Otters are semiaquatic members of the Mustelidae family, which also includes weasels, badgers, ferrets, and mink. The IUCN Mustelid and Viverrid Action Plan include the conservation of the entire family Mustelidae with the exception of the otter.
Of the 13 otter species in the Lutrinae subfamily, the most recent edition of the IUCN Red List of Threatened Animals lists eight otters as ‘Vulnerable’ or without data. The five “endangered” species include the sea otter (Lutrafelina), the neotropical otter (L. longicaudis), the giant otter (Pteronura brasiliensis) in South America, and the river otter (Lutra lutra) in Europe and northern Asia. In Asia, the Asian small-clawed otter (Aonyxcinerea), smooth-nosed otter (Lutra perspicillata), and haired otter (L. sumatrana) are listed as “insufficiently known”.
In fact, most otters are poorly known and most are quickly disappearing along with the clean wetlands they inhabit around the world. This is the key to the importance of this action plan. It’s not just a survival plan for the otters; It is a plan for the survival of the remaining clean wetlands and the waterways that inhabit them.
The Sea Otter is a marine mammal with 3 subspecies: Southern Sea Otter, Northern Sea Otter, and Russian Sea Otter. The Southern Sea Otter can be found in California. The northern sea otter is found in Washington, Canada, and Alaska. The Russian Sea Otter is found off the eastern coast of Russia and several have been reported in Japan.
Otters are increasingly being used as a symbol of the survival of these habitats for the reasons detailed below. Historically, sea otters have ranged in number from several hundred thousand to more than a million. But because of the fur trade, the global numbers dropped to a total of 1,000, 2000 in the early 20th century. As of 2010, the three-year average is about 2,700 southern sea otters off the California coast. Between 64,600 and 77,300 north sea otters live in Alaska, Canada, and Washington. There are about 15,000 in Russia and fewer than a dozen in Japan. The sea otter was nearly wiped out in the 19th century. Today the species is protected by the Endangered Species Act and the Marine Mammal Protection Act.
Although there are several conservation projects to increase the population of the sea otter, the species is still “Endangered” by the IUCN Red List. Oil spills have been identified as one of the reasons that keep sea otters from thriving. Research shows that the Alaska Marine Lont, originally from the Aleutian Islands, has also disappeared due to the increase in the predation of whales killed. The problem as nearly 6,000 otters were confiscated in Asia between 1980 and 2015.
The Defenders of Wildlife resource, based on harvest reports, estimates the total population size of the North American river otter at more than 100,000 individuals. This species is currently listed as Least Concern (LC) on the IUCN Red List and numbers remain stable.