AN INVESTIGATION has been launched after more than 1,000 fish were found dead in the River Lark.
The Environment Agency (EA) were called to the banks of the river next to the Jubilee Fields in Mildenhall to find dangerously low levels of dissolved oxygen in the water.
A spokeswoman for the EA said it would now be looking into how the fatal conditions were brought about.
“The established cause of death was by lack of oxygen but samples are currently being analysed,” she said.
The incident took place on the morning of July 26 when a member of the public reported seeing fish ‘struggling’.
After arriving on scene, EA officers treated the water with hydrogen peroxide to increase oxygen levels.
This rescued a large number of fish, according to the EA spokeswoman.
Rodger Pigerham, of Lark Angling and Preservation Society, was one of the first on the scene and described it as looking like ‘an oil slick’.
“It was only when I looked closer that I realised it was hundreds of dead fish floating on the surface.
“The water was literally black and it was full of baby chub and other fish.”
Mr Pigerham and other members of the preservation society set to work removing the fish, pulling out more than 500 roach, bream, perch, chub and pike in one day.
He said: “There’s no real reason why this should happen, a stretch just up the river was absolutely fine.
“It can only be that someone has been dumping something in the river - either accidentally or deliberately.
“It’s affected the fishing there but not greatly. It was probably about two to 5 per cent of the fish in the river that were affected so there are plenty more in there.”
Anyone who may have witnessed anything that led to the incident should contact the EA’s 24-hour incident hotline on 0800 807060.