Common name:

Hawaiian green sea turtle

Scientific name:

Chelonia mydas 

Critter contributor:

Konrad Kendrick, Flickr

Distribution: Can be spotted in any tropical or subtropical sea. Although the highest population levels are in the Pacific and the Atlantic.

Size: Can grow up to 5 feet long and weigh up to 420 pounds!

Coloration: The turtle’s shells have various color patterns that change over time, but typically brown and yellow undertones.

Habitat: These turtles occupy three habitat types: nesting on beaches, convergence zones in the pelagic habitat, and benthic feeding grounds in relatively shallow waters; all depending on their life stage.

Depth: Relatively shallow waters around convergence zones or feeding grounds.

IUCN Red List Status: Endangered

Diet: Adults primarily eat seagrass and algae, while juveniles can eat a wide variety of plants, crustaceans, seagrass and worms.

If you are lucky enough to spend a generous amount of time on Hawai‘i beaches, you are most likely going to spot a sea turtle. There are three species of sea turtles native to the Hawaiian Islands: the green (Chelonia mydas), the hawksbill (Eretmochelys imbricate) and the leatherback (Dermochelys coriacea). These fascinating creatures have played important roles in the environment and culture of Hawai‘i’s people. Of the three native sea turtles, the green turtle (honu) is the most common. They are easily distinguished from other sea turtles because they have a single pair of prefrontal scales (scales in front of its eyes), rather than two pairs as found on other sea turtles. They are also the largest hard-shelled sea turtle in the world, reaching lengths of five feet and weights over 420 pounds!

The colors of their carapace (upper shell) can have various color patterns that change over time but typically they are brown with yellow undertones, sometimes having black streaks. So why are they called green sea turtles instead of brown? Green turtles were given their name due to them pigging out on so much algae and sea grasses, that their fat layer actually turns green! Although, their diets do change significantly throughout their lives, it seems only adult sea turtles mostly eat seagrass and algae. When the sea turtles are young (less than 8 to 10 inches), they have been known to eat worms, young crustaceans, aquatic insects, grasses and algae.

These beach dwellers mainly stay near the coastline and around islands and live in bays and protected shores, especially in areas with seagrass beds. It is not unusual to spot a green sea turtles basking in the sun for hours on shore — not too bad of a life, huh? While sea turtles are almost always spotted cruising tropical waters, eating or basking in the sun, they do unfortunately encounter many threats. Human actions, both intentional and unintentional, are currently having major effects. Intentional threats include hunting, poaching and egg harvesting. Unintentional threats include boat strikes, fish nets, pollution and habitat destruction. Chemical pollution has also been known to create tumors on sea turtles; this has been common near harbors. Due to the many threats turtles face every day they have been listed as endangered by the IUCN and are now protected from exploitation in most countries. It is illegal to collect, harm, kill and even touch sea turtles. In addition, many countries have laws and ordinances to protect nesting areas. Whether the turtle is in the water or resting on a beach, any physical contact is prohibited.

With all laws in place, sometimes nature still takes the upper hand. In October 2018, a category five hurricane swept over the pacific region causing East Island to nearly vanish. East Island is a small but extremely important island in French Frigate Shoals, only measuring 11-acres long. However, this stretch of sand and gravel is one of the most important nesting sites for green sea turtles. The island represents the nesting site for 96 percent of the world’s Hawaiian green sea turtle population and the tiny islet has been host to 50 percent of those breeding turtles. The hurricane also swept away the home to critically endangered Hawaiian monk seals (Monachus schauinslandi). Each year about 200 of these seals visit East Island to birth their pups. It is unclear so far if the island will return or if the animals will return to what is left of East Island.

Current research in Hawai‘i shows the green turtle population has been stabilizing and in some cases increasing since they have been protected by federal law. Researchers stated in 2016, the green sea turtle population has had an increasing nesting population trend of 5% per year over the last two decades. So next time you spot one of these fascinating creatures be sure to give them their space to protect them for generations to come.