Had a walk down the tidal river Trent today. I got talking to a couple of barbel anglers who were packing up. Apparently fishing has been very difficult recently ,as far as catching barbel is concerned. Lots of twitches on the tip but no bites developed, bait damaged or missing or hooklink bitten off. They tell me it's due to the recent increase/ invasion of crabs. Mitten crabs and mud crabs, non native species.....I was shown a picture of one hanging from a bollie baited hook it was about 8" long. Then I was Informed that there is a short video on the internet. Has anyone else had contact with these bait stealing creatures ?