If you want to catch crayfish, you must have written permission from the Environment Agency and follow their strict rules
The law surrounding the trapping of crayfish is very strict. This is mainly due to the Seventies crash of imported farmed crayfish when many North American crayfish escaped in to native waters. Our small white-claw crayfish have been threatened ever since, as the intruders are bigger, stronger and breed faster, and they brought associated plagues to which native species are highly susceptible.
In June 2005 the Environment Agency (EA) introduced a list of crayfish by-laws that, under certain conditions, would allow the trapping of non-native crayfish in England and Wales. No one is allowed to trap native crayfish, only the larger “alien” varieties. Any fisherman who catches an alien crayfish must kill it rather than return it to the water.
You can only catch crayfish with the permission of the EA.
The easiest way to catch crayfish is with a trap. Your local EA needs to know exactly where you will be setting your trap, and you must attach the identifiers the EA gives you. Permission will be dependent on the situation and the EA will take in to account the possible effect that trapping could have on other species. As many water courses run through private property it would be your responsibility to obtain permission from the landowner before you start. All traps must be inspected every 24 hours.
Your local EA office will advise on the best place to purchase crayfish traps and give you a guide on identifying invasive species. When purchasing a trap it is important not to buy one with too large a mouth, which is often the case with illegal traps, as the EA has seen a spate of otters drowning in them.
Using a line with meat attached is not a recommended way of catching crayfish and is not covered by the licence