Espèces

Lake Victoria

Freshwater biodiversity in the Lake Victoria Basin: Guidance for species conservation, site protection, climate resilience and sustainable livelihoods


Location: Lake Victoria Basin, East Africa, including Burundi, Kenya, Rwanda, Tanzania and Uganda

Status: Completed.

Lake Victoria Map Photo: Open Street Map contributors and the GIS User community

Project Partners: Uganda Coalition for Sustainable Development (UCSD); Rubicon Foundation

Background:
The Lake Victoria Basin is internationally recognised for its high levels of freshwater species diversity and endemism, which are of critical importance to local livelihoods and national economies within the basin. However, freshwater ecosystems within the region are also highly threatened, in particular by pollution, overharvesting, agriculture and invasive species. Current safeguards are proving inadequate, with protected areas being poorly matched to the distributions of freshwater species, and the focus of much past and ongoing conservation work in the region focussing on terrestrial ecosystems. Given the unique and diverse nature of freshwater species within the basin, the dependence of rural communities and regional economies on these species, and the high levels of threat, there is a clear need for a stronger focus on conservation of freshwater biodiversity.

Objectives:
The primary goals of the project were to:

  1. Assess the status and distribution of freshwater biodiversity in the Lake Victoria Basin;
  2. Raise awareness of value and status of freshwater biodiversity; 
  3. Refine, expand and validate the existing network of freshwater Key Biodiversity Areas (KBAs) throughout the basin;
  4. Identify a climate-resilient network of priority sites for the conservation and sustainable use of freshwater biodiversity in the basin. 

Project Activities:

  • Field surveys: Field surveys to fill information gaps for freshwater fishes and odonates (dragonflies and damselflies) were conducted in the upper and lower Kagera satellite lakes of Tanzania, and in Rwanda, respectively.
     
  • IUCN Red List assessments of extinction risk: The previously published IUCN Red List assessments of all described species of freshwater crabs, fishes (with the exception of the haplochromine cichlids), molluscs, odonates and selected aquatic plants native to the Lake Victoria Basin were updated and newly described freshwater species of the region were assessed. These species assessments are freely available through the IUCN Red List of Threatened Species™.
     
  • IUCN Red List Index (RLI): Regional RLIs for each comprehensively assessed freshwater taxonomic group within the Lake Victoria Basin were calculated to investigate trends in the status of biodiversity. 
     
  • Climate change vulnerability assessments: Assessments of the vulnerability of the freshwater species (with the exception of decapods) native to the Lake Victoria Basin to climate change were made.
     
  • Species use and livelihoods assessments: Assessments of the importance of freshwater fishes and aquatic plants to human livelihoods within the Lake Victoria Basin were made.
     
  • Key Biodiversity Areas (KBAs): KBAs for freshwater biodiversity were delineated within the Lake Victoria Basin, using data from the updated Red List assessments.
     
  • KBA site champion training: Training workshops were held for potential KBA site champions for a subset of the newly delineated KBAs.
     
  • Systematic conservation planning: A network of sites within the Lake Victoria Basin for the conservation of freshwater biodiversity was identified, based around the existing protected areas and KBA network and the newly delineated freshwater KBAs, and using the recently updated Red List and climate change vulnerability assessments.
     
  • Dissemination: Information gathered during the project will be disseminated through a published technical report and policy briefs. These will be distributed at strategic meetings with key policy makers at regional and national levels, and also through the media.

Donor: MacArthur Foundation 

MacAuthur Foundation Photo: MacAuthur Foundation   

 

 

Key messages:

  • The Lake Victoria Basin has exceptionally high diversity and endemism of freshwater species. Of the 651 species of freshwater decapods, fishes, molluscs, odonates and selected aquatic plants considered in this project, 204 (31.3%) are endemic to the region. 
     
  • Freshwater species in the basin are highly threatened, primarily by pollution, overharvesting, agriculture and invasive species. These threats have resulted in 19.7% of freshwater biodiversity in the region and 76% of the region’s endemic freshwater species being assessed as threatened on the IUCN Red List.
     
  • We lack sufficient information on freshwater species to effectively inform environmental and development decision making within the basin. The current lack of basic information on the status and distribution of freshwater species, and the absence of long-term monitoring of freshwater biodiversity were noted as major failings.
     
  • Freshwater biodiversity in the basin is suffering ongoing decline and the risk of species extinctions is increasing. The situation is particularly dire for the native haplochromine cichlid species flock of Lake Victoria, for which the Red List Index (RLI) value declined by 63% between 1960 and 2010.
     
  • The region’s freshwater fishes are highly vulnerable to climate change, having high sensitivity, seemingly poor adaptive capacity and an expected high exposure to change.
     
  • The ongoing decline in freshwater biodiversity is impacting livelihoods of the rural poor in the basin. The Lake Victoria fishery supports household livelihoods of millions of people in the basin, and freshwater plants constitute an important resource, since many communities either lack access to or cannot afford market goods.
     
  • Site-scale conservation, focussed on freshwater Key Biodiversity Areas (KBAs), can help to guide conservation of freshwater species in the region. Thirty-nine important river, lake and wetland sites have been delineated as KBAs for freshwater biodiversity, including two Alliance for Zero Extinction (AZE) sites. It is now important to raise awareness of their status as validated KBAs and to develop plans for conservation action at these sites. Eighty-two potential KBA site champions have been identified as individuals or organisations well placed to do this.
     
  • A critical sites network for freshwater biodiversity in the Lake Victoria Basin has been identified using a system conservation planning analysis. We recommend this is used as a scientific basis for potential development and expansion of the existing protected areas network in the Lake Victoria Basin to better represent threatened, endemic and climate change vulnerable freshwater species. 
     
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