The Saltwater Lake has again turned pink – March 2017! The last time this happened was 2014/15 when the pink hue continued through summer to winter.
We urge visitors to take care and please do not damage the salt marsh vegetation around the banks of the lake. And, whilst we understand the pink water is not harmful to humans, it is possible that the lake bed was contaminated back when the much of the site was a rubbish dump so please do not enter the water!
Why is it pink?
As far as we know, it is pink because of the natural interaction of a harmless, single cell micro green algae – Dunaliella salina – and an also harmless halobacterium – Halobacteria cutirubrum – in response to very high levels of salt, temperature and light. (The first two weeks of March have been much hotter and drier than average and this pattern forecast to continue.) The red pigment; betacarotene is produced by the bacteria, allowing the algae to absorb sunlight and keep salt out of its cytoplasm.
In the pink Lake Hillier, WA, scientists also found red-coloured microbes, including species of archaea and a bacteria known as Dechloromonas aromatic, which is good at breaking down the compounds like the chemical solvents; benzene and toluene. Lake Hillier was once used as a leather tanning station in the early 1900s and it may be that those chemicals were used in the tanning process.