Both sea otters and river otters are some of the most adorable and charismatic critters on our continent. They each play an important role in the ecosystems they inhabit, however they are often mistaken for each other. This article outlines several ways you can spot the difference. Confusingly, river otters can live in both salt and freshwater areas while sea otters only live in salt water. Regionally, both animals are found in Central California, Washington, or Alaska.