Species found around the world
Otters live on every continent except Australia and Antarctica. Most people know of sea otters and river otters — but that's not the only classification. There are actually 13 different species of otter found around the world. These range from the tiny Asian small-clawed otter which is only 2-3 feet in length, to the giant otter which can reach 5-5.5 feet in length.
According to the IUCN, 12 of the 13 otter species are listed as vulnerable, threatened or endangered and are experiencing population declines. The North American river otter is the only species not threatened, thanks to existing recovery efforts that are successfully protecting river otters from pollution and other factors.
On an upswing, however, is the California sea otter. Reported in 2016, the California sea otter population reach 3,272 otters, the highest number since 1982 and an 11% increase since 2013. Conservationists credit a surplus population of sea urchins in helping the otters recover, but they caution that there is still a lot of work to be done to help the California sea otter off the endangered species list, including fuller ecological recovery.
This slide has been updated with new information since it was published in September 2015.