HUNDREDS of fish died – but this week, the Environment Agency has announced that no enforcement action will be taken over the fatal pollution of a north Hampshire stream.

The Government agency said that it could not find “any one identifiable cause” of low oxygen levels in Silchester Brook and Foudry Brook, that led to the death of 750 fish in August last year.

But the agency has said that it will work with Thames Water, which has an unmanned sewage treatment works to the south-west of Silchester, to “minimise the risk of pollution incidents in the future”.

About 22,000 fish died in the same stream in 2010 after a pollution leak from the sewage work. In 2011, Thames Water Utilities Limited was ordered to pay more than £61,000 in fines and costs at Winchester Crown Court after admitting causing the pollution.

The alarm for the 2013 incident was raised by Linda Alexander, of Clappers Farm Road, near Silchester, when she noticed dead fish floating in murky water.

She called the Environment Agency before saving as many fish as she could by putting them in a tank filled with oxygenated water.

Among the fish affected were trout, bullhead, stickleback and stone loach.

The agency said this week that it had finished its investigation into the pollution, and found that the deadly, low oxygen levels were caused by “a high level of organic matter in the water and not due to any chemical toxins”.