In this March 28, 2018, file photo, a North Atlantic right whale appears at the surface of Cape Cod bay off the coast of Plymouth, Massachusetts. Credit: Michael Dwyer / AP

An endangered North Atlantic right whale was videotaped a few miles off Portland Harbor last month. The animal was filmed just weeks before controversial new rules that aim to protect the species from entanglement with lobster gear go into effect.

In the video, the whale can be seen slowly swimming along in Casco Bay, diving, surfacing, then diving deeper, with its tail flukes last to disappear. A recreational boater who filmed the animal said it seemed curious about the boat’s occupants, swimming alongside, occasionally pausing and seeming to take in the sun.

The videographer, who preferred to remain anonymous, said the whale, which is one of roughly 370 left on the planet, seemed healthy and calm during its 15-minute sojourn between Peaks Island and Cape Elizabeth.

A spokesperson for the National Oceanic and Atmospheric Administration said the agency considers the sighting to be “definite” and it will be entered in the national catalog of confirmed North Atlantic right whale sightings.

Amy Knowlton, a whale expert at the New England Aquarium, said white scar tissue seen on the flukes indicate that the young whale likely got entangled with fishing gear.

“They seem to be minor injuries, but clearly it did get entangled with some sort of gear. Seemed to be healed injuries,” Knowlton said.

In less than two weeks, more than 950 square miles of fishing grounds will be put off limits to traditional rope-and-trap-pot lobstering. That’s some 30 miles off Maine’s coast, where regulators said thicker gear-rope and longer trawl lines pose a bigger threat to the whales. Next spring measures to make it easier for whales to break through rope used closer to shore will also go into effect.

This article appears through a media partnership with Maine Public.