Delhi Lake Suffocates: Fish Die-Off in Heatwave

Sanjay Lake in East Delhi has witnessed a massive fish kill, with hundreds of fish found dead as the city endures its fourth consecutive day of heatwave conditions. The lake's water levels have critically receded, turning parts of it into shallow, stagnant pools.

Officials attribute the crisis partly to ongoing repairs of a pipeline that supplies treated water from the Kondli sewage treatment plant to the lake, which had developed leakages. The prolonged heatwave is also suspected of reducing dissolved oxygen in the already stagnant water, creating a hostile environment for aquatic life.

Environmental experts highlight that low water levels during heatwaves concentrate pollutants. Higher temperatures decrease water's oxygen-holding capacity, while decomposing waste further consumes available oxygen, leading to fish deaths. Experts also noted that local drains and sewage inflows contribute to the lake's poor water quality.

This incident revives concerns previously raised by the National Green Tribunal, which in 2022 noted high pollution loads in Sanjay Lake. The tribunal had urged further examination of contamination sources, including local drains and sewage, which negatively impact the water quality and aquatic ecosystems.

This mass fish mortality is not isolated, with similar events reported in the Yamuna river and its associated water bodies recently. Experts criticize government agencies for failing to maintain freshwater flow and control pollution, leading to the regular perishing of aquatic species during summer months.