The diet of sea turtles varies by species and size. Some are generalists that consume fish, jellyfish and crustaceans, while others feed exclusively on a single prey, such as sponges. While adult sea turtles are only vulnerable to large sharks and similar predators, the eggs and young are eaten by a wide variety of predators. Sea gulls, raccoons, skunks, dogs and crabs consume eggs and newly hatched sea turtles.
Loggerhead sea turtles have very large heads, which help them crush well-protected prey, such as conchs and whelks. Leatherbacks, which are the world’s largest sea turtle species, have sharp beaks that help them catch jellyfish. Green sea turtles are herbivores that primarily consume sea grasses and related plants. However, young green sea turtles subsist primarily on small animals, such as crustaceans and hydrozoans. Flatback and olive ridley sea turtles are opportunistic omnivores that consume a variety of plants and animals. Kemp's ridley eat crabs, fish, jellies, shrimp and molluscs.
Tiger sharks are well-documented predators of sea turtles, although other large species consume them as well. Killer whales have been documented catching large leatherback sea turtles. Nevertheless, hatchlings are at the greatest risk. According to Sea World, predators eat approximately 90 percent of the eggs and young in each sea turtle nest.