Diet composition of smelt Osmerus eperlanus (Linnaeus) in brackish near-shore ecosystem (Eru Bay, Baltic Sea)

摘要

We present new data on seasonal diet composition of subadult and adult smelt Osmerus eperlanus in near-shore areas of the eastern Baltic Sea (Gulf of Finland). These findings elucidate the food web structure and the ecological role of smelt in the shallow littoral zone. The seasonal diet composition and feeding activity of adult and subadult smelt in the coastal area of the Gulf of Finland were studied by examining the stomach contents of 1397 individuals collected from April to December 2009. Amphipods and mysids were the most common prey. Piscivorous feeding was also very important, particularly in larger smelt during August-October. Seven fish species were recorded in the stomach contents; gobies and sticklebacks dominated. Smelt preyed also on isopods, cladocerans, decapods, molluscs, insects, insect larvae as well as polychaete annelids. Prey composition varied monthly and depended on smelt size. The higher proportion of empty stomachs was observed during June, September and October.