Fish release to rejuvenate polluted river
Just three months ago tens of thousands of fish were wiped out after chemicals from a sewage works were accidentally released into a south London river.
Now the Environment Agency is planning to release nearly 5,000 specially-reared juvenile fish back into the River Wandle next week in the first phase of an attempt to rejuvenate the river’s eco-system.
The batches of chub, dace, roach and barbel will be released in three areas along a 5km stretch of the river between Merton and Beddington – the home of the treatment works responsible for the chemical spill.
The move follows a survey of pollution levels which revealed that some fish had survived in the areas furthest from the original leak.
Theo Pike, trustee of the Wandle Trust, said: “The recent surveys have confirmed the serious impact of the pollution but they have also demonstrated that there is adequate food and shelter for this limited initial restocking.
“This is important because we need to give nature a helping hand to restore fish stocks as there are many barriers to the free movement of fish up and down the river, meaning natural recolonisation would be very slow.”
However, anglers have been warned that it will take several years for fish levels to sufficiently recover.
Thousands of fish from a variety of species were killed when workers at Beddington Sewage Treatment Works accidentally released sodium hypochlorite used for cleaning into the river on September 17.
Thames Water, which operates the plant, assumed full responsibility for the incident and launched an internal investigation.
The Environment Agency confirmed this week that it was continuing its own investigation and the water company could face prosecution.
Team leader Mike Denbigh said: “With incidents of this severity, it is the Environment Agency’s policy to fully investigate the incident and, where possible, to gather evidence for submission.
“Our Enforcement and Prosecution Policy and Guidance indicates that, where the evidence exists, the normal response to such an incident is to prosecute where the likely offender is identified.”