Sea turtle bycatch patterns in small-scale fisheries of the East China Sea and South China Sea

Knowledge regarding sea turtle bycatch in Chinese small-scale fisheries remains limited despite the country's massive fishing fleet and the overlap between fishing grounds and sea turtle migratory routes. This study compares regional sea turtle bycatch patterns in Zhejiang (East China Sea, ECS) and Hainan Island (South China Sea, SCS), using semi-structured interviews with 281 fishers to assess reported frequency, gear use, and species and size composition. Results indicate that 85.4% of respondents have encountered sea turtles, though SCS fishers reported lower bycatch frequencies than those in the ECS (46.3% “never” vs. 10.6%). ECS fishers showed a notably lower ability to identify species (33.9%) compared to SCS fishers (6.7%). While green and loggerhead turtles were commonly reported in both regions, green and hawksbill turtles were significantly more likely to be reported in the SCS. A regional life stage difference was observed: ECS reports mainly involved adults, whereas SCS fishers more often reported subadults and juveniles. Gear type is the primary predictor of bycatch reporting, with stow and trawl nets showing the strongest associations across both regions. Co-reporting patterns identified loggerheads in trawl nets and olive ridleys in stow nets, while greens and hawksbills were frequently associated with gillnets. This regional comparison of sea turtle bycatch in Chinese small-scale fisheries reveals spatially structured threats and provides an evidence base for developing locally adapted, gear-specific conservation measures in data-poor fisheries across China and East Asia.