SPECIES FACTS
Scientific Name
Eumetopias jubatus
Life Expectancy
18 – 30 years
BIRTH FACTS
Weight
50 lbs (23 kg)
Length
45 in (1.1 m)
ADULT FEMALE FACTS
Weight
550 lbs (250 kg)
Length
8.5 ft (2.6 m)
ADULT MALE FACTS
Weight
1250 lbs (567 kg)
Length
10.5 ft (3.2 m
Steller sea lions, also known as Northern sea lions, are the largest of the eared seals, sometimes reaching ten feet in length and 2,500 pounds. They are the fourth largest pinniped world wide, behind the northern elephant seal, southern elephant seal, and walrus. Steller sea lions are light brown to blonde with dark flippers. The males are noticeably larger than females and also have a thick mane made of very coarse hair. Hundreds of sea lions are known to congregate at rookery sites that have been used for generations. These rookery sites are used primarily for resting and mating. Steller sea lions are endangered but appear to be recovering, with population numbers increasing each year. George Wilhelm Steller, a German surgeon and naturalist observed and described these pinnipeds in 1742, hence the name Steller sea lion.
WHEN AND WHERE TO SEE
Steller sea lions can travel long distances and disperse to find prey, but are not known to migrate. They are seen more frequently in the spring months.
The best place to view Steller sea lions along The Whale Trail are in the San Juan Islands and the Strait of Juan de Fuca. They can also be observed hauled out on buoys along The Whale Trail.
RANGE
Steller sea lions prefer colder waters and live in the Northern Pacific Ocean ranging from California to Japan. In the United States, Steller sea lions are divided into two distinct populations, the western and eastern. The two populations vary in genetic makeup, physical characteristics, and population trends. In the inland waters of Washington State, large males and sub-adults can be seen.
BIOLOGY
Like other pinnipeds, Steller sea lions have a coat of fur that molts, or sheds, every year. The coats of adult males and females are blonde/reddish brown. Both sexes have long whitish whiskers, called vibrissae, on their muzzle. The flippers and hairless parts of the skin are black in color. The fore-flippers are broader and longer than the hind-flippers. The hind-flippers are primarily used for locomotion in the water and on land they are used for walking. The ability to “walk” on land is a major difference between sea lions and seals.
They feed primarily on fish such as rockfish, herring, and greenling. They also feed on squid, octopus, shrimp, salmon, and other marine species. They have been observed swallowing rocks which biologists believe helps with digestion.
BIRTH FACTS
Like other pinnipeds, Steller sea lions have a coat of fur that molts, or sheds, every year. The coats of adult males and females are blonde/reddish brown. Both sexes have long whitish whiskers, called vibrissae, on their muzzle. The flippers and hairless parts of the skin are black in color. The fore-flippers are broader and longer than the hind-flippers. The hind-flippers are primarily used for locomotion in the water and on land they are used for walking. The ability to “walk” on land is a major difference between sea lions and seals.
They feed primarily on fish such as rockfish, herring, and greenling. They also feed on squid, octopus, shrimp, salmon, and other marine species. They have been observed swallowing rocks which biologists believe helps with digestion.
SOCIAL STRUCTURE
Adult males, also called bulls, form a harem at rookeries to establish their territory for breeding seasons. This is called colonial breeding. Females arrive and give birth starting in mid-May to June, mating again only two weeks after giving birth. The adult males can go 1-2 months without eating while they are aggressively defending their territory.
Steller sea lions have a low-frequency vocalization that sounds like a roar compared to California sea lions, which is more of a dog bark. These vocalizations are accompanied by a head bobbing motion.
At sea, Steller sea lions are normally seen alone or in small groups, however, near rookeries or haul outs they can be seen in larger numbers. Steller sea lions are known for their curiosity and playfulness, sometimes leaping from the water. They have even been seen jumping across surfacing whales! Sea lions can also be aggressive and will bite if they feel threatened.
BEHAVIOR
Steller sea lions are opportunistic predators and most foraging and feeding occurs at night. They forage both near shore and offshore and can dive around 1,300 feet (400m). They have an extremely varied diet and feed on many species of fishes (capelin, herring, salmon, rockfish), as well as bivalves, gastropods, and cephalopods (squid and octopus). Steller sea lions have been observed swallowing rocks which biologists believe helps with digestion.
STATUS
Steller sea lions are protected under the Marine Mammal Protection Act and were listed under the Endangered Species Act as threatened in 1990.The western stock population declined 75% between 1976 and 1990, and again by 40% between 1991 and 2000 (265,000 animals to less than 50,000). In 1997, the western stock was listed as endangered and the eastern stock remained as threatened. In hopes to recover the population, haul out sites have been protected and new rookeries have been created. The eastern population was removed from the Endangered Species List in 2013 but the western population is still listed. An abundance survey for the western stock in 2015 estimated a minimum of around 51,000.
CURRENT AND HISTORICAL THREATS
Threats to Steller sea lions are habitat degradation, ship strikes, contaminants, entanglements, modifications to critical habitat, and illegal hunting/shooting. In the 1800s, Steller sea lions were hunted for their meat, fur, and oil, among other things. In the 1900s, there were bounties on Steller sea lions as fisherman blamed them for stealing their fish. The sea lions were also killed due to the perceived competition and predation on fish in fish farms. Subsistence harvest by native tribes in Alaska and Canada also occur, with around 150-300 taken a year.