Green turtle -- Green turtles are unfussy nesters, landing on tropical and sub-tropical beaches to lay their eggs. Adult green turtles are predominantly herbivores, feeding on grasses and algae, making them a dietary outlier among the seven turtle species.
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Green turtle -- It's thought there were once as many as 500 million green turtles in the Caribbean alone. However, the species was at one time eaten by European explorers and later used for turtle soup.
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Green turtle -- It is classed as endangered by the International Union for Conservation of Nature (IUCN), which considers the harvesting of eggs and adults as the biggest threat green turtles face, along with incidental bycatch (when turtles are caught unintentionally during fishing for other species).
Loggerhead turtle -- The loggerhead diet is typically made up of crabs, crustaceans, molluscs and jellies. Known for their long migrations, in 1996 one female named Adelita was tracked crossing the Northern Pacific, from Mexico to near Japan.
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Loggerhead turtle -- The IUCN listed loggerheads as vulnerable in 2015, having been endangered in the 1990s. However, improvements in a species' status can reflect both genuine population growth and just better data.
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Olive ridley turtle -- Olive ridleys like to do things in numbers. The most populous turtle species, they descend on beaches in their thousands for huge nesting events known as arribadas. Unusually, it's a turtle species that nests during the day, making arribadas a huge tourist draw.
Olive ridley turtle -- Listed as vulnerable by the IUCN, the olive ridley faces the same human dangers as other turtle species. In 2018, over 300 olive ridleys were found dead, tangled in a single illegal fishing net off the Mexican coast.
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Leatherback turtle --The leatherback's shell is covered with a thick leathery skin, with grey hues as adults, and ridges along their back that distinguish them from other sea turtle species. There's a reason for these differences -- leatherbacks are part of a different family, "Dermochelyidae." In fact, they're the only member still alive today.
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Leatherback turtle -- Leatherbacks can dive to over 1,000 meters to feed on plankton and have highly adapted bodies to cope with different water temperatures (helping explain their worldwide spread). Once considered critically endangered and now listed as vulnerable by the IUCN, SWOT (The State of the World's Sea Turtles -- a series of reports compiled by the Oceanic Society) states numbers are rapidly declining in many parts of the world.
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Hawksbill turtle -- The hawksbill sea turtle is named for its sharp beak, which it uses to feed on reef sponges; it's the only marine consumer with a diet predominately made up of sponges, according to SWOT. Hatchlings weigh a mere five grams, while fully-grown adults can weigh up to 150 kilograms.
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Hawksbill turtle -- The hawksbill exists throughout the world's oceans but was listed as critically endangered by the IUCN Red List of species in 2008 (its last assessment of the hawksbill). Its shell has historically been used for jewelry, and though international trade of tortoiseshell is prohibited, it still occurs.
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Hawksbill turtle -- The World Wide Fund for Nature lists loss of nesting and feeding habits, excessive egg collection, fishery-related mortality, pollution and coastal development among the threats hawksbills face. SWOT says hawksbills in the Eastern Pacific are "probably the most endangered sea turtle population in the world."
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Kemp's ridley turtle -- The Kemp's ridley is known for its limited range. It spends most of its time around the Gulf of Mexico, Caribbean and eastern coast of the US, although it has been found across the North Atlantic.
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Kemp's ridley turtle -- It's the smallest sea turtle, growing up to 70cm and 60 kilograms, and taking 10-15 years to reach sexual maturity. Along with olive ridleys, it is the only sea turtle to exhibit mass nesting.
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Kemp's ridley turtle -- Last assessed by the IUCN in 2019, the Kemp's ridley is critically endangered, with just over 22,000 adults thought to be in existence. It was nearly extinct 50 years ago according to SWOT, which says the species has shown signs of recovery despite myriad threats.
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Flatback turtle -- Flatback turtles have only existed since 1988 -- that is, according to science. Once considered a type of green turtle, they were formally described as a separate species in the late '80s.
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Flatback turtle -- Flatback turtles nest only along Australia's northern coast and live in the ocean between Australia, Papua New Guinea and southern Indonesia. They can stay active underwater longer than most other sea turtles.
