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Based on two large-scale surveys in the Norwegian Sea in July 2004 and 2006 we investigated the potential overlap in distribution and diets and association with environmental variables for mackerel, herring and blue whiting. Mackerel and blue whiting had low overlap in both distribution and diets, and were associated with warm Atlantic and cold prey-rich Arctic waters, respectively. Also, herring and mackerel were negatively correlated, associated with different environmental variables and even had low diet overlap in Atlantic water where the highest overlap in distribution was observed, but these trends were much clearer in 2006 than in 2004. Prey was patchily distributed and data from single stations indicated that feeding was opportunistic, in particular for mackerel. However, mackerel diet width and feeding incidence were similar between the years, whereas herring was more selective in 2004, probably reaching the end of the feeding season. A delayed peak in Calanus availability was indicated in 2006 and may have prolonged the feeding season, partly explain the difference between the years. Our data did not indicate a prey shift due to encounters between mackerel and herring. Concentrated efforts in limited areas are needed to further elucidate this aspect of interaction.

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Impacts of climate change on ocean productivity sustaining world fisheries are predominantly negative but vary greatly among regions. We assessed how 39 fisheries resources-ranging from data-poor to data-rich stocks-in the North East Atlantic are most likely affected under the intermediate climate emission scenario RCP4.5 towards 2050. This region is one of the most productive waters in the world but subjected to pronounced climate change, especially in the northernmost part. In this climate impact assessment, we applied a hybrid solution combining expert opinions (scorings)-supported by an extensive literature review-with mechanistic approaches, considering stocks in three different large marine ecosystems, the North, Norwegian and Barents Seas. This approach enabled calculation of the directional effect as a function of climate exposure and sensitivity attributes (life-history schedules), focusing on local stocks (conspecifics) across latitudes rather than the species in general. The resulting synopsis (50-82°N) contributes substantially to global assessments of major fisheries (FAO, The State of World Fisheries and Aquaculture, 2020), complementing related studies off northeast United States (35-45°N) (Hare et al.,