The river otter and sea otter are both members of the family of animals called mustelidae that includes badgers, weasels, minks, wolverines, and skunks. The primary difference between the two species has more to do with where they live than actual physical differences. Sea otters are true marine mammals, found only in the ocean and rarely seen on land. They are really quite clumsy on land and are perfectly capable of spending their entire lives at sea.
River otters are land mammals that inhabit fresh water lakes, rivers, and streams.
They are amphibious creatures that are well adapted to a life in water and on land. In North America, sea otters can only be found in the shallow waters of the Pacific Ocean along the coast of California and Alaska. In North Carolina, river otters are found chiefly in the coastal and central portions of the state. A relocation program instituted by the North Carolina Wildlife Resources Commission in the early '90s reintroduced otters to the river systems of western Carolina. River otters, like this one, are better suited for life on land than their cousins, sea otters.