Atlantic salmon, the native salmon that used to inhabit the northern Atlantic Ocean, rivers and seas, is a species now represented by an impostor: farmed salmon. Also known as cultured salmon, farmed salmon comes from hatchery genetic stock and unlike its native ancestors, lacks wild genetic variation. The wild fish our ancestors ate is gone. What appears on our dinner plates is a substitute copy, a genetic dilution of a once mighty fish, the adaptive king of the sea, and a significant food for coastal humans since prehistoric times.
The change in genetic stock has been happening for decades, as farmed salmon are released into native waters via restocking programs (in an attempt to reduce the negative impacts of overfishing of wild salmon) and also unintentionally as a consequence of faulty containment in sea net-cages. The resulting “swamping out” effect — farmed in, wild out — along with several other insidious factors, has driven native salmon to effective extinction.
Genetic erosion