The fishing season and the exploitation status of mud crab (Scylla serrata) in Asahan Sea, North Sumatera, Indonesia

Abstract

Crab is one of the resources that can be found in almost all areas in Indonesia, and its export increases every year. However, increase in its exploitation and mangrove forest damage affect crab availability. Scylla serrata is one of the crab commodities for export in Asahan sea, North Sumatera. Scientific studies are necessary to determine the fishing season and the exploitation status of crabs in the area. Therefore, this study was carried out for 3 years, i.e. in April-December 2018, February-December 2019, and March-December 2020, at one crab landing site in Asahan. The fishing season for S. serrata in this area occurred all year long, with peak seasons in April-June and September-December. The crab's carapace width (CW) was 65-175 mm, where 71.2% of which were below 120 mm. Its carapace width at first capture (CWc) increased from 103.2 mm to 112.1 mm. Its fishing mortality (F) was 1.40 per year, higher than its natural mortality (M) (0.84 per year). Therefore, its exploitation rate (E) was 0.63, indicating that the species was already overfished. Suggested measures to control the fishing activity include limiting the crab size for capture in accordance with the Regulation of the Minister of Marine Affairs and Fisheries No. 12 Year 2020 and improving the environment of mangrove habitats.