The Kemp’s Ridley turtle (Lepidochelys kempii) is found mainly in the Gulf of Mexico and the southeastern shores of the USA.
Unknown to science until the 1940s when a home-made film showed them nesting in their thousands on a deserted beach in Mexico, Kemp’s Ridley turtles have since then suffered catastrophic declines, mostly due to being accidentally caught in shrimp trawler nets. Fortunately, turtle excluder devices (TEDs) have been invented and are now widely used. Even so, the Kemp’s Ridley is still considered Critically Endangered (http://www.iucnredlist.org/apps/redlist/details/ 11533/0) on the IUCN Red List of Threatened Species (http://www.iucnredlist.org)
Flatback – Australia’s turtle.
The Flatback turtle (Natator depressus) is indigenous to Australian waters. Unlike other species, these turtles do not have a substantial oceanic drifting phase as hatchlings and juveniles. They stay relatively close to Australian shores and are one of the least understood of all species, rating a ‘Data Deficient’ designation under IUCN’s Red List of threatened species.
The leatherback turtle (Dermochelys coriacea) is without doubt the largest of all extant turtle species. It can grow to the size of a Volkswagen Beetle and weigh in at a mighty 1000kgs! Yet it does so on a diet of very little else but jellyfish, and spends much of its time roaming the oceans in search of them. It can dive deep, over 1000m, and is the only species to have a rubbery black carapace for a shell, unlike its hard-shelled cousins. Globally, the leatherback is another species that is considered Critically Endangered.
Green – because it’s vegetarian?
One of the two species commonly found in the waters of the Gulf, the green turtle (Chelonia mydas) is the only truly herbivorous sea turtle, feeding predominantly on seagrass as an adult. Even on that diet, it can grow to over 150kg. They get their ‘green’ name for the colour of the fat inside the shell, not for any exterior appearance!
In the olden days of ocean discovery, Christopher Columbus and other transatlantic crews found thousands of green turtles when they arrived in the Americas, and since that time overhunting has led to massive population declines in some places. However, concerted conservation action has brought many green turtle colonies back from the brink of extinction, although they are still considered Endangered at a global level. (http://www.iucnredlist.org/apps/redlist/details/4615/0)
Hawksbill – too attractive for its own good.
The second species, frequently found around the Gulf, the hawksbill turtle (Eretmochelys imbricata) is a small, beautifully adorned turtle with intricate shell designs. This feature has made it widely sought after for centuries, by artisans who wanted to use it to make jewellery. Massive trade in earlier days brought many hawksbill populations to near extinction, and only the curbing of the trade and long term conservation action have saved it from severe decline. Despite these measures, it too is listed as Critically Endangered worldwide (http://www.iucnredlist.org/apps/redlist/details/ 8005/0).
Olive Ridley – too many to count.
Cousin to the Kemp’s Ridley, the Olive Ridley (Lepidochelys olivacea), is a small turtle that grows to just 50-60 kgs. It is most famous for nesting in literally hundreds of thousands over just a couple of days in amazing events called arribadas, a Spanish word for mass arrivals. The Olive Ridleys come ashore in droves in just a few key places in the world - mostly Costa Rica and India - but can be found in smaller numbers throughout the tropics. The Olive Ridley has managed to avoid the endangered list but is still classified as Vulnerable. (http://www.iucnredlist.org/apps/redlist/details/11534/0)
The loggerhead (Caretta caretta) has massive, powerful jaws, which it uses for munching hard- shelled clams and other molluscs. Beware putting a finger anywhere near them! The loggerhead’s two key nesting homes are Florida and Oman, where over 20,000 animals nest each year. This is also the only species to have a mysterious hump on the back of the shell, which may be the source of the ancient myth that the world was carried on a turtle’s back. The loggerhead is classified as Endangered.