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 2010, the vice president of Cooke Aquaculture in New Brunswick told La Presse they “lost 500,000 fish this year” to sea lice infestation.
- 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.
- Intrafish – an online publication for global seafood professionals – reported that in October 2009, there was a 380% increase in farmed salmon and trout escapes in Norway compared with the previous 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 in 2008.
- In September 2009, 58,800 salmon escaped from a farm in Scotland due to a hole in the net-cage.
- 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 were approximately 500 tonnes.
- In March 2009, thousands of Scottish farmed salmon had to be culled on account of a diesel spill. The spill occurred 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.
- 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 nutrient levels in the water. These nutrients cause the quick reproduction of algae, which rob the available oxygen in the water and block sunlight, leading to the suffocation of area fish. Toxic blooms are caused by toxin-releasing algae. Algal blooms, therefore, can lead to serious financial losses for the industry.
- In 2008 Marine Harvest’s financial reports revealed that Marine Harvest Canada suffered 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.”
- In 2007 Infectious Salmon Anemia (ISA), a highly contagious virus that can be lethal to fish, broke out in Chile and resulted in losses of approximately 70% of the industry’s stock. It was reported that Marine Harvest went from 70 operational Chilean farms to 10 in the wake of ISA – reporting hundreds of millions of dollars in global losses in 2008 while thousands of Chileans lost their jobs as result of the ISA crisis. The annual cost of infectious ISA outbreaks among farmed fish was reported by the Globe and Mail to be $11-million (U.S.) in Norway, $14-million in Canada, and $32-million in Scotland.
- 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, a decline in value of 27 percent over the previous year. 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) 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.