Developmental disorders in larvae of eelpout (Zoarces viviparus) from German and Swedish Baltic coastal waters

Pregnant eelpout were collected for several years at German and Swedish Baltic coastal stations with different impact of pollutants and the prevalence of fry abnormalities compared between sites. Mortality of apparently normal developed larvae was observed with high variability in both German and Swedish sites. Malformation of larvae was a prominent disorder at all German stations with a prevalence ranging from about 50% up to a maximum of 90% in almost all analysed samples. At the Swedish stations malformation rates were significantly lower (range: 0–6%). Growth retardation of fry was clearly more prominent in eelpout from German coastal waters as well. Taken together the field data suggests that impaired larval development was associated with the state of environmental pollution at the sampling locations.