Effects of Contaminants on the Reproductive Success of American Eels

Environmental contaminants, such as polychlorinated biphenyls (PCBs) may be a factor contributing to the population decline of the American eel, Anguilla rostrata.  Due to their catadromous life cycle mature adults are not accessible for study and little is known about the effects of PCBs on fertilization and larval development.  A. rostrata males and females were artificially matured by weekly injections of hormones.  Males were co-injected with either a low or a high concentration of PCBs.  Sperm from different males were used in separate fertilizations using oocytes from one female.  Fertilization success and embryogenesis were assessed 2-4 hours post fertilization (PF), 24 hours PF, and 48 hours PF and survival effects were determined 6 days after hatching.  These data will be analyzed for differences between treatment groups.  Also, in order to determine the possible maternal transfer of contaminants, egg and muscle samples were collected from the females and will be analyzed for contaminant loads.  Our results will shed light on whether environmental contaminants are contributing to the decline of A. rostrata.  These findings will be of value for future conservation efforts and the management of the American eel, an ecologically important species.