Stock Assessment of Molluscan Fisheries in Pakistani Marine Waters by using CEDA and ASPIC computer packages

Abstract

Molluscan fishery input and output data, 1999-2009, from Pakistani marine waters was analyzed by using two specialized software, CEDA and ASPIC, used in fisheries management. The highest and the lowest molluscan catch values were observed in 1999 (10208 t) and 2006 (6162 t) respectively, with an average catch of 8109 t y^-1. Among five surplus production models (SPMs) used in this study, three were from CEDA i.e. Fox, Schaefer and Pella-Tomlinson along with log error assumption and two were from ASPIC i.e. Fox and Logistic. Calculated MSY and <i>R</i>² values for CEDA models, by using IP (<i>B</i>₁/<i>K</i>) of 1, were 8449 t, 7248 t, 7248 t and 0.52, 0.50, 0.50 respectively. While for ASPIC, their values remained 8527 t, 7343 t and 0.711, 0.698 in that order. Computed MSY values, along with higher values of <i>R</i>², validate ASPIC results as compared to CEDA and suggest that overall this fishery resource is in safe condition and in future catch should be managed at current level. However, molluscan fisheries sub-groups should be further investigated for their stock status.