Sea turtle bycatch by different types of fisheries in southern Spain
The bycatch of sea turtles by large-scale fisheries is receiving an increasing attention in recent years due to the high impact it causes on these endangered species. This issue was evaluated in southern Spanish waters that harbor an important feeding ground of loggerhead and leatherback turtles, including the endangered Eastern Atlantic loggerhead population. To quantify the impact that different fisheries represents to sea turtles, 272 fishermen answered to detailed illustrated questionnaires in all the main ports of Andalusia and Murcia (Spain) during 2014. This study has updated the knowledge of turtle bycatch in the southwestern Mediterranean revealing a widespread impact of fisheries on sea turtles. Fishermen recognized an annual catch of 2.3 turtles per boat. Considering the census of operative large-scale fishing boats in the study area (1182), more than 2840 sea turtles could be bycaught per year in that area. Most captures (96.2%) were produced during the summer. These fisherman answers suggest a severe impact of most legal fisheries (surface longline, purse seine, trawling and small-scale fisheries) on loggerhead feeding grounds in the southwestern Mediterranean. Fishermen suggested that drift fishing conducted by foreign or illegal fishermen and almadrabas are also causing a significant bycatch of turtles. Several measures such as reviewing compliance of current fishing and environmental regulations, modifying fishing techniques to reduce turtle bycatch, facilitating the rescue and handle of wound turtles and their transport to the port for recovery, and recognizing the efforts of anglers to perform a more sustainable fishing, are recommended to mitigate this impact.