Last Saturday, April 13, Sharon Melin, wildlife biologist at NOAA’s National Marine Mammal laboratory, came to the Aquarium and shared her experience with wild northern fur seals. Working with biologist Julie Carpenter and our male northern fur seal Commander, she demonstrated how satellite tags are placed on adult fur seals to track their ranges (see photo).
Tracking has shown scientists that in winter, from about December to March, animals from the two main populations, Alaska and California, gather together off the coast of Washington. Here they swim constantly, feeding on schooling forage fish such as herring. They are completely pelagic at this time—which means they’re living in the open ocean—and only an injured or ill animal would leave the water and haul out on land (such strandings should be reported to the Marine Mammal Stranding network at 800-562-8832).
Commenting about Commander, Sharon said, “I could never get this close to a healthy adult male in the wild. A wild male of his size would be very aggressive toward humans. At his current weight of 329 pounds, Commander is about the size of typical adult males from the San Miguel area in California; males from the Alaska population can weigh 800 to 900 pounds.”
The southern population of northern fur seals in California is actually increasing, but the Alaskan population is declining. “We think the decline in the north may be due to decreasing food availability and disease,” said Sharon. The Alaskan population still represents about 90% of the entire population of northern fur seals; these animals are found in conjunction with remote islands in Alaska and Russia.
Happily, Commander never has to worry about his food. The enrichment item in our photo, an empty five-gallon water jug with a 3” hole, contains herring on ice. Yum.