I've added wild salmon sampling to Modail Mara's Salmon and Sea Lice site. Using data collected by the Salmon Coast Field Station, I show the yearly prevalence of sea lice on wild out-migrating salmon. The data is from three areas in the Broughton Archipelago sampled every year since 2001, which is an impressive record.
The charts show prevalence as the percentage of fish that have a certain number of sea lice on them. The blue bar is likely the most interesting, showing the percentage of fish that had no sea lice on them. I notice that the results change substantially around 2005/2006, maybe there was a change in the data collection process around then?
I've included all species and all developmental stages of sea lice when calculating the prevalence. That includes species Lepeophtheirus salmonis
and Caligus clemensi
as well as cases where the species could not be determined. It also includes all developmental stages - copepodids, chalimus 1 and 2, pre-adult male and female, adult male and female (gravid and non-gravid). Counting all the species and stages is not typical, as older stages of Lepeophtheirus salmonis
are considered more harmful to the fish and so are usually of interest to research. So realise that the lice numbers here are likely inflated compared to other sources.
The DFO industry data and the Salmon Research Field Station wild data are the only publicly available raw data that I know of. MOWI Canada West
publishes annual sustainability reports that make use of a lot more wild salmon sampling data. However, they are PDFs so it's tedious and annoying to extract the data. I'll see if I can get it in a slightly friendlier format.
If you are aware of public salmon data from Canada or other parts of the world, then please get in touch: email@example.com