BAR HARBOR – Scientists on Tuesday were dissecting the body of a young pilot whale that captivated residents all along Penobscot Bay as it strayed close to shore during its final two weeks of life.

The 12-foot-long light gray pilot whale was recovered from the Penobscot River early Tuesday morning.

A fisherman found the body and towed it to Turtle Head Marina in Hampden, where scientists claimed the animal to take it by truck to Bar Harbor, said Kate Doan, a student researcher at Allied Whale on the College of the Atlantic campus who works primarily with stranded sea mammals.

Scientists began their necropsy – the autopsy-style investigation on an animal – Tuesday afternoon. Work was expected to continue late into the night, Doan said.

Tissue samples will be collected for further testing, which could take as long as a week to complete before conclusive results about the whale’s illness are available, she said.

The animal had been dead for days and was spotted Saturday by Hampden and Winterport residents. Bad weather kept Allied Whale scientists from recovering the body immediately, and the whale drifted downriver before it was found Tuesday morning.

Scientists now know that the small pilot whale is a male and that it has a number of lesions on its head and body. The injuries could have been caused by an illness or by the impact of rocks as the whale beached itself in recent weeks, Doan said.

The whale first appeared in shallow water off Stockton Springs, near the mouth of the Penobscot, just over two weeks ago. Allied Whale scientists nudged the animal into deep water after it repeatedly beached itself on sandbars and mudflats near Cape Jellison.

As it swam close to shore as far up the Penobscot River as Hampden, the whale behaved strangely, floating on the surface of the water, and swimming in tight clockwise circles, according to dozens of local residents who observed the whale.

The odd behavior could be caused by a neurological illness, such as a brain worm, or could be related to a head trauma, according to previous interviews with Allied Whale scientists.

Long-finned pilot whales, Globicephala melaena, live all along the North Atlantic coast and are neither common nor rare in Maine waters. Adults can reach 20 feet in length.

They are not endangered. In fact, the species is still hunted for sport off the coasts of Newfoundland and the Faeroe Islands, where it is plentiful.

Pilot whales typically travel in pods of 50 to 100 individuals. Solitary pilot whales of any age are rare and are typically ill or injured.

Yet stranded pilot whales, alone or in groups, are seen more commonly than many other species. The Maine Mammal Stranding Center reports 29 stranded pilot whales in the past 20 years.

Although scientists do not know the reason for the beachings, some scientists surmise that boats, nets, even certain shapes of shoreline may interfere with pilot whales’ sensitive system of communication.