2018 Aug 17
Sri Lanka is home to many marvelous migratory creatures from around the world. Of those many migratory visitors, turtles place themselves as one of the most paramount creatures contributing to the diverse ecology of our island and around the world. Turtles date back to more than 100 million years and are one of the oldest oceanic dwellers.
Sea turtles play a vital role in maintaining oceanic habitats by prolonging healthy seagrass beds, coral reefs, and also in vegetating and stabilizing ecosystems in scarce sand dunes. There are 7 different species of sea turtles swimming in the ocean in their vast migratory paths running across the globe. Out of these 7, there are 5 who find nesting grounds in the shores of Sri Lanka to lay their eggs. Male turtles never come ashore, while females only swim to shores solely for their nesting purposes.
Here is an outline of what we do know and things we don’t know about these mysterious visitors from the ocean.
Hawksbill turtle (Eretmochelys imbricata)
Hawksbill turtles are highly migratory but are mainly found in the tropical and subtropical waters residing in coral reefs and one of frequent visitors of Sri Lankan beaches. Listed as critically endangered by the IUCN, Hawksbill turtles can be considered as one of the most important contributors in oceanic habitats. Feeding predominantly on sea sponges, these creatures allow corals to colonize and grow by doing so. They forage depending on the habitats varying from algae, soft corals to shellfish.
Weighing up to 50-90 pounds, these creatures can get bigger as 1 meter long in size! With an olive green shell and a distinctive zigzag overlapping scale pattern on their shells have made them considered to be highly-valuable in domestic trades in the production of jewelry, souvenirs and other items.
Leatherback turtle (Dermochelys coriacea)
Largest of all sea turtles, majestic Leatherback is also one of the largest reptiles on the planet. Of all the species, Leatherback is the most migratory swimming swiftly with the use of underwater currents crossing both the Atlantic and Pacific oceans. These mammoths grow up to 600-1500 pounds lengthening up to more than 4 feet.
Even though the Leatherback population is widely distributed circumglobally, their numbers have seen a drastic decline over the last decade. They are listed as vulnerable to extinction on IUCN red list due to intensive egg collection and fisheries bycatch that continue largely to this day.
Loggerhead turtle (Caretta caretta)
Rarest of Sri Lankan oceanic turtles, loggerhead turtles are easily identifiable because of their large head and, as their name suggests, striking reddish brown outer shell. Weighing up to 175-400 pounds, adult loggerheads will grow up to more than 2 – 3 feet long. Even though these turtles are less likely to be hunted for meat, they continue to fall in engagement in fisheries bycatch, death by entanglement of debris, and egg collection for human consumption.
Green Turtle (Chelonia mydas)
Of all the sea turtles found in Sri Lanka, the Green turtles are the most common, growing into herbivores as they reach adulthood. They are named after the green colored fat found on their olive/black outer shells making them one of a kind amongst of all turtles. Unluckily, these turtles were once used to make turtle soup, a practice that has decreased over the years. These turtles are commonly found in tropical and subtropical water islands with wide beaches foraging on seagrass beds and coral reefs. Green turtles would migrate long distances between feeding grounds and beaches where they hatched for nesting purposes.
Listed as endangered, these turtles are continuously threatened by incessant egg collection, hunters, death by entanglement of fishing gear and most importantly loss of habitat and nesting grounds.
Olive Ridley Turtle (Lepidochelys olivacea)
The smallest and most abundant of all sea turtles, Olive Ridley acquired its name from the olive- green/grey color of their shells. Weighing up to 75-100 pounds these turtles can grow up to more than 2 feet long. Because of its selective nesting habits these turtles are listed as endangered due to loss of nesting beaches, egg collection and hunters. These omnivorous turtles mostly feed on small crustaceans, fish and other marine vegetation.
Although all of these sea turtles are protected by the law in Sri Lanka they continuously fall prey and decrease in numbers because of poachers, shell trade, entanglement, ingestion of marine debris, destruction of nesting and foraging habitats, and ocean pollution. With proper education and awareness on the importance of sea turtles, there is a chance of averting the endangerment of these majestic species.