i fish a weirpool with a small head of barbel from 5,lb to 10lb,ish ,,they have been getting caught in there summer haunts in the streamer weed in the white water,till bout few weeks ago now the water temp has crashed what i dont no is now were do they go to ,,will they still be in the same place or do they head for deeper more calmer water i have nevered fished for them in winter so have no clue if i am wasting my time ,,,what depth water do they go to, depths in weirpool range from 2ft to 15ft,help please,,cheers ,,..