Prediction of Maximum Sustainable Yield and Optimum Fishing Effort for the Nile Perch (Lates niloticus L.) in Lake Chamo, Ethiopia

Abstract

The study was conducted to assess the current status and determine the maximum sustainable yield level of exploitation for the Nile perch (Lates niloticus L., 1758) a stock in Lake Chamo, Ethiopia. Data were collected from eight major landing sites of Lake Chamo for three days in a week for ten months (February to November, 2018). The total length, sample weight and total weight of L. niloticus caught by the fishers and the fishing efforts were the basic information collected from these sites. Totally, 544 L. niloticus samples were collected in 120 days. Jones length based cohort analysis model and length-based Thompson and Bell yield prediction models were employed to estimate the maximum sustainable yield. Overall about 0.25 million L. niloticus populations were estimated to exist in the lake. The estimated current annual yield was 102.4 tons per year. However, the predicted value of MSY was 74 tons obtained at fMSY of 9,007 nets. The maturity length (L50) was 100 cm and out of the total annual catches 87.9% of L. niloticus were below their respective size of maturity. Thus, the reduction of yield was due to experiencing both growth and recruitment overfishing with increased effort and reduced mesh size. Lates niloticus of Lake Chamo is overfished. Therefore, conservation and rehabilitation as well as co-management practices are required for sustainable utilization of the resource.