Novel tools and knowledge for a future with no lice infestations in Norwegian aquaculture

Funding agency: The Research Council of Norway, Collaborative projects to meet challenges in society and business Program.
Project period: 2021-2024
Project leader: Nicholas Robinson (NOFIMA)
Workpackage leader for semiochemical WP: Aleksei Krasnov (NOFIMA) – Howard Browman, Anne Berit Skiftesvik and David Fields are participants in this WP.
Project summary
The overall aim of this project is to identify compounds (semiochemicals) that are associated with Atlantic salmon susceptibility and resistance to the parasitic copepodids Lepeophtheirus salmonis and Caligus elongatus and to develop tools that can be applied to boost Atlantic salmon resistance and reduce lice infestation in Norway. We have previously established that there is substantial genetic variation in susceptibility to L. salmonis within farmed Norwegian Atlantic salmon populations and also detected some compounds released by the skin of Atlantic salmon that are associated with this variation. However the mechanisms triggering the release of these compounds, and their underlying genetic basis is still unknown. This project will identify host-specific semiochemicals (kairomones that attract and/or allomones that deter lice) within the Atlantic salmon population associated with the level of lice parasitisation, test whether measurement of semiochemical production could provide an accurate and more ethical phenotype (without challenge testing) for breeding to boost resistance, identify and test feed additives that could potentially block semiochemical attractant production or boost mucosal secretion of semiochemicals repelling lice and test for additional effects on the reproductive capacity of the lice and its epidemiology that might be derived from breeding for resistance. The research objectives and results of this project will integrate with those of a separate research project funded by FHF, and utilise results from our previous projects, to enhance genomic selection and prioritise candidate genes for manipulation via feed additives to produce salmon with full or high resistance. Outcomes will include improved fundamental knowledge of lice resistance mechanisms and development of tools that can be applied to boost genetic and non-genetic resistance to sea lice.