Out yesterday on a lower reach of the river Earn i was surprised that all the trout and parr had freshwater lice on them. In the past they were just very small light brown spots. Yesterday the they were from 1/4 _1/2 inch long. Is this usual or has anyone else know about there lice. A number of years ago we did a study of the lice and in one case a 1/2 lbs. brown had several hundred on them.
Any help information on this would be most welcome.
Bob.
