I turned up at a local 14th century mill pool today with carp in mind never fished it nor do I know anyone who has, one thing I do know I found a lot of big scales on the bank which tells me an otter has had carp out of this lake, these are the scales of a 20lb fish I have no doubt. What worriws me is am I now fishing a lake that has no carp in it? how quickly can these things destroy fish stocks?