Seasonal distribution and richness of fish species in the Badagry Lagoon, south-west Nigeria

We recorded 37 fish species representing 21 families in the Badagry Lagoon, south-west Nigeria. Adult stages of 13 (35.14%) of them were freshwater, 7 (13.51%) estuarine, and 19 (51.35%) near-shore marine species. The seasonal variation in the fish catch composition of the lagoon was attributed to the seasonal fluctuation in salinity. Availability of food organisms was also noted to affect the seasonal distribution of the fish fauna. Other physical features such as temperature and pH varied slightly, while the concentration of dissolved oxygen was higher in the dry season than in the rainy season. The highest species richness was observed in September with 11 species, while the lowest with the smallest abundance was observed in February with 5 species. The most abundant species during their occurrence were Cynoglossus senegalensis (7.92%), Tilapia mariae (7.17%), and Ilisha africana (6.04%). Species richness and total abundance were found to increase during the rainy season.