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Would you swim with Hawaiian spinner dolphins if you knew that they were trying to sleep?

SIX FACTS
about
SWIMMING with WILD SPINNER DOLPHINS:

When people swim with resting wild spinner dolphins, the dolphins may be drawn out of their resting state to investigate the swimmers. This may be a change in behavior which may constitute " harassment" under the Federal law that protects them and other marine mammals - the Marine Mammal Protection Act (MMPA). Any act of pursuit, torment, or annoyance that has the potential to disrupt a marine mammal's behavior is “harassment" under this Act and is, therefore, against the law.

Swimmers and boats that come to visit wild spinner dolphins in sheltered bays and coastlines during the day could potentially be disturbing a critical period of spinner dolphin rest and potentially be harming the dolphins. Hawaiian spinner dolphins feed off-shore at night and return to sheltered bays and coastlines during the day to rest and tend to their young.

To learn more, read the article, "A Hard Day's Night: Spinners Also Need Their Rest" (Oct 2006, pdf 5MB)

Drawing: Spinner dolphins rest in shallow bays during the day and feed in deeper waters at night. NOAA

Even when spinner dolphins are swimming, they actually may still be resting and sleeping. When dolphins sleep they must be partially awake to keep breathing, so they swim slowly, occasionally surfacing for air, allowing half their brain to sleep at a time.

If spinner dolphins are disturbed while in their nearshore resting habitat, they may be forced to move to a location not as favorable, putting themselves at risk of predation by animals, like sharks. They may also be forced to use more energy to reach their feeding grounds – energy that would otherwise be used to breed, nurse, and rear their young. Hawaiian spinner dolphins choose certain sheltered, sandy bottom areas to rest because they are close to their feeding sites. The white sand background also makes it easier for them to see predators.


Photo: Hawaiian spinner dolphins resting in a sheltered, sandy bottom habitat.

Studies have shown that some of the dolphin-tourism programs in other parts of the world have caused significant declines in dolphin populations. Read an article about a dolphin-tourism study done in Australia: "Decline in Relative Abundance of Bottlenosed Dolphins Exposed to Long-Term Disturbance" (L. Bejder et. al, Nov 2006, pdf 175 kB)

The natural curiosity of wild dolphins should never be misinterpreted as “friendly” behavior in which they are purposefully seeking out human attention. Wild dolphins have unpredictable, untrained behaviors. Dolphins seen at marine parks are not “friendly” wild dolphins. These animals are trained Atlantic bottlenose dolphins that were either born or raised in human care. 


Photo: Trainers use hand signals, whistles and positive reinforcement to communicate with bottlenose dolphins in human care. Photos of dolphins with people (right, below left) courtesy of Dolphin Quest.

Current NOAA Dolphin Viewing Guidelines:

• Remain at least 50 yards (1/2 a football field) from spinner dolphins.

• Limit your time observing to 1/2 hour.

• Spinner dolphins should not be encircled or trapped between boats or shore.

• If approached by a spinner dolphin while boating, put the engine in neutral and allow the animal to pass. Boat movement should be from the rear of the animal.

The MMPA does not provide for a permit or other authorization to view or interact with wild marine mammals, except for specific listed purposes such as scientific research. Therefore, interacting with wild marine mammals should not be attempted and viewing marine mammals must be conducted in a manner that does not harass the animals.

NOAA Fisheries does not support, condone, approve, or authorize activities that involve closely approaching, interacting, or attempting to interact with whales, dolphins, porpoises, seals, or sea lions in the wild. This includes attempting to swim with, pet, touch, or elicit a reaction from the animals.

Learn more about Hawaiian spinner dolphins and dolphin-tourism research:

• Frequently Asked Questions (FAQ) sheet: Hawaiian Spinner Dolphins
• NOAA Fisheries, Protected Resources Division, Hawaiian Spinner Dolphins