Appearance

Appearance

Adults have a shell about 2.6–3.6 ft (80–110 cm) long and typically weigh roughly 150–420 lb (70–190 kg), with Hawaiian adults often 300–350 lb (135–160 kg). The shell is brown, gray, or olive, and the underside is yellowish white. The head is small and rounded, with one pair of large scales between the eyes and a serrated jaw edge.

Look-alikes

Loggerhead sea turtleCaretta caretta

Loggerheads have a big orange-brown head, two pairs of scales between the eyes, and five pairs of side scutes on the shell. Green turtles have a small rounded head, one pair of scales between the eyes, and four pairs of side scutes.

Why they get mixed up · Both are large, brownish sea turtles that nest on the same Florida beaches.

Images coming soon

Hawksbill sea turtleEretmochelys imbricata

Hawksbills have a narrow head with a pointed beak, two pairs of scales between the eyes, and jagged (serrated) shell edges. Green turtles have a rounded head, one pair of scales between the eyes, and smooth shell edges.

Why they get mixed up · Both live around Hawaiian reefs, though hawksbills are rare there.

Where it lives

Typical habitats

• Warm coastal seas
• Seagrass beds
• Sandy beaches (nesting)

Range

Tropical and subtropical oceans worldwide. In the US it nests in Florida, Georgia, South Carolina, North Carolina, Hawaii, Puerto Rico, the US Virgin Islands, Guam, the Northern Mariana Islands, and American Samoa.

Preferred conditions

Young turtles drift in the open ocean, often among floating Sargassum seaweed, then move to shallow coastal feeding grounds.

Migration

Every 2 to 5 years, adults travel back to nest near the beach where they hatched.

Seasons

In Florida

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Breeding

Breeding Jun–Sep

Behavior

Diet

Hatchlings eat small plants and animals in floating ocean drift. Adults mostly eat seagrasses and algae. In Hawaii they feed mainly on red and green algae (limu) and seagrass, plus some invertebrates such as jellyfish.

Activity

In Hawaii it's common to see green turtles resting (basking) on the beach. Federal wildlife officials ask people to stay at least 10 ft (3 m) away, on land and in the water.

Life cycle

Breeding season

In Florida, nesting runs from June through September; about 99% of nests are on the Atlantic coast. In Hawaii, nesting and hatching run from May to December, mostly at French Frigate Shoals (Lalo) in the Northwestern Hawaiian Islands.

Clutch size

About 100–136 eggs per nest, several nests per season

Incubation

About 2 months in warm sand (52–56 days on average in Florida)

Time to maturity

Females start nesting at about 25–35 years old.

Lifespan

Not known for sure; estimated at 70 years or more.

Connected species

Close relatives

• Kemp's ridley sea turtleLepidochelys kempii

  A relative in the same family, and the world's smallest sea turtle at about 2 ft (60 cm). Unlike the grass-grazing green turtle it prefers crabs, and it nests mostly in Tamaulipas, Mexico, with smaller numbers in Texas.

Conservation

IUCN Red List

LCLeast Concern·Low risk of extinction

Status

Protected under the US Endangered Species Act as 11 distinct population segments: 3 endangered and 8 threatened, including the North Atlantic (Florida) and Central North Pacific (Hawaii) populations. Globally, numbers have grown enough since the 1970s that the species was moved down from Endangered in 2025.

Threats

Getting caught in fishing gear is a primary threat. Others include harvest of eggs and turtles in some countries, beach development and lighting, boat strikes, marine debris, and a tumor-causing disease called fibropapillomatosis.

Culture and stories

Culture and stories

• In Hawaii the green turtle is called honu. Honu appear in the Kumulipo, the Hawaiian creation chant, and some families still honor sea turtles as ʻaumākua, or spiritual guardians.