GOA Report Card - 2023

Western Gulf of Alaska 2023 Report Card (pdf)

For more information on individual Report Card indicators, please see "Report Card indicator Description and Methods" in the Appendix (p.218) and relevant sections of this Report .

  • Winter average PDO index (Dec.-Feb., 1980–2023) continued its negative trend in 2023, re- flecting cooling sea surface temperatures in the GOA.
  • Sea-surface temperatures in the summer (°C) (Jun.-Aug., 1985–2023) 2023 in the western GOA were cooler than average, but remained within 1SD of the long-term mean.
  • Copepod biomass (g m-3) was 1SD below average (1998–2023) in 2023, indicating below average foraging conditions for planktivorous predators. Total (large and small) calanoid copepods are surveyed south of Seward in May of each year. Euphausiid biomass was above average during the same time period.
  • Copepod community size (ratio of large calanoid copepods to total calanoid copepods) remained elevated in 2023, close to 1SD above average (1998–2023), indicating increased large copepods in the community, relative to small copepods. Total (large and small) calanoid copepods are surveyed south of Seward in May of each year.
  • Motile epifauna biomass (1,000 t) increased from 2021 to 2023 and is near the long term mean (1984 – 2023). The biomass of this guild is dominated by hermit crabs, brittle stars, other echinoderms, and octopus. In 2023, brittle star biomass has declined from 2021 while the biomass of hermit crabs, octopus, and other echinoderms have all increased.
  • Capelin abundance (proportion of diet by weight), as sampled by rhinoceros auklets at Middleton Island (Apr.-Aug., 1986–2023), continue to be minimalslightly increased in seabird chick diets in recent years, and remain within 1SD of the long-term mean.
  • Fish apex predator biomass (1,000 t) decreased from 2021 to 2023 and is more than one standard deviation below the long term mean. The biomass trends for apex predators are primarily driven by arrowtooth flounder, Pacific cod, Pacific halibut, and sablefish. In 2023, arrowtooth flounder, Pacific halibut, and sablefish all declined from 2021 and are below their long-term means. Pacific cod biomass increased from 2021 to 2023 but remain below their long term mean.
  • Black-legged kittiwakes reproductive success in 2023 (Jun.-Jul., 1980–2023) experienced re- productive failure (no reproduction) at the Semidi Islands, a sharp decrease from the production in 2022. This drop indicates below-average prey (sandlance and age-0 pollock) availability for these surface-feeding, piscivorous seabirds.
  • Western Gulf of Alaska Steller sea lion non-pup model predicted counts continued a slightly decreasing trend from previous years, remaining within 1SD of the long-term mean (1980–2021). These data have not been updated since 2021 due to lack of GOA surveys.

*indicates time series updated in 2023 Mean Trend  
*Pacific Decadal Oscillation (winter)
download data(.csv)
*Western GOA SST Jun-Aug
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*Western GOA Copepod Biomass
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*Western GOA Copepod Community Size
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*Western GOA Motile Epifauna Biomass
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*Western GOA Capelin in Rhinoceros Auklets Chick Diets
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*Western GOA Apex Fish Biomass
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*Western GOA Black-legged Kittiwake Reproductive Success
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Western GOA Steller Sea Lion Non-pups
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Figure 1: Western Gulf of Alaska report card indicators. For additional information on these indicators, refer to “Report Card indicator Description and Methods” in the Appendix of this Report (p.???) and relevant contributions in this Report. * Indicates time series updated with 2023 data.




Eastern Gulf of Alaska 2023 Report Card

  • Multivariate ENSO Index was negative, La Niña conditions for the third consecutive winter of 2022/2023 (Dec./Jan., 1980-2023). The North Pacific transitioned to El Niño conditions (positive ENSO index) in the summer 2023, which are predicted to persist through 2024.
  • Sea-surface temperatures (°C) in the summer of 2023 (Jun.-Aug.), were approximately average (1985–2023) in the eastern GOA.
  • Total zooplankton density (# m-3) in southeastern Alaska inside waters (May-Aug., 1988– 2023) deccreased from 1SD above long-term mean, to average, including a decrease in calanoid copepods. Euphausiid densities remained above average. This suggests below-average foraging conditions for planktivorous fish, seabirds, and mammals.
  • Copepod community size (ratio of large calanoid copepods to total calanoid copepods) increased to 1SD above average in 2023 (May-Aug., 1997–2023). The copepod community is sampled in Icy Strait (southeast Alaska Inside waters). This suggests above-average quality zooplankton prey in SEAK inside waters (but at lower biomass).
  • Motile epifauna biomass (1,000 t) has decreased from 2021 to 2023 and is below the long term mean. Eelpouts, hermit crabs, brittle stars, and other echinoderms are dominant components of this guild. Brittle stars have decreased from 2021 to 2023 and are one standard deviation below their long term mean, while eelpouts, hermit crabs, and other echinoderms have increased from 2021 to 2023.
  • Estimated total mature herring biomass (age 3+) of Sitka herring in spring 2023 remains 1 SD above average (1980–2023) continuing a 5 year trend of the largest value in the time series (since 1980). The population is declining due to the reduced abundance of the large 2016 year class. The two populations with ocean influence (Sitka Sound and Craig) were elevated while populations in southeastern AK inner waters and Prince William Sound increased but remained low.
  • Fish apex predator biomass (1,000 t) has increased 79% from 2021 to 2023 and is more than one standard deviation above their long-term mean. Apex predator biomass in the eastern GOA is primarily driven by arrowtooth flounder and Pacific halibut, both of which increased in biomass by more than 100% from 2021 to 2023. Pacific cod biomass continued to increase in 2023 from their low in 2017 and are above their long-term mean.
  • Growth rates of piscivorous rhinoceros auklet chicks (g d-1) remain 1SD below the long-term mean in 2023 (Jun.-Jul., 1995–2023), but continue a multi-year increasing trend.
  • Eastern Gulf of Alaska Steller sea lion non-pups model predicted counts continue a decreasing trend, but remain above 1SD of the long-term mean (1980–2021) through 2021. However, counts suggest that non-pup have been lower than predicted in 2019 and 2017. These data have not been updated since 2021 due to lack of GOA surveys.

  Mean Trend  
*Multivariate ENSO Index (MEI Dec-Jan))
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*Eastern GOA SST Jun-Aug
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*Zooplankton Density Icy Straight (#/m3)
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*Eastern GOA Copepod Community Size
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*Eastern GOA Motile Epifauna Biomass
download data(.csv)
*Sitka Herring Mature Biomass (tons)
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*Eastern GOA Apex Fish Biomass
download data(.csv)
*Rhiniceros Auklet Chick Growth (g/d)
download data(.csv)
Eastern GOA Steller Sea Lion Non-pups
download data(.csv)
  2019-2023 Mean   2019-2023 Trend
  1 s.d. above mean   increase by 1 s.d. over time window
  1 s.d. below mean   decrease by 1 s.d. over time window
  within 1 s.d. of mean   change <1 s.d. over time window
  fewer than 2 data points   fewer than 3 data points

Figure 2: Eastern Gulf of Alaska report card indicators. For additional information on these indicators, refer to “Report Card indicator Description and Methods” in the Appendix of this Report (p.???) and relevant contributions in this Report. * Indicates time series updated with 2023 data.