WESTBROOK – Seals look up with sad eyes, some too tired or sick to lift their heads. Some have been abandoned by their mothers; others are ill or malnourished. Sometimes they’ve been injured by sharks looking for a seal pup snack.

The Marine Animal Lifeline, which rescues and rehabilitates these seals, has neared capacity for the first time this summer, with the number of seals approaching 60.

“We’re pretty much the county hospital. We take anything and everything, and we’re filled to capacity,” founder Greg Jakush said over the sound of barking seals that drifted in through his open window as workers fed the animals.

Jakush isn’t complaining. If anything, the organization he created a decade ago has become a victim of its own success.

More people are calling the Marine Animal Lifeline when seal pups are abandoned, he said, and the organization is doing a better job of saving those rescued pups. The combination has led to a population explosion at the facility.

On a recent day, workers were evaluating the latest arrivals, a pair of young harbor seals, one of which had a broken flipper.

The injured seal from Biddeford was in the treatment room, while the other one from Harpswell was quarantined with other sick and emaciated seals.

Next to the treatment room, workers and volunteers were busy using a blender to make fish frappes for the young pups, who are fed five times daily.

Others were studying the seals’ medical charts, preparing medications and rinsing out seal pens.

A staff member reported that seal No. 338 had thrown up. Jakush ordered intravenous fluids and medicine, but the female seal had to be euthanized later.

While there’s plenty of daily drama, motorists zooming by on a two-lane highway probably don’t have any idea that the Marine Animal Lifeline is there.

The organization is based in a nondescript two-story building along with several other structures and Quonset huts. The offices have no markings because there are no shows and no public tours. Jakush wants to minimize the seals’ exposure to humans.

The Marine Animal Lifeline is the largest of a handful of organizations that rescue and rehabilitate stranded seals in New England.

Last year, it handled 805 reports of stranded, injured or dead seals. But there were no more than 47 seals at the Westbrook facility at any given time. Last week, the number swelled to 59, prompting Jakush to put out a call for more volunteers.

“There’s no doubt that he sees more seals than anyone. And thank goodness he’s there,” said Heather Medic, coordinator for marine animal strandings for the Mystic Aquarium in Connecticut, which handles about 20 seals a year.

The Marine Animal Lifeline handles rescues from the New Hampshire border to Rockland and takes in seals for rehabilitation from across the region.

Allied Whale, which is operated by the College of the Atlantic in Bar Harbor, handles Down East rescues and sends seals to Westbrook for rehabilitation. The University of New England in Biddeford also has a small seal rehabilitation program.

To the south, the Mystic Aquarium handles rescue and rehabilitation in Connecticut and Rhode Island. In Massachusetts, the Cape Cod Stranding Network and New England Aquarium in Boston handle rescues. Many of those seals end up in Westbrook.

Jakush of Chicago, who went to Florida for college and became a dolphin trainer, came to Maine because he wanted to help sick seals and give them a second chance. At the time, there was no seal rehabilitation in Maine.

Maine’s harbor seal population is flourishing after nearly being eradicated from parts of the coast a century ago when they were viewed as a nuisance and killed by fishermen because they became entangled while trying to raid traps and nets.

These days, they’re protected by the Marine Mammal Protection Act of 1972. The latest survey by University of Maine professor James Gilbert published this month in Marine Mammal Science estimated there were 99,340 harbor seals in 2001.

“That’s a healthy population,” Gilbert said.

Typically, a quarter of seal pups die in their first three weeks, and only half of them make it to be a year old. Pups sometimes get separated from their mothers, and sometimes they fall ill. They can be bitten by sharks or hit by boats.

People who see an abandoned pup on shore are encouraged to call the Marine Animal Lifeline, which will dispatch one of 200 volunteers to assess the situation. Sometimes, the mother has simply gone temporarily to forage for food.

If a pup is truly abandoned, it will be taken to Westbrook and quarantined for three or four days. After that, the rehabilitation process begins as the seals are nursed back to health and fattened on pureed fish.

Eventually, the young seals learn how to eat by gnawing on fish before chasing and eating live fish in a 5,000-gallon tank. They have a healthy layer of fat by the time they’re moved to an even larger tank and then released into the wild.

During the summer, when harbor seals migrate to the Maine coast, the Marine Animal Lifeline is hopping. The workers continue a ceaseless cycle of feeding the seals, giving them medicine and vitamins, and cleaning their pens.

The space problem will end later in October or November when the Marine Animal Lifeline moves to a seven-acre site in Scarborough.

For now, Jakush is more worried about his budget than the lack of space. At its current levels, the seals are eating 500 pounds of fish a day. That, along with medicine, consumes a large portion of the $250,000 budget.

The only paid staff are Jakush, a veterinarian and three veterinary technicians. The rest are volunteers.

“I guess we’ve been in tough spots before,” he said. “I get more stressed worrying about how we’re going to pay the bills than how we’re going to provide the care. I know we’re going to provide the care.”