Fishermen Interviews: A Cost-Effective Tool for Evaluating the Impact of Fisheries on Vulnerable Sea Turtles in Tunisia and Identifying Levers of Mitigation

SIMPLE SUMMARY: Fisheries represent one of the main threats to sea turtles in the Mediterranean Sea, but the level of interaction of sea turtles with fisheries remains poorly assessed. Using interviews with fishermen as its basis, this article assesses the interaction of sea turtles with fisheries in Tunisia. The interview results allowed the calculation of the bycatch per unit effort (BPUE) for the most common fishing gear used in Tunisia, and they showed that ray nets, trawls, and pelagic longlines represent the greatest threat. This confirms the value of the interview approach when assessing the impact of fishing gear on sea turtles. In addition, the analysis of the bycatch risk factors based on the interview data provides a critical early step towards a reduction in the fisheries’ impact on sea turtles in Tunisia. ABSTRACT: Fisheries bycatch is considered one of the main threats to sea turtles. To provide an updated assessment of the bycatch impact on loggerhead turtles in Tunisia, 483 interviews were conducted with fishermen in 19 ports along the Gulfs of Gabes and Hammamet. The interview questions included data on vessel and fishing gear characteristics, monthly fishing effort, and monthly sea turtle bycatch of the last year. Results revealed that sea turtle bycatch per unit effort (BPUE) was the highest for ray nets (0.73 turtles/vessel/day, 95% CI [0.02–1.15]), followed by pelagic longlines (0.6 turtles/vessel/day, 95% CI [0–4.23]) and shark nets (0.4 turtles/vessel/day, 95% CI [0–2.12]). However, due to the trawlers’ high fishing effort, the cumulative impact of the trawl nets was the highest with an estimated number of 11,740 (95% CI [0–41,525.75]) turtles caught per year in Tunisia. Factors influencing the bycatch risk were gear characteristics (mesh size for nets, hook size for longlines, vertical opening for trawls), as well as season and location of operations. These factors will guide the research of mitigation solutions. The interviews with fishermen proved to be a cost-effective approach for the rapid assessment of sea turtle interactions with fisheries in the context of Tunisia.