113-hectare Lonar Lake in Buldhana turns pink

The water at the 113-hectare Lonar Crater Lake in Buldhana district turned reddish-pink over the past week. A similar phenomenon was reported from the Talawe wetlands in Navi Mumbai on May 16 as one section of the wetland patch had turned pink.

In the Lonar case, after local residents shared photographs with the Maharashtra forest department, the latter on Wednesday asked the National Environmental Engineering Research Institute (NEERI), Nagpur to assess why there has been a change in colour.

“We will be collecting water samples and sending it to NEERI soon. We will know the exact reason within two weeks,” said MS Reddy, additional principal chief conservator of forests (wildlife) and field director, Melghat Tiger Reserve.

Other officials said some local residents had informed the department about a similar change in water colour last year during this period as well. “The colour, however, was not this dense. Although this needs to be verified by scientists, but this is most likely due to algal growth. During late summer season when water levels reduce and there is high salinity, an algal bloom results in such changes in colour,” said Nitin Kakodkar, principal chief conservator of forest (wildlife), Maharashtra.

There are several examples of such a phenomenon across the globe due to high salinity and action by algae, but it needs to be confirmed based on scientific studies, said Reddy.

In Talawe’s case, researchers and microbiologists had attributed the change in colour to vigorous growth of algae or bacteria (halobacteria) growing in an extremely high saline environment having beta-Carotene, which gives this type of characteristic colouration to the water.

“The uniqueness of this lake is that it is alkaline as well as saline at the same time, and the water level parameters change as we move from one end to the other making it a complex ecosystem home to large biodiversity,” said Kakodkar.

Located 500km from Mumbai and over 90km from Buldhana city, the oval-shaped Lonar Lake is a part of the 383-hectare Lonar Wildlife Sanctuary declared on June 8, 2000 as part of the Deccan plateau. The lake has an average diametre of over 6,000 feet, while it is 449 feet deep. According to the National Aeronautics and Space Administration, it was said to have formed as a result of a meteorite impact that occurred between 35,000 and 50,000 years ago. It was identified as a unique geographical site by a British officer C J E Alexander in 1823, and also declared a notified National Geo-heritage Monument in 1979. A combined area of 366-hectare of Lonar Lake and surrounding regions was first proposed to be declared as a Ramsar site, a wetland of ecological importance, in 2017 by the state forest department. “The area is expected to soon be declared as a Ramsar site as the final documentation process is underway,” said a joint secretary from the Union environment ministry.