Veterinarians in Murmansk have noticed a decline in the sickness rate of wild salmon on Tuloma river. No toxic changes that could damage their immune systems have been uncovered along migration routes.
The veterinary committee for Murmansk region held an interdepartmental meeting concerning illnesses in wild fish populations of the area.
Representatives of the regional state veterinary service, the Murmansk branch of Glavrybvod and the PINRO scientists noted that, compared with previous years, the situation with regard to the incidence of wild salmon population by ulcerative dermal necrosis (UDN) in the Tuloma River is looking very promising. According to the results of observations from the beginning of the fish ladder, a smaller number of diseased and non-viable fish is noted, Fishnews was informed in the press service of the veterinary committee of the Murmansk region.
Specialists of the State Veterinary Service selected samples for a complex of laboratory and diagnostic studies in the Murmansk regional laboratory, samples were prepared for molecular level research at the Russian Research Institute of Experimental Veterinary named after Y. Kovalenko. Ichthyopathological studies of biomaterial taken for the evaluation of the physiological state of fish against the background of climatic conditions of the current year were also conducted.
Monitoring of salmon spawning rivers is continued. Samples of water and soil from Tuloma were collected. It was noted that earlier studies, including those on migration routes in the Kola Bay, did not reveal significant deviations in toxic indicators that could significantly affect the immune system of fish.
Due to the late arrival of summer heat to the Kola Peninsula, the high water level in the Kola River extended the monitoring period for the Kola salmon until the second decade of July. However, no information from amateur fishermen about the discovery of ill salmon both in Kola and other rivers of the Kola Peninsula in 2017 has been received.
The participants of the meeting agreed that further interdepartmental activities to collect information on reservoirs of the region is required, including sampling of biomaterial, water and soil from the salmon migration sites, the accumulation of statistical data and its analysis.
To recap, massive loss of salmon was recorded in 2015 in the basins of the Colas and Tuloma. Subsequently, ulcerative dermal necrosis was diagnosed in the salmon. The disease was provoked, according to veterinarians, by an abnormal drop in water temperature.