Green Turtle Information

Hawaiian green sea turtles do not reach sexual maturity until they are about 25 years old, sometimes taking up to 50 years.Once sexually mature, adults migrate from the foraging grounds to the nesting grounds, primarily at French Frigate Shoals, located 800 miles northwest of the main islands.Males appear to migrate every year, arriving ahead of the females. Females only migrate 2-4 years.

It is believed that females return to the same birth where they were born. Mating starts in March and occurs in the waters adjacent to the nesting beaches. Nesting occurs from late April through September, with a peak in June and July. Nesting occurs at night, with each nesting female coming ashore to lay eggs as many as five times, at 11 to 18 day intervals.

The female digs a broad pit with its fore flippers and an egg chamber with its rear flippers, and then deposits a clutch of 100 to 120 ping-pong ball sized eggs. The female gently then covers the nest by flinging dirt over it with its flippers. The temperature of the eggs during incubation determines the gender of the hatchings: lower temperatures produce males, higher temperatures produce females.

Hatching occurs at night, after about 60 days of incubation. Working as a group, hatchlings dig to the surface of the nest. They head to the ocean immediately, attracted to the light reflected off the ocean. After reaching the water, the hatclings disappear and are not seen by humans until they appear as juveniles in the nearshore waters of the main Hawaiian Islands.

Sea Life Park takes great pride in maintaining an active breeding colony of Hawaiian green sea turtles (Chelonia mydas). Our colony is the only such type of program in the State of Hawaii and releases young hatchlings into the ocean every year. The colony, which consists of 11 female and 6 male turtles, is one of Sea Life Park’s public displays. Guests are able to learn about and even feed these amazing reptiles.

Every spring, the turtles begin the mating process, and shortly thereafter, the females will haul out on the sandy beach, dig a nest 24 – 30 inches in depth, and lay approximately 100 eggs! The same female may return to the beach to lay up to 5 new nests throughout the nesting season.

The turtle eggs remain in the nest incubating for approximately 60 days the hatchlings begin the process of cracking open their own shells with their beaks, called “pipping”. Unlike a bird, turtle pipping is a slow process and the hatchlings can remain in their opened shell up to 5 days until their external yolk sac is absorbed. This yolk provides nutrition and energy for the hatchling to continue it’s journey.

Once the yolk is fully absorbed, the turtles climb out of their nest and make a “mad dash” for the ocean. With any luck this occurs during the evening hours sparing the hatchlings from predators such as seabirds. Scientists speculate that only 1 out of every 1000 hatchlings survive to maturity. Once in the ocean the hatchling feeds on plankton and small jellyfish. As the turtles grow, they begin to graze on lush beds of marine algae found in the costal waters surrounding the Hawaiian Islands. It is estimated that a green sea turtle reaches sexual maturity at approximately 25 years of age. Scientist believe that female turtles will lay there eggs on the very same beach that they were once hatched.

Sea Life Park by Dolphin Discovery’s captive green sea turtle breeding program produces between 200-800 hatchlings per year. Researchers carefully measure and tag each hatchling for identification should it be observed in the wild or nesting in the future.