Sea turtles have been around for more than 110 million years and are ancient species which have co-existed with the dinosaurs. In our present time, there are only seven species of sea turtles globally.

In the order of increasing size, the turtles are the Kemp’s ridley, olive ridley, hawksbill, flatback, loggerhead, green and the largest sea turtle, the leatherback, which can grow up to 2 meters in length. All except the flatback turtle is listed as vulnerable, endangered or critically endangered on the IUCN Red List.

An infographic of the 7 species of sea turtles and their respective conservation status. (Photo by The State of the Worlds Sea Turtles)

Each species is unique in their own way, with different characteristics and feeding strategies. Feeding on a wide variety from jellyfish to seaweed is the generalist, the olive ridley turtle. Then there is the carnivorous specialist with a strong liking for crabs, the Kemp’s ridley turtle. Each species is also distributed differently, with the loggerhead turtle occurring worldwide from tropical to temperate waters, to the most range-restricted flatback turtle, found only in some regions of Australia.

With their diversity in feeding and habitats, sea turtles are keystone species of multiple ocean ecosystems. By maintaining healthy coral reef and seagrass meadows, they provide homes to a great biodiversity of marine life and stabilise the food webs of the ocean.

A green turtle swimming in the reefs. (Photo by Tom Fisk from Pexels)

Aside from spending most of their lives in the sea, you may chance upon female turtles coming up onto the beach during the breeding season to nest. Sea turtles can lay an average of about 100 eggs, depending on the species, and can produce between 2 to 8 nests within one season. Despite their reproductive productivity, it is estimated that only 1 in a 1000 hatchlings survive and make it to maturity to produce its next generation of offspring.

This number is driven even lower by human-caused threats that includes consumption and illegal trade, climate change, plastic ingestion and bycatch in commercial fishing gear.

Click below to find out more about the threats that sea turtles face!