The state of Atlantic salmon stocks (Salmo-SalarL.) of the Tuloma river (Kola Peninsula)

Long-term abundance dynamics of Atlantic salmon in the Tuloma River were analyzed. It was an opinion given that the Nizhne-Tulomskaya and Verkhne-Tulomskaya hydropower plants have no significant impact on the reproductive capacity in the river. Ulcerative dermal necrosis causing spawners mortality and illegal fisheries were also considered to have an impact on the abundance dynamics. It was concluded that all these cumulatively have recently had a negative impact on the stock. Being the cause of mass mortality of juveniles in Norwegian rivers and in the Keret’ River (Russia), monogenean Gyrodactylus salaris was detected and identified as a risk factor. A number of practical measures were suggested to restore the stock abundance up to the long-term means.