First evidence of trace metals and persistent organic contaminants from an endangered marine species, Mobula mobular (Bonattere, 1788) caught in Hellenic waters (Saronikos Gulf)

The number of cartilaginous fish is declining worldwide and contaminants are one of the primary stress factors in marine organisms. The spinetail devil ray or giant devil ray (Mobula mobular) is listed as an 'Endangered species' globally in the IUCN Red List of Threatened Species. One individual devil ray caught in Saronikos Gulf was tested for trace metals (Zn, Cu, Fe, Mn, Ni, Cr, Pb and Hg) and organochlorine contaminants (PCBs and DDTs). The concentrations of contaminants in the muscle tissue of the devil ray did not exceed safe human consumption limits. However, relatively elevated levels of trace metals and PCBs were measured in the liver and in particular the PCB congeners were five times higher than the European Commission limit. This study highlights the need for future research on the potential impacts of trace metals and organic contaminants on elasmobranchs and more specifically on threatened species.