The Superb Sea Otter

For reasons that I never understood, visitors to pretty much every zoo I've ever worked at or even visited have always insisted that the otters are sea otters.  Never mind if the animals in question are the North American river otters which are among the most common of zoo mammals, or Asian small-clawed otters, which aren't much bigger than guinea pigs, or the far-less commonly displayed giant otters.  It's always "come look at the sea otters!"  No idea why.  When you see a sea otter for the first time in real life, you know it's something different.

Sea otters are huge, massive compared to North American river otters, even more so compared to the small-claws.  Their fur is luxurious and shaggy, their whiskers long and prominent.  Their feet have a ore than passing resemblance to flippers.  Whereas river otters are very much terrestrial animals which have evolved for a more aquatic lifestyle, sea otters are very plainly marine mammals.

Since their unmistakable from other otters when you see them in the flesh (or fur), I can only assume that most visitors who call river otters sea otters never saw one.  Which is reasonable - they're fairly uncommon in zoos and aquariums... though not nearly as uncommon as they once wore.  The species was once considered impossible to keep alive under human care, both due to its need for clean, cold water and its seemingly insatiable appetite for expensive, high quality seafood.  As is the case with many species in zoos and aquariums, enormous progress has been made in the management of these animals.  You can now find them in a number of facilities across the world, some in the US that are pretty far removed from the northern Pacific coastlines where they live, such as the Georgia Aquarium, Minnesota Zoo, and Pittsburgh Zoo and PPG Aquarium.

Of course, part of the reason that the numbers of sea otters in zoos and aquariums are increasing is that the numbers of sea otters in the wild are increasing.  The species, once hunted almost to the edge of extinction for its incredibly soft, warm fur, has rebounded and is now a common sight along much of the Pacific coast.  As a result, there has also been an increase in the number of orphaned or abandoned pups found every year.  Many of these youngsters are unable to be reintroduced back into the wild, and these are the animals that you see in zoos and aquariums.  There is no breeding of sea otters in American zoos and aquariums so as to ensure that there is sufficient space to take in rescued animals.  Even with the increased number of holders, there still is need for more space to take in non-releasable otter pups.

Photo Credit: Monterey Bay Aquarium

The feel-good science behind sea otter surrogacy

In recent years, the Monterey Bay Aquarium has spearheaded an effort to take some of the rescued pups which are found every year and return them to the wild.  The program, launched in 2002, takes lost or orphaned youngsters and pairs them with wild-born adult sea otters living at the aquarium, who teach the youngsters how to swim, forage, feed, and, most importantly, maintain their fur coat, which is essential for keeping otters warm and dry in the cold waters (unlike seals, sea lions, and dolphins, sea otters don't have blubber).  When the pups are deemed ready, they are reintroduced into the nearby waters of Elkhorn Slough to resume their lives in the wild.  Recently, the Aquarium of the Pacific has also joined the sea otter surrogacy program with a new facility on their campus.  Surrogacy is work that takes place off-exhibit to help limit the exposure of the animals to people, but it is some of the most important work that the aquariums do.

Sea otter surrogacy and reintroduction does more than give individual otters another shot at life in the wild.  It can help change the face of their ecosystems.  Sea otters are now recognized as keystone species, which play an outsized impact of their kelp forest environment.  They are the most important predators of sea urchins, which, left to their own devices, multiply out of control and mow down the kelp forests, depriving other species of food and habitat.  By controlling the number of urchins, otters help maintain healthy kelp forests which support a tremendous variety of marine life.

In saving sea otters, aquariums can do their part to maintain diverse, thriving ecosystems along the Pacific coast.

Photo Credit: Monterey Bay Aquarium