Every year, the world’s rivers deposit between 1.15 and 2.41 million tonnes of plastic waste into the ocean: grocery bags and shampoo bottles, plastic straws and microplastics make their way into the sea via riverine systems, hugely impacting marine life.
Now, a new study finds that the Ganga is the world’s second biggest riverine contributor to plastic pollution in the oceans, discharging 1,20,000 tonnes annually. This quantity is exceeded only by Yangtze in China, which transports 3,30,000 tonnes, says a paper published in the latest edition of the journal Nature Communications.
While the average Indian generates relatively little ‘mismanaged plastic’ (3.2 kg/year) compared with the rest of the world (17 kg/year per person), “with half a billion people living within the Ganges catchment, the overall pressure on the river is very large,” lead author Laurent Lebreton, Data Scientist at The Ocean Cleanup Foundation told The Hindu.
However, in rapidly developing economies like India, “a rise in the middle class population has meant a higher level of consumption — and plastic waste generation — but this is not matched by infrastructure to manage the waste,” he added.
Monsoon swell
The pollution swells during the southwest monsoon, peaking in August with 44,500 tonnes discharged by the Ganga.
Most of top 20 polluting rivers around the world are located in Asia, accounting for 86% of the global annual input of plastic debris. This “emphasise[s] the need to focus monitoring and mitigation efforts in Asian countries with rapid economic development and poor waste management,” says the paper. Also among the top 20 polluters are Xi and Huangpu rivers in China, Cross river (Nigeria, Cameroon), Brantas river in Indonesia and the Amazon.
For the study, the researchers looked at indicators within the river catchment such as mismanaged plastic waste, population density, monthly catchment runoff and dams and weirs that act as particle sinks.
