Environmental challenges in the aquaculture industry increases the need for river and wildlife monitoring
Fish can escape from both onshore plants (through the drain) and plants in the sea. Escaping has been pointed out as a serious problem for many years. The reasons why the fish are escaping are many. Escapes can occur during operation and handling of the nets, such as when removing salmon lice, or it can occur in connection with sorting, fish harvest or changing the nets. Escaping may also occur due to technical defects, wear and tear from weights, collisions with boats or due to bad weather.
After escaping, the farmed salmon can get lost in the sea, but can also swim up a river to spawn. For many, this is highlighted as the greatest environmental threat, because escaped farm salmon that spawn with wild salmon could affect the genes of the wild salmon and thus make it less robust.
Work is being carried out to monitor the rivers in Norway, which includes assessment of the quantity of escaped farmed salmon that exist. This work is being done within a national monitoring programme for escaped salmon. The fish farmers have a shared responsibility for fishing out escaped farmed fish. In addition, the condition of the wild salmon stocks is assessed every year. This is done by the Scientific Advisory Committee for Atlantic Salmon (Vitenskapelig råd for lakseforvaltning, VRL).