Estimation of Fisheries Reference Points for (Scomberomorus guttatus Bloch & Schneider, 1801)Using the Catch-Maximum Sustainable Yield (CMSY) and the Bayesian Surplus Production (BSM) Models in the Southern Waters of Iran (Persian Gulf and Oman Sea)

Scomberomorus guttatus (Bloch and Schneider, 1801) is one of the most important commercial fish of the Scombridae in the southern waters of Iran, which plays an important role in the human diet. The catch of this species has increased in recent years, and due to the limited data available on its stock in southern waters, it is not possible to use models based on complementary data to assess its stock. In the present study, the catch-maximum sustainable yield (CMSY) and the Bayesian surplus production (BSM) models were used to determine the sustainable exploitation and fisheries reference points of Scomberomorus guttatus caught in the southern waters. Data related to the last 23 years from 1997 to 2019 were collected and entered into the model to calculate fisheries reference points. According to the results, it seems that the BSM model applies the estimates with less sensitivity. The calculated value for B/BMSY by the CMSY model was estimated to be more than 1.0 and the value of F/FMSY was less than 1.0, which indicates the healthy stock status of this species in the southern waters of Iran. By applying the forecasting model, the increasing trend of fishing was predicted in 2033. If this trend continues, the value of B/BMSY will fall below 1.0 and the value of F/FMSY will increase to about 1.99. If the catch is not reduced from 2028, the stock will start to decrease in the years after 2030 and will be overfished. Based on the obtained fisheries reference points, the maximum sustainable yield (MSY) was estimated as 9,000 tons, and this amount was predicted to be 15,000 tons in 2033. In general, the estimated fisheries reference points in this study can be an effective aid in understanding the status of Scomberomorus guttatus stock in the southern waters of Iran and reveal the effects of the application of management policies on its stocks, which can ultimately develop compatible management plans for proper exploitation of its stocks in the region.