While adult sea turtles have few natural predators, large sharks, such as the tiger shark, have been known to eat sea turtles. Killer whales have also been known to prey on sea turtles. Baby sea turtles are preyed upon by fish, dogs, raccoons, seabirds and crabs, and more than 90 percent of baby sea turtles are eaten by predators.
Sea turtles live in warm and temperate waters throughout the world and frequently migrate long distances between their nesting and feeding grounds, sometimes even up to 1400 miles. Like salmon, sea turtles return to their birthplace to lay eggs. While a sea turtle's diet varies between subspecies, some commonly consumed foods are jellyfish, crabs, seaweed, snails and other mollusks.
One of the greatest challenges sea turtles face is human expansion. Litter, such as plastic bags, can be mistaken by sea turtles for jellyfish and can result in serious injury or death for the turtle if consumed. If sea turtle nesting sites are filled with trash or other disturbances, female turtles return to the sea rather than nest. Illegal poaching, motorboat collisions and commercial fishing are some other threats faced by sea turtles. Sea turtle nesting sites can also be affected by natural disasters, such as hurricanes.