Seasonal development of plankton in the Barents Sea: A conceptual model

Capelin (Mallotus villosus) is a small salmonid fish that forms the basis of one of the most important fisheries in the Barents Sea. Relatively large variations in growth of capelin prompted ecological investigations on the feeding conditions of capelin and these were initiated by the Institute of Marine Research in 1979. The studies were expanded in 1984 with the start of the Norwegian Research Program for Marine Arctic Ecology (PRO MARE). A conceptual model for the seasonal development of plankton has provided a framework for our studies in the Barents Sea. The model emphasizes the importance of the ice edge spring phytoplankton bloom for the spawning and development of zooplankton and for the northwards seasonal feeding migration of capelin. The model is reviewed in light of field observations and some remaining key questions for our further studies are pointed out. While the main elements of the model have in broad terms been verified, it will in the future be necessary to put more emphasis on large scale processes such as transport of plankton by dominant currents and the ecological feedback interactions such as predation by capelin and grazing by zooplankton