Rising ocean temperatures force North Atlantic right whales to move for survival: study

The baleen is visible on a North Atlantic right whale as it feeds on the surface of Cape Cod bay off the coast of Plymouth, Mass., on March 28, 2018. CANADIAN PRESS/AP, Michael Dwyer

Warming waters in the Atlantic Ocean appear to be forcing North Atlantic right whales into the Gulf of St. Lawrence and could lead to their extinction by the end of the century, a new study suggests.

The study, published on Tuesday in the journal Oceanography, examined North Atlantic right whale tracking data going back to the 1980s, and found that the species suffered a significant decline in the Gulf of Maine beginning in 2010 -- around the same time that a Gulf Stream shift northward warmed the waters in the area.

The researchers suggest that the warming waters led to a reduced amount of copepods in the Gulf of Maine, which happen to be a popular food source for the whales. This reduced food then corresponded to a 32-per-cent decline in females giving birth compared to the prior decade.

Since 2015, researchers have been reporting an unusually high number of right whale sightings in the Gulf of St. Lawrence, where the cooler temperatures would mean plenty of food for the whales, but increased danger from boats and fishing gear.

In 2017, U.S. National Marine Fisheries Service reported 17 dead right whale carcasses had been discovered throughout the summer, 12 of which were found in Gulf of St. Lawrence.

The researchers are calling for federal agencies in both the U.S. and Canada to “adopt more dynamic management plans” to help preserve the whales, including providing more thorough tracking of ocean conditions and whale sightings.

“As their forecasting skills improve, they will eventually be able to provide a basis for regulating shipping, fisheries closures, and gear restrictions when whales are expected to be present,” the researchers wrote in the study.

“Failure to adopt such measures and significantly reduce anthropogenic mortality sources could commit the right whale population to extinction before the end of the century.”

The researchers did not rule out natural climate variability for the rising temperatures in the Gulf of Maine, but note that “high-resolution ocean circulation models” predict that the rise is in response to climate change.

There are an estimated 368 North Atlantic right whales left, including less than 100 breeding females, according to the U.S. National Oceanic and Atmospheric Administration.

The World Wildlife Fund list the species as “endangered.”