Why Are Australia’s Pink Lakes Pink?

Lake Hillier, Western Australia

You’ve surely seen one of the many photos of a milkshake pink lake splashed across social media if you follow any travel accounts. Lake Hillier (pictured above) is not Australia’s only pink lake, but it is the most famous and photographed. Australia has over 10 pink lakes that have occurred organically in a stunning natural phenomenon.

The unique pink colour has been a mystery for many years, but it is now believed to be due to presence of the organism, Dunaliella salina, which is a naturally occurring green algae found in hyper saline environments, such as salt lakes. These organisms have high concentrations of β-carotene, the red-orange pigment found in carrots, and glycerol, which protect against strong sunlight and osmotic pressure.

Research suggests that when the lakes contain a high concentration of salinity, the water warms to a higher temperature, at which point the algae begins to produce its redish pigment β-carotene, which helps it to survive. Other bacterias, such as Salinibacter ruber, also contribute to the colouration. These bacterias produce a reddish pigment called bacteriorhodopsin, which absorbs light in the green part of the spectrum and reflects the pink colour.

The pink colour is permanent year-round, but the intensity can vary on temperature and sunlight. You can even bottle the salt water and it’ll retain it’s pink hue even within a container. It’s completely safe to swim in the lakes, but swimming can be difficult due to the extremely high levels of saline causing you to float, so most visitors choose to wade through the dense water.

If you’re interested in seeing the infamous Lake Hillier, the only way to see the lake is from the air or sea as it’s located on a separate island called The Middle Island which is inaccessible. We’d recommend seeing Lake Hillier from the air for the best aerial view. There are six flights per day from Esperance Airport that will take you on a sightseeing tour. You won’t be able to land on the Middle island, but you can take in the captivating view from the plane window of your Cessna.

Lake Hillier was founded in 1802 by William Hillier and spans 600 metres in length and 250 metres in width. The other pink lakes in Australia include Hutt Lagoon, Lake Warden, Rottnest Island Salt Lake, Westgate Park, Pink Lake in Dimboola and many more. Some lakes, we would argue, are actually more impressive than the now famous Lake Hillier, such as Lake Macdonnel, which has a causeway separating the lake and sea to give a stunning contrast of blue and pink.

Lake Macdonnel, South Australia (near Adelaide)
Pink Lake, Dimboola
Hutt Lagoon, Western Australia