Other meanings of Green sea turtle
Marine reptiles
The green sea turtle (Chelonia mydas) is a large marine turtle species found in tropical and subtropical oceans. It is the only herbivorous sea turtle as an adult in most populations, although young turtles eat a broader range of animal and plant material. Despite its name, the shell is usually olive, brown, or gray; “green” refers chiefly to the color of its body fat, associated with its diet. The species migrates between feeding grounds and nesting beaches, and its survival is shaped by coastal development, fisheries bycatch, hunting, pollution, and climate change.1
The green sea turtle is distinguished by a smooth, high-domed carapace, a relatively small head, and a single pair of elongated scales between the eyes.1 Adults commonly have an oval shell with variable olive, brown, gray, and yellow patterning, while the plastron is often pale. Unlike the hawksbill turtle, it has a short, blunt snout rather than a strongly hooked beak. Adults are generally larger than most other hard-shelled sea turtles, although size varies substantially among populations and islands.
Green turtles are adapted to a marine life of prolonged diving and long-distance travel. They use their powerful fore flippers for propulsion and their hind flippers mainly for steering. Hatchlings are dark and proportionally small; juveniles may drift or forage in oceanic habitats before recruiting to shallow coastal feeding areas. Sexual maturity is reached only after many years, and growth is especially slow in cooler or food-poor environments.
Green sea turtles occupy warm waters of the Atlantic, Pacific, and Indian oceans, with nesting colonies concentrated on tropical and subtropical beaches.2 Adults often travel between protected nesting beaches and shallow feeding grounds such as seagrass meadows, lagoons, and coral-reef margins. Their migrations can span hundreds or thousands of kilometers, and many females return to the region where they hatched, a behavior known as natal homing.
Young turtles are relatively omnivorous, consuming crustaceans, jellyfish, sponges, and other material, whereas older turtles feed mainly on seagrasses and algae.3 Females crawl ashore, usually at night, dig nests above the high-tide line, and lay several clutches during a nesting season. Incubation commonly lasts about two months, and temperature during development influences hatchling sex: warmer nests produce more females. Hatchlings emerge together and orient toward the brighter open horizon, though artificial lighting can disrupt this movement.
Green turtles influence coastal ecosystems by grazing seagrass and algae, transporting nutrients between ocean and shore, and serving as hosts for diverse organisms.4 Regular grazing can stimulate seagrass productivity and alter the structure of feeding meadows, while eggs and hatchlings provide food for beach and nearshore predators. These effects make the turtle an ecological participant rather than merely an indicator species.
The International Union for Conservation of Nature classifies the species globally as endangered, while the status of individual regional populations can differ greatly.5 Major threats include accidental capture in trawl, gillnet, longline, and other fisheries; direct harvest; loss or degradation of nesting beaches; boat strikes; marine debris; disease; and warming beaches. Turtle-excluder devices, protected nesting sites, lighting controls, fisheries regulation, and community monitoring have improved outcomes in some areas, but recovery remains uneven.
Green turtles are not uniformly herbivorous across their entire lives: the shift toward plant-based feeding generally occurs as juveniles move from oceanic habitats into coastal developmental areas.3 Their diets and migration routes also differ among populations, so conservation plans cannot assume that all green turtles use the same habitats or face identical risks. Some populations feed in temperate waters seasonally, extending beyond the species’ usual tropical image.
Temperature-dependent sex determination creates a particularly acute climate risk because warmer nesting beaches can produce strongly female-biased hatchling cohorts and may also reduce embryo survival at extreme temperatures.6 Nest depth, shade from vegetation, beach orientation, and changing rainfall can modify this effect. Green turtles also carry distinctive local histories: ancient and modern coastal societies have used them for food, oil, shell, and ceremonial purposes, while contemporary programs increasingly combine Indigenous knowledge, tagging, satellite tracking, and genetic studies to manage connected nesting and feeding habitats.
Common names and population-level conservation categories can vary by region; the global species assessment does not describe every regional population equally.
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