A lake in Melbourne Australia turned pink and the internet is abuzz of the unusual water shade but locals aren't so shocked. The saltwater lake located in Westgate Park has turned pink several times over the decade and Aussies are getting used to it. Is there a mystery behind this unusual coloration?
Parks Victoria turned on the social media to explain that there is nothing amiss with the pink lake. Neither toxic spill nor industrial accident made the water change its color. However, several factors like high salinity, lack of rainfall, increased temperature and sunlight played together to create the pinkish water shade. The Facebook post invites everyone to enjoy the view but warned against being in contact with the water.
According to chief conservation scientist Mark Norman, the water itself is not dangerous. However, there are unlucky few who dipped in the water and got encrusted with crystalline salt. Some also reported extreme pain in the eye, similar to being sprinkled saline solution.
Norman also explained that there is a concentration of green algae at the bottom of the lake. A single-celled plant called Dunaliella was traced as the culprit behind the pink lake popping every summer. Logically, a decrease in water volume causes very high salt concentration. The pink lake is prevalent during intense summer months but reverts on winter and fall seasons.
In 2013, a research was done by eXtreme Microbiome Project to solve the mystery. They used a scientific approach and collected sediments together with water samples from several locations within Lake Hillier. Test results revealed that algae, archaea and bacteria are all thriving in this extreme environment.
Dunaliella salina was confirmed to be the one who produces pink compounds called carotenoids. Further studies also reveal that apart from Dunaliella, other pigment-producing microbes like Salinibacter are producing similar pigment as well. At any rate, although these extremophile microbes were clearly identified, the pink lake is still drawing a lot of baffled tourists every year.
