A new study found that deep water in the Gulf of Maine has been warming twice as fast as the surface in the last 15 years.

The findings are not necessarily new, according to the Bangor Daily News. Researchers suspected warming was the reason endangered right whales are moving farther north in search of food, but they didn’t know the extent of the warming in deeper sections of the gulf.

According to previous reports, the Gulf of Maine has been warming faster than 99.9 percent of the world’s oceans. A study published earlier this year in the scientific journal Oceanography reported that sections of the gulf from 65 feet to 500 feet deep have been warming as fast as nearly 1 F a year from August through February. Since 2004, some deeper areas have reportedly warmed by nearly 9 F, about twice as much as the water at the surface.

“The climate-driven changes rippling throughout the Gulf of Maine have serious consequences for the smaller number of remaining right whales,” Nick Record, a senior research scientist at Bigelow Laboratory in Boothbay Harbor, Maine, 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.”