Wild fish monitoring expands to Quatsino Sound and Holberg Inlet

October 15, 2015 - Campbell River, B.C.

This winter, Marine Harvest Canada will begin the certification process for its first site in the Quatsino Sound operating area against the Aquaculture Stewardship Council standard. An important part of this process is to conduct sampling on wild salmonids in the area to determine baseline sea lice abundance. The study was undertaken by Mainstream Biological Consulting in the spring of 2015. This first year study will provide a baseline from which to compare data obtained in future years.

Mainstream Biological sampled ten locations within Quatsino Sound and Holberg Inlet in April and May, 2015. Fish species sampled included chum, coho, pink and chinook salmon, as well as threespine stickleback. Results show overall prevalence in the area (the number of fish with one or more louse) at 22.9%. Total abundance (lice per fish) was 0.45.

The study finds that high levels of lice were obtained from a site in Holberg Inlet. Fish at this location would not yet have passed by a salmon farm on their journey from river to ocean. This suggests that the Holberg Inlet area may have, in some years, natural conditions that are highly favourable to sea lice. 

Results obtained in this study align with results obtained from the same time period in the Port Hardy area, where prevalence of 23.6% and abundance of .38 was found. The Port Hardy study suggested that higher temperatures and salinity, combined with large returns of wild salmon the previous fall may have contributed to higher lice levels in the area.

Sampling of outmigrating salmon will continue annually in the Quatsino and Holberg areas. By obtaining multiple years of data, comparisons of lice levels to environmental conditions (such as salinity and temperature), local salmon farm data, and wild salmon returns will be possible. 

The full report for the Quatsino area is available here.

The report for Goletas Channel and Queen Charlotte Strait is available here