"Closed containment" is not a commercially viable or environmentally friendly means of raising Atlantic salmon at this time.

Mainstream Canada is following the development of closed-containment aquaculture closely, and will explore the possibilities of closed-containment fish farming if suitable projects and partners are presented. However, we are confident that our sustainable, ocean pen farms are the best and most sustainable way to grow salmon.

In 2008, the Canadian Science Advisory Secretariat Science Advisory report  "Assessing Potential Technologies for Closed-Containment Saltwater Salmon Aquaculture concluded:

"A review of over 40 closed-containment systems from around the world found that none was producing exclusively adult Atlantic salmon and that many previous attempts to do so had failed. Reasons for failure were numerous and were often interrelated. These reasons included but were not limited to mechanical breakdown, poor fish performance, management failure, declines in market price and inadequate financing."

In 2010, Fisheries and Oceans Canada published a study titled "Feasibility Study of Closed-Containment Options for the British Columbia Aquaculture Industry," a financial analysis based on the 2008 report. It concluded that while it is technically possible to grow fish to market size on land, using the same kind of recirculating aquaculture system (RAS) technology Mainstream uses at its land-based Oceans hatchery in Duncan, B.C., the costs are prohibitive and profit margins slim (see table below for a comparison). It also pointed out that the environmental costs of farming commercial-scale numbers of fish on land need to be considered (costs such as fresh water use, increased energy use, land footprint and other costs).

In March, 2011, Cermaq ASA, Mainstream Canada's parent company, released a statement on its position in respect to closed-containment aquaculture.

Cermaq believes that present technology for open net pens allows for sustainable aquaculture, and we aim at demonstrating this in our operations.

Closed-containment technology does not currently represent a viable alternative, especially related to energy usage but also escapes remain a risk in closed containment farming.

However, managing environmental impact is key for a sustainable future for fish farming and Cermaq is always looking for ways to improve. Cermaq will be following the development of closed-containment aquaculture, and will consider testing of new concepts and explore the possibilities of closed-containment fish farming if suitable projects are presented.

 Scientific studies have been done on the environmental costs which would come from farming fish on land. One of the most comprehensive, a life-cycle analysis study by independent Canadian scientists, found that

"while the use of these closed-containment systems may reduce the local ecological impacts typically associated with net-pen salmon farming, the increase in material and energy demands associated with their use may result in significantly increased contributions to several environmental impacts of global concern, including global warming, non-renewable resource depletion, and acidification."

 The full study is available online here. It points out that land-based recirculating systems use 22,600 kilowatts of electricity to produce one tonne of fish, and also waste more feed than any other systems because of higher mortality rates for fish growing in land-based tanks. Overall, the study showed land-based recirculating systems to have the highest negative impacts on the environment:

Source: Nathan W. Ayer, Peter H. Tyedmers, Assessing alternative aquaculture technologies: life cycle assessment of salmonid culture systems in Canada, J Clean Prod (2008), doi:10.1016/j.jclepro.2008.08.002