Leatherback sea turtles are modern-day dinosaurs.
There are seven species of sea turtle. All sea turtles share common life history characteristics and even face common threats from nest disturbance, development, fishing, pollution and climate change.
Nearly all sea turtle species are endangered. Each population is classified by conservation status: vulnerable, endangered, or critically endangered. Endangered means the species is in danger of extinction and critically endangered indicates a high risk of extinction. A population is determined vulnerable when it shows a high probability of becoming a species at risk of extinction.
Leatherbacks are the largest sea turtles. Males can reach up to 8.5 ft (2.6m) and 2000 lbs (900 kg). Unlike other sea turtles, leatherbacks have a flexible, rubbery carapace that allows them to dive deeper than 4100 feet (1250 meters). Leatherbacks nest on tropical beaches and are found in all the world’s oceans except the Arctic and Antarctic. The leatherback’s esophagus is extra-long and lined with spines to facilitate digestion of jellyfish.
Green turtles have small rounded heads and a smooth carapace. Ranging throughout the tropical and subtropical Atlantic, Pacific and Indian Oceans, they eat sea grasses and rooted algae. Green turtles received their name due to their diet, which gives their fat a greenish color. The East Pacific green turtle subspecies (Chelonia mydas agassizii) is often called the black turtle, due to its somewhat darker appearance.
Loggerheads have large heads with powerful jaws for crushing crabs, mollusks and other marine invertebrates. They nest on subtropical beaches and forage in estuaries, along continental shelves and in pelagic habitats. Loggerheads populations are declining rapidly and fewer turtles are returning to lay eggs at nesting beaches.
Hawksbills have narrow heads and hooked beaks for eating sponges. They nest on tropical beaches and are mostly found near coral reef habitats. The hawksbill’s carapace has thick overlapping scutes with beautiful coloration, which made these turtles prime hunting targets for tortoiseshell” trinkets.
Olive ridleys are considered the most abundant sea turtle, although the current global population is only 0.2% of the species’ historical abundance. Females often nest together in large aggregations, known as arribadas, of up to 200,000 turtles at once. Olive ridleys forage along drift lines on a number of species, including crabs, jellyfish, clams, snails and some algae.
Kemp’s ridleys are limited to the Gulf of Mexico and North Atlantic, where they feed on crabs, clams and snails in shallow coastal waters. Kemp’s ridleys are also known to nest in arribadas, but only during daylight hours. A successful "headstart" program gave the species a chance at recovery after the population in the Gulf of Mexico was severely reduced by incidental take from shrimp trawling.
Flatback turtles received their name for their flattened shell. Their range is limited to the tropical waters of Australia, where they feed in shallow waters on jellyfish, sea pens and other soft-bodied invertebrates. Although the flatback’s nesting beaches are remote and undeveloped, feral pigs are known to disturb nests. Flatbacks also face significant threats from shrimp trawling and other fishing activities.