International Courant
KOLKATA – Wetlands simply exterior Kolkata, India, have supplied tons of meals a day and hundreds of jobs for generations as they filter sewage via fish ponds – however speedy urbanization threatens the ecosystem.
Conservationists warn that air pollution and land grabbing are a lifeline for the megacity’s 14 million residents.
“We’re destroying the setting,” mentioned Mr Tapan Kumar Mondal, who has spent his life elevating fish within the ingenious system of canals and ponds that stretches over about 125 sq. kilometers.
“The inhabitants … has elevated, there’s strain on nature, they’re ruining it,” Mondal, 71, added.
Listed as Wetlands of International Significance underneath the United Nations Ramsar Conference, the waters present pure local weather management by cooling sweltering temperatures and act as invaluable flood defenses for low-lying Kolkata.
However Ms Dhruba Das Gupta, from scope for wetlands conservation, mentioned myopic constructing improvement was encroaching on the wetlands.
“The wetlands are getting smaller,” says the researcher, who’s making an attempt to fund a examine into what’s left of the water.
‘Ecologically sponsored metropolis’
Every day, 910 million gallons of nutrient-rich sewage flows into the wetland, feeding a community of about 250 hyacinth-covered ponds.
“Daylight and sewage are inflicting a large enhance in plankton,” mentioned West Bengal State Chief Environmental Officer Mr. Okay. Balamurugan, explaining that the microorganisms within the shallow fishponds feed fast-growing carp and tilapia.
As soon as the fish have had their fill, the runoff water irrigates the encircling paddy fields and the remaining natural waste fertilizes the vegetable fields.
“The sewage of town is of course purified by the wetlands,” mentioned Balamurugan, who nicknamed them “the kidneys of Kolkata.”
The community-developed system was created by “the world’s foremost specialists on the prudent use and conservation of wastewater,” in keeping with the UN’s Ramsar Record, which additionally warns it’s underneath “intense detrimental stress from city sprawl.”
The late ecologist Dhrubajyoti Ghosh, who performed a key function in Ramsar’s entry in 2002, known as Kolkata an “ecologically sponsored metropolis”.
The wetland system handles about 60 p.c of Kolkata’s sewage at no cost, saving town greater than US$64 million (S$85 million) a yr, in keeping with a 2017 College of Calcutta examine.
Farms within the wetlands present about 150 tons of greens day by day, 10,500 tons of fish a yr and make use of tens of hundreds of individuals, the Ramsar Record estimates.
The ‘kidneys of Kolkata’: endangered Indian wetlands
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