Fishing regime, growth, mortality and exploitation rates of Scomber Japonicus (Houttuyn, 1782) from catches landed along the eastern coastline of Ghana

Abstract

Population parameters (growth, mortality and exploitation rates) and the fishing regime of Scomber japonicus along the eastern coastline of Ghana were assessed using FiSAT II software for samples collected from August, 2014 to January 2015. The asymptotic length (L∞), growth rate (K) and length at first maturity (Lm50) were 26.78 cm (standard length), 1.30 per year and 17.85 cm (standard length) respectively. The annual instantaneous rate of total mortality (Z), fishing mortality (F), the natural mortality (M) and the length first capture (Lc50) were estimated at 5.02 per year, 2.92 per year, 2.10 per year and 13.19 cm respectively. The exploitation rate (Ecurrent) was 0.58 with the Lc/L∞ estimated at 0.49. The present study indicated that the maximum exploitation rate for Scomber japonicus could be achieved at Emax = 0.72. Results from the study showed relatively heavy exploitation for Scomber japonicus with its fishing regime as overfished. Such observations demand urgent implementation of management policies in order to ensure its sustainability for both future and present generation fish protein needs