Sea otter populations
haven’t fully recovered
We’ve released the Sea Otter Bracelet in partnership with Monterey Bay Aquarium to raise awareness about threatened southern sea otters and the important role they play in maintaining a healthy ocean ecosystem. Every bracelet purchased pulls one pound of trash from the ocean and coastlines.GET THE BRACELET
Sea otters are perhaps one of the ocean’s most adorable inhabitants, but these iconic creatures are more than a cute face. They’re a keystone species that plays a critical role in maintaining healthy nearshore marine ecosystems in the Paciﬁc.
Despite their importance to coastal kelp forests and seagrass beds, sea otters have been listed as an endangered species on the IUCN Red List since 2015. However, the IUCN doesn’t differentiate between specific sea otter populations, some of which are considered endangered while others are considered threatened.
It’s estimated that California’s southern sea otter population numbers just over 3,000 individuals. While this threatened population of sea otters has been growing slowly, decades of protection haven’t helped it bounce back as dramatically as researchers had hoped. Elevated mortality is largely due to non-consumptive predation by sharks, disease and contaminants, limited food availability, oil spills, and human disturbances.
While we do understand some of the threats southern sea otters face, more research is needed to understand what’s been hindering their recovery. With better insight into the complex and intertwined challenges they face, it’s possible to develop and implement more effective, long-term management that could help southern sea otters move back into more of their historical range along the California coast.
Healthy kelp forests are crucial to a balanced marine ecosystem. Not only do they act as nurseries and provide food and habitat for countless species, they also help mitigate the impacts of climate change by absorbing vast amounts of carbon from the atmosphere.
Sea otters play a pivotal role in keeping kelp forests healthy because they feed on the sea urchins and other invertebrates that forage there. Without sea otters to keep their populations in check, sea urchins can eat up all the kelp and transform the kelp forest into an urchin barren.
Before the Paciﬁc Maritime Fur Trade of the 18th and 19th centuries, sea otters numbered in the hundreds of thousands and were found all along the North Paciﬁc Rim from Japan to Mexico. Their pelts were valued because of their thick, lush fur, which was used in the production of coats, hats, and trim.
As demand for sea otter pelts rose, so did the price. In fact, they became known as “soft gold” in some markets and were harvested with reckless abandon throughout their range. By 1911, sea otter populations were severely depleted and the species was on the brink of extinction. Today, sea otters occupy less than 25% of their historical range.
Sea otters have very little fat to keep them insulated and rely on their extraordinarily thick fur to stay warm and dry. Their incredibly dense fur traps air between the hairs, which accounts for about 70% of their coat’s insulating properties. In fact, they have the thickest fur of any mammal with nearly one million hairs per square inch.
In an oil spill, crude oil quickly penetrates their fur and destroys the air layer that insulates them. Sea otters exposed to an oil spill can quickly die of hypothermia.
Otters exposed to oil will also groom themselves in an attempt to remove the oil from their coat. Ingesting crude oil and inhaling the fumes can lead to severe, long-term organ damage and other potentially life-threatening conditions.
The 1989 Exxon Valdez disaster in Alaska made it abundantly clear that oil spills pose the single largest threat to sea otters. Just one large oil spill off the Central Coast of California would be catastrophic because it could threaten a signiﬁcant number of southern sea otters at once.
Monterey Bay Aquarium scientists have found that the absence of signiﬁcant kelp canopy coverage at the peripheries of the sea otter range, especially in waters north of Santa Cruz and south of Point Conception, can inhibit sea otters’ ability to reproduce and survive.
Without sufﬁcient kelp canopy cover, sea otters (especially reproductive females and their pups) can be left vulnerable to white shark bites — a multi-faceted problem that might also reﬂect a shift in the predatory behavior of sharks from open ocean to nearshore waters.
Clusters of sea otter deaths tend to occur near areas with dense human populations. Contaminated runoff from these areas into nearshore waters introduces diseases, parasites, and toxic compounds that can pose serious health risks to sea otters.
Diet plays a huge role in their susceptibility. Sea otters’ high metabolic rate requires them to eat up to 25% of their body weight in invertebrate prey every day. This includes a high volume of ﬁlter-feeding animals, like mussels and clams.
Because they indiscriminately sieve particles out of the water, shellﬁsh can accumulate high concentrations of pollutants and disease pathogens. When sea otters consume these shellfish they’re exposed to bacteria, parasites, and pollutants in harmful or even lethal doses.
Pollutants such as polychlorinated biphenyls (PCBs) and dichloro-diphenyl-trichloroethane (DDT) can damage otters’ nervous systems, affect pregnancy, overall health, and compromise their immune systems.
Because of their vulnerability to toxic contaminants, sea otters are considered a sentinel species, which means they can serve as indicators of the ocean’s overall health. In fact, otter die-offs have alerted scientists to several harmful events in the marine environment.
Raising pups is a strenuous task for sea otter moms. Depending on their geographic location, otters can spend up to 10 hours per day foraging. The demands of motherhood naturally leave female sea otters vulnerable to energy deﬁcits that can threaten their survival.
Harassment and human disturbances can force moms to dive or swim away, costing precious energy stores they need to care for their babies and themselves. Overexertion can make moms more vulnerable to infection and disease. It may even cause them to abandon their pups because they’re unable to provide for them.
Released in partnership with Monterey Bay Aquarium, our Sea Otter Bracelet helps raise awareness about the threats facing this endangered species and the actions we all can take to protect and restore their populations.
We’re also donating $25,000 to Monterey Bay Aquarium to support their work to protect and conserve southern sea otters. Our donation will help fund education, research, and outreach.
Monterey Bay Aquarium partners with state, federal, and academic researchers to study sea otters in the wild. Their Sea Otter Program has focused on the threatened southern sea otter population since 1984. Their goal is to better understand the challenges this population faces and promote its recovery.
Through the Sea Otter Program, Monterey Bay Aquarium rescues, treats, and releases injured sea otters. They also raise and release orphaned pups through their surrogacy program, seek homes for sea otters that can’t return to the wild, and conduct scientific research that advances conservation efforts.
A variety of sea otter research projects are currently being conducted along the California coast. In a multi-year collaboration with the US Geological Survey, California Department of Fish and Wildlife, and University of California Santa Cruz, the aquarium helped capture, tag, and release dozens of sea otters back into the wild where they can be tracked and monitored. Some are tracked from birth to death. The data these trackers provide will help researchers better understand how they live and what’s causing their sluggish recovery.
By purchasing a Sea Otter Bracelet, you’ll remove one pound of trash from the ocean and coastlines while raising awareness about the importance of sea otter conservation. Wear it as a reminder to curb your plastic habit, live more sustainably, and encourage others to take action to protect what they love.
Sea otters are crucial to a healthy, balanced, and resilient marine ecosystem. If you’d like to do more to support their recovery, we encourage you to get involved with or donate to Monterey Bay Aquarium directly.
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