Southern Sea Otter

Southern sea otters, also known as California sea otters, can be found in nearshore areas along the central California coastline, including areas of high human activity, like harbors. As a keystone species, they play a fundamental role in the natural food web, and keep important elements of coastal ecosystems like kelp forests and seagrass beds in balance.  

Kelp forests provide numerous benefits, including habitat for hundreds of invertebrate and fish species, reductions in coastal erosion and carbon storage that can moderate climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change . Seagrasses also provide important benefits, like nursery habitat for many other species, shoreline protection and carbon sequestration. 

Unlike whales and seals, sea otters lack blubber. Instead, they rely on their dense fur coat and elevated metabolism to stay warm. The average adult sea otter must eat 20 to 30 percent of its body mass in food each day just to meet its energy requirements. Sea otters need to conserve energy, which means that uninterrupted rest is an important part their well-being. To minimize the potential for disturbance and harm to sea otters, people sharing sea otter habitat should: 

• Maintain a safe distance - if a sea otter notices you, you are likely too close and should back away

• Keep kayaks at least 60 feet (or five kayak lengths) away, passing by parallel rather than pointing directly at any animals and moving slowly but steadily past rather than stopping

• Keep pets on a leash on and around docks and harbors and never allow interactions, even if the animals appear to be playing

• Never feed sea otters, as they can become aggressive, which could result in their removal from the population

Like all sea otters along the North Pacific rim, southern sea otters were hunted to near extinction during the fur trade of the 1700s and 1800s. The subspecies survived because a few dozen animals eluded hunters off the rugged coast of Big Sur. Southern sea otters are now protected under the Endangered Species Act, Marine Mammal Protection Act and California state law. The southern sea otter population has grown slowly since receiving federal protections in the 1970s, fluctuating around 3,000 in recent years.

Learn more from the U.S. Geological Survey population survey for southern sea otters.

To support southern sea otter recovery, we translocated 140 sea otters from the central California coast to San Nicolas Island in the late 1980s to create a secondary population to buffer against the chance of extinction. Most sea otters immediately swam back to their home range or into other areas of California, and some died, but about a dozen stayed, forming a small core population that grew slowly for many years. One requirement of that translocation program was that sea otters entering a no-otter management zone, which extended throughout southern California except the translocation zone around San Nicolas Island, be removed by non-lethal means. Non-lethal removal proved impractical, expensive, harmful to the animals removed, and due to the strong homing impulse of sea otters, it also proved futile. We terminated the program and its associated zones in 2012. Now, more than three decades after the program was initiated, the population is growing more rapidly, though it remains small and represents less than five percent of the southern sea otter population overall. 

Range expansion is a key part of southern sea otter recovery and is critical to the restoration of ecosystems in which sea otters evolved as a keystone predator. Southern sea otters have reached carrying capacity in the central part of the mainland range, with mortality from shark bites at the range peripheries preventing range expansion from happening naturally. As a result of shark-bite mortality, no net range expansion has occurred in more than 20 years. 
 
Under a directive from Congress, we worked with partners and stakeholders in 2021 to evaluate the feasibility of reintroducing sea otters to the West coast of the contiguous U.S., where sea otters historically thrived. Assessment of feasibility is the first step in any reintroduction effort, but it is not a reintroduction proposal. If reintroduction consideration continued, any reintroduction proposal would be developed with extensive input from a broad range of stakeholders. 
 
We are currently reviewing the status of the southern sea otter under the Endangered Species Act. The species status assessment is based on the best available scientific and commercial data regarding the species, including population trends, distribution, demographics, genetics, habitat conditions, threats and conservation measures. By thoroughly reviewing the best available data, we will have a better understanding of all the factors influencing the sustainability of southern sea otters in the wild - now and into the future.