Green Sea Turtles and the Beach They Always Come Back To
- Gregory Andrews
- 1 day ago
- 4 min read
#FloraAndFaunaFriday this week shares the story of Australia's extraordinary Green Sea Turtles.
A decade ago, I travelled as Australia’s Threatened Species Commissioner with scientists, rangers and Eddie Mabo’s relatives to Raine Island, at the very top of the Great Barrier Reef.
It was one of the most extraordinary places I've ever been.
Raine Island isn't just a speck of sand and coral in the northern Reef. It is the world’s largest green sea turtle hatchery. In big seasons, tens of thousands of female turtles return there to nest. In some years, more than 60,000 turtles have been recorded in a single season. For the northern Great Barrier Reef green turtle population, Raine Island is the source of almost 90 per cent of the population.
That's hard to comprehend until you see it. At night, the beach seems to move. Huge female turtles haul themselves out of the ocean, slowly and heavily, driven by an ancient instinct older than human memory. They cross the sand, climb up to high ground, dig their nests, lay their eggs, cover them again, and return to the sea. And even then, their ordeal isn't over: many have to run the gauntlet of tiger sharks waiting in the shallows knowing that the turtle mums' exhaustion makes them vulnerable.
Many of the turtle mums have travelled thousands of kilometres to get there. Some migrate all the way across the Pacific - taking extraordinary ocean journeys linking Australia to distant feeding grounds in South America. But the turtle mums come back. Not just to any beach. To their beach. The beach where they themselves hatched. That fact fills me with wonder.
We spent two days on Raine Island. We watched mother turtles nesting. We helped rescue females that had become stuck or overturned. In the early morning, I found myself picking up hundreds of hatchlings to help them make their way down to the water before the seabirds took them.
Raine Island is a place where life and death are happening everywhere, all at once. It's beautiful. It's brutal. And it's deeply humbling. But the warning signs are clear.
Climate change is the biggest threat to green sea turtles. Rising seas and stronger tidal inundation erode nesting beaches and flood nests. When turtle eggs are submerged for too long, the developing hatchlings suffocate and drown before they ever reach the surface. At Raine Island, this has been a serious problem for decades, reducing hatching success and threatening the future of the population.
And then there's the heat. Green turtles are a temperature sex-determined species. That means the temperature of the sand around the eggs determines whether hatchlings become male or female. Warmer sand produces more females. Cooler sand produces more males. For the northern Great Barrier Reef green turtle population, the pivotal temperature is around 29.3°C. Above that, the balance tips increasingly towards females.
This isn't a distant theoretical risk. It's already happening. Research on northern Great Barrier Reef green sea turtles has found a profound female bias, with some studies reporting more than 99 per cent of juveniles as female from warmer nesting beaches. Think about that. A species that has survived since the age of dinosaurs is now facing a future where the sands of its birth beaches may become too hot to produce enough males.
That's what climate change does. It doesn't just make weather more extreme. It interferes with the most intimate cycles of life.
The good news is that people aren't standing by. At Raine Island, Wuthathi and Meriam Nation Traditional Owners, government agencies, scientists, rangers and conservation partners are implementing the Raine Island Recovery Project to give the turtles a fighting chance. The work has included beach reprofiling to reduce nest flooding, construction of turtle ramps and fencing to prevent nesting females falling from cliffs, rescuing stranded turtles, monitoring the turtles and seabirds, and building First Nations ranger capacity.
When I visited, I saw all of this up close. It was practical, collaborative and full of care. We literally loaded up stranded mother turtles into motorised wheelbarrows to take them back to the sea before they died of heat exhaustion. People were not just studying decline. They were intervening, respectfully and intelligently.
There's a lesson in all of this. Conservation can work. But the other sad reality is that if global emissions don't start coming down rapidly, efforts like this will only be stop gap.
At the end of the day, this is a story about responsibility. The turtles know what to do. They cross oceans. Read currents. And return to the beach where their lives began. They've been doing it for thousands of years. The question is whether we will do what we know we need to do. First and foremost, that means cutting climate pollution.
Because somewhere, right now, a tiny green turtle like this one is breaking out of its shell under the sand. It's never seen the ocean. It doesn't know about climate politics, fossil fuel lobbying, plastic pollution or government failure. It only knows to dig upwards, follow the light, and head for the sea. We owe it, and all of them, a future.
What a sad but beautiful story. It's breathtaking how uncaring and arrogant our politicians are about our environment.
So precious. I wish the world was willing to do what's needed to save them from extinction.