Sea Turtle Evolution

Look into the wizened face of a sea turtle while diving in Maui. Turtles, both sea and terrestrial, are some of the oldest species on the planet.

Sea turtles belong to the order Testudines whose first specimens date back to about 220 million years ago, making them one of the most primitive groups of reptiles that still inhabit the earth. This order is part of the class Reptilia, which also includes animals like snakes, crocodiles, and lizards.

Turtle history goes back even further. Sea turtles evolved from land and freshwater turtles, that lived about 230 million years ago in the Cretaceous period. Even though our modern turtle species has changed over time, they are still a species that survived through the last ice age, while others like dinosaurs did not.

Sea Turtles in Hawaii

Sea turtles have been around longer than the Hawaiian Islands themselves. The green sea turtle and hawksbill sea turtle are the species most frequently observed in Hawaii. Three other species occur, the Leatherback, Loggerhead and Olive Ridley sea turtles, but are very rarely seen in our coastal waters.

The green sea turtle is the largest hard-shelled sea turtle. They are unique among sea turtles in that they are herbivores, eating mostly seagrasses and algae. This diet is what gives their fat a greenish color (not their shells), which is where their name comes from. Adults can be 3 to 4 feet in length and weigh 250 to 400 pounds. Their lifespan is 70 years or more. Their population status is Threatened.

Photo: US Fish and Wildlife Service

Hawksbills get their name from their unique beak-like mouth, which resembles that of a hawk and is perfect for finding food sources in hard-to-reach cracks and crevices. They are the only species of sea turtle that can survive on a diet consisting mainly of sponges. Adults can be 2 to 3.5 in length and weigh 100 to 150 pounds. Their lifespan is 50 years or more. Their population status is Endangered.

Sea turtles hold revered status in Hawaiian culture. Known as “honu” some Hawaiians consider these special sea creatures their ancestral guardian, or aumakua. 

How close can I get to sea turtles?

There is no law specifying the minimum distance people can approach a sea turtle. However, state and federal laws do restrict against disturbing turtles or their natural behavior patterns. This includes no touching, feeding, etc. NOAA and DLNR recommend, for your safety and the animals’ protection, that everyone stay 10 feet away from all sea turtles. However, it is also recognized that maintaining this distance isn’t always possible, including when an animal swims toward you or crosses your path. If in close proximity, keep safety in mind, don’t make sudden movements, and when possible, move away from the animal carefully. Purposely getting too close for a selfie is not ok, but quiet observation is great!

More information

One of the best ways to learn about a species is direct observation through a scuba charter. While turtles are spotted on most Lahaina Divers charters, the afternoon Turtle Reef charter affords the best opportunity for multiple sightings and good visibility. For more information on sea turtles, visit the NOAA marine turtles site and the NMFS Pacific Islands Regional Office turtle site. You can also download NOAA’s “Hawaiian Hawksbill Sea Turtles” brochure.