Estimation of maximum sustainable yield of bombay duck,harpodon nehereus fishery in pakistan using the CEDA and ASPIC packages

Maximum sustainable yield (msy) of bombay duck harpodon neherus fishery from pakistan was estimated from the catch and effort data during 1995 - 2009. the average landing from fifteen years of bombay duck fishery was 66 t. the highest catch was 101 t in 1996 and the lowest catch was recorded at 43 t in 2008. the ceda and aspic non-equilibrium surplus production models were used in this study. ceda includes three surplus production models of fox,schaefer and pella-tomlinson with three different error assumptions of normal,log-normal and gamma. here we use initial proportion (ip) value of 0.9 because the starting value of the catch was roughly 90% of the maximum catch. the estimated msy values from fox model and three error assumptions were 25.57 t (r2 = 0.900),31.42 t (r2 = 0.916),29.11 t (r2 = 0.909),respectively,while from schaefer and pella-tomlinson models were 27.34 t (r2 = 0.895),36.64 t (r2 = 0.911),32.54 t (r2 = 903) from three different error assumptions respectively. the msy values from schaefer and pella-tomlinson models were the same. the msy values from aspic when ip = 0.9,for the fox and logistic models were 34.4 t (r2 = 0.926),30.5 t (r2 = 0.931) respectively. therefore we may suggest that ceda and aspic estimated the msy of the bombay duck fishery from pakistan at 25 - 35 t,which were lower than the current catch,and therefore we would recommend a reduction of fish landing for this fishery. © 2013 zoological society of pakistan.