Thousands of green sea turtle hatchlings swim to sea in a conservation win

The project to move eggs from one island has allowed for more males to develop. (Supplied: Queensland Parks and Wildlife) An 82 per cent of the northern Great Barrier Reef green sea turtle eggs relocated between two islands have hatched. The species has faced increasing threats nesting on Raine Island, its main rookery. Researchers say future testing will be needed to determine if the successful hatchlings are also the same fitness. Link copiedShareShare articleMore than 9,100 northern Great Barrier Reef green sea turtle hatchlings have begun their journey to sea after a project relocating eggs between two islands achieved promising results. It is the second time eggs have been moved from Raine Island to Sir Charles Hardy Island, about 600 kilometres north of Cairns in the north-east Coral Sea, in an attempt to boost hatchling numbers and produce more males. Queensland Parks and Wildlife Service senior project officer Katherine Robertson said the latest results were encouraging. "Of those eggs, 82 per cent of them hatched and the hatchlings made it to the water," she said. Researchers collect eggs straight away as they are laid by female turtles. (Supplied: DETSI) Raine Island, a tiny coral cay, is the world's largest nesting site for 90 per cent of the endangered species, and can attract up to 100,000 nesting females in a year. However, rising sea levels, warming temperatures and climate change have created major threats at the rookery. The turtle eggs are being destroyed by higher sea levels, and rising tides are creating steep slopes that hatchlings struggle to climb, which can cause them to flip and sometimes die. Researchers collecting green sea turtle eggs on Raine Island. (Supplied: DETSI) Sand temperature also affects the sex of the hatchlings, with warmer sand meaning fewer males. "This population is almost entirely female," Ms Robertson said. During the first relocation trial in 2024, teams moved 3,000 eggs from 38 nests, with 70 per cent of them successfully hatching. This summer, researchers dramatically expanded the program, moving almost 9,000 eggs from more than 100 nests. The eggs are placed in dug out nests under a shade on Sir Charles Hardy Island. (Supplied: Queensland Parks and Wildlife) The eggs were carefully collected by researchers on Raine Island before being placed into oxygen-free vacuum-sealed bags, temporarily pausing their development. Teams then took the eggs about 80 kilometres by boat to Sir Charles Hardy Island, where they were reburied beneath a custom shade structure. It lowered sand temperatures by about 1.5 degrees Celsius, helping create conditions to produce some male hatchlings. Scientists vacuum seal eggs with nitrogen to remove oxygen and temporarily pause development. (Supplied: Queensland Parks and Wildlife) The work is part of the Raine Island Recovery Project, which has run for more than a decade to improve the future of the green turtle population. Sir Charles Hardy is in Wuthathi country, while Raine Island spans both Wuthathi and Meriam countries. Meriam Nation elder Falen Pasi, who is the chair of Mer Gedkem Le Corporation, said the project was helping protect a species deeply connected to culture and identity that held a special significance across Torres Strait communities. Falen Pasi says turtles are culturally significant to his people. (ABC Far North: Rosanne Maloney) "Turtles for Indigenous people are very significant and spiritual," he said. Mr Pasi said the project showed the value of combining traditional knowledge with scientific research, as traditional owners had long noticed a decline in male hatchlings. "The true knowledge has got to be shared between traditional knowledge and Western science." Some 90 per cent of the endangered species nests on Raine Island. (Supplied: Queensland Parks and Wildlife) Wuthathi Tribal Elder chair Johnson Chippendale said traditional owners spent years working with scientists to find solutions. Mr Chippendale said protecting turtles meant protecting future generations. "It's really about saving the species," he said. About 2,000 adult turtles have died during one nesting season on Raine Island, many after falling. (Supplied: Queensland government) James Cook University researcher Caitlin Smith said the success rate of the hatchings was in line with other healthy nesting beaches. "Hatching success from those relocated clutches is phenomenal," she said. Caitlin Smith has been working on a similar egg relocation project for loggerhead turtles. (Supplied: Caitlin Smith) Dr Smith is also leading separate but similar research for loggerhead turtles at a key rookery near Bundaberg. Her project is now examining whether successfully relocated hatchlings are as physically fit as turtles produced in nests left untouched. Dr Smith said research in Indonesia found that while nest relocation was crucial for protecting sea turtle eggs, it could reduce the fitness of new turtles. Caitlin S

Thousands of green sea turtle hatchlings swim to sea in a conservation win

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