Environment Agency launches Thames investigation

The Environment Agency is monitoring oxygen levels in the River Thames, [del comma] after a sewage spillage killed more than 300 fish last week.

Following heavy rain on Friday, waste from the Combined Sewer Overflow (CSO) at the Mogden Sewage Treatment Works in Isleworth was discharged into the water.

Investigators are currently monitoring oxygen levels at stations along the river, after most of the fish were seen around the Kew Gardens area of London.

Commenting on the incident, Environment Agency fisheries officer Tanya Houston said: "Additional water is being released into the river at Teddington Lock, which will improve freshwater quality further downstream."

The exact number of fish killed may never be known, she added.

Discharges from CSOs are a common occurrence and can happen after just 2 mm of rain, according to the Environment Agency.

The Environment Agency launched a similar investigation in Manchester last week, after it emerged that fish stocks at Whitewell Brook in Rossendale had been "devastated".

Written by Claire Manning