thanks guys for the fast responses - I knew I'd get some sense here, I've been reading as a guest for the last year.
I've shown the manager an actual fish which was in a hell of a state - he took it off me and chucked it behind the lodge.
there are 2 lakes,the other one is a carp lake which I suspect will be the same.
I'm also worried that the Argulus may get spread to other places by other fishermen, including our local river system....
As a result of your responses I've now sent the EA an email - I'll let you know.