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SEA OTTER
Enhydra lutris
meaning of scientific name: otter
DESCRIPTION:
Sea otters are members of the weasel or mustelid family.
Like other members of this family, they have very thick fur.
In fact, at 850,000 to one million hairs per square inch,
they have the thickest fur of any mammal. Their fur actually
consists of two layers, an undercoat and longer guard hairs.
This system traps a layer of air next to their skin so their
skin does not get wet. Sea otters are usually dark brown,
often with lighter guard hairs. Alaskan sea otters tend to
have lighter fur on their heads. Sea otters are the smallest
marine mammal. Adult females weigh 35-60 pounds (16-27 kg);
males reach up to 90 pounds (40 kg). Alaskan sea otters are
bigger with males weighing up to 100 pounds (45 kg).
RANGE/HABITAT:
Sea otters once ranged from Mexico to Alaska and even to Japan.
Currently, the California population numbers around 2,000
and is found from Half Moon Bay to Morro Bay. There is a much
larger population in Alaska, and sea otters are still found
in Russia. Sea otters inhabit shallow coastal areas and prefer
places with kelp. The kelp acts as an anchor that the sea
otters use to wrap themselves in when they are resting.
BEHAVIOR: Sea otters are social animals, with females
and pups spending time together in one group and males in
another. Pups stay with their mothers for the first eight
months of their life. The pups' fur traps so much air that
they actually cannot dive under water. When mothers leave
the pups wrapped in kelp to hunt, pups bob on the surface
of the ocean like a cork. Mothers spend much time grooming
pups and often carry them on their chests. Pups begin to learn
to swim at around four weeks of age.
Sea otters are one of the only marine mammals to use tools.
They eat animals with shells, like clams and abalone, and
use a stone to break open the shells. When sea otters are
under water searching for food, they store what they have
found in the loose skin folds at their armpits. Adult sea
otters can eat 25%-30% of their body weight in one day!
MATING AND BREEDING: Females usually have their first
pup at the age of four or five. Their pregnancies last four
to five months. Pups can be born any time of year, but in
California, most are born between January and March, and in
Alaska, most are born in the summer. When born, the pups weigh
from three to five pounds.
STATUS:
Sea otters in California are a threatened species due
to past over hunting for their beautiful fur. Although sea
otters are protected now, they remain vulnerable, especially
to oil spills. Unlike other marine mammals, sea otters do
not have a blubber layer. Therefore, they rely on their fur
to keep warm. If their fur is oiled, it loses its insulating
qualities and the sea otters soon chill. Otters are also affected
by the oil fumes or poisoned by eating food exposed to oil.
Most sea otters quickly die in an oil spill. Several thousand
sea otters died in the 1989 Exxon oil spill in Valdez, Alaska.
Other threats to sea otters include infectious diseases, parasites,
boat strikes, entanglements, and toxins.
AT THE MARINE MAMMAL CENTER: The Marine Mammal Center began
rehabilitating sea otters in 1995. Since that time, we have
rescued up to 45 sea otters. The various reasons for their
care at The Marine Mammal Center are infectious diseases,
the most common being parasite infection, and separation from
their parents.
May be reprinted for scientific and educational purposes
Revised 1/01
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Sea
Otters 