Why are some lakes in Australia pink?
Some lakes in Australia are pink because of salt-loving microalgae, especially Dunaliella salina, and bacteria that produce red and orange pigments. In very salty water, these organisms thrive and turn the water pink.
Dunaliella salina produces beta-carotene, a pigment also found in carrots, to protect itself from strong sunlight. When the algae grow in large numbers, the water takes on a pink or red color.
The color can vary with the season, weather and salt levels. On sunny days with high salinity, the pink is usually brightest.
Famous pink lakes
Hutt Lagoon, near Port Gregory in Western Australia, is one of the best-known pink lakes. The algae there are farmed commercially to produce beta-carotene, used as a food coloring and supplement.
Lake Hillier, on Middle Island off the coast near Esperance, is famous for its bubblegum-pink color, surrounded by green forest and blue ocean. It is best seen from scenic flights.
Other pink lakes include Lake Bumbunga in South Australia and lakes in Victoria's Murray-Sunset National Park. Visitors are asked not to drive or walk on fragile lake beds, as damage can last for years. Some lakes have lost their color in dry or wet years.