POLLUTION is believed to have caused the deaths of hundreds of fish in the River Weaver in Nantwich last week.

But for an eagle-eyed member of the public and Environment Agency officials the death toll could have been much higher.

Oxygen levels in the waterway, near Beam Bridge, had fallen dangerously low and a passer-by noticed fish gasping for air on the surface.

Fisheries officers were alerted and raced to the scene to install temporary pumps to increase oxygen levels.

The pumps were deployed until the situation had returned to normal and the fish could breathe normally.

It is estimated that several thousand fish, including bream, roach, carp, pike and chub were placed in jeopardy because of the incident.

Agency chiefs have launched an investigation into the pollution outbreak, believing that a foreign substance is responsible.

Fisheries officer Paul Blake said: "We acted as quickly as we could because we were keen to save as many of the fish as possible.

"If we hadn't taken action, thousands of mature fish of different species could have been lost and the impact on the Weaver would have been much more serious.

"Our environment management team believe some form of pollution was responsible for the sudden drop in oxygen levels, although a lack of any visual clues or odours is making it hard to trace.

"We will continue investigating possible sources, but in the meantime we're pleased that we've been able to restore the river to its normal healthy state."

The public is asked to call the agency's 24-hour emergency hotline, on 0800 807060, if they spot any similar incidents.