If Ashton canal was polluted all the fish and crays would be dead, and it has been polluted many times previously as has the nearby river Tame. It's relatively clean nowadays pal. And eating crays and pike etc is harmless. Doesn't seem to affect the Eastern Europeans that help themselves to whatever they can catch.
As an angler I know the EA(environment agency) face an uphill battle to stop this happening, and if it wasn't for anglers, many of our UK waterways would become a cesspit of pollution like they once were.
the one i pulled out was big and about the size of my hand and it was in a bad mood, so i somehow got hold of it and put it back in the canal, but scary for the grandkids hahaha
so if you could eat them after a couple of days in detox this would have been worth eating ?? i know its a shell fish and most of it is not used or broke up for making broth, so 2 or 3 of them would make a great meal ?? sounds daft but when needs must and you get all bear grylls i would eat them hahah