Salmon and Trout Association: Aquaculture

The Salmon & Trout Association (S&TA) is lobbying for a sustainable aquaculture industry which does not impact wild salmonid stocks. If fish farming and wild fisheries in Scotland were allowed to flourish together at their optimum, sustainable levels, the benefit to local employment and economies, often in remote communities, would be enormous. As it is, S&TA feels that aquaculture has been allowed to expand with limited consideration given to its impact upon the environment or wild fisheries interests.

Marine fish farming has advantages:

• The price of salmon has dropped, taking some pressure off wild stocks
• Farmed salmon accounts for 40% of Scottish food exports
• Aquaculture is an important employer, often in remote communities.

However, there are also significant disadvantages:

• Sea lice. Lice emanating from farmed salmon attach to wild salmon and sea trout smolts, causing widespread mortalities and the collapse of many Scottish W coast salmonid populations. This has resulted in the loss of fisheries and hotel jobs, a fact seldom taken into account when talking-up the social benefits of aquaculture.
• Chemicals, including antibiotics, used in aquaculture to combat disease and parasites are invariably harmful to the environment, potentially creating barren habitat around farms and killing shellfish populations and many other marine organisms
• Farm escapees endanger wild salmon populations through cross-breeding, creating offspring that are less fit for survival at sea. This puts the wild population at risk.
• Threat to UK salmon biodiversity. UK salmon have unique genetic lineage specific to each river system.
• Net loss: Farmed fish are fed pellets made from marine fish – often depleting those wild fish species on a global scale.
• Sewage from farms pollutes surrounding waters.
• Location of farms. Farms are placed in estuaries and lochs into which salmonid rivers flow – forcing migrating wild salmon and sea trout to run the gauntlet of lice infestation.

Action

1. Sea Cage Location. The need is to; prevent the transfer of mobile sea lice passing from farms to wild salmon smolts, and/or locally resident sea trout smolts; avoid the transmission of disease and the effects of biological and chemical pollution; and reduce the risk of adult fish farm escapees interbreeding with wild fish. To this end, salmon farms should be moved away from the path of migrating salmon and sea trout smolts. Ideally, this should apply to sites in all estuaries and salt water lochs, as well as on offshore migration routes. In practical terms, it will be necessary to give priority to cages whose location affects the most significant runs of salmon and/or sea trout. Work to establish relative vulnerabilities, and to identify acceptable sites for relocation at or beyond an appropriate safe distance, should proceed as a matter of urgency. Further research will be required to establish offshore migration corridors where a threat may exist. Meanwhile, effective fallowing and stocking cycles, timed to avoid mobile lice production during wild smolt migration periods, must be applied. No new sites should be allowed in or near sensitive estuaries or lochs, or on potential migration routes. A thorough independent Environmental Impact Assessment must be undertaken on all new applications to ensure minimal impact on wild migratory salmonids. The Precautionary Principle must apply in all cases where doubt exists.
2. Smolt farm location. To avoid the risk of interbreeding by escaped smolts, the installation and operation of smolt farms should not be allowed in any river system containing wild salmonids. This is already the case in Norway, the world’s largest producer of farmed salmon, and must be the same in Scotland – within time scales set by the Scottish Government.
3. Stocking policy. To allow for the perennial potential for escape from the strongest sea cages, whether due to storm damage or sabotage, interbreeding of wild fish with escaped adults should be avoided by the mandatory stocking of triploid (sterile) salmon in fish farm units - to be achieved within time scales set by the Scottish Government.
4. Enclosed systems. Because the remedial actions listed above are limited both in feasibility and effectiveness, the ultimate solution should be for all installations to consist of totally enclosed systems, either land or sea based. Such installations would minimise escapes, prevent the transfer of parasites and the spread of disease, and allow waste effluents to be collected and treated in order to avoid pollution. The industry must research new technology as a matter of urgency, and within time scales set by the Scottish Government after consultation with aquaculture and wild fish interests. No new sites should be permitted unless assurances of security can be supported; essential in light of the industry’s stated objective of increased production within Scottish waters.

The S&TA therefore calls for:

• The target of the industry and Scottish Government must be for the statutory use of enclosed systems for rearing fish, whether on land or at sea, therefore cutting out any interaction between farmed and wild salmon and sea trout. This should be within a timescale agreed between Government, industry and wild fish organisations
• Meanwhile, the Precautionary Principle (as enshrined in EU legislation protecting habitats) should be adhered to at all times
• An effective lice dispersal model must be developed in order to assess acceptable maximum farm/area lice levels
• A list of ecologically and economically sensitive sites should be drawn up immediately
• Sea-based salmon farms must be moved away from locations with significant salmon and sea trout migration runs, within estuaries, lochs and offshore. As a practical start, an experiment should be conducted by removing an individual farm from a sensitive site - agreed with wild fish organisations - and the effect on wild salmon stocks monitored
• No new sites should be permitted in sensitive areas highlighted by the list above
• New fish farm applications must be supported by independent Environmental Impact Assessments
• Salmon smolt farms should be banned from operating within any wild salmonid river
• The impact of escapees should be reduced by the mandatory stocking of sterile fish within an agreed timescale

Other information

Executive Summary of the Impact of Salmon Aquaculture on Our Native Fisheries and the Aquatic Environment. (2010)
Impacts of salmon aquaculture on native salmonids fisheries and the aquatic environment- briefing paper (2010)
Aquaculture Policy Statement (2010)
Salmon Aquaculture Dialogue; Draft indicators for environmentally, socially and economically responsible salmon farming. (2009)
Ford and Myers. (2008). A Global Assessment of Salmon Aquaculture Impacts on Wild Salmonids
Marine Conservation Society. (2007). Principles and Criteria for Sustainable Fish Farming
Lenfest Ocean Program. (2007). Aquaculture Impacts on Wild Salmon