The water temperatures were recorded by scientists from the Department of Fisheries and Ocean (DFO) during a regular survey on Sunday and Monday of the Northeast Channel in the Gulf of Maine between Georges Bank and the Scotian Shelf, reports CTV News Canada.
“It’s sort of a shock,” said Dave Hebert, a veteran ocean climate scientist with DFO in Halifax, reports CBC News. “I was really surprised it was that high.”
The temperatures were six degrees warmer than the average water temperature. “I expect the Gulf of Maine will be really warm this summer,” Hebert said.
Scientists were aboard the Canadian Coast Guard ship Hudson on April 8 and 9 in the Northeast Channel. The channel is 60 kilometers (37 miles) wide and 250 meters (820 feet) deep. The channel is a pathway for water flowing from the Atlantic into the Gulf of Maine and Bay of Fundy.
Hebert said it was unclear what was causing the spike in water column temperatures, adding that it was too early to say whether climate change was behind the anomaly. However, he did suggest the warmer temperatures might have been caused by the Gulf Stream pushing warmer water from the south right up to the Scotian Shelf.
Further reading: Slow down of Atlantic Ocean circulation is bad news for everyone
Ocean temperatures off the east coast of Canada have been consistently above normal for the past ten years. The record high was in 2012 when ocean temperatures were two to four degrees above normal.
The big red blob of 2012
Talking about the ocean water temperatures in 2012, Hebert said at that time, “On average, it’s probably three to five times the normal variability. So it’s quite extreme.”
He also noted the National Oceanic Atmospheric Administration in the U.S. reported sea surface temperatures on the northeastern shelf in 2012 averaged 14 C, the highest temperature recorded in 150 years. Climate temperature maps showed a big red blob around Nova Scotia.
“Surface, right to the bottom. All across the Scotian Shelf. It’s in the Bay of Fundy and in the Gulf into the St. Lawrence. The amazing thing is, it is such a large extent. It goes all the way down to North Carolina and all the way up to Labrador,” Hebert said.
Further reading: High Arctic sea ice breaking off and moving toward coastlines
So is it climate change?
While Hebert is reluctant to call the abnormally warmer temperatures the result of climate change, he points out that ocean temperatures do vary over the decades, noting that in the 1960s and 1970s, water temperatures on the Scotian Shelf were below normal.
“That’s why you have to be very careful when you do trends, like when you pick your start and and stop times,” he said. “If you started at the very coldest time and went to now, you would have a very big trend, whereas if you took a longer time series, it might not be as big.”
