Hawaiian Spinner Dolphins Need Protection

Hawaiian Spinner Dolphin - NOAA

NOAA Fisheries’ Pacific Islands Region has a webpage designed to educate the public about the negative consequences of swimming with Hawaiian spinner dolphins, which are sometimes also referred to as long-snouted dolphin.

The spinner dolphin usually is dark gray with a white patch on the belly and its beak is long and thin with a dark tip. The adults vary in size, from 4.23 feet to 7.70 feet (1.29 meters to 2.35 meters).

Dolphin sounds appear to be in the form of click-whistles and pulse sounds which are a mix of echolocation and communication. Spinner dolphins also communicate by slapping the water with various body parts. For instance, “nose-outs” occur when beak is thrust from the surface. This action is commonly used when the pod is emerging from a rest period.

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

When people swim with resting wild spinner dolphins, the dolphins may be drawn out of their resting state to investigate the swimmers. 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. 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 harming the dolphins.

It may look like the animal is not sleeping, but in fact, even when spinner dolphins are swimming, they may actually still be resting and sleeping as during this resting time they still need to keep breathing, so they swim slowly, partially awake, and surface for air, allowing half their brain to sleep at a time.

Hawaiian Spinner Dolphin, spinning - Courtesy of Wilde Side Specialty Tours

Any act of pursuit, torment, or annoyance that has the potential to disrupt a marine mammal’s behavior is considered “harassment” under the Marine Mammal Protection Act, and is therefore against the law.

A new public outreach brochure that responds to frequently asked questions is available online.

To learn more about spinner dolphins visit the Pacific Islands Regional Office website here.

Spinner dolphins, Northwest Hawaiian Islands - Photo by Dr Dwayne Meadows - NOAA/NMFS/OPR

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