Wild salmon populations in Orkla and Gaula face critical decline

Wild salmon and sea trout populations in the Orkla and Gaula rivers in Trøndelag, Norway, are experiencing a severe crisis due to high mortality rates and disease outbreaks. Recent drift counts in the Orkla river revealed a dramatic drop in spawning salmon; only 14 healthy fish were recorded in a 3.4-kilometer stretch, compared to an average of 1,170 living fish recorded annually between 2015 and 2025.

The Norwegian Institute for Nature Research (NINA) reports that nearly the entire spawning population in certain sections may have been eradicated. The Veterinary Institute is investigating the situation, noting that both adult and juvenile fish are dying. Preliminary findings suggest the presence of ulcerative dermal necrosis (UDN) and saprolegniose, a fungal infection that attacks the skin and gills, making fish more vulnerable to secondary infections.

Due to the severity of the decline, the Orkla landowner association has recommended a fishing ban for 2027. The Norwegian Environment Agency has indicated that these rivers may face fishing closures for several years. Researchers and veterinary experts are currently conducting diagnostic tests to determine the full extent of the disease complex and to find effective treatments.