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Steller Sea Lion (Eumetopias jubatus)

Status | Species Description | Habitat | Distribution | Population Trends | Threats | Conservation Efforts | Regulatory Overview | Taxonomy | Key Documents | More Info

Status

ESA Endangered - Western Distinct Population Segment
ESA Delisted - Eastern Distinct Population Segment was delisted in 2013
MMPA - like all marine mammals, Steller sea lions are protected throughout their range by the MMPA.

Species Description

Weight:
males: up to 2,500 pounds (1,120 kg)
females: up to 770 pounds (350 kg)
pups: about 35-50 pounds (16-22.5 kg)
Length:
males: about 10-11 feet (3 - 3.4 m)
females: about 7.5 - 9.5 feet (2.5 - 3.0 m)
pups: about 3.3 feet (1 m)
Appearance:
adults: light blonde to reddish brown and slightly darker on the chest and abdomen
pups: dark brown to black
Lifespan:
20-30 years
Diet:
variety of fishes (capelin, cod, herring, mackerel, pollock, rockfish, salmon, sand lance, etc.), bivalves, squid, octopus, and gastropods
Behavior:
use land habitat as haul-out sites for periods of rest, molting, and as rookeries for mating and pupping;
colonial breeders, adult males ("bulls") establish and defend territories on rookeries to mate

The Steller sea lion, also known as the northern sea lion, is the largest member of the Otariid (eared seal) family.

Steller sea lions exhibit sexual dimorphism, in which adult males are noticeably larger than females and further distinguished by a thick mane of coarse hair.

Adult males may be up to 10-11 feet (3-3.4 m) in length and can weigh up to 2,500 pounds (1,120 kg). Females are smaller than males, at 7.5-9.5 feet (2.5-3.0 m) in length and weigh up to 770 pounds (350 kg).

The coats of adult males and females are light blonde to reddish brown and slightly darker on the chest and abdomen. The light coloration is still visible when the body is wet, which is different from many pinniped species. Like other pinnipeds, their coat of fur "molts" every year. Both sexes also have long whitish whiskers, or vibrissae, on their muzzle. The flippers and other hairless parts of the skin are black. The fore-flippers are broader and longer than the hind-flippers and are the primary means of locomotion in water. On land, sea lions, unlike "true" seals, can turn their hind flippers forward for walking.

Steller sea lions forage near shore and pelagic waters.They are also capable of traveling long distances in a season and can dive to approximately 1300 feet (400 m) in depth. They use land habitat as haul-out sites for periods of rest, molting, and as rookeries for mating and pupping during the breeding season. At sea, they are seen alone or in small groups, but may gather in large "rafts" at the surface near rookeries and haul outs. They are capable of powerful vocalizations that are accompanied by a vertical head bobbing motion by males.

Steller sea lions are opportunistic predators, foraging and feeding primarily at night on a wide variety of fishes (e.g., capelin, cod, herring, mackerel, pollock, rockfish, salmon, sand lance, etc.), bivalves, cephalopods (e.g., squid and octopus) and gastropods. Their diet may vary seasonally depending on the abundance and distribution of prey. They may disperse and range far distances to find prey, but are not known to migrate.

Steller sea lions are colonial breeders. Adult males, also known as bulls, establish and defend territories on rookeries to mate with females. Bulls become sexually mature between 3 and 8 years of age, but typically are not large enough to hold territory successfully until 9 or 10 years old. Mature males may go without eating for 1-2 months while they are aggressively defending their territory. Females typically reproduce for the first time at 4 to 6 years of age, usually giving birth to a single pup each year.

At birth, pups are about 3.3 feet (1 m) in length and weigh 35-50 pounds (16-22.5 kg).

Adult females, also known as cows, stay with their pups for a few days after birth before beginning a regular routine of alternating foraging trips at sea with nursing their pups on land. Female Steller sea lions use smell and distinct vocalizations to recognize and create strong social bonds with their newborn pups. Pups have a dark brown to black "lanugo" coat until 4 to 6 months old, when they molt to a lighter brown. By the end of their second year, pups are on the same color as adults. Females usually mate again with males within 2 weeks after giving birth. Males can live to be up to 20 years old, while females can live to be 30.

Habitat

steller sea lion critical habitat in alaska
Steller Sea Lion
Critical Habitat (AK)

(click for larger view PDF)


steller sea lion critical habitat in california and oregon
Steller Sea Lion
Critical Habitat (CA, OR)

(click for larger view PDF)

Steller sea lions prefer the colder temperate to sub-arctic waters of the North Pacific Ocean. Haul outs and rookeries usually consist of beaches (gravel, rocky or sand), ledges, rocky reefs. In the Bering Sea and Okhotsk Sea, sea lions may also haul out on sea ice, but this is considered atypical behavior.

Critical habitat has been defined for Steller sea lions as a 20 nautical mile buffer around all major haul-outs and rookeries, as well as associated terrestrial, air and aquatic zones, and three large offshore foraging areas (50 CFR 226.202 on Aug. 27, 1993).

Distribution

Steller sea lions are distributed mainly around the coasts to the outer continental shelf along the North Pacific Ocean rim from northern Hokkaiddo, Japan through the Kuril Islands and Okhotsk Sea, Aleutian Islands and central Bering Sea, southern coast of Alaska and south to California. The population is divided into the Western and the Eastern "distinct population segments" (DPSs) at 144° West longitude (Cape Suckling, Alaska). The Western DPS includes Steller sea lions that reside in the central and western Gulf of Alaska, Aleutian Islands, as well as those that inhabit the coastal waters and breed in Asia (e.g., Japan and Russia). The Eastern DPS includes sea lions living in southeast Alaska, British Columbia, California, and Oregon.

Population Trends

For management purposes, Steller sea lions inhabiting U.S. waters have been divided into two DPSs: the Western U.S. and the Eastern U.S. The differentiation is based primarily on genetic and physical differences, but also on differing population trends in the two regions. 

The most recent stock assessment reports with population estimates are available on our website.

Threats

Threats to Steller sea lions include

Historically, threats included:

Conservation Efforts

Protective zones, catch/harvest limits, various procedures and other measures have been implemented around major haul-outs and rookeries in order to safeguard their critical habitat. The IUCN Red List of Threatened Species This link is an external site. considers this species to be "Endangered."

Subsistence harvests by natives in Alaska and Canada (150-300 taken a year) also occur.

Regulatory Overview

The Steller sea lion was listed under the ESA as threatened throughout its range on December 4, 1990. This listing included animals from Alaska, California, Oregon and Washington in the U.S., as well as Canada, Japan, and Russia. 

On June 4, 1997, the population west of 144° W longitude was listed as an endangered DPS (the Western DPS) under the ESA; the population east of 144° W remained listed as threatened as the Eastern DPS. The Western DPS declined by 75% between 1976 and 1990, and decreased another 40% between 1991 and 2000 (the average annual decline during this period was 5.4%) leading us to divide the species into the two distinct population segments (DPS) and listing the Western DPS as endangered.

Under the MMPA, all Steller sea lions are classified as "strategic stocks" and are considered "depleted".

Critical habitat has been designated (50 CFR 226.202 on Aug. 27, 1993) for Steller sea lions as a 20 nautical mile buffer around all major haul-outs and rookeries, as well as associated terrestrial, air, and aquatic zones, and three large offshore foraging areas. We also designated no-entry zones around rookeries (50 CFR 223.202). We implemented a complex suite of fishery management measures designed to minimize competition between fishing and the endangered population of Steller sea lions in critical habitat areas.

A recovery plan was developed for Steller sea lions in 1992. A revised recovery plan, which discusses separate recovery actions for the threatened and endangered populations, was issued in 2008.

The Eastern DPS of Steller sea lions was delisted on November 4, 2013 due to recovery, a great success story of the conservation benefits provided by Endangered Species Act protections.  

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Otariidae
Genus: Eumetopias
Species: jubatus

Key Documents

(All documents are in PDF format.)
Title Federal Register Date

Permit for incidental take of Western U.S. stock of Steller sea lions in Bering Sea and Aleutian Islands (BSAI) flatfish trawl, BSAI pollock trawl, BSAI Pacific cod longline fisheries 

81 FR 40870 06/23/2016

Final Rule to Delist the Eastern DPS of the Steller Sea Lion

78 FR 66139 11/04/2013

Proposed Delisting of Eastern DPS of Steller Sea Lions

77 FR 23209 04/18/2012
90-Day Finding on Petitions To Delist the Eastern Distinct Population Segment of the Steller Sea Lion 75 FR 77602 12/13/2010
5-year review of the eastern DPS initiated 75 FR 37385 06/29/2010
Protection Measures for the Groundfish Fisheries Off Alaska 68 FR 204 01/02/2003
ESA Listing Rule: Endangered Status for Western population 62 FR 24345 05/05/1997
Critical Habitat Designation 58 FR 45269 08/27/1993

Recovery Plan, Revised

n/a 03/2008

12/1992
ESA Listing Rule: Threatened Status for Eastern and Western populations 55 FR 49204 11/26/1990
Stock Assessment Reports n/a various

More Information

Updated: June 17, 2016