Ichthyofaunal Diversity and Fisheries Status of Oguta Lake, Imo State, South East Nigeria

This study assesses the ichthyofaunal diversity and fisheries status of Oguta Lake, Imo State, located in Nigeria's South East geopolitical zone. Oguta Lake is Imo State's only natural lake and supports artisanal fishing communities, yet a current systematic species inventory and fisheries assessment are lacking. Fish samples were collected over six months using gill nets, cast nets, and hook and line at five stations. Fish were identified morphologically to species, measured for total length and weight, and the condition factor was calculated. Artisanal fishing effort data were recorded through interview surveys with 40 fishing households. A total of 33 fish species from 19 families were recorded. Cichlidae dominated by species number (8 species) and Mormyridae by individual abundance at deeper stations. Hemichromis fasciatus, Tilapia zillii, and Parachanna africana were the most abundant species. The electro-sampling confirmed the presence of Heterotis niloticus, a large-bodied species indicating relatively good lake ecosystem integrity. Length-frequency analysis suggested recruitment overfishing in at least three commercially targeted species. Fishing households reported a 30 to 40 percent decline in catch per unit effort over the preceding five years. The study recommends the establishment of a minimum mesh size regulation of 5 cm, a closed fishing season, and a participatory fisheries management committee for Oguta Lake. Keywords: ichthyofauna, Oguta Lake, fisheries status, Imo State, species diversity.