Several dead fish have been spotted along the Yamuna near Burari in north Delhi since Wednesday night, raising concerns over the river’s water quality and possible industrial pollution. Wildlife experts and activists have flagged the incident, citing the possibility of untreated industrial effluents and low dissolved oxygen levels.
“We have our fellow boatmen upstream who have reported that dead fish have been seen upstream in Haryana as well. Bhim Singh Rawat, a Yamuna activist and member of the South Asia Network on Dams, Rivers and People (SANDRP), said that such mass fish mortality incidents are usually reported in summer months when high temperatures lead to lower levels of dissolved oxygen. The water usually clean here. We should be wary as drinking water is also sourced from this part of river.
The fish were observed last night and thousands of dead fish have been seen way upstream up to shank number 10, 11 and 12.
Ranjan Mukhia, a boatman in Burari, said that the water has a strong stench and the fish deaths are not restricted to this stretch alone. We have to remove dead fish to ensure water doesn’t get even more polluted with carcasses,” he said. Wildlife enthusiast and conservationist Hemant Garg, who spotted the dead fish on Wednesday, said, “We regularly go in Yamuna to wildlife conservation, bird census and tracking wildlife.
There is drain number 2 from Panipat, drain number 8 and one drain in Burari which may have discharged large amounts of untreated industrial effluents,” Rawat said. In May 2026, hundreds of fish died at Sanjay Lake in east Delhi amid a heatwave and receding water levels. Earlier, in April 2026, thousands of dead fish surfaced in Delhi’s Najafgarh drain, with locals reporting that industrial effluents from Haryana were a likely cause. In May 2025 and, before that, in July 2024, hundreds of dead fish were recorded along the Yamuna banks near Burari in north Delhi. A comparison of the water quality reports for September 2025 and September 2026 shows that the biochemical oxygen demand (BOD) and faecal coliform levels were much higher at several locations along the river. At Palla, the faecal coliform level this year was 1,100 units (MPN/200 ml), compared with 790 units last year. At the ISBT Bridge, it was recorded at 35,000 units, compared with 2,800 units last year. At Okhla barrage, faecal coliform levels of 21,000 units were recorded —six times higher than the 3,500 units recorded in September last year. The level should ideally be below 500 units, with a maximum limit of 2,500 units. At ISBT Bridge, BOD was 30 mg/l this year, compared with 8 mg/l on September 3 last year. Chemical oxygen demand (COD) rose from 44 mg/l to 92 mg/l over the same period. A BOD level of 3 mg/l or less and dissolved oxygen of at least 5 mg/l are specified for bathing. At ITO Bridge, BOD climbed from 4 mg/l to 18 mg/l, while COD rose from 20 mg/l to 60 mg/l. Faecal coliform levels increased from 1,800 to 17,000 MPN/100 ml.
“We cant recall the last such episode in winter months. The possibility in this case could be untreated industrial effluents. Yamuna activist Pankaj Kumar wrote to the Delhi Pollution Control Committee, seeking urgent intervention. “Fish mortality is critical bio indicator of severe ecological stress the primary causes are low dissolved oxygen, high biochemical oxygen demand and presence of toxic industrial effluents. Specific cause not established. Locals allege chemical waste discharged from Haryana through canals. Could it be related to the acid rain on Oct 12th? Experts pointed to a combination of high temperatures, concentrated pollutants and declining dissolved oxygen, which can make aquatic conditions lethal for fish. The monthly Yamuna water quality report for September shows that, despite the monsoon season, the river stretch in Delhi failed to show significant improvement or dilution of pollutants. Faecal coliform is an indicator of untreated sewage in the water.
“The flow in the river has been restricted despite monsoonal flow,” he added. If toxic substances are present in river in sufficient quantity to kill fish, the same water being abstracted downstream at Wazirabad for drinking purposes poses direct health risk to public health,” he said. The New Delhi Nature Society, in a post on X, said, “Hundreds, maybe thousands, of fish found dead on 14th October in the Yamuna river near Burari, Delhi.
