Fisheries interaction lesions on sea turtles: WWF Lampedusa sea turtle rescue center case history since 2003 to 2010.

In the Lampedusa Rescue Centre, each year a great number of animals accidently captured by longline, trawl-net and drift-net engines or found suffering adrift, are rescued. The purpose of this work was to analyze clinical data and surgically treatable lesions for the period ranging from January 2003 to December 2010. For each subject the following was considered to verify the real interactions’s degree: localization, kind and seriousness of lesions, capture method, fishing gear used. For each animal a health examination was drawn up in a clinic folder within general health condition, clinical and diagnostic procedures, type and location of the lesions, and therapeutic treatment used. Biometrical data, rescue modality, general health condition, lesions, mark of fisheries interaction and duration of hospitalization were related. The presence of external lesions was examined, an x-ray exam put into evidence the presence and the number and localization of hooks. From January 2003 and December 2010, 1496 turtles were rescued. 877 subjects were captured by trawl net, evidence of a good collaboration with this fishery. 294 were catch accidentally with longline, 310 subjects were found suffering adrift and manually rescued, the remain group stranded. Our study shows as turtles with hooks fixture in the upper digestive tract (mouth and oesophagus) were mostly captured by longline and assisted directly by fishermen, while turtles with hooks in the lower digestive tract (stomach and intestine) were mostly found in trouble adrift and manually rescued, evidence of a past interaction with longline. This data confirm that very often, in case of accidentally capture by longline, turtles are released into the sea, just cutting the line. In this way the hook progress deeper, and line, when swallowed, causes foreign body injuries. The number of external injuries attributable to trawl net appears small compared with the great number of animals caught with this fishery system and conferred to the centre. Few days after interaction with longline, surgery on turtles is almost always decisive. Otherwise, when animals are rescued highly weaken after a long period from interaction, surgery becomes complex. The importance of timely action is further confirmed by the different location of hooks and lines in relation to the time from ingestion. In the subjects accidentally caught by longline, hooks are mainly present in mouth or in oesophagus and lines come out from mouth. In turtles manually rescued hooks are generally located in the lower digestive tract and lines cross all intestinal canal, coming sometime out of cloaca. In conclusion, longline and trawl net are both a dramatic menace for sea turtle conservation: damages caused by trawling do not allow many opportunities for treatments, but damages caused by longline can be largely resolved only with a well-timed action.