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Net Cages or Closed Containment?
Industry opponents of closed containment aquaculture often raise the specter of “catastrophic events” in a contained system as an argument against adopting this technology. If a farm is fully dependent on pumps and power sources, it is argued, a power and back up generator failure, for example, means all farm stock could be lost. However, the occurrence of “catastrophic events” in net-cage systems is well documented and a shift to closed containment would decrease these types of crop losses:
- In October 2009, Marine Harvest Canada reported an escape of 40,000 salmon from an open net-cage farm at Port Elizabeth near Gilford Island in the beleaguered Broughton Archipelago. This will result in major financial losses for the company.
- In September 2009, 58,800 salmon escaped from a farm in Scotland due to a hole in the net-cage.
- Intrafish – an online publication for global seafood professionals – reported that so far in 2009, there has been a 380% increase in farmed salmon and trout escapes in Norway compared with the same time last year. A total of 288,581 fish escaped along the Norwegian coast after 22 escape events - up from 59,993 escaped salmon and trout from 15 escape events last year.
- In August 2009, Marine Harvest Canada reported that two farms in the Klemtu area experienced mortality of salmon as a result of a harmful plankton bloom. Heterosigma is a naturally occurring organism that multiplies in warm ocean temperatures and may become toxic to fish in its path. The bloom originated within channels far to the east of the farms but made its way by ocean current to the farm locations. Initial estimates of mortality are approximately 500 tonnes.
- Marine Harvest's Financial Reports reveal that Marine Harvest Canada suffers substantial losses due to problems inherent to open net-cage systems. The company's 2008 Annual Reports cites "Mortality from a major algae bloom and a sea lion attack resulted in exceptional costs in the amount of NOK 9 million (1.6 million CAD, 1.4 million USD) for the year." (2008 Annual Report)
- In March 2009, thousands of Scottish farmed salmon had to be culled on account of a diesel spill. The spill occured a few months before, in November 2008, at the onshore storage tanks at the Scottish and Southern Energy (SSE) South Uist power station. Later tests showed the immature salmon at nearby Loch Carnan suffered contamination from the diesel and could not be sold for food.
- Also in March 2009, toxic algal blooms were reported in Chile's Region XI, a salmon-producing region already plagued by the Infectious Salmon Anemia (ISA) disease. Algal blooms are caused by excessive nutriuent levels in the water. These nutrients cause the quick reproduction of algae, which rob the available oxygen and block sunlight, leading to the suffocation area fish. Toxic blooms are caused by toxin-releasing algae. Algal blooms, therefore, can lead to serious financial losses for the industry.
- In November 2007, 20% of Marine Harvest Chile’s farms were infected with a deadly disease known as ISA – Infectious Salmon Anemia. Whole pens of fish and in some cases entire farms have been emptied and fish destroyed. 11 of Marine Harvest’s Chilean farms have been affected by the virus and 13 more are under observation for potential outbreaks as the disease spreads from one net-cage to the next. As of April, 2008, 1,200 of the company’s farm workers have lost their jobs and one processing facility has been closed, displacing a further 600 workers.
- In mid-November, 2007, rampant disease outbreaks, combined with rising oil prices and declining market value for farmed fish led to a significant downturn in investor confidence. In just one week, Marine Harvest shares lost one quarter of their listed value, with a year-to-date decline in value of 27 percent. Third quarter revenues were $88 million dollars lower than the previous year.
- On the coast of Ireland in November 2007, a wave of stinging jellyfish killed all the fish in two salmon farms. Northern Salmon Co lost 100,000 salmon – valued at more than £1 million (approx. CDN$2 million) worth of stock in the fist attack and jellyfish wiped out another farm a week later.
- In the summer of 2007, a joint venture farm run by the Kitasoo First Nation and Marine Harvest lost an estimated 300 tonnes of salmon due to exposure to a plankton bloom that was toxic to fish.
Financial Analysis of Closed Systems
To inform discussions of financial viability, cost-benefit comparisons need to explicitly assess externalities. Externalities are costs currently borne by society or the environment and not by salmon producers, such as ‘free’ waste disposal from open net-cage farms. Feces and waste feed is currently not recaptured by the farms but deposited into the ocean.
In BC, a Future Sea flexible bag system installed at a Marine Harvest Canada salmon farm off Saltspring Island proved that growth rates and feed conversion rates are similar to open net operations. A land-based tank farm south of Nanaimo run by Agrimarine Industries was able to market salmon locally at a premium price with an “EcoSalmon” label.
These projects were short term trials developed as part of a temporary provincial pilot program and have since been discontinued. The land based tank farm successfully raised several generations of healthy salmon for market, but the trial site leased for the project was not ideally designed and energy costs of pumping sea water into the tanks were prohibitive.
However, Agrimarine Industries and Yellow Island Aquaculture are now working towards ocean-based closed containment technologies that would use large floating systems (Sargo tanks) with saltwater circulated through high-efficiency pump systems. It is expected that ocean-based tanks will cut down significantly on the cost and energy requirements of pumping water from sea level to land-based tank farms.
“The large B.C. salmon farming companies are going to be
watching this pilot project closely. They’re watching it,
they’re going to be the beneficiaries.
We have to prove to them it’s economic, that’s part of our goal.”
---John Moonen, Board Member, Middle Bay Sustainable Aquaculture
In Normandy, France, a land-based recirculation system has been approved to grow Atlantic salmon. The project has received start-up funding and plans to start construction shortly.
In 2003, PriceWaterhouseCoopers conducted an assessment of a land-based system, Eco-Farm, in Norway and concludes that profitable land based fish farming is possible. Summary of PriceWaterhouseCooper’s findings (pdf).
Cost-benefit analyses also have to consider the value of our wild salmon runs that net-cage salmon farms are damaging. CAAR, wilderness tourism operators and other businesses are confident that closed system aquaculture provides a viable, long-term solution to the costly environmental and economic problems posed by open net-cage salmon farms in BC.
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