June 17, 2021 — The following was released by NOAA Fisheries:
Temperatures are above the long-term average, but remain below marine heatwave conditions. These conditions are wavering near conditions observed in 2017 and 2018 for this season. Recent warming has been sporadic in the region with warmer conditions in the western sector and cooler conditions near Kodiak Island and eastward.
Why monitor marine heatwaves in the Gulf of Alaska?
Climate change is impacting the ecosystem of the Gulf of Alaska and effects are expected to magnify as warming increases over the coming decades. Over the past 6 years, the Gulf of Alaska has been experiencing extended and severe marine heatwaves. From June 2014 to January 2017 the North Pacific, including the Gulf of Alaska, had increased temperatures over a region of approximately 2 million km2 with more than 2.5 °C warmer than the long-term mean (1982–2012). The 2014–2016 marine heatwave changed the ecology of the region with reduced phytoplankton production, a shift in zooplankton production from large lipid-rich (higher fat) copepods to small lipid-poor copepods, and reduced forage fish populations such as capelin (Mallotus villosus) and Pacific sand lance (Ammodytes hexapterus). Species at the top of the marine food chain experienced lower recruitment (reduced juvenile survival) and increased mortality in fishes, birds, and mammals.
We will provide monthly updates on marine heatwave conditions in the Gulf of Alaska via social media @NOAAFisheriesAK and via this webpage. We will share what we are learning about current conditions in the Gulf of Alaska this year.