Temperature-dependent effects of sea lice on Atlantic salmon

Recipient: Dalhousie University (Hutchings)
Approved Amount: 40 350 $ pour 2019-2020

Open net-pen salmon farms are artificial reservoirs for parasites called sea lice that transfer between wild and farmed fish. In Norway, Ireland, and Pacific Canada, sea lice from salmon farms have been implicated in declines of wild populations due to high infestation levels of wild juvenile salmon. Sea lice affect the growth, survival, physiology, and behaviour of wild salmon, and it’s possible that these effects will worsen as our coastal waters continue to warm from climate change.  To investigate the temperature-dependent effects of sea lice on Atlantic salmon, a laboratory experiment was conducted in which juvenile Atlantic salmon were infected with sea lice across a range of temperatures. Survival was tracked and body growth and organ development of the fish were measured throughout the experiment. Blood, skin, and kidney samples were also collected to assess the stress and immune responses of the hosts. Using these results, this project will evaluate how temperature and sea-louse infestation affect stress and immune responses, growth, mortality, and organ development of Atlantic salmon. The results of this project will be shared with scientists, DFO managers, and the public.

Contact: Dr. Jeff Hutchings, 902-494-2687,