Advances in Aquaculture and Fisheries Management

Advances in Aquaculture and Fisheries Management ISSN 2756-3278 Vol. 10 (2), pp. 001-003, February, 2022. © International Scholars Journals

Short Communication

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

Abstract

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, t_o = 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 E_max 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.