Restoring the critically endangered Haplochromis granti fish in Lake Victoria, Koome Islands.

Assessing the threats

Lake Victoria has experienced dramatic changes over the past century, especially in its aquatic biodiversity. These slow but steady changes have mostly been caused by humans through changes to vegetation, agricultural developments, introduction and invasion of non-native species and intensive, non-selective fishing. This has led to the destruction of many important components of the Lake Victoria basin and is a huge threat to many local fish species.

Haplochromis granti is a cichlid fish only found in Lake Victoria. Their population has plummeted, and they’re now faced with extinction. Urgent conservation action is needed to save this critically endangered species. One of the major threats is Nile perch- a piscivorous (fish-eating) fish introduced to Lake Victoria in the 1960s. The Nile perch, Lates niloticus, are large, voracious predators and have contributed to the huge decline of Haplochromis granti.  Another key threat is decreased water transparency caused by environmental degradation of the lake’s buffer zones which, in-turn, makes it harder for Haplochromis granti to identify a mate.

Saving Haplochromis granti fish from extinction

Our conservation partner, William Isebaiddu, is leading a team of conservationists on Koome Islands, Uganda, to tackle the threats facing Haplochromis granti and halt their decline. They’re setting up a breeding program, establishing conditioning cages and forming fish conservation zones in the lake to restore the population and improve survival rates. Wild fish will be used for supportive breeding and their offspring released back into conditioning cages and fish conservation zones. Increasing the brood stock – or founders – will ensure that the genetic diversity of the captive population is as varied as possible. The young fish will be released into the lake shallows waters (areas that are less than 10m deep) to boost the numbers in these regions of the lake. Larger populations would increase the species resilience against the Nile perch which live in the deeper, more central areas. The team will closely monitor their numbers following the releases.