Naturalists from two whale-watching companies based in Boothbay Harbor confirmed the rare sighting Sunday afternoon of an endangered blue whale, the largest mammal on Earth.

Naturalists on the Pink Lady II, which is operated by Cap’n Fish’s Whale Watch, and the Harbor Princess, operated by Boothbay Whale Watch, confirmed the sighting of the blue whale about 15 miles south of Boothbay Harbor.

The whale was believed to be “logging,” or what humans would define as sleeping.

Dominique Leclerc, a marine biologist based on the Pink Lady II, took video of the animal as it slept.

Leclerc, who narrates the cruise’s whale watches, said the blue whale surfaced every five to eight minutes to breathe before returning to a shallow depth just below the ocean’s surface.

In the video, passengers could see the whale’s grayish-blue skin in the water as it slept. The whale surfaced once during the video clip.

Leclerc said the whale-watch vessel, which had about 150 people on board, floated near the whale for roughly 45 minutes. She estimated that the whale was about 80 feet long.

“We could see its entire body,” said Leclerc, who has a degree in marine sciences and zoology from the University of Maine in Orono. “The passengers were cheering and clapping and having a ball. It was the chance of a lifetime.”

It’s rare to see a blue whale in the Gulf of Maine, she explained. That’s because blue whales prefer the deeper waters of the North Atlantic. Only a few hundred blue whales live there, she said.

The species became endangered as a result of whale hunting that depleted the population. The International Whaling Commission banned all hunting of blue whales in 1966.

Blue whales can grow to enormous sizes, sometimes weighing as much as 150 tons. They can live to be 70 years old, Leclerc said.

The whales have tongues that can weigh as much as an elephant. They feed on small, shrimp-like creatures called krill. A female killed in Antarctica holds the record for length, at 106 feet.

Whale-watch boats based in Maine typically spot fin, humpback and sei whales in the Gulf of Maine.

Another whale-watch vessel, the Harbor Princess, also spotted the blue whale.

The crew could not be reached late Sunday, but its naturalist posted a comment Sunday on the company’s website that said, “After pushing 25 miles out, we made our turn back north and what did we see … A 70- to 80-foot blue whale! What an amazing sight!”

Staff Writer Dennis Hoey can be contacted at 791-6365 or at:

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