The mangroves along the Thane creek store 2,38,417 tonnes of carbon, mostly from the pollutants that humans release into the atmosphere, Thane-based BN Bandodkar College of Science has said in a study which comes at a time when mangroves are being increasingly threatened by encroachments, infrastructure and industries.
The mangrove species Avicennia marina, which covers 70% of the creek’s banks, captured carbon dioxide (CO2) from the atmosphere and stored them as carbon. This process is called carbon sequestration, and it helps control global warming by reducing CO2 levels in the atmosphere, according to climate scientists.
The mangroves along the creek are not only a green lung, but have also been designated as an Important Bird Area. However, despite its significance, the city’s mangroves are being slowly destroyed.
The area houses one of Asia’s largest industrial complexes and effluents from these factories are released directly or indirectly into the creek, affecting the growth of mangroves.
“The mangroves are depleting at such a fast rate, I don’t know whether the locations I visited for my research still exist. Despite facing the severe threats it does now, the creek still has so much potential, therefore conserving its ecosystem is important,” said Sheetal Chaudhari Pachpande, the lead investigator and a professor of environmental sciences.
That mangrove forests act as a buffer zone against tidal action is known. That they can absorb pollutants from the air is one more reason they should be protected, experts said.
“Today, however, the creek is being filled up to make way for unauthorised structures. If the creek is not saved, Thane will face the same situation Mumbai did during the July 2006 deluge, owing to the reclamation of the Mithi River,” said professor Madhuri Pejaver, the dean, faculty of science.
To study the carbon content, researchers collected fresh and fallen mangrove leaves from Bhandup and Airoli. While the fresh leaves and litter showed organic carbon ranging between 15% and 30%, surface soil sediments also showed it composed up to 6% carbon. The mangroves in the entire creek area have an estimated 4,76,835.7 tonnes of biomass.
“The entire creek is a valuable carbon sink and needs to be conserved. Unfortunately, because of the lack of awareness, the ecosystem value of carbon sequestration is lost,” the study said.