Scattered throughout the broad expanse of the Gulf of Maine are dozens of oceanographic buoys. Some have been operating for more than two decades, recording data on water temperature, salinity, currents, even wave heights. The buoys, managed by the Northeastern Regional Association of Coastal Ocean Observing Systems (NERACOOS), have given scientists an undersea window into the oceanographic changes taking place in the Gulf due to a rapidly warming climate.
A NERACOOS buoy ready for deployment. UMaine photo.
Nick Record, senior scientist at the Bigelow Laboratory for Marine Sciences in East Boothbay, pays attention to the Gulf of Maine buoys. He, like so many other scientists, knows that the Gulf has warmed rapidly in recent years and shows little sign of stopping. By studying buoy data, Record had noticed that it took about two years before the warmer temperatures recorded in Gulf deep waters were seen in the surface waters. Then in May 2024 he spotted something unusual in the data from a deep-water buoy stationed at Jordan Basin.
“In the fall of 2023 the deep water first appeared cooler, about 1°C (1.8°F). cooler than average,” Record said. “Before 2010 it wouldn’t have been a cool year, just average, but compared to water temperatures since 2010, it was colder.”
The cooler water last year was due in part to the strength of the Labrador Current, which brings colder, oxygen-rich water south from the sub-Arctic into the eastern Gulf of Maine. The influx of colder water set off a cascade of changes in the eastern Gulf. The current carried different species of plankton into the area, which in turn supported cold water species of copepods, including Calanus finmarchicus, the preferred food of right whales. Then researchers reported greater numbers of right whales in the eastern Gulf of Maine in 2024.
“We are seeing the same pattern this year, cooler water at depth,” Record said. “Tracking the deep water can give us an indication ahead of time of where the whales might come. They follow the ocean’s clues.” Right whales made a surprising show in January this year when more than 95 individuals were identified feeding around Jeffreys Ledge.
One consequence of climate change is increased variability in the Gulf of Maine. Temporary shifts in water temperatures, even the strength of major currents, are taking place, leaving researchers and fishermen alike uneasy. “Things will be a little more different,” Record said. “There will be surprises.”
Comments