A killer shrimp which anglers fear could have a devastating impact on fish stocks and the leisure economy is rapidly spreading through the Broads, ecologists have confirmed.

The Broads Authority earlier this month issued a call to water users to help control the spread of the voracious predator dikerogammarus villosus after a few specimens, smaller than a 20p piece, were found at Barton Turf on the edge of Barton Broad.

A working party set up by the authority in co-operation with the Environment Agency and Natural England has now discovered the shrimp in all parts of the broad, along the River Ant and spreading into the River Bure.

John Currie, regional organiser for the Pike Angling Club of Great Britain, said: 'We are at the start of something which is going to have an impact on angling and the whole leisure economy.

'We don't yet know how big that impact will be on the Broads, but we could be in big trouble.'

A spokesman for the Angling Trust described the latest news as a 'devastating blow for anglers'.

The authority's senior ecologist, Andrea Kelly, said the shrimp, which has spread from eastern Europe over the last 15 years, was now top of the Broads Most Wanted list of invasive species threatening its delicate ecosystem.

She said: 'The shrimp first showed up in Britain at Grafham Water in Cambridgeshire in 2010 and the Broads is only the fourth place in the country it has been found.'

Ms Kelly appealed to water users to follow the Environment Agency's Check Clean Dry campaign to stop the spread of the shrimp on clothing, boats or fishing gear.

She said: 'The shrimp can survive 15 days in damp conditions so it is vital people carry out these checks.

'It is in the Broads now but we have a responsibility to stop it spreading into other waterways.'

The authority is launching a poster campaign to heighten awareness of the menace which kills a range of native species such as shrimps, damsel flies, young fish and insect larvae.

Ms Kelly said while most areas of the Broads did not provide the ideal gravelly habitat for the shrimp, it was too early to gauge the possible impacts, including that on fish stocks.

Ms Kelly said the Check Clean Dry procedure would also help combat other invasive species including floating pennywort, found on the Waveney, which had the potential to spread rapidly.

stephen.pullinger@archant.co.uk