Historically, Atlantic salmon was a seasonal food - fished, eaten and preserved by people around the North Atlantic since the beginning of time. It was both a staple and a luxury, pursued for subsistence, profit, and pleasure.

In the mid-19th century, twin forces began acting on wild salmon, leading to the development of the salmon aquaculture industry: the establishment of large scale salmon hatcheries to stock rivers¹, and the decline in wild salmon populations from overfishing and habitat destruction. 

Although aquaculture has been practiced around the world for thousands of years, growing Atlantic salmon in sea-cages was first attempted in the 1960s in Norway². The promise of large-scale harvests, year-round sales, and generous government support caused the industry to spread around the world over the following decades: to Scotland, Canada, Chile, the USA, Tasmania, Iceland and beyond.

Wild Atlantic salmon were captured from rivers and intensively bred for traits like fast growth and delayed sexual maturation³. The logic of industrialization took hold and farmed salmon emerged as a buyer-driven global commodity, with constant pressure on growers for more and cheaper fish. 

In the early days of salmon farming, companies experimented with Pacific species like Chinook⁴, but eventually Atlantic salmon came to dominate the industry, and global markets.

Case study: Japan

Salmon farming in Norway was firmly established by the 1980s. In fact, Norwegian salmon farmers had improved upon production techniques to such an extent that they found themselves with a surplus of frozen salmon.

This “cheap luxury” product needed new markets, to create consumer demand, and Japan was an early test case.

In the mid-1980s, marketer Bjorn Eirik Olsen launched Project Japan⁵, designed to introduce Norwegian farmed salmon to Japanese consumers, who at the time considered raw salmon a parasite-ridden fish with the wrong color, shape and smell for sushi.

Olsen reached a deal with Nichirei, a Japanese food conglomerate. They purchased Norway’s surplus salmon at a greatly reduced price on the condition that they sell it in grocery stores as sushi.

Olsen felt if he could get Japan on board with salmon, the fish’s popularity would ripple out worldwide because so many consumers across the globe viewed Japanese sushi positively, as a refined, clean and desirable way of dining.

The campaign's success hinged on clever rebranding tactics, including renaming Norwegian salmon as "sāmon" to differentiate it from local Pacific salmon varieties, and leveraging celebrity chef endorsements to shift consumer perceptions.

Today, Japanese businesses import 13,300 metric tons⁶ of fresh Atlantic salmon from Norwegian aquaculture companies every year.

The downside of “cheap luxury”

The buyer-driven expectation for more and cheaper salmon has pushed salmon farming beyond the biological limits of fish and the surrounding environment. 

Although stocking densities vary by country and region, a single planned site in Newfoundland, Canada, will include 10 sea cages stocked with up to 1 million juvenile salmon⁷, compared to an estimated 2 million wild adult Atlantic salmon in the entire North Atlantic⁸. The extreme, unnatural concentration of salmon in sea cages creates favorable conditions for parasites and viruses.

Infectious salmon anemia⁹ (ISA) is a viral disease that can infect and kill fish including salmon and trout, and can be carried by other species like Atlantic herring¹⁰. It has a mortality rate of up to 90% and can cause havoc when it gets into aquaculture operations. An outbreak of ISA in Chile in 2007, for example, caused a 60% reduction in salmon production and threw over 8,000 people out of work¹¹.

In Atlantic Canada the first outbreak of ISA was recorded in sea cages in 1996¹², causing widespread death among infected fish and leading to the government-ordered slaughter of nearly 300,000 salmon in infected areas¹³.

Some companies dragged their feet, demanding compensation for the slaughter of their salmon, allowing the disease to spread throughout the Bay of Fundy in New Brunswick and eventually to Nova Scotia, Newfoundland and Labrador, and Prince Edward Island. In 2001, there were 29 reported outbreaks of the disease in the region, and infections have been recorded every year¹⁴ since records began to be kept in 2012.

Compensation programs were established, leading to tens of millions of dollars being transferred from provincial and federal governments to fish farmers in Atlantic Canada. Today, ISA is considered endemic in Atlantic Canada. Compensation is no longer available, after the Canada Food Inspection Agency ruled that the infected fish could be sold for human consumption¹⁵.

Sea lice¹⁶ are another salmon parasite that has become common in aquaculture as a result of the dense stocking of sea cages and poorly sited farms, and they can spread to wild fish too¹⁷. 

They need to be controlled with pesticides, but some pesticides have been used haphazardly, leading to resistance¹⁸, and some companies have resorted to illegal use of prohibited pesticides, triggering investigations and fines.

In 2013 Kelly Cove Salmon in New Brunswick, Canada, was fined CAD$500,000 for using an illegal pesticide to control sea lice¹⁹, which led to the death of hundreds of local lobsters. And in 2025 the Chilean Supreme Court upheld a fine against the aquaculture company Salmones Blumar for submitting false statements²⁰ about their use of an anti-parasitic pesticide treatment on one of their farms.

Other interventions like the use of wrasse, a small fish that can eat lice off salmon in sea cages have had mixed results²¹, and resulted in extreme mortality rates²² for the cleaner fish themselves. Overall, it is estimated the industry spends almost US$900 million²³ per year fighting against tiny sea lice.

Farmed salmon also raises human health concerns, thanks to its higher levels of contaminants and the overuse of antibiotics²⁴, which may lead to chemical residues and antibiotic resistant bacteria.

CONCLUSION

The ocean is the last source of readily available, truly wild food on earth. The rise of sea-cage salmon farming is an extension of the industrial agricultural frontier into the sea, creating a need for a product that never existed previously. 

Profitability for salmon farmers depends on externalizing costs, like allowing ocean currents to carry away feces, and dumping plastic garbage along the coastline²⁵, rather than paying to dispose of it.

Overall, it is estimated that in the six year period between 2013 and 2019, companies in Canada, Norway, the United Kingdom, and Chile racked up nearly US$47 billion in externalized costs²⁶.