FaunaHub
ENEndangeredPartial review

Sea Otter

Enhydra lutris

Sea otter (Enhydra lutris) floating on its back at the surface.

Sea otter (Enhydra lutris), Morro Bay, California.

Image: Mike Baird from Morro Bay, USA (bairdphotos.com), CC BY 2.0, via Wikimedia Commons.

At a glance

IUCN category
EN · Endangered
Animal group
Mammals
Population trend
Increasing
Last verified

Conservation overview

The sea otter is a marine mammal of the North Pacific that famously uses tools and wraps itself in kelp to rest. It is assessed as Endangered.

It has the densest fur of any animal and eats sea urchins and other invertebrates.

Range & habitat

Coastal North Pacific, from California through Alaska to the Russian Far East and northern Japan.

Major threats

Threats below are drawn from the authoritative sources listed on this page. For the current, complete assessment, see the IUCN Red List.

  • Oil spills
  • Historical fur hunting (now recovering)
  • Entanglement and prey-related pressures

Why it matters

By eating sea urchins, sea otters protect kelp forests from being overgrazed — a classic example of a keystone species shaping an entire ecosystem.

Gallery

A sea otter resting at the surface with a pup.

Sea otter (Enhydra lutris) with a pup.

Image: Mike Baird, CC BY 2.0, via Wikimedia Commons.

Sources

Sources for Sea Otter

Frequently Asked Questions

Why are sea otters important to kelp forests?
They eat sea urchins, which would otherwise overgraze and destroy kelp. By keeping urchin numbers down, sea otters allow kelp forests — and the many species that depend on them — to thrive.
Why is the sea otter Endangered?
Published assessments note that, although recovering from near-extinction caused by the historical fur trade, sea otters remain vulnerable to oil spills, entanglement, and other pressures. See the IUCN Red List.

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