Sea Turtle
Chelonioidea
Animal Type: Reptile
Habitat: Open ocean, coasts & reefs
Diet: Varies by species
Species: 7 living species
Breathing: Air-breathing lungs
About Sea Turtles
Sea turtles are large marine reptiles that spend most of their lives in the ocean. Unlike fish, they breathe air with lungs and must regularly return to the surface to breathe.
Their bodies are specially adapted for swimming. Instead of the feet seen on many land turtles, sea turtles have powerful flippers that help propel them through the water.
There are seven living species of sea turtle: green, loggerhead, hawksbill, leatherback, Kemp's ridley, olive ridley, and flatback sea turtles.
Life in the Ocean
Sea turtles may travel enormous distances during their lives. Some migrate hundreds or thousands of miles between feeding areas and nesting beaches.
Although they spend most of their lives at sea, female sea turtles must return to land to lay their eggs. They crawl onto sandy beaches, dig nests, lay their eggs, and then return to the ocean.
When the young turtles hatch, they emerge from the sand and make their way toward the sea.
Sea turtles can navigate across enormous stretches of ocean. Scientists have found evidence that they can use Earth's magnetic field like a natural map and compass, helping them find important feeding and nesting areas.
The Sunlight Zone
Sea turtles spend much of their lives in the Sunlight Zone, also known as the Epipelagic Zone. This is the uppermost layer of the open ocean, extending from the surface to about 200 meters (656 feet) deep.
Sunlight penetrates this layer strongly enough for photosynthesis to occur. Phytoplankton, algae, and marine plants use sunlight to create energy and support enormous ocean food webs.
The Sunlight Zone contains a huge variety of animals, including tuna, sharks, dolphins, jellyfish, and countless smaller fish.
Living near the surface is especially important for sea turtles because they breathe air. Even species capable of making deep dives eventually have to return to the surface.
What Do Sea Turtles Eat?
A sea turtle's diet depends on its species and age. Some eat seagrass and algae, while others feed on jellyfish, sponges, crabs, mollusks, and other marine animals.
Green sea turtles are especially interesting because adults mainly eat seagrasses and algae. Hawksbill turtles specialize heavily in eating sea sponges, while leatherback turtles feed primarily on jellyfish and other soft-bodied animals.
Built for Swimming
Sea turtles cannot pull their heads and flippers completely inside their shells like many land and freshwater turtles can.
Instead, their bodies are streamlined for ocean life. Their large front flippers provide most of their swimming power, while their smaller rear flippers help with steering.
Their shells are also generally flatter and more streamlined than those of many land-dwelling turtles, allowing them to move efficiently through the water.
Sea Turtle Nests
Female sea turtles come ashore to reproduce. After finding a suitable location on a sandy beach, a female uses her rear flippers to dig a nest and deposits a clutch of eggs inside.
She covers the nest with sand before returning to the ocean. The developing turtles are then left to hatch on their own.
Interestingly, the temperature of the developing eggs influences whether many species of sea turtle hatch as male or female.
Where Are They Found?
Sea turtles live in oceans around the world, especially in tropical and subtropical waters. Different species can be found around coral reefs, seagrass beds, coastal waters, and the open ocean.
The leatherback has an especially wide range and can travel into much colder waters than most other sea turtle species.
Protecting Sea Turtles
Sea turtles face many threats, including accidental capture in fishing gear, loss of nesting habitat, pollution, marine debris, boat strikes, and climate change.
Protecting nesting beaches, reducing plastic and other marine debris, and developing safer fishing practices are some of the ways people work to protect sea turtle populations.