Maharashtra's Lonar lake turned pink due to 'Haloarchaea' microbes, reveals probe

A team of scientists from the Agharkar Research Institute (ARI) in Pune has revealed the reason behind the discolouration of Lonar lake's water. As per the findings in their report, in summer, the lake water turned pink due to the increase in the number of Haloarchaea bacteria in the lake water.

Pune (Maharashtra): The colour of Lonar lake water in Maharashtra's Buldhana district turned pink due to a large presence of the salt-loving 'Haloarchaea' microbes. This was revealed after an analysis carried out by a Pune-based institute.

The situation at the Lonar crater lake, the colour of which has turned pink, is bad and pathetic, the Nagpur bench of Bombay High Court has said.

It rapped the Buldhana district collector and the Lonar Municipal Council for their “callous and indifferent attitude” in preserving and protecting the lake and its surrounding area.

An analysis conducted by the Agharkar Research Institute (ARI) in Pune has revealed that the reason behind the discolouration of the lake water is the bacterium Haloarchaea in the water. ARI has recently sent the report of the analysis to the Forest Department.

The oval-shaped Lonar lake, formed after a meteorite hit the Earth some 50,000 years ago, is a popular tourist hub and also attracts scientists from across the world. The mean diameter of the lake is around 1.2 km.

The water in this lake is salty and green in colour. However, the green-coloured Lonar Lake suddenly turned pink in the first week of June, much to the surprise of several people. The water samples of the lake were then given by the Forest Department to ARI in Pune and NEERI in Nagpur for analysis to find out the reason behind the change in watercolour.

ARI has recently submitted a report on the analysis of this sample to the Forest Department. As per the findings in their report, in summer, the lake water turned pink due to the increase in the number of Haloarchaea bacteria in the lake water.

The pink pigment is formed during the metabolism of these bacteria with the help of sunlight. These bacteria already exist in Lonar water. However, due to lack of pre-monsoon rains, the salinity of the lake water increased during summer. There was no human obstruction due to the lockdown. In such a situation, the level of Haloarchaea on the surface of the lake increased and the colour of the lake water turned pink for some time, informed Dr Monali Rahalkar.

Meanwhile, researchers say that the condition of the lake has been restored due to rains since June.

However, the water here was found to contain Haloarchaea. Dr Karthik Balasubramaniam, Dr Sumit Dagar and Dr Scientist Monali Rahalkar were involved in the study of Lonar Lake's water colour change.

Lonar crater lake was identified as a unique geographical site by a British officer named C J E Alexander in 1823.

READ:Why's Lonar lake water turning into pink, experts to analyse