Closed Containment: The Best Solution
As consumers become more aware of the true costs to society and the environment from large scale salmon farming, they may willingly pay a little more for salmon raised in cleaner, less polluting, closed containment systems. By doing so, they can help preserve wild salmon stocks, protect the marine environment and enjoy a healthier, tastier meal.
Closed-Containment: The Best 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 twelve to eighteen 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].”1
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.”2 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. Moreover, closed systems could win wide social acceptance.3
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, Preline, 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.”4
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”
- Is 21 percent cheaper than conventional salmon farming in open net pens.5
Mariculture Systems — This Company uses floating containers made of a hard polypropylene and fiberglass shell.
Preline Fish Farming System — Has developed a unique process for fish farming:
- The water is pumped from an adjustable depth (25m) with a tube.
- The water temperature, pipe transparency and water flow is adjustable for the needs of different types of fish.
- Feed waste and firm sedimentation materials are caught by the sludge filter, allowing the monitoring of feed use and optimizing feed ratios.
- The system is practically escape proof and greatly minimizes the amount of harmful organisms in the system.6
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.7
Neptune Industries – The Aquasphere system is a floating, semi-rigid containment system that uses a series of jointed, articulating tanks. The tanks function as both nursery and grow-out systems. The Aquasphere system works with a self-regulating, air-injection floatation system and includes a solid waste removal system as well as an air-lift pumping system. It is also designed to operate using alternative energy sources. This technology has been used successfully to grow a generation of hybrid striped bass to harvest. See www.aquabiologics.net
Silfurstjarnan Fish Farm – A land-based system in Iceland where fish are reared in a number of individual tanks of various sizes. The tanks are circular, different in diameter and depth, the smaller tanks used for fingerlings and the biggest for fish in the 1 - 5 kg size. The smaller tanks are made of fiberglass; whereas, the bigger ones are precast concrete elements, held together by tensional steel cable girths and surrounding soil. Installed fish tank capacity at present is about 15,000m3 in the main plant.
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 long-term profitability for farms.8
Read more about the Economic Case for Closed Containment, Containment Technology, and Closed Containment in BC and Examples of Closed Systems
1 Environment Protection Agency, “Collection and Treatment of Waste Chemotherapeutants and the Use of Enclosed-cage Systems in Salmon Aquaculture.” SNIFFER/SEPA, 1998, <www.fwr.org/fisherie/sr9705f.htm>.
2 G3 Consulting, “Executive Summary,” Salmon Aquaculture Waste Management Review and Update, prepared for the British Columbia Ministry of Environment, Lands and Parks, 2000, p. iii, <http://www.env.gov.bc.ca/epd/industrial/aquaculture/pdf/salmon_aqu.pdf>.
3 L. Pendleton et al., “Closing in on Environmentally Sound Salmon Aquaculture: A Fresh Look at the Economics of Closed Tank Systems,” A Report by the UCLA Program Environmental Science and Engineering, David Suzuki Foundation, Conservation Strategy Fund, Friends of Clayoquot Sound and the Raincoast Conservation Society for the Coastal Alliance for Aquaculture Reform, 2005. <www.farmedanddangerous.org/?action=d7_article_view_folder&Join_ ID=82852>
4 “Will Concrete Keep Farmed Salmon Home?,” Short Takes, International Foundation for the Conservation of Natural Resources, Fisheries Committee, April 9, 2004, <http://fisheries.ifcnr.com/article.cfm?NewsID=523>.
5 Eco Farm, Environment, “Environmental Advantages,” <www.eco-farm.no/ environment.shtml> and “Economy,” <www.eco-farm.no/economy.shtml>.
7 G3 Consulting, op. cit., p. iv, <http://www.env.gov.bc.ca/epd/industrial/aquaculture/pdf/salmon_aqu.pdf>.
8 L. Pendleton et al., op. cit., p. 10.