Sea turtles are ancient reptiles that have navigated the world’s oceans for millions of years. These animals spend almost their entire lives in tropical and temperate waters, only coming ashore for females to lay eggs. They are known for their long migrations, and what they eat depends entirely on the species.
Feast Time! Meet the Different Eaters
The adult Green sea turtle is primarily herbivorous, making it the ocean’s main gardener. They use their finely serrated jaws to graze on large meadows of seagrass and algae along the shallow coastal seabed. By constantly trimming these plants, Green turtles help keep the marine ecosystem healthy.
The Loggerhead and Kemp’s Ridley turtles prefer a hard-shelled, meaty diet. Loggerheads have powerful, massive jaws and large head muscles that allow them to crush the hard exoskeletons of crabs, whelks, and conchs. The Kemp’s Ridley is a carnivore specializing in consuming crustaceans, especially crabs found on the ocean floor.
The Hawksbill turtle is a specialist often found near coral reefs, feeding almost exclusively on sea sponges. These creatures are one of the very few animals that can eat sponges, which are often protected by indigestible glass-like spikes called spicules. Hawksbills use their narrow, pointed beak to reach into tiny reef crevices and chip away at their fibrous meal.
The Leatherback turtle, the largest of all sea turtles, primarily eats jellyfish. These soft-bodied invertebrates are their main source of nutrition, earning the Leatherback the nickname of a gelatinivore. To sustain their huge bodies on this low-nutrient prey, Leatherbacks must consume enormous quantities of jellyfish every day.
How Sea Turtles Eat Their Food
Sea turtles do not have teeth, but they possess strong, sharp beaks called mandibles that are perfectly shaped for their particular diets. The Green turtle’s beak is serrated, or saw-like, which helps them shear off tough blades of seagrass and scrape algae off rocks. The Loggerhead turtle has a blunt, heavy beak that acts like a powerful nutcracker to easily crush the shells of crabs and mollusks.
The Hawksbill’s beak is shaped like a bird of prey’s, allowing it to delicately slice and tear away pieces of sponge from the coral structure. Meanwhile, the Leatherback turtle’s jaws feature two sharp, pointed cusps that help them pierce and hold onto slippery jellyfish. This specialized beak allows them to grasp their soft-bodied prey without letting it slide away in the water.
A remarkable feature is found inside the throats of many sea turtles, especially the Leatherback. Their esophagus is lined with hundreds of backward-facing, spine-like projections called papillae. These spikes point toward the stomach, acting like a one-way conveyor belt. This ensures that once slippery prey is caught, it cannot escape back out of the mouth. The papillae also help the turtle squeeze out excess seawater before swallowing the meal.
The Dangerous Pretend-Food
Unfortunately, some of the objects floating in the ocean look exactly like the sea turtle’s natural food. This is particularly true for the Leatherback turtle, whose primary food, the jellyfish, is clear and gelatinous. A common plastic bag floating just beneath the surface looks strikingly similar to a bell-shaped jellyfish, tricking the hungry turtle.
Juvenile Green turtles, which are omnivores that eat a variety of floating matter, also frequently mistake plastic for a meal. Plastic bags and balloons are among the most harmful items because they can be easily swallowed whole. The plastic cannot be digested and stays in the turtle’s stomach, creating a dangerous blockage.
This blockage gives the turtle a false sense of being full, even though it receives no nutrition. The animal stops trying to find real food and slowly starves, or the sharp edges of the plastic can perforate its internal organs. We can all help keep the ocean clean by reducing our use of single-use plastics, especially bags and balloons, to ensure these mariners only eat real food.