Expert insights from: Peter Gros, co-host of Mutual of Omaha’s Wild Kingdom Protecting the Wild, Jessica Fujii, sea otter program manager and principal investigator at the Monterey Bay Aquarium, Gena Bentall, director and senior scientist at Sea Otter Savvy
Sea otters are one of the few animals known to use tools, cracking open sea urchins and shellfish with rocks. That appetite is exactly what makes them a keystone species — a threatened marine mammal whose presence has a powerful effect on the coastal ecosystems around them. Along the California coast, southern sea otter populations can help support kelp forests, eelgrass beds and nearshore ocean habitats.
Key takeaways
- Sea otters are marine mammals and members of the weasel family.
- Southern sea otters, also called California sea otters, are protected under the Endangered Species Act.
- Sea otters are a keystone species, meaning their presence can have a large effect on kelp forest and nearshore ecosystems.
- By eating sea urchins, sea otters can help keep kelp-grazing populations in balance, which supports healthier kelp forest habitat.
- Major threats include oil spills, food limitations, disease, pollution, pathogens, fishery interactions and predation.
- People can help sea otters by keeping a safe distance, reducing pollution and following responsible coastal recreation habits.
Why are sea otters important?
Sea otters are important because they help keep coastal ecosystems in balance. In kelp forests, they eat sea urchins and other grazers that feed heavily on kelp. When present in healthy numbers, sea otters can ease that grazing pressure and help protect the kelp forest habitat that fish, invertebrates and other marine animals depend on.
Sea otters are also an indicator species. Their health can reflect larger changes in the ocean, from pollution and disease to prey availability and habitat conditions. When sea otters struggle, it’s often an early sign that the wider coastal ecosystem is under stress too.
Why are sea otters a keystone species?
Sea otters earn the keystone species label because of what they eat. By preying on sea urchins and other grazers, they keep those populations in check. That stops the urchins from mowing down kelp, so a single species ends up shaping the whole underwater forest. That ripple effect is why sea otter recovery is so closely tied to kelp forest health, ocean health and the recovery of coastal habitats.
To see that connection up close, the Wild Kingdom team traveled to Monterey, California, where the crew met with scientists and conservation experts working to better understand these marine mammals and the habitats they influence.
Are sea otters endangered?
The answer depends on the population. The southern sea otter, also known as the California sea otter, is listed as threatened, not endangered, under the Endangered Species Act and designated as depleted under the Marine Mammal Protection Act. “Threatened” means a species is likely to become endangered without continued protection.
In other words, southern sea otters aren’t considered fully recovered, even though conservation work has helped the population rebound from historic lows. Sea otters were once heavily hunted for their dense fur, and by the early 1900s, only a small remnant population remained along parts of the Pacific Coast.
Today, southern sea otters are protected by federal and state laws, and scientists continue to monitor their population, range and threats.
The complex history of sea otter recovery
Sea otters have long called the California coast home. But by the early 1900s, the maritime fur trade had pushed them close to extinction across much of their historic range. Along the California coast, a small surviving group became the foundation for the southern sea otter population that conservationists study today.
Protection, monitoring, rescue work and public awareness have helped southern sea otters recover from those historic lows. Even so, their range remains limited, and their recovery is still vulnerable to environmental change, disease and human-related threats.
Climate change tested that recovery again in the 2010s. A massive marine heat wave nicknamed “the blob” warmed coastal waters — bad news for kelp forests, which grow best in cold water.
Meanwhile, another species suffered at the same time — the sea star. Its population was devastated by sea star wasting disease, which the warm water made worse. The sea star is an important predator of the purple sea urchin, the same urchin that grazes on kelp. In an ecosystem this interconnected, when one species struggles, the effects ripple through the entire food web.
How do sea otters help kelp forests?
Sea otters help kelp forests by eating sea urchins and other animals that graze on kelp. When urchin populations grow too large, they overgraze kelp and leave behind urchin barrens.
Diving in a remnant kelp forest in Monterey Bay, Peter Gros, co-host of Mutual of Omaha’s Wild Kingdom Protecting the Wild, saw the damage firsthand. Sea urchins, he notes, “have been mowing down the kelp at astonishing rates, leaving behind barren patches of reef where the giant forests once stood.”
Normally, predators such as sea otters and sea stars keep urchin numbers in check. But with sea star populations hit hard by wasting disease, sea otters play an even bigger role. As Peter puts it, “sea otters love to feed on urchins, and their foraging is one of the things maintaining the few remaining patches of kelp forest in the area.”
That said, sea otters can’t solve every challenge facing kelp forests. Ocean warming, disease and pollution all put pressure on the ecosystem. But sea otters are an important part of the conservation story, because their feeding behavior helps shape the underwater habitat around them.
What threats do sea otters face today?
Southern sea otters are protected, but they still face several threats that can slow recovery or harm individual animals. These can include:
- Shark bite mortality
- Disease and parasites
- Fishing gear entanglement
- Oil spills
- Contaminants and pollution
- Harmful algal blooms
- Limited range and prey availability
- Human disturbance from boats, kayaks, paddlers or shoreline activity
Because sea otters spend much of their time near shore, they often live close to people. That makes responsible wildlife viewing and clean coastal habitats especially important.
How does sea otter surrogacy support conservation?
Sea otter surrogacy supports conservation by giving orphaned pups a path back to the wild. Over time, it helps rebuild the population. Through the program, a rescued pup that can’t be raised by its biological mother is paired with an adult female sea otter under expert care. The surrogate teaches the pup the skills it needs to survive, including grooming, diving, foraging and resting in the water.
The Monterey Bay Aquarium pioneered the approach, which grew out of rescue work that began there in 1984.
“From there, we were really learning how to care for these animals; could we get them back into the wild by release; can we pair a pup that has stranded with a female that is not their biological mother,” said Jessica Fujii, sea otter program manager and principal investigator at the Monterey Bay Aquarium.
When successful, programs like this can help give stranded pups a better chance of returning to the wild while also supporting long-term research and conservation.
How can people help sea otters?
People can help sea otters by giving them space and making coastal habitats safer and less stressful for wildlife.
The Wild Kingdom team saw this firsthand while filming in Monterey Bay. At the Monterey Bay Aquarium, the crew watched sea otters somersault through their exhibit during a morning meal. Later, Co-Host Peter Gros dived the kelp forest with underwater photojournalist Jennifer Adler. He then kayaked through Elkhorn Slough — a tidal estuary where sea otters live — with a representative from Sea Otter Savvy.
There, the team saw sea otters resting in kelp and learned why distance matters. Sea otters need energy to stay warm, groom, forage, rest and care for their pups. If people approach too closely, a sea otter may stop resting, dive away or change its behavior, wasting energy and creating stress, even when the disturbance is unintentional.
Gena Bentall, director and senior scientist at Sea Otter Savvy, explained that giving sea otters space is one of the most direct ways people can help.
“Sometimes we can really feel overwhelmed by climate change and the plastic crisis and feel that it’s hard for us to make a difference,” Bentall said. “But if you come out here in Elkhorn Slough or anywhere within the sea otters’ range, you can make a conservation statement and take active measures to preserve these animals just by giving them space.”
When visiting sea otter habitat:
- Watch from a respectful distance
- Never touch, feed, chase or try to interact with a sea otter
- Keep kayaks, paddleboards and boats from surrounding or crowding sea otters
- Reduce noise near resting sea otters or rafts
- Keep trash, fishing line and plastics out of waterways
- Follow local wildlife viewing rules and posted guidance
- Report stranded, sick or injured sea otters to local wildlife professionals instead of trying to help on your own
These actions may seem small, but they help reduce preventable disturbance in the places sea otters need to rest, feed and raise pups.
Support sea otter conservation
Sea otters are recovering, but their future still depends on the choices people make along the coast. The most powerful one is also the simplest: give them space. On the water or near the shore, keep a respectful distance and set an example for others.
The same habit helps wildlife everywhere. Watch from a distance, never feed or touch animals and follow local guidance so people and wildlife can safely share natural spaces.
Learn how to be a responsible wildlife viewer and support sea otter conservation through Sea Otter Savvy.
Sources:
U.S. Fish and Wildlife Service. Marine Mammal Program. May 2026.
U.S. Geological Survey. Dynamic and Context-Dependent Keystone Species Effects in Kelp Forests. March 3, 2025.
NOAA Office of National Marine Sanctuaries. Restoring Balance: What Sea Urchins Reveal About Ecosystem Health. June 25, 2026.
NOAA Office of National Marine Sanctuaries. Sea Otters in Washington State: Lessons Learned from the “Grand Experiment” of the Maritime Fur Trade. Feb. 25, 2025.
Barrett et al. Energetic Cost of Human Disturbance on the Southern Sea Otter. Journal of Wildlife Management. March 5, 2025.
Shedd Aquarium. Growing the Next Generation of Sea Otter Surrogates. May 12, 2025.
