Red And Purple Microbes Give Australia’s Mysterious Pink Lake Its Hue

The unusual bubblegum pink colour of a remote lake in Western Australia has long been a mystery, but new research suggests it is caused by a mix of colourful bacteria and algae.⁠ Lake Hillier is located on Middle Island off the southern coast of Western Australia. The lake is 600 metres long, 250 metres wide and extremely salty about eight times saltier than the ocean.⁠

Analysis revealed that Lake Hillier contains almost 500 extremophiles organisms that thrive in extreme environments including bacteria, archaea, algae and viruses. Most were halophiles, a sub-group of extremophiles that can tolerate high levels of salt.⁠

⁠Several of these halophiles were colourful microbes like purple sulphur bacteria; Salinibacter ruber, which are red-orange bacteria; and red-coloured algae called Dunaliella salina. The mix of these microbes, and possibly others, explains the pink colour of the lake, says Tighe.⁠