A very unusual lake in the Indian state of Maharashtra has stunned scientists and observers, as it has made a complete color transformation from green to pink. The oval-shaped depression was formed over 50,000 years ago when a meteorite crashed into the earth, resulting in one of the largest crater lakes on the planet.
The lake has always been known to scientists and tourists who visit as having a blue-green hue, yet recently, Maharashtra tourism authority has posted shocking pictures of it appearing a pastel pinkish-red.
Gajanan Kharat, a member of the lake conservation committee, speculated that “the low level of water may lead to increased salinity and change in the behavior of algae because of atmospheric changes,” News18 reported.
Lake Lonar’s formation story is unique, as its geological composition is the largest basaltic impact crater on Earth. The lake has incredibly high salinity levels because it wasn’t formed by input from rivers or streams. In recent years of drought, though, the rain-fed lake has lost a great deal of its volume to evaporation.
Because of the basaltic rock underneath, the lake has a very high pH that prevents many forms of life from developing, around 7 near the shore and up to 11 in the center, the Times of India reported.
These two factors combined lead to the most plausible explanation for the change in color: the normal types of algae that give it its color have been replaced by other kinds that produce carotenoids, reddish-colored pigments.
In local newspaper Lokmat, Dr. Suresh Mapari suggested that halobacteria and dunaliella salina (types of fungi), both of which flourish only in highly salty environments, might be responsible for the color transformation.
The rapidity of the change is definitely remarkable. While the lake didn’t turn pink instantaneously, the transformation was quick enough to shock the local population. Kharat explained in a video, produced by Maharashtra Tourism, that “[s]alinity in the lake has increased as water level has gone down drastically this year and it has become warmer too resulting in overgrowth of algae.”
Though scientists are still awaiting the results of tests that are being performed on water samples, they have raised the possibility that human activity, or rather the lack thereof, could have had an effect.
“In case of a natural phenomenon, there are fungi which generally give a greenish color to water most of the times. This (the current color change) seems to be a biological change in the Lonar crater,” Madan Suryavashi, professor of geography at the nearby Babasaheb Ambedkar University, told NDTV.
India’s strict lockdown to deal with the coronavirus pandemic meant that the lake has been closed to the public for several months. “There wasn’t much human activity due to lockdown which could also have accelerated the change,” Suryavashi said to AFP.
The remote lake has been mentioned in ancient Indian texts and also became an object of curiosity when British explorer James Edward Alexander rediscovered it in 1823. Nowadays, the lake attracts crowds of curious tourists and scientists alike, whose wonder will only be piqued further by this fascinating color change.