June 9, 2020 — Over the last decade, two massive marine heatwaves, better known as “blobs” swept the North Pacific Ocean, raising surface temperatures more than 5 degrees Fahrenheit causing blooms of toxic algae and major die-offs in the ecosystem. A new study from the University of British Columbia reports that as these heatwaves continue, they may have far more devastating implications to fisheries than previously predicted.
Climate scientists have known for years that global warming would have devastating long-term impacts on marine species. Already, fast-melting Bering Sea ice is threatening spotted seals and other marine mammals. Warming Gulf of Alaska waters wiped out cod eggs in 2019, causing a crash in cod stocks. Record warm waters in the Yukon River last summer killed thousands of migrating salmon with heat stress.
While climate change is steadily warming oceans all over the world, marine heatwaves, like the two North Pacific “Blobs,” are causing more dramatic swings in surface temperatures. In 2014 and again in 2019, ocean temperatures in Alaska rose as much as 5 degrees Fahrenheit.