Skip to main content

Sea Lion, Steller's

Sea lion, Steller's

Eumetopias jubatus

phylum: Chordata

class: Mammalia

order: Carnivora

family: Otariidae

status: Endangered, IUCN Endangered, ESA (USA: Alaska, Russia); Threatened, ESA (USA: California, Oregon, Washington), Canada

range: Canada, Japan, Russia, USA (Alaska, California, Oregon, Washington)

Description and biology

Sea lions and fur seals are members of the family of eared seals. They differ from true seals in that they have external ear flaps, a flexible neck, and hind flippers that can be turned forward for walking on land.

The Steller's sea lion, also known as the northern sea lion, is one of the largest species of sea lion. Males may grow up to 13 feet (4 meters) in length and weigh as much as 2,200 pounds (1,000 kilograms). Females are much smaller, weighing about half as much. The sea lion's thin coat of short, coarse hair is tawny brown in color.

Steller's sea lions feed primarily on fishes, squids, octopi, and crustaceans (shellfish such as shrimp and crabs). They hunt in relatively shallow waters, but can make 20-minute dives down to depths of about 650 feet (198 meters).

During the spring breeding season, the sea lions gather in large groups called rookeries. The Aleutian Islands, a chain of volcanic islands curving in an arc about 1,200 miles (1,931 kilometers) west off the Alaska Peninsula, are one of the animals' principle gathering places. Males come ashore first and stake out their individual territories, occasionally through fighting. They will try to mate with females that pass through their territory. A dominant male who is able to defend his territory successfully may mate with as many as 30 females over a two-month period.

Females arrive on the islands shortly after the males. They first give birth to pups that had been conceived during the previous breeding season. A few weeks later, they are ready to mate again. The pups remain dependent on their mothers for about a year.

Habitat and current distribution

Steller's sea lions inhabit the coastal waters around rocky islands. They occasionally come on shore to rest and sun themselves on the beaches. Their range extends from the Aleutian Islands west into the Bering Sea and down the Asian coast to northern Japan, and east into the Gulf of Alaska and down the Canadian and American coasts to southern California.

History and conservation measures

Steller's sea lions, along with other sea lions, were hunted extensively in the nineteenth century for their hides and blubber (fat that was melted down to make oil). In the twentieth century, they have been killed by fishermen who have blamed the animals for robbing their catch of fish.

In 1972, the U.S. Congress passed the Marine Mammal Act, which prohibited the hunting of sea lions in U.S. territorial waters. The Steller's sea lion received further protection in 1990 when it was placed on the Endangered Species List. The National Marine Fisheries Service has acted to protect breeding spots from shipping and to reduce the number of accidental deaths of sea lions during commercial fishing operations.

Despite these protective measures, the population of Steller's sea lions continues to decline. Disease, pollution, predators, habitat destruction, and other possible causes have all been investigated. Not one of these has proven conclusive. Scientists remain baffled as to the reason. If the decline continues unchecked, the Steller's sea lion may soon disappear from most of its range.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Sea Lion, Steller's." Endangered Species. . Encyclopedia.com. 17 Nov. 2018 <https://www.encyclopedia.com>.

"Sea Lion, Steller's." Endangered Species. . Encyclopedia.com. (November 17, 2018). https://www.encyclopedia.com/environment/applied-and-social-sciences-magazines/sea-lion-stellers

"Sea Lion, Steller's." Endangered Species. . Retrieved November 17, 2018 from Encyclopedia.com: https://www.encyclopedia.com/environment/applied-and-social-sciences-magazines/sea-lion-stellers

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.