Sea otters live in the north Pacific in near shore coastal waters. The populations of sea otters have been heavily diminished due to human predation. Sea otter populations used to flourish from Japan in the west to southern California in the east. Now only parts of those regions have sea otter populations and most are smaller populations than in the past.

range of sea otter population: http://www.werc.usgs.gov/otters/rangemaps.html

They live by rocky shores, barrier reefs, and dense kelp forests. The kelp forests are usually less than 1.5 miles away from a coastline and only about 54 meters deep. The kelp beds provide a home for the otter as well as its favorite foods. It is also a great place to escape predators, such as the shark and orca. The sea otter often wraps the kelp around its body when sleeping to the current will not make the otter drift away from its home.

otter in kelp bed: http://oceanexplorer.noaa.gov/explorations/02quest/background/uses/seaotter_220.jpg