Advances in the development of non-lethal biomarkers for ecotoxicological study of the Mediterranean logger-head turtle (Caretta caretta)

The loggerhead turtle (Caretta caretta) is a long living species on the red list of threatened species. The Mediterranean population of C. caretta, living in a polluted land-locked basin, may be particularly threatened by pollution, hence the need for ecotoxicological studies using non lethal techniques. Our recent studies aimed to develop an ecotoxicological protocol based on non destructive biomarkers to investigate the health status of this species. In a first study 53 live stranded and/or hospitalized specimens were sampled from four sites along the Italian coasts. Blood was analyzed for vitellogenin, AChE and BChE activity, 17-(beta)-estradiol levels and several blood chemistry parameters (gamma-GT, AST, ALT). Excreta samples were analyzed to evaluate porphyrin concentrations. Biomarker responses showed considerable differences between the various specimens analyzed, both in relation to sex and maturity and to area of collection. In a second study 15 specimens of C. caretta were sampled for blood and/or excreta and skin biopsy from the recovery center on Linosa island (Sicily). The aim of this step was to develop and validate new biomarkers using skin biopsy and blood lymphocytes. Presence of CYP1A was measured by western blot and ELISA. Real-time PCR was also performed to detect gene expression. The results obtained represent a step forward in the development of a non lethal protocol for ecotoxicological study of C. caretta.