The cause of salmon kills in the River Tornionjoki still unclear


<p>The causes of the skin lesions and death of salmon that died in the summers of 2014 and 2015 are still unclear. As the cause of the disease is unknown, control of the disease is impossible. The Finnish Food Safety Authority Evira and the Swedish authorities continue their efforts to find the cause of the salmon kills in the Tornionjoki river basin.</p>

On the Swedish side of the Bay of Bothnia, symptoms of UDN (ulcerative dermal necrosis), a skin condition of salmonoid fish, have been found in ascending salmon (Salmo salar) in several rivers. In studies carried out by the Swedish National Veterinary Institute (SVA), two ascending salmon have diagnosed with UDN.

“According to Evira’s knowledge, UDN or skin conditions resembling it have not been found on fish farms in the Finnish sea areas,” says Perttu Koski, DVM PhD, Senior Researcher of Evira’s Production Animal and Wildlife Health Research Unit.

UDN research requires special research funding

The pathogenic mechanism of the disease is still unclear, and so is the question of whether UDN is caused by an infectious agent or by some other reason. In order to be able to examine the cause of the salmon kills in the River Tornionjoki more efficiently and extensively in summer 2016, special research funding is needed.

Evira has launched the planning of cooperation with the Centre for Economic Development, Transport and the Environment in Lapland and the Natural Resources Institute Finland (Luke) to be prepared, should the salmon kills continue in the River Tornionjoki in 2016. In addition, cooperation to be carried out with fishermen and the Swedish authorities will be planned and agreed in more detail than before.

Salmon samples still welcome

Evira would like to have samples from salmon in poor condition, caught alive or found newly dead in the River Tornionjoki. Salmon in poor condition or newly dead salmon should first be chilled ( +1…+5 °C), but not frozen. When finding salmon in poor condition in the River Tornionjoki, you can contact Evira’s Oulu office directly by phoning 040 569 4541.

The River Tornionjoki is the most important salmon river and the largest reproduction area in the Baltic Sea area.

For further information, please contact:
Perttu Koski, Head of Section, Senior Researcher, tel. +358 40 569 4541


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