The baby harbor porpoise that washed ashore Thursday in Ocean City has been destroyed because of the severity of its injuries, National Aquarium officials said yesterday.

The porpoise, thought to be a female less than 6 months old, was suffering from 10 broken ribs, internal bleeding and organ damage and had little hope of recovery, said Vicki Aversa, the aquarium's public relations director.

The porpoise was destroyed Friday night with the same kind of injection used for dogs and cats, Ms. Aversa said.

"It was the humane thing to do," she said.

She added that a necropsy will be performed Monday to further pinpoint the scope of injuries.

Ms. Aversa said that some of the injuries suggested that the harbor porpoise had been caught in a fishing net before it was battered by a storm last week.