ENVIRONMENTALISTS are surveying the impact of cyanide pollution in the River Trent to determine if they need to restock the fish population.

Nearly two weeks after the chemical leak devastated the ecosystem on the 30-mile stretch between Stoke-on-Trent and Yoxall, the Environment Agency is searching for signs of life.

The cyanide has diluted and disappeared further downstream, allowing teams to safely enter the water at Stone yesterday.

They are spending three days searching for barbel, chub, perch, pike, roach and invertebrates which may have survived, and could support any new fish stocks.

Environment Agency manager David Lowe said: "We haven't got much experience of cyanide pollution in rivers.

"Rivers are becoming more healthy and the Environment Agency is working hard to see improvements in fish stocks, but when we get pollution like this it has a proportionally bigger impact.

"Our message to anyone dealing with chemicals, either in industry or for personal reasons, is to make sure they are handling, using and disposing of them correctly.

"The Environment Agency has powers under the Water Resources Act, 1991, to prosecute any pollution of rivers. In this case we will be looking to recover some of the costs of the surveying and investigation, when we carry out the prosecution."

Hazardous waste firm Red Industries, based in the Sneyd Industrial Estate, Burslem, was served a notice of suspension following the pollution.

The investigation is ongoing and the notice stopping the company discharging industrial effluent into the sewer system still applies.

The European Water Framework Directive requires the UK to bring all of its rivers up to 'good' status, or above, by 2015.

The River Trent is one of 117 rivers, classified as 'bad', making them among the worst in Europe. The Environment Agency will have to work on improving water quality, bank environments and wildlife refuges in the coming years to reach this standard.

Rowland Ely, team leader for environmental monitoring for the Environment Agency, said: "During the survey fish are immobilised by an electric current, emitted by an electrode which is put in the water.

"It creates an electric field and then the fish are netted and put in a tank, sorted into species, counted and measured.

"We are also carrying out invertebrate samples.

"The area of the river near Stone is heavily weeded and it is the area where the pollution has had the greatest impact. This three-day survey and the results will be used to debate whether we can do anything to help the river recover.

"Restocking fish is a possibility but farmed fish are only available up to one-year-old. If some adult breeding fish managed to survive the cyanide, they will breed faster than these young fish.

"Therefore, restocking will only move us 12 months down the recovery path."

Chairman of Fenton and District Angling Society, Peter Fieldhouse, aged 64, said: "We have fishing rights for a mile stretch of the river at Weston near Stone and another mile at Alrewas.

"We haven't been fishing since the pollution because there's just no point. It will take the river at least five years to recover and it's up to our members to decide whether we continue to pay for stretches of the river which we cannot fish."

Read more about the pollution of the River Trent

Boats used in pollution recovery tests

Cyanide-hit sewage plant working again

Devastation as work to clean up river destroyed

'It will take up to five years for river to recover'

Environment officers visit company over River Trent cyanide leak

Investigators search for source of cyanide river pollution

Cyanide levels falling in River Trent

Utility fined for polluting River Trent