The practice of swimming with Hawaii's lively spinner dolphins sparks ongoing debate

In the early hours on Hawaii Island's west coast, the sun casts its glow over towering volcanoes and the expansive Pacific Ocean at Honokohau Harbor, just outside Kailua-Kona. Excited tourists board boats in anticipation of an unforgettable experience swimming with the island's renowned spinner dolphins.

Swimming alongside dolphins is a dream for many adventure-seekers.

On Hawaii, encountering wild dolphins in their natural habitat is a popular activity, partly because these playful marine mammals often approach swimmers along the shoreline.

Spinner dolphins are found in tropical waters worldwide and belong to the toothed whale family. These sleek, agile gray-and-white dolphins are best known for their acrobatic jumps and spins through the air. The Hawaiian spinner dolphin is a subspecies that inhabits the islands of the Northern Pacific.

Around the island, spinner dolphins seem as intrigued by humans as we are by them.

While humans and spinner dolphins have coexisted peacefully for years, some scientists and conservationists fear that the growing influx of tourists seeking close encounters with these charming creatures—often aided by fast tourist boats—may be causing the dolphins stress.

Experiencing a vacation with dolphins

In the last decade, the popularity of boat-based dolphin swim tours has surged, fueled in part by countless social media posts showcasing tourists floating alongside dolphins.

To ease the growing pressure on spinner dolphins, the National Oceanic and Atmospheric Administration (NOAA) suggested a 2016 rule to prohibit swimming within 50 yards of the animals. The proposal received over 22,000 public comments, highlighting the ongoing debate about whether these interactions are beneficial or harmful to the dolphins.

According to Adam Kurtz, marine wildlife management coordinator at NOAA’s National Marine Fisheries Service, 'Research indicates that when humans approach spinner dolphins within 50 yards, it constitutes 'harassment' as outlined in the Marine Mammal Protection Act.'

One of the agency's primary concerns is that swim tours could be disturbing the dolphins during their critical daytime resting period, when they recover from their nighttime excursions into the open ocean to hunt for fish.

Kurtz explains that if NOAA's proposed regulation is enacted, it could help mitigate the negative effects on dolphins caused by repeated close encounters with boats and humans.

The final decision on the rule is anticipated in the spring of 2020.

Like any regulation, this one will include exceptions—such as when dolphins choose to approach swimmers on their own.

Affable mammals

Few animals captivate people around the world like wild dolphins, likely due to their human-like behaviors and mutual curiosity towards humans.

"Dolphins are the free spirits of the ocean. They thrive on love, fun, and play," says Eric Schmidt, who works for Sunlight On Water, a dolphin swim company based in Hawaii.

It’s not just tourists who are drawn to Hawaii's dolphins; locals of the Kona Coast have been swimming with wild spinner dolphins for over three decades. Some even relocate to Hawaii Island specifically to form a deeper connection with the resident dolphins, feeling a spiritual bond with the creatures.

Each morning, locals gather on the beaches and swim out to meet pods of spinner dolphins, named for their elegant leaps and mesmerizing spins in the air.

Surprisingly, these wild dolphins frequently emerge from the deep blue to greet the swimmers.

Joan Ocean, 79, a counseling psychologist, has swum alongside dolphins thousands of times since moving to Hawaii 33 years ago. She notes that dolphins can move through water far more quickly than humans.

"It’s always the dolphins’ decision," says Ocean. "If they choose to swim with us, we mirror their behavior—when they’re calm, we are too."

For over 30 years, Ocean has guided swimmers, boat crews, and marine lifeguards to follow a few simple rules: enter the water gently, never swim over the dolphins, float or kick calmly with your arms at your sides, and avoid touching the dolphins.

"If we float quietly and avoid chasing them, they’ll approach us and stay close to play," she says.

Ocean has swum with whales and dolphins in 20 different countries, yet she believes the human-dolphin interactions in Hawaii are one of a kind.

"I’ve noticed more and more dolphins coming here to greet people, just as more people are coming to swim with them," says Ocean.

Respecting personal space

Biologists, however, are concerned about the cumulative effects of frequent human interactions on the spinner dolphins.

Lars Bejder, director of the Marine Mammal Research Program at the University of Hawaii at Manoa, emphasizes that while spinner dolphins are naturally curious, constant interaction with hundreds of humans daily may not be beneficial for them.

Spinner dolphins hunt at night, forming pods to forage offshore for fish. In the morning, they return to the shore to rest, socialize, and avoid predators. They typically spend their days resting in four or five specific bays along the Kona Coast of Hawaii.

"Their dining room is the open ocean, while their bedroom is a peaceful bay. But these dolphins are constantly sharing their bedroom with humans," explains Bejder.

Marine mammals don’t sleep in the traditional sense. Instead, they alternate shutting down half of their brain at a time, swimming slowly to remain active and rising to the surface to breathe.

One recent study found that spinner dolphins are exposed to human activity 83% of the time while resting in bays around Hawaii Island, with only a 10-minute gap between each human encounter.

While the study found no immediate effects on the resting behavior of spinner dolphins, Bejder notes that it's challenging to observe long-term impacts on the population, given the dolphins’ long lifespan.

"Constant disruption may impair the dolphins’ cognitive functions over time, much like how a lack of sleep can affect humans," says Bejder.

Cherish and protect

Tourists flocking to Hawaii Island to observe dolphins and whales contribute significantly to the local economy, providing essential revenue for Hawaiian communities.

The proposed NOAA regulation has raised concerns among dolphin swim tour operators who fear a loss of income. However, some businesses have already adopted more sustainable dolphin viewing practices, and many encourage swimmers to follow the respectful guidelines promoted by Ocean.

Colin Cornforth, owner of Captain Zodiac Raft Expeditions, trains his boat captains to recognize when dolphins are resting, ensuring they know when to give the animals space. He also enforces a strict rule that his boats depart from dolphin areas by 9 a.m., whereas other boats may 'chase' the dolphins much later into the day.

Cornforth points out that operator behavior, particularly that of third-party booking agents who often promise guests a chance to swim with dolphins, can be problematic. His company, however, maintains a firm policy: no dolphin swims after 9 a.m.

"Many of us who have been involved for years believe that regulations are now essential, simply because people love the dolphins too much," says Cornforth.

Adam Kurtz of NOAA agrees, stressing that the agency is not looking to outlaw the practice of observing wild dolphins.

"Getting people enthusiastic about marine mammals offers educational and conservation benefits. We just want to ensure it’s done in a way that is responsible and sustainable over time," says Kurtz.

Still, some tour operators, scientists, and dolphin-swim advocates remain doubtful about NOAA’s proposed 50-yard 'no approach' rule.

"It would be difficult to determine whether a dolphin approached a human or the other way around," says Cornforth.

From an enforcement standpoint, many believe that implementing timed closures in the dolphins' primary resting bays off Hawaii Island would be a more effective solution. This would prohibit boats and swimmers from approaching dolphins during their peak resting times.

Cornforth observes that, until recent years, people were content to view dolphins and whales from above the water. He believes that visitors can still have a "tremendously positive experience" by watching spinner dolphins from a boat.

Currently, Captain Zodiac Raft Expeditions offers dolphin swims only twice a week, but if the no-swimming rule is enforced, Cornforth says he would have no problem complying with it.

"I hope as a community, we can all agree that we want these animals to remain healthy so that future generations can experience them too," says Cornforth.