Maternally transferred dioxin-like compounds can affect the reproductive success of european eel

Reported concentrations of dioxin-like compounds accumulated in the European eel (Anguilla anguilla) were used to perform a risk assessment for eel larval survival, taking into account a modelled amplification of tissue concentrations with a factor of 1.33 during spawning migration. The calculated concentrations of dioxin-like compounds finally deposited in the eggs were compared to the internal effect concentrations for survival of early life stages of the European eel; these concentrations, by lack of experimental data, were estimated from a sensitivity distribution based on literature data by assuming that eel larvae are among the 10% most sensitive teleost fish species. Given concentrations of dioxin-like contaminants, and assuming a relatively high sensitivity it can be expected that larvae from eggs produced by eel from highly contaminated locations in Europe will experience increased mortality due to maternally transferred dioxin-like contaminants. As historical POP concentrations in eel tissue were higher this impact must have been stronger in the past. Potential effects of other compounds or effects on the migration, condition and fertility of the parental animals were not taken into account. It is important to further study the overall impact of contaminants on the reproduction success of the European eel, as this may have been underestimated until now.