Open net pen salmon farms use the constant flow of marine waters as a “free” resource to fill and flush their salmon pens, meaning that pathogens produced in these dense farms flow freely into the surrounding marine habitat. This enables pathogens and disease to spread incessantly from farmed to wild fish.
Using wild waters as a “free” resource means that mass volumes of effluence and concentrated fish manure pour into the marine environment, smothering the sea floor and its diverse life and feeding cyanobacterial algae mats and algae blooms that can become toxic in wild salmon habitat.
Salmon farms call themselves “environmentally friendly” as their carbon footprint of water and electricity is seemingly smaller than other land-based factory farming facilities. However, using marine waterways as a free resource is not only unsustainable, but environmentally damaging. What they really mean is that the industry’s running costs are lower than usual because they have an unimaginable cost on the surrounding marine environment.
Salmon farms threaten our oceans and environment
Salmon are a keystone species, meaning that the whole surrounding food-web and ecosystem relies on them for survival. Predators such as bears, eagles, sea lions, seals and orcas are particularly threatened by a lack of Pacific salmon as a major part of their diet.
The critically endangered population of Southern Resident Orcas is down to 73 individuals. This type of Orcas feed almost exclusively on Chinook salmon. An alarming decline on this species of salmon, which can be severely affected by salmon farms, is causing the Southern Resident population of Orcas to starve to death. In the first half of 2019, 3 deaths of the southern residents were declared.
Seals, sea lions, whales and birds become tangled and trapped in the nets and anchor lines, and in some places are harmed and displaced by the use of acoustic repellent devices.
Routine pesticides pollute entire waterways and are particularly harmful, if not lethal, to other crustaceans such as lobsters.
As salmon are carnivorous, salmon farms depend on massive commercial fisheries that kill off larger ratios of forage fish biomass to feed farmed salmon, starving many oceans to pollute others.
Salmon farms threaten our communities
Wild salmon have gone into steep decline if not extinction in places where salmon farms have been installed – including Chile, Norway, Scotland and the East Coast of Canada. But wild salmon remain abundant in places like Alaska, one of the few places to ban salmon farms.
Wild salmon not is key to First Nations’ constitutional rights to access food, fish and clean water. Loss of wild salmon threatens rural coastal indigenous communities more than anyone else, wherein lives and people’s subsistence depend almost exclusively on wild salmon’s existence.
Wild salmon represent the cultural lifeblood of many diverse coastal First Nation cultures, heritage and territories. Therefore the loss of wild salmon threatens the heritage and continued existence of many of these communities. These salmon farms represent a new corporate commodification of the ocean, limiting public access to resources by privatizing the commons.
Farmed salmon are fed pesticides and antibiotics to keep them alive and colorants to make them appear pink or orange instead of grey. Their high fat content feed gives them extra fatty bands throughout their flesh, acting a binding material for POP’s, heavy metals and toxins found in the water. When eaten, the toxins in this fat binds with the fat of the person or creature eating it.
The loss of wild salmon negatively affects entire coastal economies, especially much larger and more profitable locally owned tourism industries. Wild salmon is more economically viable than farmed salmon. Most salmon farming companies are foreign owned, and the farms are increasingly automated meaning that very little money flows back into local economies.
Farmed salmon threaten wild salmon
Salmon farms attempt to raise huge quantities of fish in unnaturally high densities. These densities act as a breeding ground for disease organisms which transmit quickly between fish; multiplying and loading the waters with viruses, parasites and bacteria.
Piscine Reovirus (PRV) is present in most of the farms in BC waters. This virus originates from Norway and can cause heart and skeletal muscle inflammation (HSMI) in Atlantic salmon, or anemia and jaundice, i.e. “mass cell rupture” for Pacific salmon.
In the wild, sick salmon are picked off quickly by predators as a natural disease defense mechanism. But salmon farms are built to keep out predators and therefore diseased or sick fish remain to infect surrounding wild and farmed fish.
Parasites, especially sea lice have become a huge problem in salmon farms, named as one of the industry’s major costs.
Salmon farms create the perfect environment for sea lice to reproduce, increasing in dense environments whereas in the space of the wild their numbers would remain low. This especially impacts juvenile wild salmon, that would not encounter sea lice until later on their life cycle. The survival of juvenile salmon can be severely compromised by sea lice, since their skin is not fully developed, and their size is small. They can also act as disease spreading agents between farmed and wild salmon.
Pesticides used against sea lice are not only ineffective in the face of inevitable resistance, creating intense parasite plagues that are infesting wild salmon populations at record levels and killing off juvenile wild salmon that are not equipped to survive major infestations. In 2018 and 2019, salmon in BC waters were found with up to 50 lice per fish. This is extraordinarily dangerous as 1 lice per 1 gram of fish can be lethal for wild populations not being treated with pesticides.
Attracted by feed and lights, several species of smaller wild fish such as juvenile wild salmon and herring can get trapped inside these pens. As salmon are carnivorous, and predatory behaviour has been observed within these pens, rather than escaping these wild fish are more likely to end up being eaten by farmed salmon. Wild salmon and herring are both in serious decline all along the B.C. coast. The exact numbers and impacts of the individuals trapped is still unknown, and so the impacts on wild fish populations are relatively unknown.
Escapes of non-native fish is approximately 10% of farm stock, and threatens biodiversity, with escaped Atlantic salmon not only competing with wild salmon for resources but breeding with them, overall reducing the genetic diversity and quality of wild salmon populations.
Salmon farms often claim to participate in initiatives aimed at preserving wild salmon stocks. What this usually means is that they invest in hatcheries, and these hatcheries often are the sources of their farmed salmon eggs. Unfortunately, while hatcheries buoy up dwindling wild salmon populations momentarily, on a broader scale they deplete the genetic quality and diversity of wild salmon stocks, by interbreeding and competing for resources. The success of a species relies on its genetic diversity and evolutionary adaption to disease and other environmental struggles.