Executive Summary of Recent Trends in the Gulf of Alaska (pdf)
This section summarizes highlights of those indicators that show noteworthy status or trends. The links are organized within three sections: Physical and Environmental Trends, Ecosystem Trends, and Fishing and Human Dimensions Trends.
Physical and Environmental Trends
• Fall 2018 through summer 2019 included a range of atmospheric circulation patterns and generally warmer than normal temperatures for the North Pacific (p. 35).
• The climate models used for seasonal weather predictions are forecasting ENSO-neutral conditions for the winter of 2019-2020, and warmer than normal SSTs through early 2020 (p. 41).
Gulf of Alaska
• Sea level pressure patterns over the Gulf of Alaska resulted in suppressed storminess and contributed to the development of very warm sea surface temperatures (p. 36).
• The western Gulf of Alaska shelf area has largely remained in heatwave conditions since September 2018 (p. 27).
• Satellite-derived sea surface temperatures confirmed that the moderate temperatures of 2017-2018 ended during fall 2018 and that both the western and eastern Gulf of Alaska have been warm since(p. 48).
• The thermal profile suggests that water temperatures in 2019 may have been as warm or warmer than those observed in 2015 and 2017, particularly near the surface in the western Gulf of Alaska (p. 49).
• Bottom temperatures recorded during the summer larval fish surveys were higher in summer of 2019 relative to 2015 (p. 55).
• Ocean temperatures along the Seward Line were well above normal during May 2019, with increased stratification (p. 59).
• After returning to near-average temperatures in late 2017-early 2018, temperatures in Prince William Sound during 2019 again shifted towards strongly above average, with magnitudes exceeding those observed during the 2014-2016 heat wave (p. 62).
• Chlorophyll concentrations during 2019 in the GOA saw a late bloom overall, with low early season biomass, which could possibly affect some larval fish populations depending on their spawn timing and location (p. 73).
• In the Alaskan Shelf region sampled by the continuous plankton recorder, zooplankton biomass anomalies were negative, ending the run of positive values that had occurred from 2014-2017 (p. 74).
• Acoustic estimates of euphausiid biomass in 2019 increased slightly from the previous low estimate in 2017 (p. 81).
• Along the Seward Line, large calanoid copepod biomass in May 2019 was substantially lower than it was in 2015-2018. Euphausiid biomass during May 2019 was also below average, while biomass during September 2019 was among the highest in the time series (p. 83).
• In Icy Strait, the 2019 total density and lipid content of zooplankton were below 2018 values (p.88 and 91).
• The 2019 relative catch per unit effort of jellyfish during the NOAA bottom trawl surveys was the highest ever observed during the survey time series (p. 92).
• Over the years, small numbers of market squid have been sporadically observed at Little Port Walter in Southeast Alaska. Sizable schools and spawning events occurred for the first time in 2015 and were observed again in 2016, 2018, and 2019 (p. 31).
• In 2019, the abundance of all assessed larval fishes within the main grid area of the spring larval survey was below average and low relative to 2017 (p. 97).
• Catches of age-0 pollock during late summer surface trawl surveys were second lowest on record, with the majority of fish found in Shelikof Strait and near the Semidis. No age-0 pollock were found at the majority of stations to the south and east of Kodiak as well as near the Shumagin Islands in the southwest (p. 102).
• In nearshore waters of Icy Strait in northern southeast Alaska during 2019, juvenile and adult salmon catch rates were among the lowest since the survey began in 1997 (p. 117).
• In 2019, groundfish condition sampled during the NOAA bottom trawl survey was below the time- series average for all species except Pacific cod. Northern and dusky rockfish had the lowest condition on record, and for Pacific Ocean perch was the second lowest on record (p. 126).
• Diving, fish-eating seabirds in the Gulf of Alaska had generally high reproductive success (and some highest on record) at monitored colonies in 2019, the exception was poor productivity for murres at East Amatuli (Barren Islands). Kittiwakes experienced complete breeding failure at Chowiet (Semedi Islands) but had a normal year at East Amatuli (Barren Islands). Storm-petrels had poor breeding success at East Amatuli but had higher than average breeding success at St. Lazaria (southeast Alaska)(p. 139).
• An unusual mortality event was declared for gray whales in May 2019. Between January 1-October 30, there were 48 strandings in Alaska and 213 total along the west coast between Mexico and Alaska (p. 30).
• Humpback whale calving and juvenile return rates in Glacier Bay and Icy Strait declined substantially beginning in 2015. Crude birth rates have remained anomalously low from 2016-2019 (p. 144).
• During September of 2019 in Prince William Sound more humpback whales were observed than in 2017 and 2018; however they remain well below 2008-2014 numbers. Unlike 2017 and 2018, no whales in poor body condition were observed (p. 143).
Fishing and Human Dimensions
• Trends Since 1993 discard rates of groundfish species in federally-managed Alaskan groundfish fisheries have generally declined in both pollock and non-pollock trawl fisheries in the Gulf of Alaska. Discard biomass in the fixed gear (hook-and-line and pot) sector has generally declined from 2013 onward, though discard rates increased sharply in 2018 to 18% after remaining around 10% from 2013 to 2017 (p. 156).
• In 2017-2018, non-target catch of scyphozoan jellyfish, structural epifauna, and assorted invertebrates declined from those in 2015-2016 in trawl fisheries in the Gulf of Alaska (p. 160).
• Stock composition of Chinook salmon bycatch in Gulf of Alaska trawl fisheries was relatively stable from 2010-2017, with British Columbia stocks dominating the bycatch, and West Coast U.S. stocks either similar to British Columbia stocks, or less, in most years (p. 162).
• The numbers of seabirds estimated to be caught incidentally in Gulf of Alaska fisheries in 2018 increased from that in 2017 by 19%, and was above the 2007-2017 average of 655 birds, primarily due to increases in black-footed albatross, northern fulmar, and gulls (p. 164).
• No Gulf of Alaska groundfish stock or stock complex were subjected to overfishing, known to be overfished, or known to be approaching an overfished condition (p. 175).
• Landings in the Gulf of Alaska remained stable through 2018. Landings are primarily composed of salmon, pelagic foragers, and apex predators. Pacific cod landings decreased in 2017 as a result of low abundance, and the TAC was substantially reduced in 2018 to conserve the stock (p. 180).
• Ex-vessel revenues have remained fairly stable over time but have been lower since 2003 as the relative share of landings have shifted away from the more highly priced sablefish and halibut species towards the more moderately priced Pacific cod. In 2018, cod value decreased substantially with conservation- based reduction in the TAC (p. 182).
• As of 2018, the unemployment rate in the western GOA was 11.9% and in the eastern GOA was 5.97%, which are both higher than the national rate of 3.9% (p. 186).
• The total population of the western GOA (excluding Anchorage) has steadily increased since 2010. Small community populations decreased by 21.47% between 2010 and 2018, and larger communities increased by 5.86%. The total population of the eastern GOA has remained stable since 2000, with m no significant population changes within large communities between 2010 and 2018 (p. 189).As of 2019, there are three schools in the western GOA with enrollments under 10 students facing possible closure (p. 198).
• In eastern GOA municipalities with school enrollment between 100 to 500 students, enrollment appears to be steadying since 2016. Larger districts such as Sitka and Ketchikan have the lowest graduation rates (both remaining under 60%) for the 2015-2017 cohorts, consistently placing in the lower 1/3 of school districts analyzed (p. 198).