BIDDEFORD — It was during a bad storm in February that there was an unusual sight on Goose Rocks Beach in Kennebunkport. A harbor porpoise washed up high on the beach and was stranded there. Once she was rescued and brought to the University of New England’s Marine Animal Research Center, she was found to have a host of medical problems, ranging from pneumonia to abrasions.

Today marks a happy ending for the porpoise, which is simply known as Number 12, who is ending her stay at MARC. This morning, a group of researchers and veterinarians took the porpoise for a short boat ride and slid her into the ocean, releasing her near the area where she was found.

“We’re really excited she made it through,” said MARC’s Marine Mammal Rehabilitation Coordinator Keith Matassa. “She’s been a handful. She is one feisty porpoise.”

But now, he said, “She’s really ready to go.”

Number 12 has been showing MARC’s staff and volunteers that she’s ready to return to the ocean for weeks now, said Matassa. In the outdoor pool that was specifically set up for rescued porpoises this winter, Number 12, whose age is estimated between 2 and 4 years old, has been exhibiting typical porpoise behavior, he said.

She spy-hops, which is when she brings her eyes out of the water and looks around; she does porpoising, when she jumps completely out of the water; she rolls; does speed swimming; hunts the herring that were placed in the tank with her; and she appears especially fond of lob-tailing, when she slaps her tail on the water. Matassa said she lob-tails to show when she is unhappy or annoyed about something.

“She’s showing us that she wants to leave,” he said.

But she hasn’t always been so active and ready for release.

When she was rescued off Goose Rocks Beach after the storm surge, Number 12 had liver problems, pneumonia, abrasions and lacerations, fungus in her lungs and parasites that prevented her from gaining weight.

Initially, she began to improve, but experienced a setback when she lost her companion porpoise, Toughy, which had been rescued after washing up on a beach in Pembroke in November.

Toughy’s health problems were more serious than Number 12’s and in March the decision was made to euthanize her.

Eventually Number 12 bounced back from the loss. She became so feisty that members of the swim team couldn’t keep up with her. About a month ago, Matassa said it was determined that Number 12 was healthy and the decision to release her back into the wild was made.

It’s taken about four weeks to figure out all the logistics to be able to go forward with the release. MARC has a long history working with seals that become stranded, rehabilitating them and conducting seal releases several times a year. Matassa noted the difference between a porpoise release and a seal release, which takes only a day to coordinate once the okay for the release is given.

For the porpoise release, four people are needed to corral Number 12 in the pool, carry her to where they can put her in a box for travel and then she must be taken on a boat to be released in deep waters. Seals need fewer bodies to get them ready for transport and then are easily released from a nearby beach.

Dr. Michelle Sims will be one of the two veterinarians who will accompany Number 12 on her return to the sea. The porpoise, who gets anxious around people, will have to be sedated for the transport, said Sims. She will be constantly monitored for her safety, as well as the safety of the people moving her, said the veterinarian.

Not only is it good for Number 12 that she will be back where she belongs, but it’s also good for MARC, said Matassa. Taking care of porpoises is very time consuming and more costly than for seals, at an average of $200-300 a day to take care of Number 12, said Matassa, and double that to care for Toughy.

Before Number 12 is released, she will be tagged so that her movement in the ocean can be tracked. The tracking information will be available over a website.

The tracking will provide valuable information, said Sims, because it will show if Number 12 travels to the same areas as other healthy porpoises in her vicinity. The travel information “helps us to know if we’ve made a good release decision,” said Sims.

If Number 12 doesn’t travel to what are perceived as normal destinations, “we may learn that some (porpoises) are difficult to treat,” said Sims.

Porpoise strandings are relatively rare, compared to seal strandings. Prior to this year the last time MARC housed a porpoise was 2004, said Matassa.

— Staff Writer Dina Mendros can be contacted at 282-1535, Ext. 324 or dmendros@journaltribune.com.