They are then probably carried by currents to favourable areas in the open ocean, where they grow for several years until they join adult and juvenile turtles at the coastal feeding grounds. While in the open ocean, young green turtles are probably carnivorous and feed on invertebrates such as jellyfish. Some hatchlings never reach the ocean and are snatched up by hungry crabs. Hatchlings may also be disoriented or impeded by obstacles and die from the sun's heat. Once in the ocean, sharks and possibly other carnivorous fish eat hatchlings.
Tiger sharks regularly feed on all sizes of green turtles.
The life span of sea turtles is unknown. Male and female green turtles look alike until they are mature. Then, the male develops a long tail extending beyond the hind flippers. A female's tail extends only a short distance beyond the end of her shell. Generally, only female sea turtles leave the ocean after entering it as hatchlings.