In a recent remarkable incident, the water of Lonar Lake, located in Maharashtra’s Buldhana district, turned pink. According to Agharkar Research Institute, this unusual shift in colour is attributed to a large congregation of Haloarchaea microbes in the lake. The phenomenon not only amazed the local population but also grabbed the attention of nature enthusiasts and scientists worldwide. Water samples were meticulously tested by the National Environmental Engineering Research Institute (NEERI) based in Nagpur and Pune’s Agharkar Research Institute.
Reason Behind the Colour Change
Several factors have played a part in this unexpected colour transformation of Lonar Lake. The prevailing absence of rain, high temperature, coupled with reduced human interference due to lockdown led to evaporation of water. This process increased the lake’s salinity and pH, which is an indicator of how acidic or basic the water is.
Role of Haloarchaea Microbes
Increased salinity and pH created favorable conditions for the growth of halophilic microbes, primarily Haloarchaea. Halophiles are a category of microorganisms capable of growing, and often flourishing, in areas of high salt concentration. Haloarchaea or halophilic archaea is a bacteria culture that produces pink pigment and is discovered in water with high salt saturation. It was the significant accumulation of Haloarchaea microbes that resulted in the lake’s surface turning pink. As the microbial biomass decreases, the lake will gradually lose its pink colour.
Return to Original Lake Colour
Now that the rainy season has arrived, the lake is reverting to its original colour. The rainwater dilutes the water, reducing its alkalinity and salinity levels. Green algae are beginning to colonize the water body, further driving the change in colour.
Impact on Flamingos
Interestingly, Haloarchaea microbes serve as a diet rich in carotenoid pigments for Flamingos. The birds derive their distinct pink colour from the pigments found in the algae and invertebrates they ingest.
About Lonar Lake
Known also as Lonar crater, Lonar Lake is a saline and alkaline water body located at Lonar in Maharashtra’s Buldhana district. It rests within the Deccan Plateau, a vast plain of volcanic basalt rock crafted by eruptions over time. The oval-shaped lake spans an average diameter of 1.2 km and serves as a popular tourist spot.
Lonar Lake holds the status of a notified National Geo-heritage Monument. This indicates the geological features of the lake are of considerable cultural or inherent significance, revealing insights into the Earth’s evolution or history related to earth science. Such sites have immense educational potential. The Geological Survey of India (GSI) is primarily responsible for identifying and safeguarding geo-heritage sites.
Contributing to its intriguing geological value, Lonar Lake is believed to have formed over 52,000 years ago due to a meteorite impact on Earth.
