Inland Fisheries Ireland is warning that a number of salmon are returning to Irish rivers with an unknown skin disease.
The fish show signs of bleeding, ulceration and haemorrhaging mainly along the area on the belly and on the head and tail.
There were reports of affected fish in at least six rivers both on the east and west coast of the country.
All anglers are being advised not to remove any affected salmon from the water until it is clear what is causing the infection.
Dr. Paddy Gargan, Senior Research Officer at Inland Fisheries Ireland says it’s unclear at this time what is causing these symptoms.