Archive · 1 Sep 2026
Durgam Cheruvu Fish Deaths Linked to Severe Oxygen Depletion
Hundreds of fish died in Durgam Cheruvu because the water did not contain enough oxygen.
Fish need dissolved oxygen in the water to breathe.
Tests in May 2026 found only 0.3 milligrams per liter, much lower than the recommended 4 milligrams per liter for fisheries.
Dirty substances in the lake gave microorganisms more work to do, so they used up oxygen quickly.
The water also contained excess phosphorus, which can cause algal blooms.
When algae die and decompose, even more oxygen is removed from the water.
This can make fish weak, suffocate them and cause them to die.
Experts said stopping sewage pollution and regularly checking the lake are important long-term steps.
Hundreds of fish died at Hyderabad’s Durgam Cheruvu after dissolved oxygen fell to 0.3 mg/l in May 2026 data.
The oxygen level was far below the Central Pollution Control Board’s minimum 4 mg/l requirement for fisheries.
Chemical Oxygen Demand measured 123 mg/l, while Biochemical Oxygen Demand reached 12 mg/l.
Phosphate and orthophosphate levels indicated nutrient pollution capable of fueling oxygen-depleting algal blooms.
Environmental scientist Srikanth Rao called for stopping sewerage inflows, continuous monitoring and long-term ecological restoration.
- Who
- Hundreds of fish at Durgam Cheruvu were affected; the Telangana Pollution Control Board released the water-quality data, and environmental scientist Srikanth Rao commented on the causes and response.
- What
- A mass fish death was linked to severe dissolved-oxygen depletion combined with organic, nutrient and likely sewerage pollution.
- When
- The reported water-quality data were collected or released in May 2026; the timing of the fish deaths is not specified.
- Where
- Durgam Cheruvu in Hyderabad, Telangana.
- Why
- High organic and nutrient pollution increased oxygen consumption and likely contributed to eutrophication, leaving too little oxygen for aquatic life.
- Dissolved oxygen
- 0.3 mg/l, compared with the Central Pollution Control Board’s 4 mg/l minimum requirement for fisheries.
- Chemical Oxygen Demand
- 123 mg/l, indicating a heavy load of oxidisable substances.
- Biochemical Oxygen Demand
- 12 mg/l, reported as six times the Class A parameter and four times the Class B and C limits.
- Total phosphate
- 0.91 mg/l.
- Orthophosphate
- 0.83 mg/l.
- Recommended intervention
- Stop sewerage inflows, continuously monitor water quality, use aeration for short-term relief and restore ecological balance.