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Description:The eastern Bering Sea in 2015 was characterized by warm conditions that were first seen in 2014, and continued through the winter, during which the PDO reached the highest winter value seen in the record extending back to 1900. The extent of sea ice during winter was reduced, as was as the size of the cold pool of bottom water relative to the long term mean during the summer. While there was no acoustic survey of euphausiids during summer, rough counts of zooplankton during spring indicated that small copepods were more prevalent than either lipid-rich large copepods or euphausiids. Jellyfish remained abundant during summer, following a new peak fall biomass recorded in 2014. Survey biomass of motile epifauna has been above its long-term mean since 2010, with no trend in the past 5 years. There has been a unimodal increase in brittle stars since 1989 and for sea urchins, sea cucumbers and sand dollars since 2004-2005. Survey biomass of benthic foragers decreased substantially in 2015, which contributed to the change in their previously stable recent trend to negative. Recent declines could possibly be related to the consecutive years of springtime drift patterns that have been linked with poor recruitment of flatfish. Survey biomass of pelagic foragers has increased steadily since 2009 and is currently above its 30-year mean. While this is primarily driven by the increase in walleye pollock from its historical low in the survey in 2009, it is also a result of increases in capelin during the cold years, which have remained high during the past two warm years. Fish apex predator survey biomass is currently above its 30-year mean, although the increasing trend seen in recent years has leveled off. The increase from below average values in 2009 back towards the long term mean is driven primarily by increases in Pacific cod from low levels in the early 2000s. The multivariate seabird breeding index is below the long term mean, indicating that seabirds bred later and less successfully in 2015. This suggests that foraging conditions were not favorable for piscivorous seabirds, a hypothesis further supported by large numbers of dead, emaciated birds observed at sea. Northern fur seal pup production for St. Paul Island remained low in 2014, indicating that fewer pups were produced in 2014 than during the year of the last survey in 2012. The maximum potential area of seafloor habitat disturbed by trawl gear has remained stable since 2011.
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