Sea Otter
Enhydra lutris
Uses tools, holds hands, and single-handedly keeps kelp forests alive.
A sea otter has no blubber at all. What it has instead is the densest fur of any animal on the planet, a rock it keeps in a pocket of skin, and a job as one of the most important species in the entire North Pacific.
On the conservation status
The fur trade cut a population of several hundred thousand down to maybe 1,000–2,000 animals by 1911. They're protected now and slowly returning, but still occupy only a fraction of their old range.
- Length
- 1–1.5 m (3–5 ft)
- Weight
- 14–45 kg
- Lifespan
- 15–20 years
- Diet
- Urchins, crabs, clams, abalone, snails
- Daily food
- 25% of body weight
- Insulation
- Fur only — no blubber
The good stuff.
The densest fur on Earth
Up to a million hairs per square inch — you have maybe 100,000 hairs on your whole head. The fur traps a layer of air against the skin, and a sea otter spends hours a day grooming because dirty fur means death by cold.
They use tools
Sea otters smash shells against a rock balanced on their chest. Many keep a favourite rock and store it in a loose pouch of skin under the foreleg — along with snacks for later.
They hold hands
Resting otters form groups called rafts and hold paws so the current doesn't separate them. They also wrap themselves in kelp to anchor in place while they sleep.
They save kelp forests
Sea otters eat sea urchins. Without otters, urchins explode in number and mow down kelp forests, leaving bare urchin barrens. Bring otters back and the kelp grows back — and kelp forests store carbon and shelter hundreds of species.
They eat a quarter of themselves daily
No blubber means burning huge amounts of energy to stay warm. A sea otter has to eat around a quarter of its body weight every day just to keep the furnace going.
Pups float like corks
Newborn fur is so buoyant a pup physically cannot dive. Mum leaves it bobbing at the surface, sometimes wrapped in kelp, while she goes down to hunt.
Wait, really?
- ✦
They're the smallest marine mammal and the heaviest member of the weasel family.
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A raft can be a couple of otters or, in Alaska, over a thousand.
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Some sea otters specialise: one individual will eat mostly crabs while its neighbour eats mostly clams, and mothers teach the preference to their pups.
What it sounds like
Squeals, coos and whistles. A separated pup screams — a sharp, piercing call that carries a long way.
Where you might see one
Monterey Bay and Morro Bay in California, Alaska's Prince William Sound, and the coast of British Columbia.
The trouble
- Oil spills, which destroy the insulating fur
- Great white shark bites
- Disease from land run-off, including cat-borne parasites
- Entanglement in fishing gear
One real thing
Never flush cat litter. A parasite in cat faeces, Toxoplasma gondii, washes into the sea and kills sea otters — this is a real, documented and completely preventable cause of death.
More ways to help