Wrappers and bottles choking mangroves: NIO study

Panaji: The state’s mangrove forests are highly vulnerable to litter pollution. Mangrove degradation induced by litter pollution may directly impact the health of mangroves and the functions of related ecosystems too, says a study titled, ‘Anthropogenic Litter Pollution in the Mangrove Blue Carbon Ecosystem’.The study has been authored by experts from the National Institute of Oceanography (NIO), Goa, and was published in the Science Direct journal last month.According to the study, plastic items, particularly single-use plastics such as various types of wrappers, bags, and bottles dominate the overall litter composition. The study states that much of the litter originates from land-based sources, including urban run-off, tourism, and improper disposal of garbage.“Macrolitters, such as bottles, bags, and packaging, accumulate in mangrove forests; they may obstruct water flow and nutrient cycling through the mangrove roots,” the study says.It adds, “Many species, particularly the commercially significant fish and shellfish, ingest these plastic particles, and when human beings consume seafood from contaminated ecosystems, they are exposed to harmful substances such as toxic additives and persistent organic pollutants associated with plastics.”

Mangroves provide homes to various marine life and help protect the land from storms while also preventing the ocean from washing away the soil, the authors of the study noted.Researchers visited seven mangrove spots in the state — Panaji, Chimbel, Chorao Island, Divar Island, Pomburpa, Agasaim, and Keri — and came across as many as 5,549 items in trash that was collected by hand.Based on their observations, 66 out of every 100 items were plastic, nine out of 100 items were juice boxes and milk packs, six out of 100 items were glass bottles, and the rest of the items discarded were old shoes, metal cans, and diapers.The most common plastic items were wrappers, bottles, straws, Styrofoam, bags, and even broken pens.Some of the trash comes from land when people throw garbage on the ground, and this then washes into the rivers during rainfall events. Some comes from the sea too, when fishing nets, ropes, or trash from vessels end up in the water.A few items had labels that showed where they came from, but many didn’t.All seven places visited by the researchers were marked as ‘extremely dirty,’ with Chimbel having the most trash and the state capital of Panaji the least.

At Keri, over 80% of the trash was plastic; however, Keri had the least hazardous items.However, Chimbel and Pomburpa had more dangerous waste, such as sharp metal or broken glass.“The current analysis makes it clear that land-based sources and related activities are the primary producers of litter accounted for during the present study,” the authors say.They add that studies suggested that due to the high magnitude of plastic emissions in the environment, litter removal and clean-up programmes have little effect on ongoing litter pollution, even though they may temporarily reduce the concentration of litter on beaches and in the mangroves.“Therefore, a focus should be placed on source control, preventing the flow of litter into water channels (rivers, urban drainage), and also strengthening collection,” the study says.