Stock Assessment and Determination of the Maximum Sustainable Yield (MSY) of Engraulidae in Qeshm Island, Persian Gulf

Clupeidae particularly Engraulidae is one of the most valuable supplies in the Persian Gulf, which plays an important role in the ecological and nutritional chain. The present study was done during from October 2015 to September 2016 with the aim of determining the amount of reserves of anchovies and adjusting its sustainable harvest pattern in Qeshm Island. Sampling was carried out in the southern shores of Qeshm Island in the fishing ports of Raش0165 Qeshm Island from October machah, Suza, Mesen and Salakh. In this research, 2553 fish samples were weighted. The caught fish were in the fork length range of 4.22-8.79 cm, with a mean fork length of 6.42 cm and an average weight of 2.2 g. The maximum weight of the fish caught was 6.36 g and the lowest total weight was 0.56 g. In the study of the frequency of fish in the 5 cm classes, the highest frequency was found in the range of 5.7-6 cm with 36.5%. The fish were in the range of 0 to 3 years old with an average age of 1.76 years. In terms of age composition, most of the fish were two years old with 68.78%. The maximum fork  length was 11.3 cm and the value of K was determined by using the Shepherd method of 0.52 × time -1 and the value of t0 was -0.88 years. Also, their natural (M), fishing (F) and total (Z) mortality rates were 1.2, 0.94 and 2.14 respectively, and the exploitation was equal to 0.44. Based on the Thompson-Bell equation, the maximum fishing mortality (Fmax) was 1.9, the maximum sustainable yield was about 38,000 kg and the total biomass was 89400 kg, while the amount of fishing carried out during the fishing period is equivalent to 35.400 kg, indicating an increase of 10% in catches. However, at present, the supply of anchovies is relatively good. Due to the importance and special position of anchovies in the Persian Gulf ecological chain, especially Qeshm Island, it is recommended that catching should not exceed more than 40,000 kg.