The data further showed that the differences in infection level for one species of louse in relation to fish farm exposure could not be
explained by differences in salinity or temperature.
"Given the high intensities of lice observed on some juveniles in this study-up to 28 lice/fish- there's an urgent need to understand
the extent of threat posed by sea lice to juvenile Fraser River sockeye" said Dr. Craig Orr, a co-author of the study.
The study also recorded the highest lice levels on juvenile sockeye near a farmed salmon processing plant in the Georgia Strait,
heightening concern for the full potential impact of the salmon farm industry on wild salmon in this region.
Sea lice from salmon farms are likely another stressor for sockeye already subjected to multiple human impacts. Importantly, however, risks to juvenile sockeye from open net-pen salmon farms can be much more easily mitigated than changes to ocean conditions from climate change and ocean acidification. Options already recommended include removal of farm salmon from the migration routes of juvenile sockeye, and transition of salmon farms to closed-containment facilities.