Stock Assessment of Indo-Pacific King Mackerel, Scomberomorus guttatus (Bloch & Schneider, 1801) in the Persian Gulf and Oman Sea, southern Iranian waters, using CMSY and DBSRA

The purpose of this study was to investigate the catch trend and estimation of the optimized catch limit of the Scomberomorus guttatus (GUT) stock by collecting catch data in southern Iranian waters. In this study, two methods were used to determine the biological reference points (BRPs) of Indo-Pacific king mackerel in southern Iranian waters i.e. the Persian Gulf and Oman Sea. Catch data was collected for 23 years (1997-2019), and the optimized catch limit was estimated using a limited data approach and R Software. The average catch (Ct) for this period was 5123 tonnes (95% confidence interval 4026 -6218 tonnes), and it had significantly increased over the past two decades. The average (maximum-minimum) of carrying capacity (K), maximum sustainable yield (MSY), the biomass of maximum sustainable yield (Bmsy), current biomass (B) and fishing mortality of maximum sustainable yield (Fmsy) were obtained by the Depletion-Based Stock Reduction Analysis (DBSRA) and Catch- maximum sustainable yield (Cmsy) models. The Bmsy and K in two models showed no significant difference from the one-sample t-test at P>0.05. The results revealed that the exploitation ratio in the Indo-Pacific king mackerel stock is full fishing (full exploitation), and do not suggest an increase in exploitation ratio and fishing effort are proposed.