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Green Sea Turtle

Chelonia mydas

Green sea turtles can grow up to 4 feet long, weigh up to 440 pounds, and live as long as eighty years. They live in tropical and subtropical waters around the world. They are herbivores and primarily eat seagrass, but as juveniles may eat sea jellies and other invertebrates (animals without backbones). Single-use plastic bags can end up in the ocean and resemble sea jellies; avoiding their use is one way to help this species.

Green Sea Turtle

Ken Kurtis/Aquarium of the Pacific

SPECIES IN DETAIL

Green Sea Turtle

Chelonia mydas

CONSERVATION STATUS: Species or Population Dependent

CLIMATE CHANGE: Vulnerable

At the Aquarium

The Aquarium’s green sea turtle, Copper, lives in the Tropical Reef Habitat in the Tropical Pacific Gallery.

Geographic Distribution

This species is found in subtropical and tropical waters worldwide.

Habitat

Green sea turtles live in the open ocean and nearshore waters.

Physical Characteristics

Green sea turtles have a small head, single-clawed flippers, and a heart-shaped shell. Their color is variable. In adults, the turtle’s hard upper shell or carapace is smooth and light to dark brown, with dark mottling. The plastron, or the portion of the shell on the underside, is whitish to yellow. Hatchlings typically have a black carapace and white plastron, with white edges on the limbs and shell. The thick and bony plates that make up a turtle’s shell are called scutes. Green sea turtles have five central scutes and four pairs of later scutes. They have one pair of prefrontal scales between the eyes. In lieu of teeth, the green sea turtle has a round beak with serrated edges that helps tear and cut food. A pair of glands near the eyes remove excess salt, sometimes giving the appearance that the sea turtle is crying.

Size

This species grows to approximately 3 to 4 feet (1.2 meters) in length.

Diet

Adults feed on seagrasses and algae. Juveniles feed on jellies and invertebrates, as well as seagrass.

Reproduction

Sexual maturity and mating varies with locality. Adults may reproduce as young as sixteen years and as old as fifty years. Juveniles in the Great Barrier Reef reach sexual maturity at twenty-five to fifty years old, while those in Florida and the Caribbean reach sexual maturity at sixteen to twenty years old.

The males and females return close to the shore near where they were born. After mating the female will climb up onto the beach under the cover of darkness to dig a nest in which she will lay 100 or more eggs. She will then bury them in the sand and return to the water. She may nest and lay eggs several times per season.

After an incubation period of approximately sixty days, the hatchlings will crawl out of the nest and down to the beach into the ocean using moonlight as a guide. Eggs in the same nest will all hatch within days of each other and move as a group to the water. A hatchling that makes it out to sea will spend the next five to seven years growing among free-floating macroalgae mats. As a juvenile, they will cross the open ocean to find new foraging fields but return to their birthplace each year.

Behavior

Green sea turtles are solitary animals. Their front flippers help them swim through the water, while their back feet are used as rudders. Unable to breathe underwater, they must surface to breathe air. They can hold their breath for four to seven hours during a dive.

Adaptation

The green sea turtle’s forelimbs are modified into long, paddle-like flippers used for swimming. Their flippers, neck, and head are not retractile. Because they are cold blooded, they have a slow metabolic rate.

Longevity

This species is estimated to live up to eighty years, although the exact lifespan is unknown.

Conservation

The International Union for Conservation of Nature lists green sea turtles as endangered. They are also listed as Endangered under the Endangered Species Act.

Sea turtles are susceptible to population declines due to human activity, including egg harvesting for food and degrading of nesting beaches and foraging grounds. Beach armoring, sand extraction or replacement, and building construction either destroy or change the beach habitat, making it no longer suitable for nesting. The presence of artificial lighting changes the behavior of nesting adults and draws the hatchlings away from the water, often with fatal results. Habitat degradation from contamination and effluent, building of marinas and destruction of seagrass beds have been implicated in the prevalence of the tumor-causing Fibropapilloma disease.

Plastic bags floating in the ocean are sometimes eaten by sea turtles who mistake them for jellies, causing their digestive system to be blocked. Sea turtles are also sometimes entangled in discarded fishing gear, causing them serious injuries or even death.

Temperature differences within the nest determine the hatchlings’ sex. Warmer nest temperature results in females and cooler temperatures result in males. Temperatures have been warming on many beaches resulting in more females being born and fewer males, which may make it difficult for future turtle generations to find a mate.

SPECIES IN DETAIL | Print full entry

Green Sea Turtle

Chelonia mydas

CONSERVATION STATUS: Species or Population Dependent

CLIMATE CHANGE: Vulnerable

The Aquarium’s green sea turtle, Copper, lives in the Tropical Reef Habitat in the Tropical Pacific Gallery.

This species is found in subtropical and tropical waters worldwide.

Green sea turtles live in the open ocean and nearshore waters.

Green sea turtles have a small head, single-clawed flippers, and a heart-shaped shell. Their color is variable. In adults, the turtle’s hard upper shell or carapace is smooth and light to dark brown, with dark mottling. The plastron, or the portion of the shell on the underside, is whitish to yellow. Hatchlings typically have a black carapace and white plastron, with white edges on the limbs and shell. The thick and bony plates that make up a turtle’s shell are called scutes. Green sea turtles have five central scutes and four pairs of later scutes. They have one pair of prefrontal scales between the eyes. In lieu of teeth, the green sea turtle has a round beak with serrated edges that helps tear and cut food. A pair of glands near the eyes remove excess salt, sometimes giving the appearance that the sea turtle is crying.

This species grows to approximately 3 to 4 feet (1.2 meters) in length.

Adults feed on seagrasses and algae. Juveniles feed on jellies and invertebrates, as well as seagrass.

Sexual maturity and mating varies with locality. Adults may reproduce as young as sixteen years and as old as fifty years. Juveniles in the Great Barrier Reef reach sexual maturity at twenty-five to fifty years old, while those in Florida and the Caribbean reach sexual maturity at sixteen to twenty years old.

The males and females return close to the shore near where they were born. After mating the female will climb up onto the beach under the cover of darkness to dig a nest in which she will lay 100 or more eggs. She will then bury them in the sand and return to the water. She may nest and lay eggs several times per season.

After an incubation period of approximately sixty days, the hatchlings will crawl out of the nest and down to the beach into the ocean using moonlight as a guide. Eggs in the same nest will all hatch within days of each other and move as a group to the water. A hatchling that makes it out to sea will spend the next five to seven years growing among free-floating macroalgae mats. As a juvenile, they will cross the open ocean to find new foraging fields but return to their birthplace each year.

Green sea turtles are solitary animals. Their front flippers help them swim through the water, while their back feet are used as rudders. Unable to breathe underwater, they must surface to breathe air. They can hold their breath for four to seven hours during a dive.

The green sea turtle’s forelimbs are modified into long, paddle-like flippers used for swimming. Their flippers, neck, and head are not retractile. Because they are cold blooded, they have a slow metabolic rate.

This species is estimated to live up to eighty years, although the exact lifespan is unknown.

The International Union for Conservation of Nature lists green sea turtles as endangered. They are also listed as Endangered under the Endangered Species Act.

Sea turtles are susceptible to population declines due to human activity, including egg harvesting for food and degrading of nesting beaches and foraging grounds. Beach armoring, sand extraction or replacement, and building construction either destroy or change the beach habitat, making it no longer suitable for nesting. The presence of artificial lighting changes the behavior of nesting adults and draws the hatchlings away from the water, often with fatal results. Habitat degradation from contamination and effluent, building of marinas and destruction of seagrass beds have been implicated in the prevalence of the tumor-causing Fibropapilloma disease.

Plastic bags floating in the ocean are sometimes eaten by sea turtles who mistake them for jellies, causing their digestive system to be blocked. Sea turtles are also sometimes entangled in discarded fishing gear, causing them serious injuries or even death.

Temperature differences within the nest determine the hatchlings’ sex. Warmer nest temperature results in females and cooler temperatures result in males. Temperatures have been warming on many beaches resulting in more females being born and fewer males, which may make it difficult for future turtle generations to find a mate.