Prey Consumption By Grey Seals in the Baltic Sea

The number of grey seals (Halichoerus grypus) in the Baltic Sea has increased considerably during the last decades, intensifying the conflicts between seals and fisheries. We estimated the magnitude in prey consumption by Baltic grey seals using data on bioenergetics population size, diet and prey energy contents. The prey consumption by seals was compared to fishery landings to evaluate potential resource competition between seals and fisheries. Locally the fish consumption by seals was similar to, or exceeded, fish catches. Indications of potential competition between grey seals and fisheries were found for cod, common whitefish, salmon, flatfish and eel. Considering the large amounts of fish consumed by seals in this study and the growing seal population, it is obvious that the fish consumption by grey seals in the Baltic Sea cannot be neglected. Results from the mid 2000s will be compared to more current estimates of seal consumption and fishery catches.