Sea otter
The heaviest weasel-family animal alive, floating on its back in Olympic's coastal kelp beds with no blubber at all, just the densest fur of any mammal.
Sea otter at a glance
Enhydra lutris SEE otter; Enhydra lutris is en-HY-druh LOO-triss
- Type
- Mammal · mustelid
- Diet
- Carnivore
- Size
- About as long as a canoe paddle, nose to tail (4 to 5 feet), and heavy enough to weigh as much as two car tires stacked together (50 to 100 pounds / 23 to 45 kg).
- Lifespan
- Roughly 10 to 20 years in the wild.
- Conservation
- Endangered (IUCN global assessment); Washington's otters are state-listed endangered, not federally ESA-listed
Eats sea urchins, clams, mussels, crabs, snails
A sea otter dives to the sea floor, pries shellfish loose with its paws, and surfaces to crack them open on a flat rock balanced on its chest. Because it has no blubber, it has to eat roughly a quarter of its own body weight in food every day just to fuel the heat its body burns to stay warm.
Should you worry?
Sea otters stay in the water and keep away from people, so a kid on shore is very unlikely to get near one. Watch from a distance with binoculars, and never approach or try to feed a resting raft of otters.
Scan a calm patch of water off one of Olympic’s outer-coast headlands long enough and the kelp bed sometimes moves on its own: a dark shape rolls, a pair of forepaws lifts clear of the surface, and a sea otter goes on grooming as if the ocean weren’t 50-degree water. It has no blubber to keep that cold out, none at all, the one marine mammal that skipped it. Instead it carries the densest fur of any animal alive, something close to a million hairs in a single square inch, packing in a layer of air that does blubber’s job instead.
That fur very nearly finished the species off. Hunters worked the coast for pelts from the mid-1700s until 1911, and by the time it stopped, Washington’s otters were gone entirely, not thinned out, gone. Every otter rafting in Olympic’s kelp today descends from 59 animals trucked down from Alaska in 1969 and 1970, a translocation so narrow that as few as ten to forty-some of them are thought to have actually survived and bred. The otters eat urchins by the fistful, and that turns out to matter beyond their own dinner: strip the urchins out of the equation and the kelp forest around them keeps growing instead of getting mowed to bare rock.
The raft drifting past the point survived a fur trade that wiped this coast bare once already. Take the otters out again and the kelp goes with them: fewer otters, more urchins, less kelp forest.
Did you know?
- A sea otter's fur holds up to a million hairs per square inch, more than any other animal, trapping a layer of air against its skin instead of relying on blubber.
- Washington's entire modern sea otter population grew back from as few as 10 to 43 survivors of a 1969-70 translocation from Alaska.
- A sea otter can crack open a shellfish using a rock as a tool, balancing the rock on its chest like a table while it works.
Common questions
Are sea otters dangerous to kids?
Not really. They live in the water and stay away from people. Just don't approach or feed one if you spot a raft resting near shore.
Why don't sea otters have blubber like other marine mammals?
They rely on the densest fur of any animal instead, up to a million hairs per square inch, which traps warm air against their skin.
Why did sea otters disappear from Washington?
Hunters killed them for their fur during the maritime fur trade, from the mid-1700s until 1911, wiping the population out along the whole coast.
How did sea otters come back to Washington?
Wildlife managers moved 59 otters from Alaska to the Washington coast in 1969 and 1970. Today's whole population grew from the handful that survived.
What do sea otters eat?
Mostly shellfish: sea urchins, clams, mussels, crabs, and snails, which they pry off the sea floor and crack open at the surface.