Effects on Marine Mammals
Salmon farms on the B.C. coast create a number of direct and indirect problems for marine mammals - in both the short and long-term.
The disappearance of wild salmon from the food chain puts the survival of other species at risk. Wild salmon are the "glue" that holds the coastal ecosystem of B.C. together. Juvenile pink and chum salmon are the most directly impacted by sea lice, and with less pink and chum salmon, there are less of the other species of salmon, such as chinook and coho, that feed on them. With this impact on the survival of all salmon species, the survival of all species that depend on wild salmon are at risk, including bears, fish-eating killer whales, bald eagles, sea lions, dolphins, porpoises, wolves and even the trees which thrive on the nutrients from decomposing salmon
Entanglement
in fish farm nets has led to impacts on seabirds, sealions, seals and smaller
cetaceans. In one incident alone, 51 California sea lions were found drowned in
the net of a salmon farm near Tofino.[1],[2]
To deter marine mammal
predators, salmon farms have used Acoustic
Harassment Devices (AHDs). Studies show that the AHDs may have had effects
contrary to those intended; actually attracting harbour seals but causing
displacement of harbour porpoise and killer whales.[3]
Furthermore, farm operators
have been permitted to cull "nuisance"
species; [4],[5]
the marine mammals attracted to the density stocked open net-cage salmon farms.
Between 1989 and 2000, federal records reflect that B.C. salmon
farmers reported killing more than 6,200 seals and sea lions between 1989 and
2000. Many more culls may have gone unreported.[6],[7],[8]
There is concern that these culls may include Steller sea lions, a species
which is to receive protection under Canada's Species at Risk Act as a population
of "Special Concern".
