Marine Mammals - Sea Otters

Sea otters are the smallest marine mammals in North America. They are furry creatures that grow to be about four feet in length and weigh up to sixty-five pounds. Otters are related to weasels and mink and are members of the Mustelidae family. Sea otters are almost entirely aquatic and inhabit relativly shallow waters along rocky coasts of the North Pacific Ocean. They eat a wide variety of marine invertebrate. Sea otters are the only animals, besides primates, known to use tools. They use rocks and other objects to smash open the hard shells of clams and crabs to get the meat inside.

FIGURE 5.7 Counts of Stellar sea lion pups at rookeries in Alaska and the Aleutian Islands, 1987–2005 Lowell Fritz, Tom Gelatt, Charles Stinchcomb, and Wayne Perryman, "Figure 3. Steller Sea Lion Pup Counts at Trend Rookeries in the Range of the Western Stock in Alaska by Region from the Late 1980s to 2005 in the Gulf of Alaska (A) and Aleutian Islands (B)," in Memorandum: Steller Sea Lion Pup Counts, June-July 2005, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center, October 20, 2005, http://nmml.afsc.noaa.gov/AlaskaEcosystems/sslhome/sslpdf/SSLPupCount2005Memo.pdf (accessed February 11, 2006)

Although they inhabit cold waters, sea otters do not have a blubber layer to keep them warm. Instead, they have extremely dense fur coats and high metabolism rates. Their fur coats are waterproof, but only if kept clean. This makes sea otters very susceptible to water contaminants, such as oil.

Imperiled Otter Populations