Northern fur seals: Cute pinnipeds of the open ocean

Our special seal

The northern fur seal (Callorhinus ursinus) is one of 34 species of the group of carnivorous mammals with front and rear flippers, called pinnipeds (fin footed). Northern fur seals are known for their extremely dense fur, with about 300,000 hairs per square inch (second only to sea otters) and the largest sexual dimorphism, or size difference, of any marine mammal. Females can weigh up to around 100 pounds, and males can weigh up to 600 pounds!

Flaherty, here at the Aquarium, is currently one of only nine fur seals in zoos and aquariums in the United States. His grandfather, Al, was rescued after a big storm off the Washington coast in 1993—he was found stranded in a cow pasture in Hoquiam!—and then rehabilitated and placed at the Seattle Aquarium. The Aquarium has a long history in fur seal care and research. We were the first in the world to breed and raise fur seals, and we work with other research partners in the field and on-site, collecting valuable information about this species.

Northern fur seal sitting on rocks with its head up, scratching itself with a flipper.
Northern fur seal Flaherty, has been at the Seattle Aquarium since 2015. 

Family ties but solo at sea

Fur seals and sea lions are closely related, and both belong to the Otariidae family. Otariids, sometimes called “eared” or “walking” seals, are different from the other pinniped families—phocids (seals like our harbor seals) and odobenids (walrus)—in a few ways: Otariids have external ear pinnae, larger fore flippers and pectoral muscles for propelling themselves through the water, and the ability to turn their hind limbs forward and walk on all fours.

Northern fur seals are highly pelagic most of the year, meaning they live in the open ocean, and are usually solitary when at sea. Both males and females can be present in coastal Washington waters from November to June but migrate to beaches on islands for resting, reproduction and molting, heading to the Bering Sea in the north or the Santa Barbara Channel Islands in the south. 

Northern fur seal sitting up on rocks looking to its right.
Lovingly called "Flare" by the Aquarium's animal care staff, Flaherty is one of just a handful of northern fur seals living in U.S. zoos and aquariums.

Protecting the pinnipeds

Until gaining some protection in 1911 along with sea otters under the first international wildlife conservation treaty, northern fur seals were highly exploited for their dense fur during the 1800s and experienced critical population declines. Northern fur seals, like all marine mammals in U.S. waters, have been managed under the Marine Mammal Protection Act (MMPA) since it was enacted in 1972. Although their populations recovered greatly since its enactment, there is concern for current population trends; their MMPA status is “depleted,” and their status given by the International Union of Conservation of Nature (IUCN) is “vulnerable.”

Northern fur seals are opportunistic—or generalist—foragers, meaning they eat a wide variety of fish and squid species and their diet differs depending on geographic area and time of year. The Seattle Aquarium’s conservation priorities include several areas of concern that affect these wide-ranging mammals, including plastic waste, ocean warming events and competing commercial fisheries that impact the availability of northern fur seals’ various prey.

See for yourself

You can observe a northern fur seal up close during your next visit to the Aquarium! Flaherty’s charismatic cuteness—come watch him on his sea cliff habitat or when he’s swimming and showing off his graceful underwater skills—gives us opportunities to get to know this unique resident in our care and learn more about how we can all protect our shared ocean.

Northern fur seal jumping out of the water, looking up towards the camera.
Come say hello to Flaherty on your next visit to the Seattle Aquarium!

Support the Seattle Aquarium

Your support connects people to the ocean in a way not otherwise possible and inspires bold action to care for animals and protect our shared marine environment.