The Environment Agency have confirmed that they have discovered Signal Crayfish in the upper reaches of The River Fowey in The Draynes Valley.
While the EA undertake trapping of the larger adults and further survey work to find the extent of the infestation they are advising anglers and anyone entering the river to follow their guidlines to stop the further spread.
Please download and follow the guidelines in the attached EA pamphlet entitled 'Clean & Dry' outlining techniques of drying off tackle and clothing between exit and entry of different watercourses.
Download it here - http://www.nonnativespecies.org/downloadDocument.cfm?id=920
There is also a copy on the FRA website here