Featured Image Credit: Pacific Southwest Region USFWS
By Shelby Hoover
The California sea otter was on the brink of extinction. However, for the first time in generations, they are making a comeback and showing signs of recovery!
Historically, California sea otters have had years of population fluctuation. According to the California Department of Fish and Game, populations before widespread hunting were estimated to be between 16,000-20,00. Unfortunately, sea otters were hunted near to extinction due to their lavish fur sought after for its softness. From 1787-1868, an average of 2,400 sea otters were killed per year. By 1914, the total population of California sea otters was estimated to be only about 50 animals.
The California sea otter has been protected and managed by the Endangered Species Act since 1973. Now, for the first time in decades, scientists have observed more than 3,000 sea otters and pups of the coast of California!
This is a huge rebound in population for a species that has had high mortality rates and little to no population growth for years.
Tim Tinker, a research ecologist who leads the USGS (United States Geological Survey) sea otter research program, believes that the “high population count this year is partly explained by an increase in food availability in the habitat range”. Sea otters feed on sea urchins. The increases in sea urchin abundance is likely due to the decline of another species – starfish. Starfish are struggling due to an outbreak of starfish wasting syndrome. However, fewer starfish mean more urchins for hungry otters which that are more likely to survive to adulthood.
While populations are growing, California sea otter are primarily found in central California. Scientist worry that if populations continue to grow only in the center of their population range there would be a strain on ecological relationships and resources.
Sea otters are considered a keystone species. A keystone species is defined to be “a species on which other species in an ecosystem largely depend on.”
Sea otters are critically important to the health and stability of the marine ecosystem. They eat sea urchins and other invertebrates that feed on kelp forests.
So, without sea otters, the ecosystem would change drastically. No sea otters = no kelp forests.