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Climate change impacts are pronounced at high latitudes, where warming, reduced sea-ice-cover, and ocean acidification affect marine ecosystems. We review climate change impacts on two major gateways into the Arctic: the Bering and Chukchi seas in the Pacific and the Barents Sea and Fram Strait in the Atlantic. We present scenarios of how changes in the physical environment and prey resources may affect commercial fish populations and fisheries in these high-latitude systems to help managers and stakeholders think about possible futures. Predicted impacts include shifts in the spatial distribution of boreal species, a shift from larger, lipid-rich zooplankton to smaller, less nutritious prey, with detrimental effects on fishes that depend on high-lipid prey for overwinter survival, shifts from benthic- to pelagic-dominated food webs with implications for upper trophic levels, and reduced survival of commercially important shellfish in waters that are increasingly acidic. Predicted changes are expected to result in disruptions to existing fisheries, the emergence of new fisheries, new challenges for managing transboundary stocks, and possible conflicts among resource users. Some impacts may be irreversible, more severe, or occur more frequently under anthropogenic climate change than impacts associated with natural variability, posing additional management challenges.

Motivated by recent evidence of Atlantic bluefin tuna spawning in the Slope Sea, we investigated the spatio-temporal distribution of oceanographic conditions that are conducive to successful spawning by bluefin in this region. Specifically, we considered advection patterns and water temperatures based on a new high-resolution ocean circulation model. After validating model velocities and temperatures using observations, three criteria were used to evaluate the success of simulated bluefin spawning during 2013: water temperature at spawning locations, mean water temperature along larval trajectories, and larval residence time within the Slope Sea. Analyses of satellite-based, decade-long (2008–2017) datasets suggest that conditions, specifically water temperatures and advection patterns, in the Slope Sea in 2013 were representative of typical years. The temperature criteria are more frequently satisfied in the southern and southwestern parts of the domain, whereas the residence time criterion favors more northern areas further from the Gulf Stream. The probability map of successful spawning locations shows a maximum near the northwestern bight of the Slope Sea. Spawning success is near-zero through most of June, increases in July, and peaks in early-to-mid August. Overall, water temperatures and retentive capabilities suggest that the Slope Sea provided suitable conditions for successful spawning of bluefin during 2013.