Spawning Chum Salmon
Sea Lice – Salmon aquaculture is prohibited in Alaska for economic and environmental reasons. Built along the shoreline, farmed salmon are particularly susceptible to diseases and parasites, such as sea lice, that can be lethal to fish. Sea lice, viruses and other pathogens have contaminated wild salmon stocks swimming nearby, many young wild salmon become infected and do not survive as a result.
Escapes – Farmed Atlantic salmon are an aggressive species that are not indigenous to the Pacific Northwest. Atlantic salmon have been found in dozens of rivers and lakes throughout BC and Alaska. There is only one species of Atlantic salmon (Salmo salar) on the east coast whereas there are several species of salmon on the west coast. Atlantic salmon are strong competitors and have historically wiped out other east coast salmon pieces.
PCBs – Farmed fish is fattier and therefore can store more PCBs and other contaminants at levels of up to 10 times higher in farmed salmon. Polychlorinated biphenyls PCBs are mixtures of up to 209 individual chlorinated compounds. There are no known natural sources of PCBs, they are either oily liquids or solids, that have been used as coolants and lubricants in transformers, capacitors, and other electrical equipment because they don’t burn easily and are good insulators. The manufacture of PCBs was stopped in the US in 1977 because of evidence that they build up in the environment and can cause serious health effects. PCBs persist in the environment, fish absorb them from contaminated sediments and their food. Government regulations allow much higher levels of contaminants in farmed salmon than are allowed in wild salmon.