Advances in Aquaculture and Fisheries Management ISSN 2756-3278 Vol. 10 (2), pp. 001-003, February, 2022. © International Scholars Journals
Size composition, growth, mortality and yield of Alectis alexandrinus (Geoffory Saint -Hilaire) in Bonny River, Niger Delta, Nigeria
S. N. Deekae1, K. O. Chukwu1 and A. J. Gbulubo2
1Department of Fisheries and Aquatic Environment, Rivers State University of Science and Technology, Port-Harcourt Rivers State, Nigeria.
2African Regional Aquaculture Centre, Port Harcourt, Nigeria. Institute for Oceanography and Marine Research, P.M.B.5122, Port Harcourt, Nigeria.
Accepted 3 November, 2021
A twelve month study on the size composition, growth, mortality and yield of Alectis alexandrinus revealed a length range of 11.5 - 33.8 cm (standard length) . Employing the length frequency method in the FISAT II package gave the following results for the Von Bertanlanffy growth parameters: L = 35.23, K = 0.680, to = 0.3214 and = 2.926. The total mortality (Z) was 2.47, natural mortality (M) 1.39 and fishing mortality (F) 1.08.The relative biomass per recruit (knife edge selection) was Lc/ L = 0.05, E10 = 0.355 and E50 = 0.278. Although the exploitation rate (E) was 0.44 the Emax was 0.421 indicating moderate exploitation of the fish in Bonny River. There is room for increased effort in the fisheries.
Key word: Size, growth, mortality, yield, Alectis alexandrinus.