We have been contacted by a number of anglers in relation to several Deveron salmon showing signs of a white fungus (photo below). We believe the fungus to be Saprolegnia, a fungal-like organism that infects freshwater fish. Infections often appear as grey, brown or white fur-like growths on the skin, fins and gills. The fungus often infects damaged skin and open wounds, and is therefore usually considered as a secondary infection. Saprolegnia is a natural infection of salmon and trout, therefore it is not unusual to see occasional infections in wild fish, especially as we approach their natural spawning time.…

Source: Deveron – RDevDSFB Statement on Reports of Fish with Fungus