Arctic ribbon seal has a surprise checkup

  • Tue Jan 31st, 2012 10:48pm
  • News

By Bill Sheets Herald Writer

EVERETT — An Arctic ribbon seal had his tropical winter vacation interrupted Tuesday by an unplanned doctor’s appointment.

The seal was basking under balmy Everett skies on a dock in Steamboat Slough when it was netted, measured, had blood drawn and was weighed by staff of the National Oceanic and Atmospheric Administration.

Marine mammal specialists with the agency wanted to make sure the animal was healthy after straying so far from home.

Not all the data were available late Tuesday, but the seal, an adult male, appeared to be in good shape, said Kristin Wilkinson, a marine mammal stranding specialist for NOAA fisheries in Seattle.

Ribbon seals are native to the waters around Alaska and northeastern Russia, particularly the Bering Sea and the Sea of Okhotsk. Researchers believe the seal is the same one seen two weeks ago on the banks of Ebey Slough near Marysville and the week before in the Duwamish River near Seattle.

This ribbon seal is only the second ever to have been recorded as having been seen on the West Coast of the 48 contiguous United States, Wilkinson said. The first was seen in Morro Bay in central California in 1962, she said.

This seal weighed 185 pounds, about average for a male ribbon seal this time of year, she said.

Researchers are unsure why the seal has strayed so far south. It might have been chasing food, which consists of a variety of sea creatures such as shrimp, octopus, crab and pollock, Wilkinson said. Right now, there’s a lot of shrimp in Puget Sound and other inland waterways, she said.

Or the seal could have been caught in a storm, Wilkinson said.

Peter Bird, who lives on the property where the seal was found Tuesday, said his wife saw it early in the morning when she was out walking the dog.

“She just saw this big, black thing on the dock,” Bird said. His wife shone her flashlight toward the object.

“The seal just kind of grunted at her,” he said.

Bird retrieved his camera, took photos and called NOAA.

When the NOAA crew showed up, the seal seemed nonchalant, showing little reaction while allowing people to get within six or seven feet, Wilkinson said.

The animal tried to flee only when one of the crew members tossed a long-handled fishing net over it. It remained mostly calm while crew members held it down to have it measured and examined.

The seal was then transferred to another net. Straps were attached to the net and also to a bipod that crew members tilted upward so the seal could be suspended long enough to be weighed.

When the work was done, after about 20 minutes, the net was removed and the seal was set free. It quickly wriggled toward the edge of the dock and slipped into the water.

The seals spend about 10 months of the year swimming, are deep divers and can stay underwater for 30 minutes without coming up for air. They “haul out” from the water only during the spring, usually on ice floes, to mate and care for their young, Wilkinson said.

Both males and females have the distinctive white stripes around their bodies, but the males otherwise are black while the females are brown.

There are two lines of thought of why ribbon seals have the stripes, according to a 2008 NOAA report. The seals are born all white and then develop the stripes over time. One opinion is that the stripes are used for mate identification. Another suggested that this pattern helps to break up the shape of the ribbon seal’s body when seen from a distance, making it less discernible from the surrounding ice and shadows.

The seal found locally will not be trapped and returned to its natural habitat, said Peter Boveng, polar ecosystem program leader for NOAA in Seattle. Ribbon seals are allowed to be taken by subsistence hunters in Alaska, and though this animal appears healthy, seals that stray from their natural area sometimes pick up diseases that could be spread among the population, he said.

“He’s kind of on his own,” Boveng said.

Officials plan to continue to track the seal, Wilkinson said. Ribbon seals, along with harbor seals, sea lions and other pinnipeds such as walruses and elephant seals, are safeguarded under the Marine Mammal Protection Act.

While ribbon seals have not suffered a decline in population, NOAA fisheries is considering affording ribbon seals additional protection under the Endangered Species Act because of shrinking sea ice, their primary habitat.

Anyone who sees the ribbon seal locally is asked to call NOAA at 206-526-4747.

Bill Sheets: 425-339-3439; sheets@heraldnet.com.