Students from three schools on Friday took part in a clean-up drive at Subhas Sarobar in Beleghata. The sprawling lake premises lie in neglect with waste strewn across the parks, green verges, walkways and the central waterbody itself.

Plastic bags, food wrappers, disposable glasses and cloth rags were found scattered throughout the park. Some plastic waste had sunk into the soil, with only parts of it visible above the surface, indicating that it had been lying there for a long time.

A total of 32 students from schools in Calcutta and Howrah spent about an hour walking around the Sarobar, picking up garbage. By the end of the exercise, the waste collected filled seven large carton boxes.

The plogging activity — a combination of jogging and picking up litter — was organised by the Bengal state office of World Wide Fund for Nature (WWF)-India in collaboration with the state pollution control board (PCB).

“We conduct nature tours for school students here. It was during these tours that we noticed the poor condition of Subhas Sarobar. There is waste everywhere,” said Sangita Mitra, director of WWF-India’s Bengal state office. “During Friday’s plogging, students had to pull out plastic waste that had gone into the underlying layers of soil. That shows how long plastic has been accumulating here.”

Plastic and other waste at Subhas Sarobar on Friday. Students clean up the mess

Students from Ashok Hall Girls’ Higher Secondary School, St Agnes’ Convent School, Howrah, and Mahadevi Birla Shishu Vihar participated in the drive. The students were from Classes VI to IX.

Aryahi Roy, 11, a student of Ashok Hall, said she enjoyed the activity. “I learned how harmful plastic is for the environment and why we should not throw plastic anywhere,” she said.

Officials of the Kolkata Metropolitan Development Authority (KMDA), the custodian of Subhas Sarobar, said unregulated human activity has contributed to the problem. Washing clothes, bathing in the waterbody and unrestricted entry into the campus have led to pollution.

“Scores of people bathe in the waters of Subhas Sarobar every day. Shampoo sachets are thrown into the water, and soap from washing clothes gets mixed with the water daily,” a KMDA official said.

The Sarobar’s main waterbody covers 47 acres, while the total area of the park is spread across 92 acres, according to KMDA.

Kalyan Rudra, chairperson of the state PCB, who was present during the clean-up, explained how plastic pollution affects ecosystems and human health. “Plastic thrown into water disintegrates over time. Aquatic animals may ingest it. When humans consume fish from such waters, plastic enters our food chain. The same happens when plastic mixes with soil,” he said.

KMDA and PCB officials pointed to a stark contrast between Subhas Sarobar and Rabindra Sarobar, another major waterbody in Calcutta. While Rabindra Sarobar is clean and well maintained, Subhas Sarobar continues to grapple with heaps of garbage and unregulated entry.

“Entry hours have been announced at Subhas Sarobar as well, but sections of local people broke open the gates. At night, motorcycle races take place inside the campus. Our security guards are often overpowered,” a KMDA official said.

WWF-India officials said they plan to involve residents of the area in initiatives to help restore and maintain the Sarobar.