This year we have received a number of reports of wild salmon and sea trout with fungal infections. We have also had reports of fish with the skin condition Ulcerative Dermal Necrosis (UDN), although confirmed cases of this disease remain scarce. These are both natural conditions that usually affect low numbers of salmon and sea trout every year as they return to our rivers. Numbers of affected fish can increase during certain conditions, such as periods of low flows, and this spring we have seen small numbers of affected fish in rivers across England. We are monitoring the situation on all our major salmon rivers and working with partner organisations to progress our understanding of these diseases. Please get in touch on 0800 807060 if you see any dead or unhealthy fish in the wild.
Fungal infections in salmon and sea trout are often confused or misreported as UDN. Fungal infections typically cause pale, cotton-wool like growths on the head, body or fins. These infections usually occur following damage or during periods of stress. Salmon and sea trout entering our rivers to spawn face many natural challenges and these infections are commonly seen from spring onwards. During heavy infections, large areas of the body may be covered. Badly affected fish become lethargic and may die as a result of the infection.