Composition and population structure of fish species landed at Katosi and Ggaba landing sites, Lake Victoria Uganda

Abstract

Lake Victoria has experienced a rapid rate of biodiversity loss which saw a significant reduction in the Haplochromine taxa from 500 species to very about 300 species. This trend is partly attributed to gaps on the current information regarding the fishery which is vital in designing the management actions that support the sustainable utilization of the fishery. This study evaluated catches landed by fishermen at two landing sites (Katosi and Ggaba) on Lake Victoria, to determine the species composition, CPUE and size structure of the landed fish species. A total of eight fish species were recorded in the commercial catches at the two study, but the dominant species were Rastrineobola argentea (locally known as Mukene), Lates niloticus (Nile Perch - NP) and Oreochromis niloticus (Nile tilapia - NT). The results show that majority of the Nile perch and Nile tilapia landed were of the recommended size (total length), however, the size of mukene shows a general reduction in Standard Length (SL) at both landing sites. Katosi had highly significant catch per unit effort (CPUE) for both mukene and Nile perch than Ggaba, whereas the CPUE of Nile perch was higher at Ggaba than Katosi. Generally, the sizes of Nile perch on the lake are recovering at a faster rate, however there is a reduction in the sizes of mukene hence a need for an in-depth study on the general sizes of mukene fished from other parts of the lake such that appropriate management measures can be formulated.