PANVEL, May 9 -- In a first-of-its-kind ecological intervention in the Mumbai Metropolitan Region, the Panvel Municipal Corporation (PMC) on Thursday launched a biological-control campaign to clear invasive aquatic weeds choking the historic Vadale Lake, one of Panvel's oldest and most ecologically significant water bodies. As part of the initiative, the civic body released cyrtobagous salviniae weevils-tiny aquatic insects that feed exclusively on the invasive Salvinia molesta weed-into the lake to naturally destroy the rapidly spreading floating plant. Spread across nearly 25 acres near the old Mumbai-Pune highway in Old Panvel, Vadale Lake is believed to be nearly 400 years old. Environmentalists often describe it as the "ecological lung" of Panvel because of its role in supporting biodiversity, groundwater recharge and urban ecological balance. Over the past few years, the rapid spread of the invasive salvinia weed has severely impacted the lake's ecological balance. The weed forms dense floating carpets over the water surface, drastically reducing oxygen levels and sunlight penetration, threatening the fish populations, lotus blooms and nearly 32 species of local and migratory birds that the lake supports. The PMC intervention came about after sustained pressure from environmentalists and citizen groups who urged it to adopt scientific and sustainable weed-management methods instead of relying solely on mechanical removal. "Vadale Lake is an important urban biodiversity habitat," said activist Jyoti Nadkarni. "Mechanical removal alone was not solving the problem because the weed kept returning." Nearly 15 tonnes of aquatic weed were earlier removed by the PMC in manual de-weeding operations, but regrowth kept occurring. The unchecked spread of the invasive weed was threatening the lake's ecosystem and bird habitat. The activists proposed the use of the weevils, noting that the insects feed only on the salvinia weed without harming native plants or aquatic life. "Vadale Lake is an important environmental and heritage asset for Panvel," said Chitale. Added Panvel mayor Nitin Patil, "We expect Vadale Lake to gradually regain its original ecological character." The project is being implemented in collaboration with the Indian Council of Agricultural Research and the ICAR-Directorate of Weed Research in Jabalpur. Results are expected within 15 to 18 months....