About the Issue

  • Salmon farms are breeding grounds for disease organisms which multiply and load surrounding waters with viruses, parasites and bacteria.
  • Pathogens transmit easily from captive to wild fish.
  • Seals, sea lions and whales become tangled and trapped in the nets and anchor lines.
  • Pollution from large and concentrated volumes of fish manure pour into the marine environment feeding algae blooms that can become toxic (in wild salmon habitat).
  • Pesticides are not only ineffective, weakening the immune system of farmed salmon and creating pesticide-resistant sea lice, but also pollute entire waterways. Routine pesticides are particularly harmful, if not lethal, to crustaceans such as lobsters.
  • Salmon farms require massive commercial fisheries to feed the salmon, starving one ocean to pollute another.
  • Local wild fish are attracted by the feed and get trapped within the nets, becoming free food for farmed salmon.
  • Escapes of non-native fish is one of the biggest threats to biodiversity.
  • The loss of wild salmon negatively affects entire coastal economies, especially much larger and more profitable locally-owned tourism industries.
  • Wild salmon go into steep decline wherever there are salmon farms, but remain abundant in places like Alaska, one of the few places to ban salmon farms.
  • Predator populations, such as whales are suffering the threat of extinction due to lack of salmon.

Foreign Companies Endanger Local Communities

Large corporations like Mitsubishi, Norwegian Marine Harvest, Cermaq and Grieg Seafood run the salmon farms in British Columbia. They make a profit at the expense of the local communities along the coast.

Salmon farms don’t “feed the world” because they feed wild fish to the farmed salmon. While creating very few jobs, they threaten the much larger local economy in wilderness tourism and fishing. They use First Nation territories with or without their permission.  The government of Canada seems blind to the impact of salmon farms on the environment and on local economies.

Industrial Fish Farms Threaten Our Oceans

Salmon farms are extremely harmful to wild fish because they release toxic levels of viruses, bacteria and sea lice into the water. These drastic changes create unstable and fragile ecosystems.

Wild salmon are declining wherever there are salmon farms. Salmon are built to move – the sick and weak are left behind and consumed by predators. This natural process stops bacteria, viruses and parasites from multiplying. But when they are contained in fish farms, salmon are forced to swim around in crowded cages, through feces where disease spreads easily from fish to fish. This gives viruses, bacteria and sea lice the perfect circumstances to mutate, amplify, become deadlier and spill out into the surrounding ocean. Without predators, each sick farmed fish remains infectious much longer, pumping out pathogens until they waste away and die.

Wild salmon fry with sea lice and scale damage

Viruses, Diseases and Pollutants

A salmon farm undergoing an epidemic can shed 65 billion infectious viral particles per hour.

The greatest threat from open-net salmon farming is viruses, because they “go viral”. Salmon farms give viruses the right set of circumstances to mutate, swap genetic material, increase in severity and spill out into the surrounding ocean at levels never seen before.

Fish farms have introduced Atlantic salmon, a nonnative species to the Pacific coast, and thus the fish pose an enormous exotic disease risk.

Salmon farms are known to increase virulence in pathogens. Farms cause pathogens to become more lethal because there are no predators to remove the sick fish and because the animals are so crowded together, pathogens multiply and mutate.

Sea Lice

Sea lice from salmon farms are killing wild salmon wherever this industry operates.  They are a parasitic crustacean that preys on salmon, grazing on the mucous layer covering their skin. Like all feedlots, salmon farms cause parasites to multiply. When young wild salmon swim past these feedlots as they go to sea, they are attacked and eaten by clouds of sea lice.

In the wild, sea lice are benign; fish farms however offer the perfect breeding grounds for these parasites.

Fish farm companies use increasingly toxic drugs to try to control the lice. These chemicals are pouring into the sea threatening everything that makes a shell – including lobsters, crabs, shrimps and prawns. Norway and Scotland have been unable to control sea lice infestations as the parasites become drug resistant and more toxic chemicals are used. The same companies are having the identical problem in BC, which threatens entire populations of wild salmon. Research on the impact of the sea louse drugs on the environment has been suppressed.

Research by Alexandra Morton and her colleagues has shown that  BC appears to have a Norwegian strain of PRV. The disease spread very rapidly through Norway.

Piscine Reovirus (PRV)

PRV is highly contagious and considered to be the cause of the salmon disease Heart and Skeletal Muscle Inflammation (HSMI). This disease weakens salmon to the point where they can barely move; researchers believe a wild salmon with this disease would not be able to swim up a river to spawn.  Over 80% of the farmed Atlantic salmon in BC are now infected with PRV and therefore the wild salmon are swimming through a soup of this virus. It appears BC has a Norwegian strain of PRV. The disease spread very rapidly through Norway.

Heart and Skeletal Muscle Inflammation (HSMI)

Heart and skeletal muscle inflammation (HSMI) is a disease that critically weakens farmed Atlantic salmon and reduces growth.

The disease causes lesions on the heart and makes fish lethargic, and since this disease is believed to be exacerbated by stress, wild salmon are specifically at risk. Scientists are currently reporting other impacts of Piscine Reovirus, which is blood disease..

Infectious Salmon Anemia Virus (ISAV)

ISAV is a highly lethal salmon virus spreading world-wide in fish farms. Like other members of the influenza family, ISAV is known to mutate to higher virulence in feedlot-type environments.  ISAV was discovered in Norwegian salmon farms in 1984, and it caused $2 billion in damages when it spread to Chile from Norway in Atlantic salmon farms. Alexandra Morton co-published a paper on ISAV in BC farm salmon, but Canada refuses to acknowledge it as that would threaten international farm salmon trade as many countries that do not want ISAV-infected fish could close their borders.

Salmon Alphavirus

Salmon alphavirus causes pancreas disease in salmon. First recognized in 1984 in Scotland, it is now the number one viral killer of farmed salmon in Norway. In 2009, Chile petitioned the World Trade Organization for permission to ban the import of eggs from areas contaminated with this virus. In 2011, Chile applied to the World Organization for Animal Health to make it a reportable virus so that it would be mandatory for companies operating in Chile to report it. Chilean authorities are trying to prevent this virus from establishing itself and trying to rebuild the industry’s reputation. The alphavirus genetic sequence has been detected in British Columbia salmon, with no visible effort by government to investigate and protect wild salmon.


Salmon farms are one of the few industrial agriculture industries that do not have to deal with their waste. They never shovel their manure. As salmon farms use roughly 7 tons of feed daily for the approximate 1,000,000 fish per farm, tons of waste spews daily per farm in a free flush.

Increasingly, farmed salmon are fed grains, chicken and pig parts, fish from different oceans, chemicals to color their flesh, delousing drugs, antibiotics and vaccinations. There is nothing natural about the amount or content of farmed salmon waste.

Farmed Atlantic salmon inside pens at Sir Edmund fish farm


  1. https://www.voyageforsalmon.ca/about-fish-farms/ 
  2. http://www.alexandramorton.ca/salmon-confidential-booklet/ 
  3. http://www.alexandramorton.ca/bad-for-our-oceans/ 
  4. https://www.ncbi.nlm.nih.gov/pubmed/19864284 
  5. http://www.alexandramorton.ca/bad-for-our-oceans/ 
  6. https://www.voyageforsalmon.ca/about-fish-farms/ 
  7. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0011487 
  8. https://virologyj.biomedcentral.com/articles/10.1186/1743-422X-10-230 
  9. http://www.alexandramorton.ca/salmon-confidential-booklet/ 
  10. http://www.alexandramorton.ca/introducing-viruses-to-new-parts-of-the-world-is-dangerous/