A rare geological formation
Lonar Crater Ecosystem Under Freshwater Stress: Lonar Lake is India’s only known basaltic meteor impact crater, located in Buldhana district of Maharashtra. It was formed nearly 50,000 years ago by a high-velocity meteorite impact on Deccan basalt.
This geological rarity makes it one of the very few such craters in the world formed on basaltic rock.
Static GK fact: Most meteor craters globally are formed on sedimentary rock, not basalt, making Lonar scientifically unique.
Global scientific relevance
The lake has long attracted planetary scientists and microbiologists due to its extreme alkaline chemistry. Historically, the lake maintained a pH level around 11.5, creating conditions unsuitable for fish but ideal for extremophile microorganisms.
This environment made Lonar a natural laboratory for astrobiology and Martian surface analog studies, as basaltic terrain and alkaline conditions resemble certain extraterrestrial environments.
Ramsar and ecological protection
Lonar Lake holds the status of a Ramsar-designated wetland, recognising its international ecological importance. It is also a closed-basin lake, meaning it has no natural surface outflow system.
Static GK Tip: Closed-basin lakes depend entirely on rainfall, evaporation, and groundwater balance for ecological stability.
Freshwater intrusion crisis
In recent years, the lake has witnessed a sharp rise in freshwater inflow. This inflow has diluted its alkaline nature, reducing the pH from around 11.5 to nearly 8.5.
Such chemical transformation directly threatens the lake’s specialised microbial ecosystem and alters its long-standing ecological balance.
Human-induced hydrological changes
The primary cause of this change is not rainfall alone. Extensive deep borewell drilling in the surrounding catchment has pierced impermeable basalt layers, activating underground aquifers. These aquifers now channel freshwater into the crater through newly formed subsurface springs, permanently altering the lake’s hydrology.
Cultural and heritage impact
Rising water levels have submerged nine out of fifteen ancient temples located around the crater rim. This includes the historically significant Kamalja Devi temple, reflecting the threat to cultural heritage alongside ecological damage.
The situation led to suo motu intervention by the Nagpur Bench of the Bombay High Court, recognising the crisis as a serious environmental governance issue.
Ecological transformation risks
Freshwater dilution has enabled fish survival for the first time in recorded history of the lake. This indicates a complete ecological shift from an extremophile-dominated system to a normal freshwater ecosystem.
Such transformation risks the extinction of endemic microbial species unique to Lonar’s alkaline conditions.
Governance and sustainability challenges
Despite excess water inside the crater, Lonar town faces water scarcity, highlighting governance failure in resource management. Experts have proposed diverting and treating spring water for local use to stabilise the lake and meet human needs.
However, progress is slowed by land-use conflicts, regulatory barriers under the Wildlife Protection Act, and stalled institutional coordination.
Static Usthadian Current Affairs Table
Lonar Crater Ecosystem Under Freshwater Stress:
| Topic | Detail |
| Location | Buldhana district, Maharashtra |
| Geological type | Basaltic meteor impact crater |
| Formation age | Around 50,000 years |
| Wetland status | Ramsar-designated site |
| Original pH | Around 11.5 |
| Current pH | Around 8.5 |
| Lake type | Closed-basin lake |
| Ecological shift | Alkaline to freshwater ecosystem |
| Cultural impact | Submergence of ancient temples |
| Governance issue | Groundwater mismanagement and regulation gaps |
