Silver <scp>E</scp>uropean eels health in <scp>M</scp>editerranean habitats

Abstract

Abstract The degradation in the quality of silver eel and their health could have been a major factor in the collapse of the E uropean eel ( A nguilla anguilla ) population. However, the health status of the spawners has been poorly studied until now. This study evaluated the quality of migrant male silver eels from four M editerranean habitats in F rance presenting different degrees of contamination: C anet‐ S aint‐ N azaire, S alses‐ L eucate and B ages‐ S igean lagoons and L a B erre R iver. We considered pathogens including A nguillicoloides crassus and EVEX virus and the concentration of chemical contaminants including PCB s, OC s and heavy metals. Our study results revealed different patterns of pollution and infection in the four habitats, with high individual variability. No single silver eel was free of pollution. Total dichloro‐diphenyl‐trichloroethane ( DDT ) and copper contaminations, as well as the S wim bladder D egenerative I ndex (induced by parasitism), were remarkably high in eels from C anet lagoon, while eels from S alses lagoon showed lower levels of contaminants and parasite infection. A non‐negligible proportion of eels were strongly impacted with levels of contaminants/parasites that could potentially impair their migration and reproduction. Our study revealed low to moderate contamination levels compared with the other M editerranean sites previously reported, except for high concentrations of DDT s and C u in C anet lagoon. We discuss the contribution of these results in the context of possible implications for silver eels reproductive success and local eel population management.