Following Flatbacks

Windswept, deserted and just far enough from Darwin to be considered remote, Bare Sand Island is an idyllic sweep of reef and sand on the edge of the Joseph Bonaparte Gulf. The Kenbi clan who won native title four years ago after the longest running Aboriginal land claim in Australian history, call it Ngulbitjik, and it’s known around Darwin as the home of flatback turtles. 

A three-legged estuarine crocodile named Graham stakes out the beach, keeping swimmers out of Bare Sand’s irresistibly blue sea. But the sunsets and starry-night skies are surreal this far from city lights, and the flatback encounters are renowned for turning first-time visitors into turtle research volunteers. 

Not much is known about Australia’s only endemic sea turtle, named natator depressus for its distinctively flat shell. Scientists stab at a 1-in-1000 survival rate but nobody really knows how close to extinction the flatback is, given that both the Northern Territory government and the IUCN Red List call the turtle’s conservation status ‘data deficient’. 

How flatbacks spend the 30 years between hatching and returning to nest for the first time on Australian shores, is a mystery. But it’s one that Darwin’s all-voluntary AusTurtle team is working to uncover, and 30 years of research on Bare Sand Island’s 650-strong nesting rookery, hopes to give flatbacks a fighting chance against the rapidly approaching onslaught of global warming.  

I meet my first flatback at 2am on a cold, balmy Top End night. I’m pacing the shoreline with AusTurtle head researcher Andrew Raith, our feet sinking into the damp sand left behind by the already retreating tide. The four-hour window for turtle nesting – two hours either side of the night’s high tide – is closing when the first flatbacks lumber ashore in a rush. 

The clusters land with uncanny timing, a technique that Andrew Raith believes indicates a ‘safety in numbers’ approach against predators, suggesting remarkable evolutionary change. Furthermore, Raith believes the nesting females communicate with each other at sea, hitting the beach in the same pairs, year after year. After 16 years of watching these flatbacks, his astute observations are the best around.  

The night passes in a quiet rush, red head torches piercing the darkness up and down the beach. I join the researchers as they time-stamp each new turtle track, scribbling numbers in the sand to form a turtle queue of sorts, before leaving each enormous, 90kg flatback to make her way into the dunes undisturbed. 

On this night, 18 flatbacks labour up the beach to nest with awkward but undeniable determination. Over the space of a few hours, each turtle clears a suitable site, digs a deep egg chamber with some slow, dexterous shovelling from their hind flippers, and finally, lays a clutch of 50 white eggs – the biggest of all sea turtles. 

Only when laying begins do the researchers quietly move in to measure each turtle’s carapace, record egg temperatures, tag flippers and remove barnacles; each night’s efforts slowly adding to a pool of research that AusTurtle hopes will one day shift the flatback’s mysterious conservation status from ‘data deficient’ to something more real. 

When the turtles return to the sea and the sun begins to rise, the research team circles the island one last time in search of nests that have hatched overnight. Not all of the 50 or so hatchlings makes it to the surface of each nest before it collapses, so the researchers become rescuers, collecting the stragglers to release under the safety of darkness of the next high tide. 

Six hatchlings are saved on our first night on the beach, and my daughter Maya, whose all-night shift has made her one of the crew, is afforded naming rights. We head back to bed and reconvene for strong mugs of coffee at AusTurtle’s no-frills, pop-up camp a few hours later. Run in conjunction with Charles Darwin University where AusTurtle runs a rescue and rehabilitation centre, the Bare Sand Island camp is a Spartan collection of hot, sandy tents. 

Their ethos is zero impact: no ground fires, no tent pegs and no waste left behind (even the composted toilet waste bricks are removed). Nothing must impact such hallowed ground, sacred to Kenbi women who believe that the monsoonal rain pools that gather over the Top End’s wet season are connected to a waterhole on their mainland traditional lands.

AusTurtle researchers have permission to camp but the centre of the island where gunnery shells lie scattered from a former military firing range, is strictly off-limits. 

The very next day, we meet a boatload of Kenbi elders and their families who arrive to plant their feet on their island, scramble up the dunes and dig up one of last night’s nests. They bag up the eggs, which they prefer to eat raw, and although I struggle to hide my conflicted state at this abrupt removal of eggs, beside me, seasoned onlooker Andrew Raith is pragmatic. 

 “I don’t feel sadness, I see the larger picture,” he says. “These people have been living and using this resource for millennia, and these sea turtles are still here. So there’s the proof that they’re doing nothing to affect this population.”

According to Raith, harvesting the eggs gives the turtle nests of Bare Sand Island a value to the Kenbi people, a reason to protect the island to ensure the resource continues. A far bigger threat, he says, comes from global heating. 

In 2020, the Northern Territory recorded its fifth hottest year in recorded history. Rising global temperatures are inevitable and that translates to hotter turtle nests; the hotter a nest becomes, the more female hatchlings it produces. The risk for turtles is that within a few generations, flatback males could become so scarce that breeding becomes impossible and rookeries falter.

And while Queensland and Western Australian sea turtles might be able to migrate south to cooler locations, the NT’s flatbacks are quite literally at the top of their territory, with no place to run. 

As the sun slips away and the cover of darkness envelops us, we release the day’s hatchlings. Andrew Raith shows Maya how to gently massage and warm up a tiny, slow-moving hatchling against the warmth of her belly before releasing it onto the beach to watch it scurry into the sea. 

I marvel at just how precious 43 grams worth of turtle truly is, and ponder how much time is left for the flatbacks. I ask Andrew Raith what happens if we lose flatbacks, and he responds with customary scientific pragmatism.

“Sea turtles are an indicator species, so if flatbacks go, you weaken the entire ecosystem and it wont just be the turtles that disappear. It will be the invertebrates, the corals, the algae that sea turtles harvest, and their predators too.”

In short, the entire ecosystem will collapse. “And that to me is way more important an issue to deal with, than a few nests being utilised as a food source,” says Raith. “Humans are part of that ecosystem; we often see ourselves as being separate from that, but really we’re not,” he says. 

Scientists agree that sea turtles have evolved to produce large numbers of offspring, gambling on the fact that the majority will be lost. But a small percentage must survive, and whether the survivors can adapt fast enough to face the enormous challenge of global heating, only time will tell. 

To find out more about NT flatback turtle conservation, head to austurtle.org

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