Hawaiian waters serve as a sanctuary for several species of sea turtles, animals deeply woven into the local ecosystem and culture. Their presence holds great ecological importance. Five species of marine reptiles are found here, navigating environments from nearshore feeding grounds to deep, open ocean habitats. The Hawaiian people have long revered these turtles, known as honu, often regarding them as ʻaumakua, or spiritual family guardians.
The Abundant Resident: Green Sea Turtles
The most frequently observed sea turtle in the archipelago is the Green Sea Turtle, or Honu. This species is the largest hard-shelled sea turtle worldwide, with adults reaching three to four feet in length and weighing over 300 pounds. The name “green” refers not to the color of their shell, but to the greenish tint of their body fat, caused by their herbivorous diet of marine algae, or limu.
The Honu is the only sea turtle species in Hawaii commonly observed basking, or resting, on the beaches of the Main Hawaiian Islands. Their foraging grounds are concentrated in shallow, nearshore areas where seaweed is plentiful, such as coral reefs and rocky outcroppings. While some nesting does occur in the main islands, approximately 96% of the entire Hawaiian population nests far to the northwest at the French Frigate Shoals.
The Less Common Species of Hawaiian Waters
Four other species of sea turtles also inhabit Hawaiian waters, though they are sighted much less frequently than the Honu. The Hawksbill Sea Turtle, called Honuʻea or ʻEa, is the second most common resident, yet its population is dramatically smaller, outnumbered by the Green Sea Turtle by an estimated 100 to one. Hawksbills are closely tied to coral reef habitats, where their distinctly narrow, pointed beaks allow them to forage for food, primarily sponges and other invertebrates.
Few female Hawksbills nest each year on the beaches of the Main Hawaiian Islands, making them a rare sight. The remaining three species—the Loggerhead, Olive Ridley, and Leatherback sea turtles—are pelagic visitors to the islands. These species prefer the deep, open ocean and are rarely seen in nearshore waters, especially the Leatherback, which is the world’s largest turtle, sometimes weighing up to 2,000 pounds.
Key Physical Differences for Identification
Observing distinct physical characteristics can help differentiate between the two most common species, the Green and the Hawksbill. The Green Sea Turtle has a notably rounded head and a blunt beak, adapted for grazing on algae. Its carapace, or upper shell, features scutes that fit together smoothly like tiles, and its flippers possess a single claw.
In contrast, the Hawksbill possesses a narrow, pointed beak that resembles a hawk’s bill, perfect for prying food from crevices. The scutes on its carapace overlap like roof shingles, and its flippers have two distinct claws. The Loggerhead is identified by its proportionally large head. The Leatherback is unique among all sea turtles for lacking a hard shell, instead having a carapace covered by leathery, ridged skin.
Legal Protections and Safe Viewing Guidelines
All sea turtles in Hawaii are protected by federal and state regulations, primarily under the Endangered Species Act. Disturbing or harming them is strictly prohibited, with violations carrying severe penalties, including fines up to $100,000. This protection requires all viewers to maintain a respectful distance from the animals.
The mandatory safe viewing distance is a minimum of 10 feet (approximately three meters) from all sea turtles, whether they are basking or swimming. It is illegal to touch, feed, or harass a sea turtle, as this constitutes disturbance and can alter their natural behavior. Following these guidelines ensures the turtles can rest and forage without stress, allowing for responsible viewing.