Some observations on the feeding ecology of Norwegian spring spawning herring Clupea harengus along the coast of Norway

The feeding ecology of Norwegian spring spawning herring Clupea\nharengus was studied with samples collected from cruises in\nFebruary -March 1991, May 1992, and February and April 1993. A\nwide variety of zooplankton organisms were observed in the diet of\nherring, with crustaceans dominating except in samples from May\n1992 when larvaceans (Oikopleura sp.) dominated. Fish were\noccasionally preyed. In addition to larvaceans, copepods (Calanus\nfinmarchicus and C. hyperboreus ) and amphipods (Parathemisto\nspp.) were important food items in the diet of herring captured in\nMay 1992. Krill (Thysanoessa inermis and Meganyctiphanes\nnorvegica) were the major prey of herring from the Møre coast in\nFebruary-March 1991 and in February 1993. Plankton samples taken\nwith MOCNESS from the same area also showed krill to be\ndominant. Sixty to seventy per cent of the stomachs examined from\nthese two cruises were empty indicating low feeding activity during\nthe spawning season.