The shell is broad and heart-shaped and the head is small. This sea turtle grows to a length of 91 to 153 cm and weigh 100 to 340 kg. The smooth, keelless carapace is brown with brown mottling. The plastron is white to yellow and the head is light brown with yellow markings. The flippers are paddle-shaped and each has one claw. The tail of the males is strongly prehensile, extends beyond the posterior margin of the carapace, and is tipped with a claw-like appendage. In females, the tail rarely extends beyond the carapace. The carapace of hatchlings and juveniles is brown to dark green and keeled. The undersurface is white, and the head and flippers are black. The limbs and all scutes on the shell are edged in white. This color pattern is an example of countershading, a means of being less visible to potential predators from above and below in the water. The breeding season varies with location but probably does not occur in Virginia. The incubation period is 48-70 days, depending on the beach conditions. Nesting occurs at 2, 3, or 4-year intervals. They have 2-7 clutches per season with 75-200 eggs/clutch. The female builds the nest at night on a sloping beach. She digs a large basin with the front flippers, and at the bottom of this digs a smaller hole with the rear flippers.
Only two live individuals have been caught in Virginia waters since 1979, one from the York River and one from the Potomac River. Six dead specimens have been found from the lower Chesapeake Bay, the Eastern Shore, and Virginia Beach. They prefer high energy beaches with sand deep enough to deposit the eggs below one meter. Juveniles live in Sargassum mats in major ocean currents such as the Gulf Stream. When not migrating, green turtles prefer sea grass flats which occur in shallow areas of the Chesapeake Bay.
The green turtle has the unique ability among marine turtles to digest plant material. Hatchlings and yearlings are primarily carnivorous. Mature loggerheads feed primarily on vascular sea grass, but will also eat marine animals, particularly cniderians, mollusks, crustaceans, sponges, and jellyfish, whenever available.