The East African Great Lakes are now well known for (1) their fisheries, of vital
importance for their rapidly rising riparian human populations, and (2) as biodiversity
hotspots with spectacular endemic faunas, of which the flocks of cichlid fishes unique
to each of the three largest lakes, Tanganyika, Malawi and Victoria, offer unique
opportunities to investigate how new species evolve and coexist. Since the early 1990s
research involving over a hundred scientists, financed by many international bodies, has
produced numerous reports and publications in widely scattered journals. This article
summarizes their main discoveries and examines the status of, and prospects for, the
fisheries, as well as current ideas on how their rich endemic fish faunas have evolved.
It first considers fisheries projects in each of the three lakes: the deep rift valley
lakes Tanganyika and Malawi and the huge Victoria, all of which share their waters between
several East African countries. Secondly it considers the biodiversity surveys of each
lake, based on underwater (SCUBA) observations of fish ecology and behaviour which have
revealed threats to their fish faunas, and considers what conservation measures are
needed. Thirdly, using the lakes as laboratories, what have the international investigations
(including DNA techniques and follow-up aquarium experiments) now revealed about the origins
and relationships of their cichlid species flocks and mechanisms of evolution?