Surface water temperatures in the Gulf of Maine this fall hit new seasonal highs, and it looks like 2021 overall will be one of the hottest ever in the gulf.
Researchers at the Gulf of Maine Research Institute said that this fall, temperatures in the gulf ran more than four degrees Fahrenheit above the historical norm.
"It is stunning in terms of the magnitude of how far above even our past experience this fall stands out," said GMRI scientist Kathy Mills. She said that over the last decade the gulf has entered a temperature "regime shift" thanks in part to persistent changes in long-standing ocean current patterns that are in turn driven by global warming.
"We're essentially turning up the dial on the warm water (flowing into the Gulf) and turning down the cold, resulting in hotter temperatures in the Gulf of Maine since 2010," Mills said.
Before 2010, average fall temperatures in the gulf rose above 57 degrees only once. Since then, the average has never fallen below 57 degrees, with temperatures above 60 persisting into October. Mills said that's affecting seasonal migration patterns for species such as lobster, and changing where and when food-web staples such as herring go to spawn.
And the temperature rise is accelerating, she said, faster than predicted by some models.
While final data aren't in yet, Mills added, it looks like the annual average gulf temperatures for all of 2021 will be on par with the warmest year ever recorded, 2012.