Juvenile salmon with multiple parasitic sea lice. Photo credit: Tavish Campbell

Every spring, starting in March, juvenile salmon begin their journey out to sea where they will spend their adult lives. Unfortunately, factory fish farms along their migration routes greatly reduce their chance of survival.

In many rivers around the province, last year’s salmon returns were the lowest on record. B.C. wild salmon are struggling, and fish farms are compounding the situation. Here are the top reasons open net-pen salmon farms threaten wild salmon.

1. Fish farm diseases threaten wild salmon

Viruses and diseases in salmon farms can spread like wildfire. If one factory farm salmon is infected, its close proximity to hundreds of thousands of other salmon means pathogens can spread rapidly fast. One highly problematic virus found in B.C. salmon farms is Piscine Orthoreovirus (known as PRV). PRV is found in over 70 per cent of farmed salmon and, according to the latest science, can be transmitted from farms to wild salmon.

An open-net pen salmon farm with dead fish. Photo credit: Tavish Campbell

A 2021 study concluded the salmon farming industry likely transported it to B.C. PRV can infect the fish’s red blood cells, reducing oxygen absorption, and is the causative agent of a life threatening disease for farm salmon–Heart and Skeletal Muscle Inflammation (HSMI). HSMI can cause lesions on the heart, weaken the muscular system, and cause mortality rates between 20 and 100 per cent. A 2018 study co-authored by Department of Fisheries and Oceans (DFO) scientists reported PRV can enter blood cells in Chinook salmon and cause them to burst. This can cause liver and kidney damage, anemia, and even death.

2.  Salmon farms can spread salmon lice to wild salmon

A salmon with wounds caused by sea lice. Photo credit: Tavish Campbell

Salmon lice naturally occur in the Pacific Ocean, but overcrowded conditions in salmon farms provide optimal breeding grounds for them. For the tens of thousands of adult farmed salmon in the pens, the contraction of salmon lice are not usually detrimental in B.C. However, problems arise for juvenile wild salmon as they migrate past the farms. On their journey, many baby wild salmon will pass at least one salmon farm on their out-migration. Parasitic lice can latch onto wild salmon, which can be devastating to the baby fish. Research reports that one to three salmon lice can kill a juvenile wild salmon.

 3. Salmon farms also kill wild species besides salmon

Factory fish farms kill many species of wild fish including herring, rockfish, hake, sole, perch and many others that become trapped in the fish farm nets. Sometimes when a fish farm experiences a bad disease outbreak, they cull their farm salmon and many other fish species caught in the nets at the time are also killed. At one B.C. salmon farm that experienced an IHNV disease outbreak over 350,000 herring were killed, along with the farm salmon. Numerous marine mammals have been killed by B.C. factory fish farms, including seals, sea lions and even humpback whales. Factory fish farms also smother countless marine animals on the ocean bottom with their waste. 

Juvenile wild salmon. Photo credit: Tavish Campbell

Despite the clear risks to B.C. wild salmon and coastal waters, factory fish farms continue to operate. But with the Canadian government’s commitment to transition them out by 2025, pressure is mounting on federal officials to get them out.

On June 30, 2022, over 95 per cent of B.C.’s factory fish farm licences will expire. The expiration of these licenses offers a huge opportunity for getting factory fish farms out of B.C.’s coastal waters and off wild salmon migration routes. We need to push hard on the government so they do not renew them. Can you send an email to your MP, asking them to remove more fish farms when their licences expire in June 2022?