Are fish farms in the Broughton Archipelago causing the dramatic increase in sea lice levels?
A4 There are two sources of sea lice in the Broughton Archipelago; from natural sources e.g. other fish, and from salmon farms. From last years studies we do know that the contribution from other fish was likely significant. It is also well recognized that in other jurisdictions where there are salmon farms there are more lice on wild salmon. However, no one has shown that the increased lice adversely impacted the adult numbers returning as spawners.
This is unlikely. Sea lice were not originally a salmon-farming phenomenon. Sea lice existed on wild salmon for tens of thousands of years before the first salmon farm was established in Canada and wild salmon have adapted to them. There are two possible sources of sea lice in the Broughton Archipelago: natural sources such as other fish, or salmon farms. Last year’s studies indicate that the contribution from other fish (sticklebacks) was significant. However, there is no evidence to suggest that the increased sea lice levels negatively affected the growth and condition of infected adult pink salmon. Sea lice levels can also be carefully controlled on the salmon farm thereby reducing the risk of infecting fish living outside the farm to a negligible amount.
This is unlikely. Sea lice were not originally a salmon-farming phenomenon. Sea lice existed on wild salmon for tens of thousands of years before the first salmon farm was established in Canada and wild salmon have adapted to them. There are two possible sources of sea lice in the Broughton Archipelago: natural sources such as other fish, or salmon farms. Last years studies indicate that the contribution from other fish (sticklebacks) was significant. However, there is no evidence to suggest that the increased sea lice levels negatively affected the growth and condition of infected adult pink salmon. Sea lice levels can also be carefully controlled on the salmon farm thereby reducing the risk of infecting fish living outside the farm to a negligible amount.
