Eastern Bering Sea 2022 Report Card (pdf)
For more information on individual Report Card indicators, please see `Description of the Report
Card indicators' (p. 224). For more information on the methods for plotting the Report Card
indicators, please see `Methods Description for the Report Card Indicators' (p. 227).
* indicates Report Card information updated with 2022 data.
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* The mean sea-ice extent across the Bering Sea (ice year is defined as 1 August to 31 July; western and eastern) exhibited no long-term trend (1980-2022), although a steep decline in ice extent was observed from 2012 (highest extent on record) to 2018 (lowest extent on record). Sea-ice extent increased from 2018 to present, with the 2021-2022 daily mean extent of 287,315 km2 being at the long-term mean. Seasonal sea-ice extent has implications, for example, to the cold pool, spring bloom strength and timing, and bottom-up productivity.
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* The areal extent of the cold pool in the eastern Bering Sea (EBS), as measured during the bottom trawl survey (Jun-Aug; including strata 82 and 90; 1982-2022), has increased since 2018. The 2022 extent (178,625 km2) was near the time series average (181,018 km2). The cold pool extent in 2022 represents a major change from the three prior survey years (2018, 2019, 2021).
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* An acoustic estimate of euphausiid density was below average in 2022 (2004-2022), but remained greater than the lowest point in the time series that occurred in 2016.
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* The biomass of pelagic forage fish (i.e., age-0 pollock, age-0 Pacific cod, herring, capelin, and all species of juvenile salmonids) sampled by surface trawl in late-summer (Aug-Sep; 2003-2022) peaked in 2004 and 2005, was below the time series average from 2006-2012, was above average in 2014, 2016, and 2018, but dropped to just below the long-term mean in 2022. The trends are dominated by age-0 pollock and juvenile sockeye salmon, largely by age-0 pollock in surface waters during warm years. The biomass in 2022 was largely driven by higher juvenile sockeye salmon and lower age-0 pollock.
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* The biomass of motile epifauna measured during the standard EBS bottom trawl survey (Jun-Aug; 1982-2022) peaked in 2017 and remained above their long-term mean in 2022. Trends in motile epifauna biomass indicate benthic productivity, although individual species and/or taxa may reflect varying time scales of productivity. Collectively, brittle stars, sea stars, and other echinoderms account for more than 50% of the biomass in this guild and the current (2016-2022) mean biomass indices for all three of these functional groups are well above their long-term means. The current mean biomass indices for king crabs, tanner crab, and snow crab are all below their long-term means.
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* The biomass of benthic foragers measured during the standard EBS bottom trawl survey (Jun-Aug; 1982-2022) increased 18% from 2021 to 2022, but remained below the time series mean. Trends in benthic forager biomass are variable over the time series and indirectly indicate availability of infauna (i.e., prey of these species). There were increases in biomass for the four most dominant species in this guild - yellowfin sole, northern rock sole, flathead sole, and Alaska plaice - though all but flathead sole remain below their long-term mean (1982-2022).
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* The biomass of pelagic foragers measured during the standard EBS bottom trawl survey (Jun- Aug; 1982-2022) increased sharply from 2021 to 2022, up more than 70%. The biomass of the pelagic forager guild was generally stable from 2016 to 2019, but dropped to its second lowest value over the time series (1982-2022) in 2021. The trend in the pelagic forager guild is largely driven by walleye pollock which, on average, account for more than 67% of the biomass in this guild. In 2022, the survey index for pollock increased 50% from 2021. Among species of secondary importance, Pacific herring were up more than 200% from 2021, well above their long-term mean.
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* The biomass of apex predators measured during the standard EBS bottom trawl survey (Jun-Aug; 1982-2022) in 2022 was up from 2021 and nearly equal to their long-term mean. Trends in apex predator biomass reflect relative predation pressure on zooplankton and juvenile fishes. The trend in the apex predator guild is largely driven by Pacific cod and Arrowtooth flounder, both of which have increased from 2021.
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* The multivariate seabird breeding index indicated that, on the whole, seabirds bred earlier and had better reproductive success in 2022 compared to years with very poor success from 2016-2018. Comparisons with the most recent two years are not possible because colonies were not monitored due to the COVID-19 pandemic. Reproductive success and/or early breeding are assumed to be mediated through food supply, therefore above-average values indicate better than average recruitment of year classes that seabirds feed on (e.g., age-0 pollock), or better than average supply of forage fish that commercially fished species feed on (e.g., capelin eaten by both seabirds and Pacific cod).
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Northern fur seal pup production at St. Paul Island in 2021 continued a declining trend since 1998 that may be partially attributed to low pup growth rates.
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