Stranded dolphin lost the battle

With a few final sorrowful pops and whistles, the dolphin dubbed “Dolly” by Braintree onlookers was euthanized last night after succumbing to apparent sickness.

The majestic dolphin’s struggle for survival ended when it stranded itself in deep mud in the Monatiquot River.

Tony LaCasse, a spokesman for the New England Aquarium, said today the “magnificent animal” was too stressed and likely too ill to save.

“It was almost gasping,” LaCasse said of the dolphin as it was stuck in the mud. “There was very little vocalizing until almost dying and then there were some pops and whistles.”

The veterinarians from the aquarium injected the dolphin with drugs to first sedate the brain to take away any pain and then suppress the respiratory system and heart.

An autopsy is being conducted now to help answer why the dolphin found its way so close to the city and stranded far from its pod.

“The prospects for this dolphin were very poor from the start,” said LaCasse, who explained dolphins seldom stray from their pods unless they are ill or old. This one did have a “significant” heart murmur.

LaCasse added that dolphins are a rarity in Greater Boston. The last one seen was in 2004 swimming in the Mystic River. A dolphin, possibly that one, turned up dead a few days later in East Boston. But almost all dolphin sightings are on Cape Cod.

“This dolphin was stunning,” LaCasse added, saying it weighed almost 600 pounds. Its exact sex and type (it’s now labeled a common dolphin) will be known after the autopsy.

Dolly was first spotted on Friday making its way down the Fore River in Braintree and Weymouth.

LaCasse said it was a strong swimmer right up until the end.