies, and selected aquatic plants, some of which were assessed as part of the Sampled Red List Index (SRLI) project.
The report highlights the increasing threat posed to these species by the growing demand for freshwater and its resources. Lake Chad now stands a fifth of its former size due to the effects of both decreased rainfall, and large scale water abstraction. This not only poses a major threat to the freshwater species in and around the lake, but the estimated 20 million people whom are reliant on its resources.
Africa is well known for its biological diversity, and large number of endemic species. Biological diversity has been further compromised by the increasing numbers of invasive species now found in lakes and rivers. The Nile Perch (Lates niloticus) has been one of the most devastating introductions. Introduced to Lake Victoria in the late 1950s, it has since resulted in the extinction of approximately 200 cichlid species.
As the human population continues to grow, so does wide-scale land clearance for agricultural land. The population of Tilapia (Tilapia flava) has been devastated by palm oil plantations, and slash and burn agriculture resulting in pollution and sedimentation of Lake Bermin, a 0.5 km2 lake in Cameroon and the only lake from which it is known.
Documenting extinction risk of species by undertaking conservation assessments is crucial for our understanding of required conservation actions. Projects such as this, enable conservation practitioners to identify species, and regions, most in need of conservation work. Freshwater taxa are amongst some of the most threatened taxa on the IUCN Red List as demonstrated by the findings of the recent SRLI review of crayfish and freshwater fish. A further research project is now underway, looking at how these different species groups combine to create areas of high freshwater biodiversity at the global scale, the results of which will be published later this year.