Thousands of fish have been released into the River Crane as it continues its recovery from two serious pollution incidents.

A total of 7,500 fish entered downstream of Staines Road in North Feltham in the hope to help revive the west London river, following major sewage spills in 2011 and 2013.

Volunteers from the London Wildlife Trust, Hounslow council and the Thames Angling Conservancy helped restock the river with 2,000 chub, dace and roach as well as 1,500 barbel, last Wednesday (Dec 3).

The Environment Agency (EA), working as part of the Crane Valley Partnership to restore the river back to life, supplied the fish from the Calverton Fish Farm in Nottingham where they were bred.

This was the first of a four-year stocking programme, funded by Thames Water, to help return the River Crane back to a thriving waterway with a rich diversity of fish and other wildlife.

Environment Agency fisheries technical officer, Neil Winter, who oversaw the operation, said: “Two major pollution events in two years had a devastating impact on large sections of the river’s ecosystem, including its fish population.

“Thanks to the combined effort of many organisations and individuals however, the river has already recovered to the point where water quality and food sources, such as invertebrates, can sustain fish once more.

“Some fish have already migrated into the previously depopulated areas from other parts of the river, but this is a slow process.

“We want to gently accelerate the increase in fish numbers, so are giving nature a helping hand by adding species commonly found in the Crane and surrounding rivers.

“We are doing this in a carefully phased way, so that we do not destabilise the river’s recovering, but still fragile, ecosystem.

"Not only does the fish stocking boost the river’s biodiversity, it will also return the river to a valuable recreational angling resource for the local community”

The new programme replaces one put in place after the first pollution incident in 2011 which was caused by an illegal discharge of untreated sewage for which Thames Water was prosecuted and fined £75,000, and made a voluntary £400,000 donation to the restoration effort.

The first successful restocking took place in December 2012, however the benefits of this were wiped out when treated sewage sludge flowed into the river as a result of criminal damage to a pipe carrying the sludge between Thames Water’s sewage treatment plants in Iver and Mogden.

The culprits for the damage were never identified and the work to restore the River Crane was setback.

Richard Aylard, external affairs and sustainability director at Thames Water, said: “No amount of money can make up for the damage caused to a river by a pollution incident, but our financial contribution is funding important work that will help restore and improve the river over time.

"We’re really pleased that some excellent projects have been put forward to the Crane Valley Partnership by local organisations and we look forward to seeing the results."

The EA has also developed a range of water quality improvement actions for the River Crane and plans are currently open for consultation until April 2015.

Visit www.gov.uk/government/consultations/update-to-the-draft-river-basin-management-plans