The green sea turtle is a large marine reptile found in tropical and subtropical waters worldwide. Its name comes from the greenish fat beneath its carapace, not its shell color, which ranges from olive to black. These endangered turtles inhabit diverse environments, from nesting beaches to shallow coastal seagrass beds.
Predators of Eggs and Hatchlings
Green sea turtle eggs and hatchlings face many natural predators. On nesting beaches, terrestrial animals such as raccoons, foxes, wild dogs, and even ants frequently raid nests, digging up and consuming the eggs before they can hatch.
Birds like gulls and crows also scavenge eggs and prey on newly emerged hatchlings as they attempt to reach the ocean. After emerging, hatchlings make a journey across the sand to the water. Ghost crabs and various bird species threaten them during this trek.
In the ocean, hatchlings remain vulnerable to marine predators. Fish, including snappers, groupers, and barracudas, along with various shark species, consume many hatchlings in nearshore waters.
Predators of Juvenile and Adult Turtles
As green sea turtles grow into juveniles and adults, their natural predators decrease due to their increased size and hard shells. Large sharks, particularly tiger sharks and bull sharks, are known to prey on both juvenile and adult green sea turtles.
In some regions, killer whales (Orcinus orca) can also hunt adult sea turtles. Adult green sea turtles, weighing over 150 kilograms with carapaces exceeding one meter, are still hunted by these powerful marine predators. On land, nesting female turtles may also face predators such as jaguars and crocodiles in specific coastal areas.
Human Impact on Green Sea Turtle Populations
Beyond natural predation, human activities represent a major threat to green sea turtle populations globally. Illegal hunting, known as poaching, targets turtles for their meat, eggs, and shells, which are used to make products like tortoiseshell.
This illicit trade significantly depletes populations and disrupts their reproductive success. Accidental capture in fishing gear, or bycatch, is another widespread human-induced mortality factor.
Turtles become entangled in equipment like trawls, gillnets, and longlines, leading to injury or drowning. Habitat degradation also severely impacts green sea turtles.
Coastal development, pollution, and marine debris diminish or destroy essential nesting beaches and foraging grounds, such as seagrass beds. Propeller strikes from boats also injure or kill turtles, adding to their threats.