Then the pools must be abandoned and the process repeated further down the coast. The wasteland left behind is deficient in soil and too polluted to replant. The companies causing this damage reap enormous short term profit. But local economies are destroyed. The impact of salmon farming is much more subtle, because it occurs underwater, out of sight.
Wild stocks are in steep decline wherever there are salmon farms.
In British Columbia, domestic Atlantic salmon are imported, because they withstand high-density stocking. Their presence in the Pacific threatens wild stocks with exotic pathogens and parasites. Thousands of Atlantics now roam the Pacific from Washington State to Alaska, ascending rivers, ready to spawn and consuming wild eggs. In addition to importing exotic pathogens, salmon farms enhance local disease populations, exposing wild fish to heavier pathogen loads than normally experienced. The coho hatchery in the archipelago where I live was disease-free 10 years before fish farms, but now suffers loss of precious broodstock.