Support for Change
Scientists, health professionals, and even retail food companies recognize the problems with salmon farming and support the need for change.
Closed Containment: One Possible Solution
Closed containers, including fiberglass, cement tanks, and heavy gage plasticized bags, physically separate fish from the external environment. The container's impermeable barrier prevents the transmission of diseases and parasites. It can eliminate escapes and discharges of wastes into the ocean. Eliminating these problems inevitably improves productivity and profits, but there are other environmental and health benefits, too:
- waste can be treated, virtually eliminating pollution of the marine environment,
- wild fish are protected from diseases and parasites,
- fewer chemicals are required, and
- feed use is reduced, lowering pressure on wild fish used in feed.
Industry resistance to containment
The farmed salmon industry has resisted closed containment systems even though all salmon must be raised in tanks for the first 12-18 months of their life. The crux of the issue is cost.
A 1998 report by the Scottish Environment Protection Agency concluded: "Although land-based systems currently offer the greatest potential for containment and treatment of wastes following [chemical treatment for parasites and diseases], the systems are not viable for commercial salmon production under present economic conditions [emphasis added]." A Canadian study in 2000 also concluded: "Closed systems have considerable potential for waste removal and treatment, and reduced escape and predation problems; however, these systems are complex and expensive to buy and operate."
A 2005 study, however, suggested that closed containment technologies could be financially viable, if measured against the actual environmental costs of net pen salmon farming.
Closed containment in practice
Closed containment salmon farming on a small scale has been practiced in Canada, Washington State, and Tasmania. The leaders in this technology are AgriMarine, Eco-Farm, Mariculture Systems, and Future Sea Technologies.
AgriMarine Since 2001, this company has raised "eco-salmon" commercially in land-based concrete tanks. Encouraged by savings opportunities and higher sales, AgriMarine hopes to get additional financing for a new farm of floating concrete tanks that "will yield all-year-round crops of ecologically sound salmon, raised in environmentally safe [closed] facilities a first in an entire industry."
Eco-Farm This Norwegian-owned company operates a contained re-circulation system for salmon with a number of important advantages. It:
- eliminates the waste problem "by concentrating, treating and disinfecting all wastes and waste water,"
- reduces feed requirements by 30-40 percent,
- has "zero escapes,"
- does not require "any antibiotics and other chemicals such as delousing treatments," and
- is 21 percent cheaper than conventional salmon farming in open net pens.
Mariculture Systems This company uses floating containers made of a hard polypropylene and fiberglass shell.
Future Sea Technologies This company manufacturers heavy gauge plastic bags for fish which are impermeable to water. One study found that even without a biological filter, there was a 12-fold reduction in sea lice compared to a net pen farm. Bag enclosures permit higher stocking densities, and remove more than 80 percent of solid waste.
Economic incentives for closed containment
Aquaculture experts agree that industry will need economic incentives before it embraces new technology. If national and regional governments calculated the true environmental costs from net pen salmon farming, they would readily offer encouragement for corporations to adopt new methods. Simply in terms of feed costs, closed containers offer real savings. A 5 percent increase in food utilization by fish would result, for example, in as much as a 40 percent increase in longterm profitability for farms.