Estimates of Population parameters for Sardinella maderensis (Lowe, 1838) in the coastal waters of Ghana

This study examined some population parameters of Sardinella maderensis landed along the eastern coast of Ghana, based on length-frequency data from June, 2014 to January 2015.  Overall, 1401 samples of   S. maderensis were measured for standard length and resultant data analysed with FiSAT II. The asymptotic length (L_∞) and growth rate (K) were 23.63 cm SL and 0.61 yr^-1respectively.  The theoretical age at birth (t₀) and growth performance index (ϕ) were -0.284 yr^-1 and 2.532 respectively. The recruitment pattern was continuous with two recruitment pulses. Total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 2.96 yr^-1, 1.30 yr^-1 and 1.63 yr^-1correspondingly. Fishing mortality rate surpassed the optimum fishing rate which showed that the assessed fish species is under high fishing pressure. The estimated exploitation rate (E_curr) was 0.55, implying that the stock is over-exploitation. VPA outcome revealed higher harvesting rate on individuals with length between 10 – 11 cm. The spawning biomass which was below the 30% of unexploited biomass indicated future recruitment failure of the stock. As a result, urgent management interventions such as the application of biological reference points and mesh size regulations are urgently recommended for sustainable exploitation of Sardinella maderensis.