Maximum sustainable yield appraisal for Indian Oil Sardine Sardinella longiceps in Pakistani marine waters: An update

摘要

The highest and the lowest catch quantity of S. longiceps was observed in 1993, 92704 Mg, and 2010, 20127 Mg respectively, whereas average catch quantity of this fishery resource remained 44265 Mg year(-1) during the study period (1990-2010). To estimate MSY we applied IP (B-1/K) of 0.7 because the initial catch was about 70% of the maximum catch. For Fox model computed values of MSY, CV and R-2 by using log and log-normal assumption were 21734 Mg, 0.2180, 0.841 and 27477 Mg, 0.1033 and 0.815 in that order. Calculated figures of same parameters for Schaefer model were 27609 Mg, 0.1925, 0.838 and 32665 Mg, 0.1217, 0.815 respectively, while for Pella-Tomlinson model their values were 27609 Mg, 0.2062, 0.838 and 32665 Mg, 0.1173, 0.815 correspondingly. Gamma error assumption did not produce rational results in all the three models used. Fox model appeared to be more conservative as compared to other models in terms of MSY calculation and produced higher R-2 values. Obtained results suggest that fishery stock of this aquatic resource is in safe condition and therefore harvest should be kept at the current level.