Mathematical ecological modelling has always been an important component of the work done at Salmon Coast. Many of our alumni, partners, and board members are experienced modellers, and we believe that this mathematical work is critical to conducting high-quality conservation science.

Connectivity Model for Sea Lice Dynamics

Finalized in 2022, PhD candidate Peter Harrington of the University of Alberta investigated the spread of sea lice between salmon farms. In the Broughton Archipelago, sea lice can spread between salmon farms either by hitching a ride on migrating wild salmon or simply by floating through the ocean as nauplii. Therefore, if a single farm experiences an outbreak of lice and subsequently treats the farm to remove the infestation, some lice will have already reached other farms before the treatment has taken effect.

The project used mathematical models to examine how times for first passage of sea lice past farms are influenced by different environmental factors, such as extent of mixing in the ocean due to tides or size of salmon farm.

Harrington’s research determined that the farms with the largest potential for sea louse production are also the most connected to each other, which means they have an even greater potential to transmit lice to wild salmon.

This information contributes to an understanding of the role that salmon farms play in the sustainability of wild salmon populations

This potential impact is based on two main factors.

The first is the potential for sea louse production at the location of a farm, which was determined by using temperature and salinity measures to establish an average number of new sea lice produced over a set time at each farm location.

The second factor is the potential for dispersal from the salmon farm into the wild salmon migration route. This was calculated using a computational model to determine the density of sea lice produced in the path of migrating wild salmon from the originating farm.

This sort of research demonstrates the direct impact that work done at Salmon Coast can have. These findings have been communicated to local First Nations, and we hope they will inform their discussions with government and industry regarding the renewal of fish farm tenures in the region.

Find out more about our work by checking out our regular reports and related publications

Check out our sea lice reports for each year, which provide detailed information on the year’s monitoring findings.

View our complete list of publications for many more articles based on sea lice research conducted at Salmon Coast.

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