Investigation of Stock Status of Hilsa shad (Tenualosa ilisha Hamilton, 1822) in the Southern Waters of Iran

Hilsa shad (Tenualosa ilisha Hamilton, 1822) is a migratory fish and as one of the most important species in the southern parts of Iran, so that during the last decade, the amount of its catch has fluctuated a lot. Due to the limited data available on the stock of this species in southern waters, it is not possible to use models based on complementary data to assess its stock. In the present study, to determine the stock status of Hilsa shad in southern waters, the catch-maximum sustainable yield (CMSY) model was used. Catch data from1997 to 2019 were collected and entered into the model to calculate fisheries reference points. The value for B/BMSY by the model was estimated to be less than 1.0 and the value of F/FMSY was more than 1.0, which indicates the critical situation of this species in the southern waters of Iran and that the stock is under fishing pressure. Based on the obtained fisheries reference points, the MSY was estimated as 4,360 Mt which due to high fishing pressure and depletion of stock that has occurred during these years, in the years after 2012, has never reached to this amount of catch and, the amount of catch has been less than the MSY. Considering that more than 92 percent of the catch of this species is done in the waters of Khuzestan province, so the management strategies for applying restrictions in the fishing effort and fishing licenses for traditional fishing vessels should be mainly concentrated in this area and it is recommended to stop fishing of this species so that the stock could find the opportunity to rebuild.