Observations of gadoid feeding by large baleen whales in the Norwegian Sea

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In this study, systematic transect observations of cetaceans were collected in the Norwegian Sea between the 4th and 28th of July 2013. Coherent multi-frequency acoustic recordings and systematic net and trawl station data were collected for analyses of potential relationships between cetacean distribution and the most abundant plankton and fish species. Preliminary results show that killer whales were allocated to the central and northern part of the Norwegian Sea associated with small and loose shoals of adult northeast Atlantic mackerel. Fin whale sightings were made in the northeastern part of the Norwegian Sea and along the coast of Finnmark. White beaked dolphins overlapped with the areas of the fin whale sightings. Humpback whale sightings were made south of Bear Island and also in the northernmost part of the Norwegian Sea. The fin whale, white beaked dolphin and humpback whale observations were associated with high and dense concentrations of juvenile cod and haddock appearing in the upper 50 m of the water column, clearly indicating foraging activity. Fin- and humpback whales are normally associated with krill, amphipods and pelagic fish in this area; this is the first time such significant overlap between large baleen whales and juvenile gadoids has been documented