In The Health of the Ocean Series #2, I discuss the environmental, social justice and health implications of two of the most unsustainable aquaculture industries in the world: open-net pen salmon farms and tropical farmed shrimp. Part 1 discusses the issues associated with open-net pen salmon farms in British Columbia.
Open-net Pen Salmon Farms
“We need to end salmon farming in our open oceans now to protect both wild salmon and Indigenous ways of being from extinction.”
~ Terry Teegee, regional chief of the B.C. Assembly of First Nations
Open-net pen salmon farming is a large, global industry which is having devastating effects on ecosystems, and in particular on wild salmon. In a 2016 report by SeaChoice, a Canadian non-profit organization that is a science-based seafood industry watchdog, open-net pen farmed Atlantic salmon comprised the highest volume of unsustainable seafood produced in Canada, an estimated 72% (SeaChoice, 2016). Open-net pen salmon farming involves the rearing of salmon fry, typically non-native to the location of the farm, in coastal waters where the salmon are contained in pens comprised of nets. The nets enable the free flow of water both into and out of the salmon pens, allowing for excrement, bacteria, viruses, parasites and pesticides to freely enter coastal waters. In B.C., an average salmon farm has between 10 and 30 pens that are each approximately 12 to 15 square metres, each containing approximately 20 000 salmon, the vast majority of which are non-native Atlantic salmon (Fraser River Keeper, n.d.). The salmon on these farms produce huge amounts of excrement which damage ecosystems through contamination and by causing toxic algal blooms. It is estimated that a farm of 200 000 salmon produces the same amount of waste as a city of 60 000 people (Sandvik et al., 2018). A typical farm in B.C. contains an average of 400 000 to 500 000 salmon. Other marine species that live in close proximity to salmon farms, such as clams and oysters, frequently become too contaminated for human consumption.
Open-net pen salmon farms are frequently referred to as “the factory farms of the sea.” The extremely high density of fish on the farms makes the salmon more susceptible to disease. The increased risk is due not only to the close proximity of the fish and the massive amount of excrement in the environment but also because the confined, crowded conditions the salmon endure causes them to release stress hormones which suppress their immune system. According to fish pathologist Gary Marty, 10% of farmed fish in B.C. don’t make it to market, the majority of which die due to environmental conditions including low oxygen, toxic algae, and predation (Amy Smart, Victoria Times Colonist, 2017). In an attempt to fend off disease, which can lead to mass culling of salmon on farms, farmed salmon are routinely fed large amounts of antibiotics which are transferred to humans when the salmon is consumed. In addition, farmed salmon require 1.2 kg of feed to produce 1 kg of meat, and a significant part of the feed for farmed salmon is wild fish (Kjerski et al., 2018). Canada is the 4th largest producer of farmed salmon in the world and farmed salmon is B.C.’s largest agri-food export (Department of Fisheries and Oceans Canada, 2017). There are currently over 100 open-net pen salmon farms in B.C.’s coastal waters and more than 90% of the salmon farming industry in B.C. is owned by three Norwegian companies: Marine Harvest, Cermaq and Grieg Seafood (Findley, 2018). In my opinion, foreign-owned corporations do not have the same incentive that local communities have to protect resources, ecosystem integrity and wild salmon. B.C. is the last place in the Pacific Northwest to allow open-net pen salmon farms. Government bans of open-net pen salmon farms exist in Washington State, Oregon, California, Alaska and even parts of northern B.C.
Most, if not all, of the salmon farms in B.C. reside in the traditional territories and fishing grounds of First Nations peoples, the first human inhabitants of the expanse of land currently recognized as B.C. Archaeological findings show they have lived in the Pacific Northwest for at least 10 000 years. Salmon are woven into every aspect of the life and culture of coastal First Nations peoples and many coastal First Nations are dependent upon wild salmon for food, ceremony, cultural identity and livelihood. The issue of salmon farming is complex, as the industry provides many jobs and has brought economic prosperity to several remote communities. However, many First Nations peoples and their leaders oppose the presence of salmon farms on their traditional territories citing damage to the ecosystem and specifically the threat to wild salmon.
On the west coast of Canada in B.C. we have seven out of the ten species of Pacific salmon and 9000 distinct salmon populations (Pacific Salmon Foundation, n.d.). Born in rivers deep in the coastal rainforest and beyond, salmon travel hundreds, and for some species thousands, of kilometres across the ocean and then return to their natal river to spawn and die. Salmon literally connect the land to the sea in the Pacific Northwest. They provide an abundance of nutrients to countless iconic, west coast organisms including orcas, bears, bald eagles and even the canopy-forming trees of the ancient temperate rainforest. First Nations and commercial wild salmon fisheries exist in B.C. in addition to robust recreational salmon fishing. Gathering with friends in the summertime with a fresh-caught salmon on the barbeque is part of the lifestyle of coastal B.C., and whole communities exist whose economies are driven by salmon charter operators. Perhaps the most urgent and detrimental effect of open-net pen salmon farms are the risk they pose to wild salmon populations.
Alexandra Morton is a marine biologist who has been studying orcas for decades. In her quest to uncover the cause of the declining numbers of B.C.’s distinct resident orca population, her focus turned toward salmon, the main food source of the resident orcas. During years of research, she discovered that salmon farms were having a detrimental effect on wild salmon populations by spreading disease and parasites. It was Morton who discovered that the Norwegian strain of piscine orthoreovirus (PRV), a highly contagious virus associated with the often fatal fish disease Heart and Skeletal Muscle Inflammation (HSMI), was present in salmon occupying farms directly in the migratory path of the Fraser River population of Chinook salmon. This population of salmon is the main food source (an estimated 82-90%) of the critically endangered southern resident killer whales (SRKW). Salmon affected by the disease are not strong enough to make the arduous swim upstream in their natal rivers in order to reach their breeding grounds. The disease can also be fatal, especially in juveniles. Studies show much higher rates of PRV in wild salmon populations close to farms where the virus is ubiquitous and some results suggest that PRV originating in farmed salmon may be affecting the fitness, reproductive success and survival of wild salmon (Morton et al., 2017). Morton has been fighting hard to bring this information to the public and to policymakers in order to bring about legislation that will protect wild salmon. PRV and its associated condition HSMI is just one of several diseases associated with farmed salmon.
Sea lice are another significant problem associated with salmon farms. Sea lice are a type of external parasite that feeds on the mucous, epidermal tissue and blood of salmon and can cause death, especially in juveniles. Sea lice can spread from farms to wild salmon and are able to live off of their host for up to three weeks. The high numbers of confined salmon make salmon farms particularly prone to sea lice infestations, and it is not uncommon for farms to have to cull their own salmon as a result. The Department of Fisheries and Ocean’s threshold for sea lice on farmed salmon during the migration of wild juvenile salmon, from March 1st until the end of June, is three per fish. The First Nations Leadership Council (FNLC) assert that reports released by international aquaculture companies Cermaq, Mowi and Grieg suggest that 35% of salmon farms on B.C.’s coast exceeded the federal allowable limit. In addition, the findings of an independent report by Alexandra Morton on migrating juvenile salmon from four areas near salmon farms found high percentages of juvenile salmon infected with sea lice. The highest percentage was found on juvenile salmon migrating past salmon farms near the Discovery Islands off of northeastern Vancouver Island, where 94% of sampled fish were infected with sea lice (Morton, 2020). This area is the migratory path for the Fraser River population of sockeye salmon, which has seen among the largest declines of any B.C. salmon population. According to Morton, half of the salmon farms in the Discovery Islands region reported exceeding the federal allowable threshold of sea lice on farmed salmon. Furthermore, Morton asserts that sea lice were not reported on wild juvenile salmon prior to the presence of salmon farms and that the levels of infestation reported in her study are lethal to juvenile salmon. The FNLC attest that sea lice spreading from open-net pen salmon farms “are contributing to the massive decline in wild salmon stocks” (Rochelle Baker, The National Observer, 2020). Moreover, salmon farms release large amounts of pesticides into the water in an attempt to suppress sea lice infestations. These pesticides are harmful to the ecosystem and sea lice are becoming increasingly resistant to them.
Another damaging and gruesome aspect of open-net pen salmon farms is that they release huge amounts of “blood water” into the ocean environment. Blood water is the waste from processing the farmed salmon. The issue of blood water was first brought to the attention of the public in 2017 when Tavish Campbell, an avid diver who works in the ecotourism industry, captured the bloody effluent on film. Campbell filmed blood water effluent from two farms off of Vancouver Island. One farm is located in a bay known to be a refuge for migrating juvenile sockeye salmon from strong tidal currents. Blood water samples have since been tested by the Atlantic Veterinary College and were found to contain high levels of PRV, the highly contagious virus associated with the potentially fatal fish disease HSMI.
The escape of farmed Atlantic salmon also has an impact on both the marine ecosystem and river ecosystems. Atlantic salmon are not native to the North Pacific and in addition to being voracious eaters, competing for the food sources of wild salmon and other wild species, may cause other unknown harms. In August of 2017, the nets of a U.S.-owned salmon farm near Victoria, B.C. broke and an estimated 305 000 Atlantic salmon escaped into the ecosystem. Farmed Atlantic salmon have been witnessed in the ocean hundreds of kilometres away from any farms. They have also been found in rivers, including the Fraser River, which is a spawning ground for Chinook salmon and contains the largest population of sockeye salmon in B.C. In June of 2020, two First Nations chiefs from the We Wai Kai and Wei Wai Kum nations called for the immediate removal of the Mowi Shaw Point farm, which is located in their traditional territory, following the escape of 1000 Atlantic salmon.
In addition to the distressing ethical issue of confining a fish that in the wild would travel hundreds, and for some species thousands, of kilometres over the course of its life, inhabiting both freshwater and saltwater, other significant ethical issues exist. The presence of thousands of fish in one area attracts large predators, including marine mammals. Even though it is illegal to shoot marine mammals in B.C., the Canadian government allows salmon farmers to shoot ‘nuisance’ seals and sea lions. Moreover, animals including dolphins, porpoises, seals, sea lions and birds get entangled in the farms’ nets and drown.
Farmed salmon can also be harmful to human health. Levels of organic contaminants such as PCBs and heavy metals such as mercury have been found to be significantly higher in farmed salmon than in wild salmon, in some cases at levels that are considered dangerous to human health (Hites et al., 2004; Easton et al., 2002). Farmed salmon often contains high levels of antibiotics, which can affect human health both directly by consuming them and indirectly by creating strains of antibiotic-resistant bacteria. In addition, there is not enough information available to know the impacts of eating fish that may be diseased. Furthermore, while salmon are considered to be an extremely healthy and nutritious food which is high in omega-3s and protein and low in saturated fat, there are differences between wild salmon and farmed salmon: farmed salmon are fed an unnatural diet which includes terrestrial-based foods such as soybeans, wheat and feathers, and have an altered nutritional make-up. For example, farmed salmon have been found to be higher in saturated fat, calories and omega-6 fatty acids than wild salmon. Farmed salmon are also artificially coloured with a synthetic form of astaxanthin in order to appear pink like their wild counterparts. Marine astaxanthin, whose original source is microalgae, is a naturally occurring compound in organisms that wild salmon eat such as shrimp and krill. Algae are also the primary source of omega-3s in salmon, and indeed in all fish.
The Department of Fisheries and Oceans (DFO), the federal agency in Canada that regulates fisheries, acknowledges the dangers of open-net pen salmon farms but despite promises to remove them, the farms remain. The latest claims made by the DFO is that by 2025 they will transition to closed containment farms, farms that are located on land. While this would protect wild salmon, it doesn’t resolve the ethical issue of the treatment of salmon on the farms nor the overwhelming increase in energy and water required to operate closed containment farms. B.C. wild salmon stocks are currently the lowest in recorded history and in 2019 there were unprecedented salmon fishery closures, including for recreational fishing.
