Marine megafauna catch in Thai small-scale fisheries

Small-scale fisheries are a global conservation threat to marine megafauna (marine mammals, sea turtles, and elasmobranchs). There is currently limited information about marine megafauna catch in Thailand's small-scale fisheries, which is required for effective management. This study represents the first independent catch assessment of marine megafauna in Thai small-scale fisheries. Data on catch and fisheries effort across 1 year (2016–2017) were collected from questionnaire interviews with 535 fishers in 17 provinces along the Gulf of Thailand and the Andaman Sea coasts. Catch per unit effort was calculated for marine megafauna by fishing gear types and extrapolated to estimate annual catches using Thai official fisheries statistics. The annual estimated catches were 5.66 million (95% confidence interval, CI: 4.10–7.82 million) rays, 457,864 (95% CI: 192,352–969,166) sharks, 2,400 (95% CI: 1610–3,537) sea turtles, 790 (95% CI: 519–1,167) small cetaceans, and 72 (95% CI: 19–194) dugongs in Thai small-scale fisheries. Gillnets had the highest catch per unit effort for all megafauna groups in both sea areas except for sea turtles, where pound nets had the highest catch per unit effort in the Gulf of Thailand. Further, among gillnets, crab gillnets had the highest catch per unit effort for all groups except dugongs, where ray gillnets had the highest catch per unit effort. Accounting for effort, crab gillnets and shrimp trammel nets were responsible for most of the megafauna catch, where crab gillnets contributed 72%–95% of the annual estimated marine megafauna catch. Crab gillnets and shrimp trammel nets were used by 46% and 40% respectively of the interviewed fishers and by 27% and 15% respectively of all small-scale fishers operating in Thai waters. Restrictions for gillnet fishing effort (crab gillnets specifically) are needed to prevent extirpation of threatened megafauna species that are important for ecosystem resilience and productivity.