Fish Farms and the Decline of Pacific Wild Salmon

The Pacific Northwest is home to one of the world’s last greatest treasures: wild salmon. But for the 2019 salmon run, only 628,000 sockeye salmon are expected to return to the Fraser River in Vancouver. Original estimates were set at nearly five million.

What’s going on? 

Since the late 1980s, wild salmon have declined dramatically in the North Atlantic and the Pacific Northwest, south of Alaska.  The causes of the decline are due to both naturally occurring fluctuations and human activity. In response to declining wild salmon populations, sensitively felt by both commercial and sports fishermen, fish hatcheries and commercial fish farms were introduced to alleviate pressure off wild salmon by spawning more fish. Ironically, it is these very practices that now endanger and threaten wild salmon populations to the point of disappearing altogether. 

The importance of wild salmon: Feeding the land, wildlife and us

Pacific wild salmon are one of the world’s ‘keystone species’, meaning that their existence is crucial to operate the natural ecosystem surrounding them. To understand their importance, imagine an enormous pump that takes nutrients and minerals from the ocean and up into land through freshwater rivers, spreading them into the nutrient-deficient water, soil and plants. This journey can reach up to 3,000km inland. That’s about half way across Canada, swam by fish that had their last meal in the ocean. When salmon reach their spawning ground, their last energy reserves are used to lay their eggs, die, and the whole cycle begins again. The journey can take up to six months at a time, and alongside obstacles such as fallen trees or collapsed banks in the river, predators await every corner. Over 137 species of plants, animals and fish rely on salmon for sustenance. Killer whales, sea lions, bears, wolves, otters, eagles and many more native B.C. species are fed from their rich nutrients and omega-3 fatty acids. For those fish lucky enough to surpass the predators and reach their original birthplace, where they procreate and then die, their bodies become food for the forest and their newly born offspring, who are fed from their decomposing bodies. The unique temperate rainforests of B.C. are fertilized from the remains of dead salmon in the riverbed, and those caught and eaten by predators who drop their carcass remains deep in the forest. An estimated 80% of nitrogen in the trees of the rainforest are derived from the remains of salmon.

Beyond plants and mammals, Pacific salmon are vitally important to humans, too. First Nations have depended on and celebrated the return of wild salmon to their inlets for thousands of years. Bella Coola, Nootka, Tlingit and many other First Nations rely on salmon as a primary dietary source year round, particularly in the winter months.

Wild salmon abundance affects the mortality of everything in its environment – lush forests, healthy freshwater rivers, unique species of wildlife – everything that makes British Columbia beautiful.

Why are wild salmon more important than hatchery salmon?

Wild salmon are able to return to the exact place they were born by following the scent of pheromones in the water. Whilst wild salmon return to and decompose in their birthplace, perhaps a natural lake, river or stream, salmon raised in man-made hatcheries don’t have the homing instinct to return to a natural environment to spawn, avoiding the crucial natural bodily decomposition needed to fertilize the ecosystem. Rivers within B.C. now only receive an estimated five to seven percent of the nutrients they used to. Not only are the rivers hungry, but with fewer wild salmon decomposing after reproduction, the less nutrients are available for their offspring – weakening their development and strength to swim back to the ocean. 

Why are wild salmon declining?

The causes affecting wild salmon mortality are extensive. Their carefully curated journeys through different environments and interactions with a variety of predators and prey means a high vulnerability to changes in the environment. Although salmon stocks have been found to naturally fluctuate throughout their returns since records began, the past few decades have seen an overall decline in returning salmon since their last returns peak in the 1980’s. Today, we know that the main threats posed to wild salmon abundance are human-caused. Commercial and recreational overfishing are usually held accountable, having caused the most endangerment to marine species throughout human history. Although the impact of fishing is significant, more harmful risks are now posed to aquatic life with the expansion of human development.

Habitat Destruction
Urban development and natural resource extraction has caused the loss of many prime salmon spawning habitats. The destruction of rivers and streams due to logging activities and hydropower dams block the salmons’ migratory path. The displacement of their spawning grounds by the building of cities, roads and bridges also has a large impact.

Climate Change
Rising global temperatures means a warming ocean. This affects salmon from all angles; their predatory sense of smell is suppressed, their instinctual navigation routes are misled due to changing currents, and the abundance of prey is declining. Pteropods, a key prey species for Pacific salmon, are rapidly declining due to changes in oceanic carbonate chemistry conditions.

Fish Farms

Research shows that situating fish farms near wild salmon populations can cause declines of more than 50 percent

Many of the prime wild salmon river runs in B.C. fall in close proximity to commercial fish farms. Research shows that situating fish farms near wild salmon populations can cause declines of more than 50 percent. In open-net fish farms, fish are kept within confined net-pens in the ocean where they are easily fed and monitored, ensuring maximum harvest and profitability. It sounds viable – surely breeding our own seafood is more sustainable than taking more wild fish from the ocean. This is a commonly assumed benefit of fish farming. But what’s hidden under the surface suggests all but sustainable incentives. Fish farms discharge large amounts of harmful waste into the ocean including fish excrement, chemicals, pesticides and parasites, impacting all surrounding marine life – including passing by wild salmon. 

Photograph by Simon Ager

Disease
As with all farmed animals in a confined space, disease is easily and commonly spread. Diseases including the PRV (piscine orthoreovirus), sea lice and HSMI (heart and skeletal muscle inflammation) are regularly found in open-pen farmed salmon in the ocean. These diseases have been proven to spread to passing juvenile wild salmon during their migratory route. Fish farmers have implemented the use of antibiotics and chemical washes to treat such diseases as far back as the 1970s, but the issues still persist to this day. In fact, studies have shown that sea lice have now developed a resistance to the drugs being used to try and eradicate them. In response to their immunity, in May 2019 the B.C. government permitted one of the largest aquaculture companies, Cermaq, to release 2.3 million litres of pesticide into 14 Clayquot Sound fish farms to rid of sea lice. The pesticide, ‘Paramove 50’ consists of hydrogen peroxide, surfactants and other chemicals which can harm surrounding marine life alongside weakening the immunity of the farmed fish, leaving them even more vulnerable to disease. 

Escaped Fish
Atlantic Salmon constitute the majority of farmed Salmon in B.C. This is because Atlantic salmon have better rates of growth and survival on fish farms than Pacific salmon. When farmed Atlantic salmon escape and mix with their wild Pacific cousins, unnatural interbreeding causes weaker genes to enter the Pacific salmon gene pool. In August 2017, 267,000 farmed Atlantic Salmon escaped from a farm in Washington’s’ Cypress Island, into Washington State waters where wild Pacific salmon are found.

What Can I Do to Help Protect Wild Salmon?

The most effective way to help wild salmon preservation is to reduce our salmon intake altogether. By opting for alternative non-threatened, equally nutritious cold-water fish including arctic char (farmed), trout or sardines, the problems facing both wild and farmed salmon will decline. If you are to buy salmon, the following guidelines will aid a lesser harmful impact.

Buying Farmed Salmon: Support Inland Farming

If ocean-based fish farms were to suddenly shut down, the demand for salmon would inevitably be sourced from the last remaining wild salmon in the ocean. If fish farming is to exist to meet human demand for salmon, the industry’s redesign is crucial. A number of aquaculture companies and the B.C. government are now looking at inland fish farming methods. Averting the endangerment of wild fish and the ocean, raising salmon in a land-based contained pen is a healthier option, too. Protected from sea lice, jellyfish pathogens and diseases, land-based farmed salmon can be raised organically and without the need for antibiotics.
Kuterra (B.C.) and Sustainable Blue (Nova Scotia) are Canada’s first inland Atlantic Salmon fish farms. By buying from and supporting such companies, consumer spending will be channeled away from open-net farmed salmon and onto more sustainable, healthy practices – encouraging other companies to follow suit.

Buying Wild Salmon: Choose Sustainable Stocks

If we are to buy wild, it’s important to be mindful of which salmon stocks we are consuming. For example, Seafood Watch recommends that buying wild salmon caught in Washington during early Summer is the most sustainable population to buy in the Pacific Northwest, instead of salmon from B.C. or Alaska.

Which seafood is most sustainable to purchase in your Country?

CAN (B.C.)
CAN (ON)
US
UK
AUS

Support non-profit organizations dedicated to protecting wild salmon 

One of the most direct and impactful ways of protecting wild salmon is to support a local salmon preservation organization. Donating to fund research, policy appeals and habitat restoration will target the issues salmon face head-on. The stronger the support, the bigger the impact.

Pacific Salmon Foundation The Pacific Salmon Foundation is an independent, nongovernmental, charitable organization to protect, conserve and restore wild Pacific salmon populations in British Columbia and the Yukon. The Pacific Salmon Foundation provides grants for community salmon programs to help conserve and restore streams across the province.

Sea Shepherd Vancouver / Dr. Alexandra Morton: Sea Shepherd’s research vessel the R/V Martin Sheen has ventured to every salmon farm on the Fraser sockeye salmon migration route with Canadian scientists on board, collecting samples to determine the impact of salmon farms on wild fish populations. Dr. Alexandra Morton, an independent biologist, is also on board. Dr. Morton has been investigating the decline of wild salmon populations for three decades.

Watershed Watch: A science-based charity working to defend and rebuild B.C.’s wild salmon by offering scientific expertise to policy makers and highlighting the large scale issues affecting local waterways, from fish farms to climate change.

• Pacific Salmon Foundation The Pacific Salmon Foundation is an independent, nongovernmental, charitable organization to protect, conserve and restore wild Pacific salmon populations in British Columbia and the Yukon. The Pacific Salmon Foundation provides grants for community salmon programs to help conserve and restore streams across the province.

• Sea Shepherd Vancouver / Dr. Alexandra Morton: Sea Shepherd’s research vessel the R/V Martin Sheen has ventured to every salmon farm on the Fraser sockeye salmon migration route with Canadian scientists on board, collecting samples to determine the impact of salmon farms on wild fish populations. Dr. Alexandra Morton, an independent biologist, is also on board. Dr. Morton has been investigating the decline of wild salmon populations for three decades.

• Watershed Watch: A science-based charity working to defend and rebuild B.C.’s wild salmon by offering scientific expertise to policy makers and highlighting the large scale issues affecting local waterways, from fish farms to climate change.
  
  
  Other noteworthy organizations:
  
  Wild First https://www.wildfirst.ca/
  Save Our Wild Salmon https://www.wildsalmon.org/
  Wild Salmon Centre https://www.wildsalmoncenter.org/strategy/