The public was invited to come face to face with 'Norfolk's most wanted' at Wheatfen Reserve, Surlingham, near Norwich.

More than 200 people dropped into a workshop organised by the Norfolk Non-Native Species Initiative, working with the Environment Agency and Broads Authority, to check out a range of invasive species threatening our natural environment.

On show at the event on Wednesday afternoon were everything from signal and Turkish crayfish - a threat to our native white-clawed variety - to killer shrimps and the rampantly spreading Himalayam balsam and floating pennywort.

Experts were on hand to show visitors how to identify the different species and explain the damage they cause.

Andrew Raine, a team leader at the Environment Agency, said: 'Killer shrimp Dikerogammarus villosus has been in the news a lot recently. It is now found in several locations across the Broads and is expected to continue to spread. We need as many people as possible to know what the shrimp looks like, and where to report any suspected sightings.'