Every year since 2011, the Norwegian Institute of Marine Research has published a risk assessment for ocean salmon farming in Norway.
The results, most recently published in July 2014, offer up some points that might surprise die-hard salmon farming critics.
The most concerning risks in Norway, according to the research, are:
- Wild Atlantic salmon face a moderate to high risk for “genetic introgression” (cross-breeding) from escaped farmed Atlantic salmon.
- About 27 of 109 farms investigated for sea lice infection indicate moderate to high risk of likelihood for passing wild salmon smolts, and 67 farms indicated moderate to high risk of mortality from sea lice for wild sea trout.
The interesting results are in what doesn’t appear to be a concern:
Despite “extensive release of virus in many areas,” screening of wild salmonids showed low to very low presence of the same viruses.
- Only 2% of all farms displayed unacceptable levels of “organic loading” (fish poop and feed) below the farms; therefore the “risk of eutrophication and organic load beyond the production area of the farm is considered low.“
- It’s interesting that, in Norway at least, the two points that salmon farm critics seize on the most — viruses and fish poop — are of least concern.
It’s debatable how meaningful it would be to extrapolate these findings to BC, but they raise some interesting points. Here in BC, where we have strong populations of wild salmon, which are unable to interbreed with farmed Atlantic salmon, the issue of “genetic introgression” is moot.
More than a decade of sea lice research has also shown that sea lice from salmon farms are unlikely to have any measurable impact on wild salmon, as experts at the Cohen Commission agreed.
Also, as BC experts said, the risk to wild salmon from farm diseases might be possible, but is also probably low.