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Sea otters aren’t just cute to look at, they also play a critical role in preserving the environment. By hunting invertebrates like clams and sea urchins, sea otters help preserve kelp forests, which in turn sequester carbon, protect coastlines and provide food and shelter for other marine life.?

Their hunting prowess makes sea otters a keystone species, meaning that other aspects of the ecosystem rely on their existence. Without the sea otter, many species that shelter in the kelp forests they help protect would die. But the species has faced numerous threats, from hunting, commercial fishing and oil spills, and populations dropped to near extinction in 1911. Thanks to conservation initiatives, numbers have started to bounce back, with around 130,000 sea otters worldwide.

Sea otters can be found across the North Pacific Ocean. Historically their range stretched from Hokkaido, Japan, to the coast of Mexico, according to <a target="_blank">the IUCN</a>. Today, they are mostly found across North America, from California to Alaska, as well as parts of Russia's far east. In this photo, a pair of sea otters are photographed resting on a float in Cordova’s boat harbor, Alaska.
Sea otters can be found across the North Pacific Ocean. Historically their range stretched from Hokkaido, Japan, to the coast of Mexico, according to the IUCN. Today, they are mostly found across North America, from California to Alaska, as well as parts of Russia's far east. In this photo, a pair of sea otters are photographed resting on a float in Cordova’s boat harbor, Alaska.
Al Grillo/AP
With the densest fur of any animal – an estimated million hairs per square <a target="_blank">inch</a> – the sea otter’s coat keeps it warm in the frigid North Pacific Ocean. While an important adaptation, it almost proved to be the otters’ downfall, as the fur became a target for hunters during the 18th and 19th centuries<strong>.</strong><br />The sea otter<strong> </strong>population dropped from between <a target="_blank">150,000 and 300,000</a> in the early 1700s to an estimated 2,000 in 1911. In the same year, sea otters were afforded protection by a treaty between the US, Japan, UK and Russia, which banned sea otter hunting and enabled the populations to rebound, although they remained widely <a target="_blank">fragmented</a>.?Here, a sea otter rests on its back in the protected waters at Moss Landing, Monterey Bay, California.
With the densest fur of any animal – an estimated million hairs per square inch – the sea otter’s coat keeps it warm in the frigid North Pacific Ocean. While an important adaptation, it almost proved to be the otters’ downfall, as the fur became a target for hunters during the 18th and 19th centuries.
The sea otter population dropped from between 150,000 and 300,000 in the early 1700s to an estimated 2,000 in 1911. In the same year, sea otters were afforded protection by a treaty between the US, Japan, UK and Russia, which banned sea otter hunting and enabled the populations to rebound, although they remained widely fragmented.?Here, a sea otter rests on its back in the protected waters at Moss Landing, Monterey Bay, California.
VW Pics/Universal Images Group/Getty Images
Oil spills have been another big threat to the species, as when oiled the sea otter fur loses its ability to insulate and, without the layer of blubber that many other marine mammals possess, they can <a target="_blank">freeze</a>.?In<strong> </strong>1989, the Exxon Valdez oil spill devastated the burgeoning sea otter population in south central Alaska, taking 25 years to return to pre-oil spill <a target="_blank">numbers</a>. In this photo, a sea otter is restrained and washed by workers at a local animal facility after being coated in oil during the spill in Prince William Sound, Alaska.<br />In California, population declines have been linked to <a target="_blank">commercial fisheries</a> and the use of gill and trammel nets, which otters get caught in and drown. Today, Californian sea otters only occupy about 13% of their original habitat, with about 3,000 <a target="_blank">individuals</a> remaining.
Oil spills have been another big threat to the species, as when oiled the sea otter fur loses its ability to insulate and, without the layer of blubber that many other marine mammals possess, they can freeze.?In 1989, the Exxon Valdez oil spill devastated the burgeoning sea otter population in south central Alaska, taking 25 years to return to pre-oil spill numbers. In this photo, a sea otter is restrained and washed by workers at a local animal facility after being coated in oil during the spill in Prince William Sound, Alaska.
In California, population declines have been linked to commercial fisheries and the use of gill and trammel nets, which otters get caught in and drown. Today, Californian sea otters only occupy about 13% of their original habitat, with about 3,000 individuals remaining.
John Gaps III/AP
Conservation efforts include translocating otters from established areas to new locations to reintroduce them to their former<strong> </strong>habitat. In the 1980s, the <a target="_blank">US Fish & Wildlife Service</a> (FWS) moved 140 otters from the central California coast to San Nicolas Island, 61 miles from the mainland, to increase the otter’s range. There is now a small but stable population of the species in the area, according to FWS. Here, a seven-week-old sea otter pup and participant in the Sea Otter Rescue Program receives her first solid food at the Monterey Aquarium, California.
Conservation efforts include translocating otters from established areas to new locations to reintroduce them to their former habitat. In the 1980s, the US Fish & Wildlife Service (FWS) moved 140 otters from the central California coast to San Nicolas Island, 61 miles from the mainland, to increase the otter’s range. There is now a small but stable population of the species in the area, according to FWS. Here, a seven-week-old sea otter pup and participant in the Sea Otter Rescue Program receives her first solid food at the Monterey Aquarium, California.
Melina Mara/The Washington Post/Getty Images
Similar efforts were made<strong> </strong>in Washington state, where the species had gone extinct in the early <a target="_blank">1900s</a>. In the 1970s, conservationists released 59 sea otters, captured from Amchitka Island in Alaska, to the state’s Olympic Peninsula. Although the initial population struggled, today, there are an estimated 1,380 otters in the state, based on <a target="_blank">2016 data</a>. In this image, a sea otter named Aniak from the Seattle Aquarium swims on her back with her daughter on her chest as her own mother, Lootas, swims by at right.
Similar efforts were made in Washington state, where the species had gone extinct in the early 1900s. In the 1970s, conservationists released 59 sea otters, captured from Amchitka Island in Alaska, to the state’s Olympic Peninsula. Although the initial population struggled, today, there are an estimated 1,380 otters in the state, based on 2016 data. In this image, a sea otter named Aniak from the Seattle Aquarium swims on her back with her daughter on her chest as her own mother, Lootas, swims by at right.
Ted S. Warren/AP
Already, the revival of sea otters has had a positive impact on the kelp forests along the California coast. After a large outbreak of kelp-eating sea urchins in 2013, otters helped to control urchin populations and <a target="_blank">keep kelp forests healthy</a>.<br />Just as kelp forests rely on sea otters, the otters depend on kelp, and not just for food. Sometimes they will <a target="_blank">wrap themselves</a> in strings of kelp to prevent themselves from floating away while asleep. Here, sea otters groom and rest together in a kelp bed near Morro Rock, California<strong>,</strong> an area which local tribal members want to be included as part of the <a target="_blank">proposed</a> Chumash Heritage National Marine Sanctuary.
Already, the revival of sea otters has had a positive impact on the kelp forests along the California coast. After a large outbreak of kelp-eating sea urchins in 2013, otters helped to control urchin populations and keep kelp forests healthy.
Just as kelp forests rely on sea otters, the otters depend on kelp, and not just for food. Sometimes they will wrap themselves in strings of kelp to prevent themselves from floating away while asleep. Here, sea otters groom and rest together in a kelp bed near Morro Rock, California, an area which local tribal members want to be included as part of the proposed Chumash Heritage National Marine Sanctuary.
Mario Tama/Getty Images