Rescue of Baby Hooded Seal in U.S. Hits a Snag

Bijal P. Trivedi
National Geographic Today

November 27, 2001

Scientists at the National Aquarium in Baltimore are concerned about the
whereabouts of a baby hooded seal they spent four months resuscitating
after it was rescued in waters off the U.S. East Coast.

The pup,
which apparently had wandered far from the Arctic, was on the verge of
death—dehydrated, malnourished, and with a disease—when found
near a beach on Assateague Island in Virginia.

The pup recovered after months of devoted care, and the scientists drove from Maryland to Long Island to release him back into the sea. Within days of his release, however, transmissions from a satellite tag on the seal's back indicated he was much farther south, close to where he had originally been rescued.

Now, a week after the pup—known as 12-CC—for Number 12 Cystophora cristata—was released, the signals are no longer being received.

"The last transmission we had from 12-CC was right off Virginia Beach," said marine mammal specialist David Schofield of the National Aquarium. "This is not the direction we wanted him to go—he was supposed to head north."

Far From Home

Hooded seals, which get their name from red nasal sacs that males can inflate during courtship, typically spend the summer north of the Arctic Circle.

They spend their time atop coastal ice floes, eating ice and diving for fish. So finding 12-CC, and many other lost seal pups, wandering in East Coast waters as far south as the Caribbean is startling.

This year an unusually large number of hooded seals have been found stranded along the eastern shoreline of the United States, and scientists have no idea why. One of the seals was discovered off the island of Bermuda, which has never been known to happen before.

Schofield and his colleagues had hoped that 12-CC would provide some of the answers.

Devoting considerable attention to the rescue and rehabilitation of a single animal is often controversial because of questions about whether it's fair to allocate so many resources to one individual at perhaps the expense of the species. But a single animal can sometimes serve as a barometer for the health of its species and of ocean health in general.

Ian Walker, an associate veterinarian at the National Aquarium, said trends such as the recent discovery of many stranded seals off the U.S. East Coast are usually an indication of a problem that's affecting the larger seal community.

All of the stranded seals that Schofield and his colleagues rescued were lethargic when they were found and had high levels of liver enzymes and chest congestion.

The scientists speculate that the hooded seal population may be suffering a virus, something like a seal version of a human flu, although it's too early to tell. Another possibility, Schofield suggests, is that climate change may have contributed to a delayed birthing season and the pups became confused by the warm water and swam the wrong way.

Lingering Questions

Lost contact with 12-CC, Schofield said, may mean that he died or that his satellite tag failed or fell off and is now somewhere in the ocean. Such tags can only send a signal when animals surface for air.

The tag was adhered to the fur on 12-CC's upper back, so he would lose it naturally during the annual molting season.

"When we released 12-CC he was pretty feisty," said Schofield. "During his week after release 12-CC was moving at about 200 to 300 miles per day, which suggests he was doing pretty well."

Schofield said he and his colleagues have attached satellite tags to turtles, porpoises, and other marine mammals, and most don't seem to mind or even notice. "But when we released 12-CC on the beach," he said, "he spent at least half an hour rolling in the sand trying to dislodge the tag—just like the way a dog tries to get rid of a collar." Schofield thinks 12-CC probably managed to rid himself of the tag.

Explaining 12-CC's heading south rather than north toward his fellow seals, Schofield said rehabilitated seals typically wander a bit before they head in the right the direction. Unfortunately, the Baltimore researchers don't have signal data to know whether 12-CC got back on track.

Schofield, who coordinates the Marine Animal Rescue Program, part of a larger network devoted to saving stranded animals from the sea, is not sure whether the recent strandings are part of a large die-off of hooded seals triggered by disease, pollution, climate change, or some other factor. The seals are usually found stranded in the winter months, so the months ahead may help the researchers determine whether the lost and sick seals are part of a much larger problem or just an anomaly.

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