Growth, mortality and exploitation rates of African moonfish (Selene dorsalis, Gill 1863) encountered in the coast of Ghana (West Africa)

Growth, mortality and exploitation rate of Selene dorsalis (Gill 1863) from the continental shelf of Ghana (West Africa) were examined between July 2018 and June 2019. This study provided results on fishery dynamics parameters to contribute to estimating the stock assessment of these fish species. Monthly length–frequency data were collected from 629 samples and analysed using fisheries models fitted in TropFish R package in R software. The von Bertalanffy growth parameters were utilised to analyse the population dynamics of the species using ELEFAN Simulating Annealing. The estimated asymptotic total length (L∞) was 28.5 cm (Total length), the coefficient of growth (K) was 0.27 year-1, and the calculated growth performance index (phi) was 2.33 with Rn value of 0.62 for S. dorsalis. The recruitment pattern was continuous with two major recruitment pulses for both species. The total mortality rate (Z) was 1.77 year-1 with natural mortality rate (M) = 0.52 year-1 and fishing mortality rate (F) = 1.25 year-1. Exploitation rate (E) estimated for both species were above the optimum level of 0.5, which indicates that this species is overexploited. Based on the E value, analyses show that the exploitation rate of the assessed fish species has exceeded the optimum limit and hence the need for proper fisheries management measures.