A critically endangered North Atlantic right whale spotted off Ireland last year has made an "extraordinary" 3,000-mile journey to Boston, scientists say.

The right whale was first seen in Ireland's Donegal Bay in July 2024 - the first time a right whale had been photographed in Irish waters in more than 100 years. Now, the New England Aquarium can confirm that the same whale was just seen on Nov. 19 about 23 miles east of Boston.

Researchers were able to identify the whale due to unique scarring patterns on its head. Ian Schosberg with the Center for Coastal Studies was on the aerial survey that spotted the whale near Boston, and didn't realize initially how unique the first right whale sighting of the season was.

"The next day, when the Aquarium's catalog team sent over a potential match, I was shocked," Schosberg said in a statement. "I remembered the Irish whale sighting from July 2024 and how we'd tried to match that to a known individual in the catalog without success."

There are estimated to be just about 384 right whales left in the world, and the researchers said this unusual sighting suggests they are still searching for the right habitat.

Only a few whales have ever been documented in both North American and European waters, and this may be the first that was ever spotted in the eastern North Atlantic and then resighted in the western North Atlantic. The scientists said it's "extraordinary" to see a whale photographed in Ireland reappear off Boston.

"But where else would one expect to find a right whale with Irish connections if not off Boston?" said Padraig Whooley with the Irish Whale & Dolphin Group.