Typically fish will be found in deeper pools or other areas of slack waters where current deposits them. Fish will be dead, or lethargic. Commonly they will have grayish, fuzzy looking patches on their skin, sometimes covering the majority of their bodies. Saprolegnia , an external fungus, causes this growth.
Brown trout are highly territorial, aggressive during spawning and sometimes make migration.
These factors lead to physical aberrations that eliminate the usual occurring mucous and allow the fungus to become established. Further, the fish have been in the rigors of spawning for several weeks and have become weakened. Anglers, if you have caught a fish with this fungus, there is no risk to human health by eating these fish. Although unsightly, we suggest you cut away affected areas before cooking. Mortality on brown trout may be higher this year because of warmer temperatures we have experienced.