Grant: Strategic Projects Supplemental Competition

As the human population continues to increase, and with most fish stocks currently being commercially fished near or beyond their maximal sustainable yield, the world's protein requirement is increasingly being met by aquaculture. Canada is poised to make significant contributions to this global demand provided a responsible balance can be struck between aquaculture and the environment in terms of resource management. Of the Pacific salmon, pink salmon may be one of the best indicators of a ecosystem health and, in the Broughton Archipelago, the impact of aquaculture on survival of pink salmon populations is a prominent topic of great public concern. Central to the debate is whether sea lice, for which fish farms are allegedly a point source, are killing wild pink salmon in sufficient numbers to threaten populations. While excessive sea lice infection could be the basis for low pink salmon returns, sea lice are only one factor affecting pink salmon stocks, and large voids remain in our understanding of pink salmon biology as well as their interaction with sea lice. The long-term scientific objective of this proposal is to develop a physiologically sound model that describes the relationship between sea lice density and the associated sub-lethal physiological disturbances and informs the assessment of sea lice effects on wild pink salmon populations. We will perform scientifically sound laboratory and field studies to reveal basic knowledge on ionoregulatory physiology and performance of developing juvenile pink salmon, and the impacts of varying sea lice densities on these functions. The proposal brings the proponents' relevant skills and knowledge to bear on the hypothesis that sea lice in the first instance impairs ionoregulatory homeostasis and whole animal performance, triggering defense responses. Our management objective is to inform fisheries managers on the predicted consequences of sea lice infections on juvenile pink salmon. By collaborating with DFO and the BC Pacific Salmon Forum, and linking with the BC Provincial Government, there will be an immediate and direct input of our novel findings to the managers of the Broughton ecosystem and the BC aquaculture industry.