An Assessment of Overexploitation Risk Faced by Penaeus Shrimps in Pakistan by using SPMs: Management Perspectives and Economic Consequences

ABSTRACT Most of the published scientific literature declares Pakistani marine fisheries a victim of open access phenomenon. Under the influence of this ongoing regime, it becomes necessary to estimate overexploitation risk and understand ongoing economic implications of particularly important fishery resources. Thus, this study is the first-time attempt to evaluate very important fishery resource, i.e., Penaeus shrimps of Pakistan by considering these aspects. A long catch and effort (CE) data series, 1971-2009, were used in this study. CE data was statistically analyzed by using non-equilibrium surplus production models (NE-SPMs), viz., Fox Model (FM), Schaefer Model (SM), and Pella-Tomlinson Model (PTM) through two specialized fishery software, viz., catch and effort data analysis (CEDA) and a stock production model incorporating covariates (ASPIC). In CEDA, FM showed highest value of R2 (0.897) and computed maximum sustainable yield (MSY) as 2471 t. On the other hand, in ASPIC, FM also produced highest R2 value (0.931) and estimated MSY as 2867 t. Obtained results indicate that fishing mortality (F) and biomass (B) showed increasing and declining trend from 2000 to 2009, in that order. Thus, results indicate overexploitation of Penaeus shrimps in Pakistan. By considering results, recommended MSY target reference point (TRP) for Penaeus shrimps is between 2600 t - 3000 t. Moreover, harvest below 2300 t and over 3200 t may be considered as limit reference point (LRP). To conserve Penaeus shrimps biologically and to keep their economic contribution continuously, it is suggested to conduct further in-depth studies in this regard.