Australia's famous pink lakes are disappearing

National Geographic

14-07-2025

Tiny extremophiles give the salty lakes their rosy hue, but over-mining and climate change are threatening their existence. Pink Lake, Hutt Lagoon, Western Australia, 2020.
Beside the ochre-colored gorges and turquoise coastlines of Western Australia lies a surprising hue: fuchsia pink. The state's pink salt lakes have been a startling part of the landscape for thousands of years. They've appeared in Dreamtime stories and family vacation photos (though in the age before digital photographs, says Tilo Massenbauer, an applied environmental scientist who has studied the pink lakes, if visitors took their film to be developed outside of Western Australia, the technician would say the machine was broken, the color settings off, otherwise how could a lake be that pink?).
More recently, the pink lakes have featured in social media posts, fashion ads and music videos (Mandopop king Jay Chou filmed his Pink Ocean track at Hutt Lagoon). But two of Western Australia's most iconic pink lakes have lost their distinctive color over the last 20 years because of climate change and resource over-extraction. Yet experts believe the lakes can bloom pink once again through both targeted interventions and letting nature run its course. Pink Lake, Hutt Lagoon, Western Australia, March 2025. The pink hue is due to the presence of a carotenoid-producing algae, Dunaliella salina. Photograph by Daniela Tommasi
Australia is studded with salt lakes in a rainbow of hues—the products of geological events spanning deep time. River systems once criss-crossed the continent and the scars of these ancient systems can still be seen from the air. But the rivers stopped flowing roughly 15 million years ago. Mega-lakes formed inside the river channels and then slowly contracted. Over time, only pockets of water remained. These pockets developed into salt lakes that exist today in a constant state of flux, disappearing and reappearing with changes in rainfall and salinity. A salt lake can sit dry for more than a decade then suddenly flourish after a heavy rainfall.
'Salt lakes don't make sense to humans,' says Dr. Angus Lawrie, a conservation biologist at Curtin University in Perth. 'They don't operate on a time scale we understand, and so we often neglect them as important ecosystems. But their potential as a productive, biodiverse environment is massive when it's realized.'
Lawrie points to the role of salt lakes as feeding grounds for nomadic and migratory birds like banded stilts and red-neck avocets, and the lakes are home to an array of invertebrate fauna like brine shrimp and the halophilic gastropod genus Coxiella, commonly called salt lake snails. Western Australia's salt lakes have even been studied to understand the potential for life on Mars. 'They produce some of the toughest organisms on the planet,' he says. 'But even though these organisms have evolved to be very tough, they're still at risk.'
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(Why are pinker flamingos more aggressive?) High salinity is not the only factor that creates the pink hue of the lakes. Mining operations and heavy rainfall events have impacted the ecosystems of these lakes and have altered their color from pink to grey-blue. Photograph by Daniela Tommasi (Top) (Left) and Photograph by Daniela Tommasi (Bottom) (Right)
Australia's salt lakes present in a kaleidoscope of colors. Some are luminescent yellow, some are persimmon-orange and some—the ones with the most extreme conditions—are neon pink. That pink color is the product of a pair of extremophiles: Dunaliella salina, a type of microalga, and Salinibacter ruber, a halophilic bacterium. When exposed to sunlight, these organisms produce beta-carotene—the same pigment that gives carrots, crayfish and flamingos their distinctive color. Beta-carotene protects these organisms from the intense ultraviolet light of the Australian sun and produces energy through a process called carotenoid biosynthesis. This allows them to outcompete green photosynthesizing organisms for the limited nutrients present in pink lakes.
As extremophiles, D. salina and S. ruber survive in conditions where most organisms can't. That's why they flourish in the bright, hot, hypersaline lakes of Western Australia. But introduce what would be considered more favorable conditions for many organisms—plenty of fresh water and nutrients—and their levels plummet. And, with them, the striking pink color of the lake.
That's what happened in the early aughts when Western Australia's most famous salt lake—Pink Lake, outside of Esperance, along the southern coast of the state—lost its distinctive color after the lake was over-mined for salt. Used as table salt, in salt licks on cattle and sheep stations, and to preserve meat and hides, the salt from Pink Lake had been mined since the end of the 1800s. But its supply eventually petered out.
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Over-extraction reduced the lake's salinity, and its salt-loving extremophiles lost their biological footing to green photosynthesizing organisms like blue-green bacteria and the Navicula genus of diatom. The lake turned a shade of blue-gray in the early 2000s and has stayed that way ever since. But word hasn't reached everyone. Caravans of tourists are still disappointed each year after trying to catch a glimpse of the famous Pink Lake. They drive dumbfounded down Pink Lake Road, past the Pink Lake IGA grocery store and the Pink Lake Golf Course, wondering what all the fuss is about. Locals have even lobbied for the lake to be renamed. Detail of Pink Lake, Hutt Lagoon, Western Australia, March, 2025. The edges of the lagoon often appear white and crystalized due to its high salt content. Photograph by Daniela Tommasi
And it's not the only pink lake in Western Australia to go blue. Earlier this year, Lake Hillier—situated off the coast of Esperance on Middle Island, part of the Recherche Archipelago—lost its bubblegum blush. This time the change in color was caused by an unprecedented rainfall event which dropped large amounts of freshwater onto the lake, lowering its salinity and allowing green photosynthesizing organisms to outcompete the extremophiles. Scientists believe the rainfall event to be the product of human-created climate change.
Yet there is hope from both nature and humans. Environmental scientist Massenbauer, who is based in Esperance and who remembers his nan painting Pink Lake when it was still rosy, believes the natural process of shifting levels of salinity will turn Lake Hillier pink again. He estimates a five to 10-year time horizon.
But for Pink Lake, Massenbauer says more direct human efforts are required. Nature would eventually turn the lake pink again, he believes, but it could take more than 1,000 years. Thankfully, Massenbauer has a plan. Esperance's Pink Lake sits at the end of a chain of salt lakes—remnants of an ancient riverbed. Its neighbor, Lake Warden, has an overabundance of what Pink Lake needs: salt. Roughly half-a-million tons of excess salt, accumulated as a by-product of nearby agricultural operations. Massenbauer believes Lake Warden's salt could be pumped into Pink Lake, returning it to pre-mining levels. An effort is already underway to make this happen. Massenbauer is part of a team of scientists contracted by the Shire of Esperance to determine the feasibility of moving enough salt from Lake Warden to turn Pink Lake pink again. He estimates a full salt—and pink tone—recovery in less than a decade if the project goes forward.
(Hunting for shipwrecks off Western Australia's coast) Salt Lakes, Hutt Lagoon, Western Australia. This processing plant is sustainably harvesting natural beta-carotene from pink lake water. Photograph by Daniela Tommasi
Western Australia's pink lakes tell the story of climate change and excessive resource extraction in a way humans can see. So often, environmental problems are only revealed in incremental changes. They take generations to play out, which makes them easier to deny and harder to address. But as the vibrant color of these iconic pink lakes fades away, it offers visually powerful evidence that the system is out of balance. And pink lakes are not unique to Western Australia. They're spread across six continents—from Lac Rose in Senegal to the Laguna Colorada in Bolivia to Masazirgol in Azerbaijan—where they serve as important visual barometers of the human effect on the landscape.
Dr. Nik Callow, a hydrologist at the University of Western Australia's School of Agriculture and Environment, believes what's happening with Western Australia's pink lakes is an empowering example of how humans can go from breaking things to trying to fix them. 'We had an age of development—the industrialization era—where humans were focused on conquering nature and the extractive use of natural resources,' Callow says. 'Now we're attempting to shift into an age of repair.'