Pink is obviously the must-have shade for water this season. Last week, the taps of a Canadian town ran with pink water due to a blunder at a water treatment plant. Around the same time, a salt lake in Westgate Park in Melbourne, Australia also turned a vivid hot pink.
Fortunately, this is not the “psychomagnotheric mood slime” from Ghostbusters (or so the scientists say), it’s actually a completely natural phenomenon.
Parks Victoria explained on their Facebook page that it is caused by a cocktail of very high salt levels, some favorable weather conditions, and a bunch of tiny organisms.
A recent spate of hot weather and low rainfall means that the lake has become even more salty than usual. This creates an extreme habitat where few organisms can live. These conditions do, however, mean that Dunaliella salin algae are in their element and allow them to bloom. The high salinity (saltiness) of the water means they also start to produce a beta carotene red pigment when they photosynthesise.
“The carotenoid also acts as a filter to protect their chlorophyll, almost like a pair of sunglasses that goes over the chlorophyll cells and aids in photosynthesis,” Dr Mark Norman, a conservation biologist for Parks Victoria, told the New York Times.
The phenomenon happens fairly regularly if the weather’s just right in a few salt lakes in Victoria and Western Australia.
Park Australia says you should avoid direct contact with the water, as tempting as it might look. As you can probably imagine, all that salt is likely to irritate your skin and eyes. Time is of the essence if you want a picture, however, as they expect the lake will return to a more typical color over the coming week or so when the weather quietens down.