Growth, mortality and exploitation rate of <i>Sardinella longiceps</i> (Valenciennes, 1847) from Pakistani waters based on length frequency distribution data

Abstract

The computer software FiSAT package was used to analyze the growth and mortality parameters of <i>S. longiceps</i>. Length weight relationship parameters of both sexes combined were at W= 0.0179xb^2.8583 (R²= 0.819). ELEFAN method was used to estimate the von Bertalanffy growth function (VBGF) parameters and were estimated as <i> L_∞</i> = 25.20 cm (FL), K = 1.4 year^-1 and t₀ value was calculated by Pauly’s formula as -0.929, hence the total mortality was estimated using length converted catch curve analysis as Z = 4.84 year^-1 at 95% confidential interval between (CI = 3.32-6.37). Natural mortality was calculated as M = 2.255year^-1 using an average sea surface temperature of 26 ^oC from Pakistani waters, hence the fishing mortality was obtained by F=Z-M = 2.560 year^-1. Exploitation rate (E) was E = F/Z = 0.534 year^-1. Present study results indicate that the stock of <i>S. longiceps </i> from Pakistani waters is in overexploitation state.