Estimates of island-wide sea otter population density as surveyed with boats circumnavigating nine focal islands within the central and western Aleutian Islands (Alaska) from 1991-2015.

Island-wide sea otter population densities were quantified at each of six focal islands (as well as three other islands) over the last three decades (1991-2015). Surveys were conducted opportunistically as part of a long-term monitoring program coordinated and overseen by the U.S. Fish and Wildlife Service.