Weed chokes Panvel’s historic Vadale Lake, greens seek Heritage tag

The centuries-old Vadale Lake in Panvel — associated with the Peshwa era — is being rapidly overrun by the invasive aquatic fern Giant Salvinia, and conservationists have urged the Maharashtra government to grant the waterbody heritage protection status to prevent further ecological decline.

Large floating mats of the weed have spread across much of the lake, restricting sunlight and oxygen exchange and suffocating life below the surface.

The lake, which has long served as a natural refuge for migratory birds and native aquatic vegetation, is showing signs of collapse as the weed spreads unchecked.

“Areas that once echoed with bird calls have turned silent,” said B N Kumar, Director of NatConnect Foundation, who has written to Chief Minister Devendra Fadnavis seeking immediate intervention.

“This is not merely a matter of appearance. The ecological balance is being disrupted, and delaying action will only make restoration more difficult.”

Panvel-based bird watcher Devendra Thakur said the change in bird diversity has been striking. Once home to dozens of species, the lake now supports only a handful. 

“During my recent visit, I could barely count 11 species. The habitat is deteriorating faster than many realise,” he said.

Experts note that Vadale Lake performs an important climate function by storing carbon. In still waterbodies like Vadale, organic matter settles and becomes buried, preventing stored carbon from re-entering the atmosphere.

When invasive plants dominate, this natural process is altered, leading to poorer water quality and reduced carbon absorption.

Kharghar naturalist Jyoti Nadkarni said that last year’s mechanical removal of the weed may have worsened the situation. “The machines uprooted native plants along with the weed,” she said. Among the lost vegetation was lotus (Nelumbo nucifera), which once helped maintain water clarity and provided nesting and resting platforms for birds.

A recent field study by former forest officer Avinash Kubal, taxonomist Dr. Suchandra Dutta, senior birder Madhav Athavale and Nadkarni documented a drastic fall in bird species — from more than 80 earlier to barely 10–15 now — highlighting the speed and scale of ecological decline.

Adventure sports enthusiast Sudeep Athavale, who has long advocated for the lake’s conservation, said local nature lovers are willing to assist the authorities in restoration efforts. “There are people ready to work. What we need now is timely civic authorities’ cooperation,” he said.

Conservation groups have called for manual and phased removal of the weed, reintroduction of native aquatic plants such as lotus, reduction of nutrient inflow from surrounding areas, and formal heritage status to ensure long-term ecological protection and management.

“Vadale Lake is part of Panvel’s natural and cultural heritage,” Kumar said. “Saving it now is far easier than trying to reclaim it after it collapses.”