Please see the link below from Fisheries Management Scotland regarding skin damage in wild Atlantic salmon:
http://fms.scot/reports-of-disease-in-wild-atlantic-salmon/
If you encounter a fish exhibiting signs of red ‘rash’, bleeding and/or ulceration, then please contact the relevant district salmon fishery board and include following:
• Date observed/caught;
• Photos;
• Size and weight estimate;
• One sea winter or multi sea winter;
• Location caught/observed (OS grid ref if known);
• Clinical signs of disease;
• Water temperature;
• Any other observations.