75% of litter on city beaches is plastic, finds study

The plastic marine debris threat has been highlighted by other researchers as well. For example, Helen White, an oceanographer at Haverford College in Pennsylvania, USA, found in her 2021 study that polystyrene comprised about 16 percent of plastic debris collected from three beaches of Mumbai

Mumbai: Plastics overwhelmingly dominate the contents of marine debris found on the city’s sandy beaches according to a new assessment of anthropogenic litter by researchers at the Aquatic Environment and Health Management Division, ICAR-Central Institute of Fisheries Education (CIFE), Mumbai. The findings, experts said, highlight the enormous threat that such pollutants pose to marine ecologies and wildlife, and also point toward the city’s poor waste management practices.

An Indian municipal authority worker cleans up plastic waste on Juhu beach in Mumbai during World Environment Day on June 5, 2018. / AFP PHOTO / PUNIT PARANJPE (AFP)

From the 52,770 individual items of litter that were collected and analysed from two beaches – Juhu and Aksa – researchers found that a staggering 75.5 percent were various kinds of plastic. The peer-reviewed study, published this month in the Arabian Journal of Geosciences, notes, “In this study, marine litter was quantitatively assessed on sandy beaches of the Mumbai coast, India. Juhu and Aksa beaches… were contaminated by macro litter having a size greater than 2.5 cm. Marine litter collected… was higher than that reported in other habitats such as creek water channels, sea floor, and mangroves along the Mumbai coast, which indicates that sandy shores are more vulnerable to litter pollution.”

Not only this, based on existing research, the abundance of marine litter on the two beaches was also higher than other prominent sandy beaches in India. For example, the mean abundance of marine litter recorded in Juhu was about 1,698 items/50 metres, while for Aksa – a relatively cleaner beach – it was about 407items/50metres. A similar assessment in 2016 had noted the marine litter on Chennai’s Marina Beach to be about 172 items per 100 metres, while an older assessment in the Gulf of Mannar recorded a marine litter of 68.5 items per 100 metres.

The plastic marine debris threat has been highlighted by other researchers as well. For example, Helen White, an oceanographer at Haverford College in Pennsylvania, USA, found in her 2021 study that polystyrene comprised about 16 percent of plastic debris collected from three beaches of Mumbai: Juhu, Mahim and Ambojwadi in Malad. PVC — typically used to make drainage pipes and medical devices — made up 40 percent. PET — usually found in food and beverage packaging — made up 17 percent. Trace amounts of Polyvinyl Acetate (PVA; 1 percent), acetal (1 percent) and silicon (1 percent) — components used as industrial adhesives and to manufacture consumer electronics — were also found.

A researcher from CIFE, who is not associated with the above study but is involved in similar research, said, “There are a string of recent studies from us which highlight the prevalence of such plastics in the marine environment of Mumbai. These plastics eventually break down in the environment and turn into microplastics under the influence of wind, abrasion and exposure to UV light. These may be ingested by marine life, and move up the food chain when humans consume fish, for example. It’s a serious concern that beach clean-ups cannot solve. There needs to be a top-down approach. Political will and government action is required to turn off the tap on plastics, so to speak.”

Another CIFE study from 2020, published in the Elsevier Journal Science of the Total Environment, estimated that the north-east Arabian Sea, just off Mumbai, contained an estimated 379 metric tonnes of marine debris, of which plastics contributed 40.6 percent by weight. CIFE studies have also found the presence of microplastics in commonly consumed varieties of seafood found in Mumbai.

Mumbai’s mangroves are also swamped by plastics according to an October 2021 CIFE study on marine debris. The study found that plastics comprised 62 percent of all surface debris items (by number) and 43 percent (by weight).