Assessing Loggerhead Turtle Exposure to Fisheries in Northwest Africa: Predicted Risk and Management Gaps

Bycatch is the accidental capture of non-target animals in fishing gear, and is a critical threat to many wildlife populations, impeding recovery and conservation efforts. Northwest Africa hosts a significant population of loggerhead turtles (Caretta caretta), particularly around Cabo Verde, which is among the world's top three largest loggerhead turtle nesting colonies. However, high-risk areas for turtle bycatch have not yet been comprehensively investigated. This study addressed this by analysing biologging data from loggerhead turtles (n = 26), quantifying their spatial and vertical overlap with fishing in the Northeast Atlantic. Results revealed extensive overlap of loggerhead turtles with fishing across seven countries, with particularly intense overlap in Cabo Verde, Senegal and Mauritania. Turtles also generally occupied the same depths as fishing gear, intensifying bycatch risk. Among fishing methods, trawling showed the greatest overlap with loggerhead turtles, and current protections appear to align poorly with our predictions of bycatch risk. Coupled with increasing fishing pressure, these findings highlight the need for strengthened conservation measures. These include gear modifications such as turtle excluder devices, as well as time and space-based fisheries management strategies. Going forward, improved bycatch reporting and monitoring across all fisheries sectors will be essential to expand upon these findings.