(TMU) – Researchers in Australia have captured stunning aerial footage of thousands of green turtles gathering on the Great Barrier Reef at the height of nesting season.
Every year, masses of the creatures make their way to the largest green turtle rookery in the world at Raine Island, a coral cay rich in vegetation that lies about 385 miles (620 km.) northwest of Cairns in Queensland, Australia.
Australian Geographic estimates that some 64,000 female green turtles migrate thousands of kilometers every year to lay their eggs at the island.
The latest footage, captured using a drone by the Queensland Government’s Department of Environment and Science (DES), could be one of the biggest turtle swarms ever observed.
Drone footage shows the largest remaining breeding ground for green turtles in the world. The video revealed up to 64,000 turtles swimming around Australia's Great Barrier Reef during nesting season. https://t.co/wVqw0ZFjur pic.twitter.com/kTQwXAQIbZ
— CNN (@CNN) June 9, 2020
The majestic green turtle is widely distributed across the world’s tropical and subtropical waters, and gets its name from the verdant deep green color of its cartilage and fat. The green turtle is one of the largest and the only herbivorous marine turtle, and thrives in the Reef due to its protected shores near the coast and around islands, according to conservationist group WWF-Australia.
However, despite the massive number of green turtles seen in the video footage, the creature is considered endangered due to the threat of hunting, overharvesting of eggs, the degradation of marine habitats and their loss of beach nesting sites. They also are frequently trapped by fishing boats.
“Marine turtles have roamed the world’s oceans for more than 100 million years, and are an integral part of our tropical coastal ecosystems,” WWF-Australia wrote on its website. “It’s taken humans just 200 years to tip the scales against their survival and these ancient mariners are now considered endangered or vulnerable.”
Despite their wide geographical distribution, only a few large nesting populations still exist, and Raine Island in the northern Great Barrier Reef is the largest among them.
However, scientists remain concerned that they are not reproducing at the expected rate primarily due to inhospitable terrain causing them to fall from cliffs or get trapped in the heat, as well as suffering flooding in their nests.
“We sort of became aware that although there’s these massive aggregations, the actual reproduction isn’t working so well,” Dr. Andrew Dunstan of the DES told CNN.
The researchers have been intervening to assist the green turtle population while also tracking them. They found that Unmanned Aerial Vehicles (UAVs) or drones had the best capabilities in terms of documenting the ancient mariners.
Researchers initially tried to pain the turtles’ shells with a white stripe of non-toxic paint, but they found that drones were far easier and more accurate when it came to tracking the sea creatures.
“Trying to accurately count thousands of painted and unpainted turtles from a small boat in rough weather was difficult. Using a drone is easier, safer, much more accurate, and the data can be immediately and permanently stored,” said in a statement.
Watch: researchers caught drone footage of 64,000 green turtles making their way to nest on the beaches of Raine Island, on Australia's Great Barrier Reef 🐢🐢🐢 pic.twitter.com/rBi53jqQCG
— World Wildlife Day (@WildlifeDay) June 9, 2020
The use of the drones showed that the 64,000 green turtles that swarmed to the island were a much a higher number than they had ever guessed – forcing them to revise their historic population estimates.
“We were underestimating that a lot. We’re finding 1.73 times as many turtles with the drone and as we do when we directly compare with the observer counts,” Dunstan added.
In the future, researchers how to use the results to further tweak their methods of managing and tracking the turtle population. They also hope to introduce artificial intelligence that can automate the counting of the creatures using the footage captured by drone.