Fishing hook lesions incidentally recorded in loggerhead sea turtles (caretta caretta) bycatched in bottom trawling.

During the period October 2010 - October 2011 the WWF Rescue Centre of Molfetta (Italy) referred 134 loggerhead sea turtles (Caretta caretta) to the Faculty of Veterinary Medicine of Bari (Italy) for clinical evaluation following to bycatch in bottom trawling in Manfredonia Gulf (Southern Adriatic Sea, Italy). After biometric assessment, all the turtles underwent clinical evaluation and radiographic examination to check for lesions ascribable to the capture (carapace and plastron trauma, skull or limb fractures, pneumonia subsequent to forced submergence and drowning). Dorsoventral, lateral and craniocaudal (horizontal beams) projections of head, total body and limbs were performed. In 8 turtles (6%) the presence of fish hooks in upper gastrointestinal tract was assessed: 3 animals presented an evident fishing line, while the presence of the hooks resulted accidentally at the x-ray examination without apparent clinical abnormalities in the other subjects. 4 hooks were localized in the intracoelomatic tract of the esophagus, in correspondence of tracheal bifurcation, and the other ones in cervical esophagus. In one case the hook was manually removed after sedation, while the others required surgical procedures. The hooks located in upper esophageal tract were removed after cervical esophagotomy, while the removal of the ones positioned deeper in non papillated esophagus was achieved after a transversal supraplastron surgical approach to access the coelomic portion of the esophagus. During surgery, one of the turtles, presented in critical conditions, revealed a long fishing line attached to the hook, so a right prefemoral approach to coelomic cavity was performed in order to remove it from intestinal lumen with multiple enterotomies on the exteriorized small intestine. In 3 turtles the hook had pierced the esophageal wall and were located extra-lumen, giving rise to large inflammatory responses with granulomatous abscessations, which caused the displacement of trachea and the partial obstruction of esophageal lumen. Nonetheless, surgery proved solving, and adequate post-surgical management (with 2 to 5 weeks of hospitalization) allowed the total recovery and the release of the turtles. Data from this study show that the major risks of longline fishing bycatch are not only the presence of tracts of lines in the gastrointestinal tube, as reported by numerous Authors, but also the hook itself, as it can give rise to foreign body granulomatous reactions that can occlude the gastrointestinal tract, and impair the feeding capacity of the turtles.