What Do Sea Turtles Eat? Diet by Species

Do all sea turtles eat the same thing?

No. Across the whole group, sea turtles eat things like sponges, jellyfish, snails, crabs, algae, plants and fish ^[8], but any one species uses only part of that menu. The shape of a turtle's head and beak is a good clue to what it eats. A broad head with strong jaws suits crushing shells, a pointed beak suits reaching into reef holes, and a jaw with sharp edges suits soft prey.

Diet also changes with age. Many young turtles spend their first years drifting in the open ocean before they move to coastal waters, and the food they find in each place is different. The article below follows the species one by one. It covers green, leatherback, loggerhead, hawksbill, Kemp's ridley, olive ridley and flatback turtles, and it says plainly when the sources we can use give only a short description.

What do green sea turtles eat?

Green turtles are "the only herbivorous species of sea turtle," according to NOAA Fisheries. Their diet is mostly algae and seagrasses, but they may also eat sponges and other invertebrates, and discarded fish and bait when those are available ^[1]. NOAA adds that the East Pacific population eats more animal prey than other green turtle populations.

A green turtle does not start out as a grazer. After hatching, young turtles live in the open ocean for several years, where "pelagic juveniles forage on plant and animal life found in oceanic drift communities," such as floating Sargassum. NOAA does not say exactly what hatchlings eat. Later the juveniles move to shallow coastal feeding grounds, and adults feed in coastal foraging areas, then migrate every 2 to 5 years to nesting beaches.

What do leatherback sea turtles eat?

Leatherbacks eat soft-bodied open ocean prey such as jellyfish and salps ^[2]. Their jaws have sharp edges and pointed cusps instead of a crushing beak, which suits soft food. Backward-pointing spines in the mouth and throat help them hold on to slippery prey.

Adult leatherbacks are about 1.5 to 1.8 m (5 to 6 ft) long ^[2]. To find jellyfish it dives deeper than any other turtle. NOAA reports dives to about 1,200 m (4,000 ft) that can last up to 85 minutes. Jellyfish are the turtle's food, so if you want to know more about them, see the jellyfish hub.

What do loggerhead, hawksbill and Kemp's ridley turtles eat?

These three species all eat animals, but each has a different favorite.

Loggerheads are carnivores that only occasionally eat plant material. Coastal juveniles and adults eat mostly bottom-dwelling invertebrates, including mollusks, crustaceans and horseshoe crabs, and NOAA names whelks and conch as typical hard-shelled prey. A large head supports powerful jaw muscles built to crush these animals ^[3]. Hatchlings and young juveniles in the open ocean eat a wide variety of floating items.

Hawksbills are omnivores whose main food is sponges that live on coral reefs. NOAA calls them "the only species of sea turtle that can survive on a diet consisting mainly of sponges." They also eat algae, corals, mollusks, tunicates, crustaceans, sea urchins, small fish and jellyfish. Their pointed, hawk-like beak lets them reach into small holes and crevices in reefs. In Hawaii, where sponges are less available, NOAA describes them as opportunistic feeders ^[4].

Kemp's ridleys change food as they grow. Young turtles that live in the open ocean near floating Sargassum feed on small animals and plants. After they move to shallow coastal areas, crabs are their preferred food, and adults live mainly in nearshore habitats with muddy or sandy bottoms ^[5]. If you are curious about the prey, browse the crab hub.

What do olive ridley and flatback turtles eat?

Olive ridleys are omnivorous and feed on a wide variety of foods, including algae, crustaceans, tunicates and mollusks. NOAA says they can dive to depths of up to about 150 m (500 ft) to forage for bottom-dwelling invertebrates ^[6].

Flatback turtles are native to northern Australia and rarely travel far from home. Animal Diversity Web says they seek out sea cucumbers, mollusks, jellyfish, prawns, bryozoans and other invertebrates in shallow waters, and that they are carnivorous and rarely, if at all, eat vegetation ^[7]. That page was last updated in 2003, so treat the details as a general guide. We could not use a NOAA species page for the flatback, which is why we rely on this older reference.

Do sea turtles eat plastic bags?

Sometimes, by mistake. NOAA says green turtles may ingest marine debris such as fishing line, balloons and plastic bags, and that they eat it because they can mistake it for food ^[1]. The leatherback page lists similar items ^[2], and the loggerhead page says that floating trash and debris can be mistaken for food and that small plastic fragments are often eaten ^[3]. NOAA calls the ingestion of debris another threat to all species of sea turtles.

The sources we can use do not explain exactly why a turtle takes a bag for food, so we do not claim a specific cause. The practical lesson is simple: what ends up in the ocean can end up in a turtle's diet. Picking up trash, using less single-use plastic and never releasing balloons are small steps that keep it out of the water. For wider context, see our pages on ocean habitats and conservation.

How do sea turtle diets matter for protection?

Because each species leans on a different food, each depends on a different part of the ocean. Seagrass beds and reefs, coastal bottoms and open-water jellyfish are all separate habitats. NOAA lists the leatherback as endangered under the U.S. Endangered Species Act ^[2]. It lists green turtles by population segment instead of as one group, with 3 endangered and 8 threatened ^[1].

Sea turtles are wild animals, and people should not feed or approach them. For a broader overview of the group, head to the sea turtle hub, or browse all animals.