One unwelcome invader to our rivers is the North American Signal Crayfish, a ferocious cannibal that will eat anything that comes its way, fish eggs, ducklings, young Moorhens and has all but finished off our indigenous species. Apart from doing harm to our wildlife they can collapse a river bank by their constant burrowing. The River Ock has its share of this monster and Steve has been doing his best to control them (over 100 in 3 days from a 10 meter stretch) You have to be licensed by the E.A to catch them and putting them back is forbidden, (failure to comply carries a hefty fine) but they do make for good eating!