Southern Sea Otter

SCIENTIFIC NAME: Enhydra lutris nereis

STATUS: Threatened

HABITAT: Coastal waters, particularly dense kelp forests

LIFE HISTORY: Must eat the equivalent of a quarter of total body weight per day to keep warm; dives up to 180 feet for food. Fur is the thickest of all animals: 100,000 hairs per cm2, or 800 million hairs on a large adult.

THREATS: Biological pollution; pesticide and chemical run-off; oil spills

FORMER RANGE: Northern California to Baja California

CURRENT POPULATION: 2,500

These clever creatures bash or pry open their shellfish suppers with small rocks; they are one of the few mammals known to use tools. Otters are a classic "keystone species"—the health of the California coast's otter population is an excellent indicator of the marine ecosystem's overall health. By eating shellfish that nibble on kelp, sea otters help maintain kelp forests, which provide habitat and nourishment for a plenitude of fish and invertebrates.

Sea otters have the thickest fur in the animal kingdom, a trait that got them into trouble in the 18th and 19th centuries, when fur-trappers nearly hunted them to extinction. In California, about 2,500 southern sea otters remain in the coastal waters off the state's central coast.

Water pollution, particularly the discharge of disease-causing bacteria into coastal waters, appears to be taking a toll on the otter, which has been on the endangered species list since 1977. The antiquated Morro Bay sewage treatment plant discharges heavily polluted wastewater into the geographic center of California sea otter habitat. After studies linked otter deaths to pollutants in wastewater, NRDC was able to prevent the issuing of Clean Water Act waivers to the plant, which is now being upgraded to become one of the cleanest in the nation.

RELATED NRDC PAGES
The Green Gate: Southern Sea Otter

Photos: Muir Woods © National Park Service; coastal California gnatcatcher © Arnold Small, USFWS; Sierra Nevada bighorn © CA Dept. Fish & Game; California condor © Scott Frier/Nikon, USFWS; southern sea otter © NOAA/Dept. of Commerce