Not only are sea otters some of the most fascinating members of the weasel family, they are also some of the smallest marine mammals, with adults weighing in at between thirty and one hundred pounds. Their pelts, which are the thickest of all animals’ fur, caused them to hunted nearly to extinction. Today, the sea otter is making a comeback in some places, but is still threatened in others.
Cold Water Survivors
Endemic to the coasts of both the northern and eastern North Pacific, the sea otter is capable of walking on land and is sometimes seen lounging in the sun onshore; but most often, you’ll find these incredible animals floating on their backs or diving to the sea floor to forage for mollusks, crustaceans, sea urchins, and fish. Interestingly, these otters are some of the only non-primates to use tools to access their food; they use rocks both to dislodge their prey from anchoring points and to smash shells to access meat.
As a keystone species, the sea otter’s role is to keep sea urchin populations under control; sea urchins destroy kelp forests when populations go unchecked, and without kelp forest homes, many other creatures would have no protection.
Sea otters were once numerous; in fact, before nearly two centuries of intensive hunting that took place between 1741 and 1911, world populations are estimated to have been close to 300,000 individuals. Wiped out over much of their historic range, their numbers eventually plummeted to include just one to two thousand individuals. Thanks to conservation efforts, a long-standing ban on hunting, and reintroduction programs, otter numbers have increased, and the species is now populating nearly two-thirds of the range it once inhabited.
While populations in British Columbia and Russia are still increasing, population growth in the Aleutian Islands and California have plateaued or even declined in recent years. Some fishermen have been caught killing them, particularly in areas where crabbing is common; otters love to eat crabs, and instead of realizing that overfishing, pollution, and even seismic activity are causing shellfish decline, some fishermen are blaming crab population decreases on otters.
While the sea otter does have some natural predators, including eagles, sea lions, orcas, and great white sharks, they have pungent glands that make them distasteful – in fact, they are not a favorite prey item of any of these predators. The greatest threat to these playful, photogenic creatures continues to come from man; though this time, it is in the form of oil spills. When a sea otter’s fur comes into contact with oil, it mats and loses its ability to maintain the otters’ body temperature, meaning that the animals often die from hypothermia. The Exxon Valdez Oil Spill of 1989 killed thousands of otters in Prince William Sound, and the oil that lingers there to this day has prevented an otter comeback. Even a small oil spill can cause otters to become ill or die; they ingest the toxic substance while grooming; one more reason petroleum producers must be very cautious.
Encountering a sea otter or a group of them is always a delight, and one of the best places to encounter them is along California’s coast, particularly within the confines of the Monterey Bay National Marine Sanctuary, where over 1,200 otters thrive, and in Western Washington state, where about 500 individuals are known to populate the Olympic Coast National Marine Sanctuary. Remember to watch from a distance, and enjoy what is certain to be one of the most memorable marine life encounters you’ll ever have.