Assessing the effect of cage fish farming on the abundance and species diversity of wild fish populations in the proximity of the cage fish farm

Abstract

The study investigated the nature of wild fish assemblages in the proximity of selected cage fish farms in Katosi Bay on Lake Victoria that cultures Tilapia in cages. The specific objectives of the study were to determine the density of wild fish aggregating in the proximity of the cage fish farm and also to determine the species diversity involved in aggregation in the proximity of the cage fish farm. Wild fish captured from sampling sites in both the vicinity of the cage fish farm and the control area were used as samples. The samples comprised of Nile Perch and Tilapia since they were easy to capture. Wild fish aggregating in the proximity of the cage fish farms were significantly more abundant than the wild fish in the control area. More Tilapia aggregated in the proximity of the cage fish farm compared to Nile Perch. More wild fish aggregate in the proximity of the cage fish farm compared to the control area. The wild fish assemblages in the proximity of the cage fish farm are dominated by Tilapia. Preliminary studies should be carried out before setting up any cage fish farm. Further studies should be carried out with more complex gear to determine if wild fish migrate to other areas during the night or they stay close to cage fish farms permanently.