Abundance and feeding of fish in the coastal zone of the Neva Estuary, eastern Gulf of Finland

Fish inhabiting coastal zone are important link between lower and higher trophic levels in its ecosystems. The aim of this study was to provide more information on the composition of coastal fish and the diet of dominant species in the Neva Estuary, one of the largest estuary of the Baltic Sea. The study showed a diverse coastal fish fauna associated with a large variety of biotopes within the estuary. We identified five freshwater fish species belonging to Cyprinidae, and high abundance of three-spined stickleback probably a consequence of high eutrophication in the coastal zone and extensive green tides of macroalgae. Diet analysis shows that zooplankton is an important food for many core fish species (bleak, three-spined stickleback and perch), whereas chironomid larvae were the main food items for benthivorous fish (roach and gudgeon), and low dependency on non-insect zoobethos.