The sea otter (Enhydra lutris) is found in coastal marine waters of the northeastern Pacific Ocean, ranging from California to as far north as the Aleutian Islands. Sea otters spend their entire lives in the ocean and even give birth while floating among the kelp beds. Their ability to use tools, often "favorite" rocks, to open clam shells and sea urchins is well-known and fascinating since few other animals are known to exhibit this behavior. Their playful, curious nature makes them the subjects of many wildlife photographers but also has aided in their demise. Many are injured or killed by ship propellers or in fishing nets.

A female sea otter eating squid. (Photograph by Karl W. Kenyon, National Audubon Society Collection. Photo Researchers Inc. Reproduced by permission.)

Some sea otters are killed for their highly valued fur. Their thick hair traps air, insulating the otter from...