Maximum Sustainable Yield Assessment for Pelagic Fish in the Andaman Sea Thailand

Thailand is located in a tropical sea and is the habitat of multiple fish species. Thailand therefore classifies aquatic animals into 3 groups: demersal fish, pelagic fish, and anchovies for the convenience of management. Maximum sustainable yield (MSY) assessments are conducted annually for three groups of fish. Fox surplus production model was used to estimate the MSY of the aquatic species group. Among pelagic fish, the important economic fish are mackerel, sardines, and scads. The MSY of pelagic fish group in Andaman Sea was 118,042 tons at the fishing effort (F_msy) of 64,524 days. While, the catch in 2022 was 114,231 tons with the fishing effort of 49,264 days. Results showed that pelagic fishing is currently being conducted at fishing effort levels consistent with Fmsy. For monitoring a status of some species of pelagic fish that by using length-based Tomson and bells model. Three species were selected to estimate: short mackerel (Rastrelliger brachysoma), Indian mackerel (R. kanagurta) and goldstripe sardinella (Sardinella gibbose) using length-frequency data in 2022. The results showed F-factor values of 3.2, 3.2, and 0.4 respectively indicating that the current fishing effort of short mackerel and Indian mackerel were lower than their fishing effort level which could produce MSY (Fmsy) while the current fishing effort of goldstripe sardinella was over its Fmsy level.