North Atlantic Salmon Conservation Organization | est 1984

Aquaculture and Related Activities


While fish farming, or aquaculture, has resulted in an abundance of salmon on supermarket shelves, it has not come without cost to wild populations. One impact of salmon farming is that it increases the abundance of sea lice in the marine environment, to the extent that it has a negative impact on wild salmon populations. The graph below shows worldwide production of farmed Atlantic salmon, 1980 to 2019.

Worldwide production of farmed Atlantic salmon, 1980 to 2019.
Source: ICES 2020

And timing can be everything, with salmon particularly vulnerable when they first leave their home rivers and head to sea. In an already challenging marine environment, the additional burden of a sea-lice infestation can greatly reduce the chances of survival. It is also recognised that large numbers of domesticated salmon escape from fish farms each year, with escapees observed in rivers in all regions where salmon farming occurs. For wild salmon, this causes increased competition for resources and may result in a wild fish spawning with a farmed one, compromising the genetic ‘fitness’ of wild populations. The latter is important because salmon populations need good genetic diversity to ensure that they are as resilient as possible to any future pressures they may experience.
So, what to do? Careful siting of fish farms away from wild salmon migration routes, state-of-the-art containment at sea, use of sterile fish, sea lice and disease management systems can all help. A further option is the development of closed-containment salmon production systems at sea or on land as an alternative method of fish farming. Such a system of aquaculture would give fish farmers complete control of the rearing environment and minimise the environmental impact of their activities on wild fish.

Introductions and Transfers

There are risks associated with movements of salmonids. These risks have been highlighted by the spread of the parasite Gyrodactylus salaris which has caused very serious problems in some parts of the North-East Atlantic Commission area following its inadvertent introduction from the Baltic Sea.

Resolutions, Agreements & Guidelines