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Deepseawaters Home Deepsea
AnimalsCalifornia Sea Lion
California Sea Lion
Common Name: California Sea Lion
Scientific Name: Zalophus californianus
Description
California
sea lions (Zalophus californianus californianus)
are large marine mammals in the pinniped family, which includes
seals and walruses. Male
California sea lions can measure eight feet
long and reach a weight of 1,000 pounds or more. Females can
reach six feet in length and weigh up to 250 pounds.
California
sea lions are one of two species of sea lions
found in Washington state waters, the other being Steller
sea lions (Eumetopias jubata), which are larger in
size.
California
Sea Lion Range
California
sea lions are found from the southern tip of Baja
California to southeast Alaska. They breed mainly on offshore
islands from southern California's Channel Islands south to
Mexico. Non-breeding males often roam north in spring foraging
for food. Since the mid-1980s, increasing numbers of California
sea lions have been documented feeding on fish along
the Washington coast and - more recently - in the Columbia
River as far upstream as Bonneville Dam, 145 miles from the
river mouth.
California
Sea Lion Population
The
U.S. population of California sea lions is
currently estimated at up to 300,000 animals, all on the Pacific
coast. From an estimated population of about 10,000 animals
in the 1950s, U.S. California sea lion numbers
have grown rapidly since the 1970s and the species is now
at "carrying capacity"-near the highest level the environment
can sustain-according to wildlife biologists. A population
survey conducted in 2006 by the Washington Department
of Fish and Wildlife (WDFW) documented 1,200 California
sea lions and 1,000 Steller sea lions
near the mouth of the Columbia River alone.
California
Sea Lion Diet
 California
sea lions feed on a variety of fish and shellfish,
including salmon, steelhead, Pacific whiting, herring,
mackerel, eulachon, lamprey, codfish, walleye Pollock, spiny
dogfish and squid. In recent years, they have also been
observed preying on Columbia River sturgeon. Studies of scat
samples collected in coastal waters and the Columbia River
estuary indicate that salmon comprise 10 to 30 percent of
the animals' diet. Additional studies have shown that the
percentage of salmon and steelhead in sea lions' diet increases
as they move upriver. Each year since 2004, California
sea lions have consumed 3,000 to 3,500 salmon and steelhead
immediately below Bonneville Dam, according to an ongoing
study by the U.S. Army Corps of Engineers.
California
Sea Lion Conservation Status
Like
all marine mammals, California sea
lions are managed under the federal Marine
Mammal Protection Act (MMPA) of 1972. They are not,
however, designated as a "depleted" population under the MMPA,
nor are they listed for protection under the Endangered Species
Act (ESA). While the MMPA was intended to protect marine mammals
from human interference, the law was amended in 1994 to provide
a process for states to lethally remove individual California
sea lions that threaten recovery of salmon and steelhead
stocks listed for protection under the ESA. This provision
does not apply to Steller sea lions, which are listed
as "threatened" under the ESA.
Additional
Information
California
sea lions, Zalophus californianus,
are probably the most familiar marine mammal at the islands.
These smart, playful animals are often seen playing in the
surf or lounging on beaches around San Miguel, Anacapa, and
Santa Barbara Islands in particular. Males may reach 8 feet
in length and 1000 lbs, females about 220 lbs. They are easily
recognized by their pointed nose, external ear flap, "Charlie
Chaplin" walk, and loud sometimes incessant barking. Sea
lions are very social animals. They can be quite
curious in the water coming to investigate divers and boats.
On the breeding they are very skittish and will retreat into
the water if disturbed. Males set up beach territories and
defend their harems from other males. Pups are generally born
in June and July and females nurse their pups for nearly year.
Sea lions feed on fish and squid near the
surface generally but can dive to 500 ft. The 2001 population
of California sea lions was estimated at
about 200,000 and 80,000 might live at San Miguel Island.
The population has been growing steadily since 1975 except
for set backs in El Niņo years.
Other Types of Sea Lion
 Steller Sea Lion
Australian Sea Lion
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