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Environment and Outdoors

Deep Gulf of Maine Has Been Warming Twice As Fast As The Surface, Study Finds

National Oceanic and Atmospheric Administration
via Bangor Daily News
Herring swim past Primnoa coral in the Outer Schoodic Ridges area of the Gulf of Maine in the summer of 2014.

Water deep in the Gulf of Maine has been warming twice as fast as the surface over the past 15 years, causing a significant disruption in the seasonal migration of endangered right whales, according to a new scientific study.The study is consistent with what many whale researchers have suspected for a couple of years — that warming water in the Gulf of Maine is driving endangered right whales further north in their seasonal search for food — but the degree by which deep parts of the gulf are getting warmer had not been previously examined.

Overall, in recent decades the Gulf of Maine has been warming faster than 99.9 percent of the world’s oceans, according to previous scientific reports.

Some portions of the gulf ranging in depth from around 65 feet to 500 feet have been warming as fast as nearly 1 degree Fahrenheit per year from August through February, according to the study, which was published earlier this month in the scientific journal Oceanography. Since 2004, some deep areas have warmed by nearly 9 degrees Fahrenheit, which is roughly twice as much as the fastest warming waters at the gulf’s surface.

That change in temperature appears to be having a significant impact on the abundance of right whales’ preferred food source, a small copepod called Calanus finmarchicus. As concentrations of the tiny high-fat creatures drop in the gulf, the whales migration patterns have been changing, challenging location-based efforts to protect them from ship strikes and entanglements in fishing gear.

“The climate-driven changes rippling throughout the Gulf of Maine have serious consequences for the small number of remaining right whales,” Nick Record, a senior research scientist at Bigelow Laboratory in Boothbay, said in a statement. “Climate change is outdating many of our conservation and management efforts, and it’s difficult to keep up with the rapid evolution of this ecosystem.”

Efforts to boost protections for north Atlantic right whales, the population of which is estimated to be a little more than 400 individual animals, has led to additional lobster fishing gear restrictions being developed to reduce the threat of entanglement along the Maine coast.

This story appears through a media sharing agreement with Bangor Daily News.