Top 3 Reasons Open Net-pen Salmon Farms Threaten Wild Salmon
This June, many provincial salmon farm tenures on B.C.’s coast are set to expire. This presents a huge opportunity for the provincial government to protect our wild salmon from Atlantic salmon farms and their diseases by simply not renewing these tenures.
Recently, our neighbours in Washington State have banned open-net salmon farming and it is time for B.C. to follow suit. Here are the 3 top reasons open net-pen salmon farms threaten wild salmon.
#1. Fish farm diseases threaten wild salmon.
Viruses and disease in salmon farms can spread like wildfire. If one farm salmon is infected, its close proximity to hundreds of thousands of other salmon means it can spread fast. One highly problematic virus found within B.C. salmon farms is Piscine Reovirus (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. PRV can infect the fish’s red blood cells, reducing oxygen absorption, and is the causative agent of a life threatening disease for 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. PRV can negatively affect wild salmon and impede their ability to complete their spawning migrations.
#2. Salmon farms can spread salmon lice to wild salmon.
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. However, problems arise for juvenile wild salmon as they migrate past the farms. On their journey, many of B.C.’s wild baby salmon will pass at least one salmon farm on their out-migration. If an opportunistic salmon louse latches onto a wild salmon it can be devastating to the baby fish. Research reports that one to three salmon lice can kill a juvenile wild salmon.
#3. Farm salmon can escape and out-compete native species for resources.
Unfortunately, large-scale escapes from open-net farms happen fairly frequently. For example, 300,000 farmed Atlantic salmon escaped from a farm in Washington in the summer of 2017. On the other hand, small-scale escapes, referred to as leakage, go under-reported. Scientists report that as much as one per cent of farmed salmon escape their pens each year via leakage. That means 160,000 farmed fish escape and go unreported each year in B.C. When farmed Atlantic salmon escape, they make the lives of wild salmon more challenging. They can compete with wild salmon for food and habitat, and they can spread diseases to wild species.
Despite the clear risks to B.C. wild salmon, fish farms continue to operate. But with Washington’s recent decision to remove open-net fish farms from coastal waters, pressure is mounting on provincial and federal officials to follow their lead and let the tenures lapse.
Help make this happen by adding your voice to the Declaration in Defense of Wild Salmon and calling for the removal of open-net fish farms.