Sea otters are marine mammals that were once a part of Oregon’s kelp forests. Sea otters currently live in two major areas in the eastern Pacific. Northern sea otters are found from Washington and British Columbia up through Alaska while southern sea otters are found along the central California coast. Sea otters live in kelp forests and feed on crabs, snails, mussels, urchins, and other invertebrates as well as fish. In healthy ecosystems, sea otters are a keystone species that maintain balance in estuaries and kelp forests. Sea otters help maintain kelp forests and seagrass beds by feeding on the grazers that eat kelp and seagrass. Southern sea otters weigh between 50-70 pounds while northern sea otters weigh between 70 and 100 pounds. Sea otters are the only marine mammal that don’t rely on blubber to keep them warm in the frigid waters of the pacific. Instead, otters have a two-layer fur that is the densest in the world with a million hairs per square inch. Along with having dense fur sea otters maintain their body heat with their high metabolism, as they need to eat close to 25% of their body weight per day.