Imagine you’re floating on a raft in a pool, in a beautiful tropical setting. Just as you’re reaching peak relaxation, two kids jump in screaming and laughing, splashing cold pool water on you.

The kids find it funny – after all, it was just an accident. But you’re gasping for air, shocked by the cold water and frustrated at their disregard for your space.

Sea otters experience something like that every day. Kayakers get closer and closer, trying to get a better look at the napping otters – the ocean’s fuzziest (and debatably cutest) creatures. That kind of disruption might be tolerable now and then, but imagine if that happened to you many times a day, every day – it adds up, and can be exhausting.

That’s exactly what’s happening to California’s sea otters. “As researchers, we constantly see kayaks and boats moving into a group where there’s otters resting, and they get too close,” says Michelle Staedler, a sea otter biologist at the Monterey Bay Aquarium. The kayakers’ approach causes the otters to swim away abruptly, she says.

Sea otters are an endangered species and are crucial to the balance of California’s coastal ecosystem. To understand how disturbances affect sea otters, scientists are figuring out how much energy it takes the otter to swim away time and time again.

Nearly every day, the researchers observe and record the activities of sea otters, including when the otters are disturbed by humans. Then they combine these observations with known data on how much energy it takes an otter to do various activities. By doing this, the researchers have discovered how much energy it costs a sea otter to swim away and then recover from disturbances.

“For a long time we kind of brushed off the effects of human disturbance,” says Lilian Carswell, the Southern Sea Otter and Marine Conservation Coordinator for the U.S. Fish and Wildlife Service. That’s because it wasn’t a major issue until recently.

An increase in the number of people participating in recreational activities over the past few years means there are more opportunities for humans and sea otters to encounter one another. Now that scientists can quantify the amount of energy used by otters, Carswell says she has “a whole new perspective” on how disturbance affects the otters. She explains that sea otters in Monterey Bay are at carrying capacity, which means there isn’t enough food in the area to sustain any more otters. Sea otters have a very high metabolism, which means they must sleep a lot and eat a lot as part of their normal, healthy routine.

Everything the otters are doing is essential to survival, and, she says, “There’s no extra energy to waste.”

A growing fan base

Ecologist Gena Bentall coordinates the study on the costs of sea otter disturbance. She says the study provides a direct way for people to understand how their behavior impacts wildlife.

Bentall is a passionate marine conservationist who deeply cares for sea otters. But she’s also staunchly committed to promoting a harmonious relationship between people and wildlife.

As ecotourism continues to grow, it’s not only sea otters that interact with humans more frequently. Around the world, human and wildlife interactions are more and more common. Sometimes this results in a positive outcome for all involved. For example, sea turtles aren’t hunted for food anymore, since they are more profitable alive as wildlife tourism attractions. But in other cases, the outcome isn’t as great; earlier this year Canadian researchers reported in Conservation Biology that caribou in Québec are abandoning their habitat to flee backcountry skiers.

Bentall says her work shows, for the first time, a way that researchers can quantitatively measure the cost of interactions between people and wildlife. Bentall has studied sea otters since 2001, when, in her late 30s, she began studying sea otters in San Simeon, on California’s Central Coast. In 2003, she began working on her master’s degree in Ecology and Evolutionary Biology at the University of California, Santa Cruz. Then, after earning her degree, she began working as a scientist with the Monterey Bay Aquarium’s Sea Otter Research and Conservation program.

In the following years, kayakers began flocking to Monterey Bay, drawn by the sea otters and other wildlife. While working at the Aquarium, Bentall and other researchers saw that the kayakers often disturbed the sea otters by paddling too close, forcing the animals to dive and swim away in response. The otters were chased away as often as every five or ten minutes on some days. Bentall and her colleagues realized the otters were far more active than usual because they were avoiding kayakers. “It was something that bothered a lot of us,” she says.

Around the same time that scientists were noticing these sea otter disturbances, the Monterey Bay Aquarium restructured its sea otter research program, and ended funding for Gena Bentall’s position in 2015. But she wasn’t about to give up her passion. Sea otters were still being stalked by kayakers, and Bentall knew someone needed to find out what that did to the otters and warn people to keep a more respectful distance, whatever that was.

So Bentall reached out to the community of scientists who study sea otters in California, including Staedler and several researchers at the California Department of Fish and Wildlife, to talk about starting a program for sea otter disturbance research and education. Thanks to Bentall’s initiative, scientists from the Southern Sea Otter Alliance, Monterey Bay Aquarium, California Department of Fish and Wildlife, Friends of the Sea Otter, and U.S. Fish and Wildlife Service collaborated to create Sea Otter Savvy, a non-profit organization funded by the California Coastal Commission.

Representatives from each of those groups make up a panel of advisors that oversees Sea Otter Savvy, with Bentall at the helm as the program coordinator. Her main mission is to educate the community about human-caused disturbances of sea otters and other marine wildlife by using science-backed evidence about the impacts of disturbance.

“She’s doing a phenomenal job of making this happen,” says Staedler about Bentall. “She’s pretty passionate about it.”

For Bentall, it’s just her way of life. As the only employee, she does everything to keep the organization going. She depends heavily on volunteers who have been personally trained by her, to observe sea otters from the shore in Moss Landing, Monterey and Morro Bay. Most of them are also well acquainted with Bentall’s beagle Henry, who goes to work with her every day – in the field and the office.

Bentall’s office is in Moss Landing, California – a small fishing village in the middle of Monterey Bay’s coastline that’s a popular destination for whale watching. It’s also at the mouth of a large estuary named Elkhorn Slough, where wildlife flourishes. Every day, Bentall is surrounded by seals, sea lions, numerous seabirds, and of course, sea otters. There are worse places for a marine ecologist to work.

Standing on a small cliff above the water at the end of Jetty Road in Moss Landing on a recent day, Bentall trains a new volunteer, Emily Nazario. They’ll observe and record the behaviors of a group of twelve or so otters floating about 50 meters away. It’s sunny, and the water is calm. One otter cruises across the surface on its belly; a couple others spin in slow circles. But most float on their backs with their eyes closed, barely moving. Watching them is relaxing.

Bentall and Nazario set up a scope on a tripod and loop binoculars around their necks – tools to better observe the otters. Amy White, a veteran volunteer, pulls out a clipboard and jots down data about the weather, wind speed, and tide. It’s warm and the skies are clear. There’s only a soft breeze and the tide is going out – perfect weather to be outdoors.

They’re preparing for a two-hour field session during which they’ll record the behavior of each otter and what’s going on around it every 15 minutes. This method of collecting data is called scan sampling, and it’s essentially recording a series of snapshots in time. It usually requires two people – one to spot the otters and describe what’s going on and another to record the information on a clipboard. But since Nazario is a new volunteer, White has come along to assist in her training.

Bentall and her team start their scan with Nazario and Bentall looking through binoculars. Nazario calls out what each otter is doing and White records.

“Okay, group one…resting, resting, resting, resting…swimming. Resting, resting,” says Nazario, as she uses her binoculars to scan the group of otters in front of us. Bentall follows along with her binoculars in case Nazario needs help.

As soon as the researchers finish their first scan, a curious bystander walks up and asks what they’re doing. The researchers explain that they’re studying whether the kayakers bother the sea otters.

“I don’t think it does anything to them,” says the man, who’s in a collared shirt with a company logo. He’s hanging out here on his lunch break. Surely the otters would just swim away if the kayakers were dangerous, he says.

Bentall tells him that sea otters feel like people who go to work stressed every day – they deal with it because they have to at the time, but it’ll lead to health problems if they keep it up. The man nods in agreement, or maybe just in thought.

“I think I was pretty naïve when I first started,” Bentall says after the man leaves. “Changing people’s behaviors and attitudes is a pretty tough nut to crack.” It’s not enough to tell people to keep their distance from the otters – she wants to show them why. But to do that, she needs evidence.

Measuring the consequences

Bentall is now working with marine ecologist Heather Barrett and her colleagues at Moss Landing Marine Laboratories to gather that evidence. Barrett is just as motivated as Bentall to determine specific impacts of sea otter disturbance. “Being able to quantify [disturbance] is a big difference from saying, ‘getting close gets them to move,’” she says.

For her part of the research, Barrett uses a computer program developed by Tim Tinker, a sea otter expert and marine ecologist with the U.S. Geological Survey. The program predicts the amount of energy sea otters use to react to various disturbances and then recover.

To do this, the program uses data from Sea Otter Savvy’s field observations. It then combines that with known information on how many calories sea otters burn doing various activities.

So far, the researchers have found that different groups of otters respond differently to disturbance. For example, otters in Elkhorn Slough and Monterey are highly likely to become active when a kayak is about 20 meters away while sleeping otters in Morro Bay aren’t likely to be active until a kayak is only 10 meters away. The reason for this difference is unclear, but the researchers think the Morro Bay otters might have become more used to people, or maybe they’re just less willing to spend the extra energy to move.

The researchers also found that sea otters are disturbed by kayaks or small boats an average of six times a day in some areas, like Cannery Row, a popular tourist spot in Monterey. For a sea otter, swimming six more times a day could be around 25 to 30 extra calories burned, which is equal to about four clams. That doesn’t sound like much. It might take an otter less than an hour to find those clams in a good situation.

But that extra energy adds up over time, especially when needed every day. So, it’s really a cumulative negative outcome that’s concerning more than the day-to-day. But figuring out what that outcome is will take years, and is the long-term goal of this research.

Until now, scientists have come up with “fuzzy conclusions,” as Carswell calls it, about the effects of disturbance, which were reasonable but not based on quantifiable data.

Barrett continues to process and analyze her data. She’s confident this will help educate people on how human disturbance can impact sea otters. “It costs [the otters] something. I think that relates to people,” she says. “When it costs you something, you care.”

This cost is particularly important for sea otters because they have a remarkably high metabolism – one of their adaptations for living in cold water. Their high metabolism requires them to eat at least a quarter of their body weight in food each day. That’s like an average human eating a little over 40 pounds of food a day; most humans actually consume just 3 – 5 pounds of food per day.

Finding that much food takes otters over nine hours a day and requires lots of energy. Otters sleep for at least another nine hours each day, to keep energy expenditure to a minimum. Barrett and her colleagues are using their computer program to figure out if swimming away from kayaks several times a day will throw a sea otter’s energy budget off balance.

Lilian Carswell says this study stands out from other research on the effects of human disturbance. “It’s really attempting to quantify the energy that is expended by sea otters,” she says. “That’s really important because it shows us the magnitude of the problem.”

Until now, scientists have come up with “fuzzy conclusions,” as Carswell calls it, about the effects of disturbance, which were reasonable but not based on quantifiable data. She says data from this study helps scientists identify areas where otters are disturbed the most or have to work harder to recover after disturbances. With that information, organizations like the U.S. Fish and Wildlife Service can determine where public outreach or restrictions are needed to protect the otters – such as restricting access to beaches where sea otters prefer to haul out.

Shifting tides

“You missed the gray whale calf!” exclaims Barrett, standing on the sunny deck of the Monterey Bay Inn on Cannery Row on a recent, and unusually warm, winter day.

Like Elkhorn Slough, Monterey Bay is teeming with wildlife, including whales. Just a moment ago, a gray whale calf surfaced and disturbed the otters that Barrett and her intern, Kate High, are observing. Barrett is still excited by the awesome sight, but the otters seem to have already relaxed. Six of them are sleeping, and a couple of them are gently back paddling with their rear flippers, rubbing their furry cheeks as they groom. They’re adorable.

A couple of kayakers think so, too. It’s a calm day – perfect weather to be on the water. The kayakers aim their boats directly for the otters, and paddle slowly forward. As the kayakers approach, some of the otters open their eyes and watch the red and yellow boats. The kayakers continue getting even closer.

All the otters focus their attention on the kayakers, and an otter at the end of the group darts away. A woman in a yellow kayak is closest to the animals. She pulls out her cell phone, then holds it up in front of her while leaning forward as her kayak drifts closer to the otters. Like a row of tumbling dominoes, the otters quickly swim away, one after the other.

The researchers have already finished their last scan, which means this disturbance doesn’t get recorded – except in their memories. It’s the most common disturbance they see, says Barrett – tourists wanting to get a photo with their cell phones. She suspects that social media has indirectly encouraged people to disturb sea otters and other wildlife. From what she’s seen, she says, it’s more important for people to get a shareable photo than it is to avoid scaring the animals.

Researchers around the world have studied the impacts of humans watching wildlife for nearly two decades. And we now know that even when animals don’t seem disturbed by human interference, it might still harm them, says Daniel Blumstein, an ethologist and conservation biologist.

For instance, he says, one study of penguins found that they wouldn’t leave their nests when humans approached. But their heart rate increased dramatically, indicating they might be stressed out anyway. And too much stress over time, he adds, can cause illness, failure to reproduce, or even force the animals to leave their homes. “You can’t always use behavior as a guide,” says Blumenstein, author of the 2017 book Ecotourism’s Promise and Peril: A Biological Evaluation. Blumstein says Barrett’s model may be useful in figuring out if disturbance influences survival or reproduction – which is essential, he says.

But aren’t people punished for harassing or disturbing sea otters? “We don’t go around advertising this, but there aren’t any consequences,” Carswell reluctantly shares. She says there are very few agents in California who deal with wildlife crimes, and all of their time is taken up by dealing with far more heinous incidents than someone getting too close to a sea otter.

But she doesn’t think imposing fines or penalties for disturbing or harassing sea otters is the best way to protect them anyway. Rather, she supports a better effort to educate the public about how their behavior affects the otters.

Right now, people get that kind of information when they rent kayaks in Moss Landing or read information signs posted on the beach. Sea Otter Savvy’s website and Facebook page also post educational messages. After more than two years studying otter disturbances, Bentall says, “We have enough data now to answer some questions, but we need to keep track of what’s happening over time.”

She wants to find out if the otters in Morro Bay will continue to become more comfortable with humans being around. And she wonders if their lack of fear will translate to being less perceptive of predators, like white sharks. “We’re really trying to keep the program going long term because we feel like we’re gaining momentum,” says Bentall.

Barrett and her colleagues plan publish their model and what they’ve learned from its results in summer 2018. And, in February 2018 Sea Otter Savvy released an animated music video encouraging people to slow down and keep their distance from sea otters when kayaking. The video, which features animated singing and dancing sea otters, has well over 1,000 views in its first month online. Its catchy, reggae-style soundtrack is a clever earworm: “Slow down, you’re getting too close. Gotta back up, and move your boat!”

Standing on the cliff at Jetty Road, Bentall watches a group of young otters in the water. As the otters settle in the kelp for a nap, Bentall says that she hopes her message inspires people to be more compassionate towards all living things. “We want people to be more aware and respect wildlife in any setting, and the things they learn about sea otters can apply broadly to those situations,” she says, as she turns her watchful gaze back towards the water and the animals she is working so hard to protect. © 2018 Kimberly Hickok / UC Santa Cruz Science Communication Program