Gillnet selectivity of Sarotherodon galilaeus of Asejire lake, Oyo state, Nigeria

Gillnet selectivity is a management tool that is used to regulate the mesh size used for exploitation of fisheries resources in aquatic ecosystems. This is done to prevent overfishing of various types. Gillnet selectivity of Sarotherodon galilaeus of Asejire Lake is estimated in this study. Three mesh sizes 50.8 mm, 63.5 mm and 76.2 mm were found used predominantly in Asejire Lake. These mesh sizes caught various sizes of fish within the range of 11–24 cm. The optimum lengths for mesh sizes 50.8 mm, 63.5 mm and 76.2 mm were 15.09 cm, 18.86 cm and 22.63 cm respectively. Therefore, 63.5 mm mesh size is recommended as the appropriate mesh size for exploitation of S. galilaeus of Asejire Lake.Key Words: Gillnet, selectivity, mesh sizes, overfishing, Sarotherodon galilaeus, Asejire Lak