Aquaculture for all
The Fish Site presents: The Vienna Sessions - Conversations about aquaculture. 9 video interviews with aquaculture thought leaders. Watch here.

Knowledge Gaps And Myths About Salmon

Salmonids Education & academia +1 more

NORWAY - A lack of knowledge, and a lack of communication, with regard to the effects of farmed salmon on wild fish stocks, have been highlighted in three new research reports. Whilst the public believe that salmon lice from farmed salmon, affect wild fish stocks, there is no actual scientific basis for this.

Senior scientist, Solveig van Nes, has led a critical review of the factual basis of interactions between farmed and wild salmon, looking specifically at salmon lice.

“Although salmon lice, like many other factors, can be fatal for individual salmon smolts, there is no documented scientific evidence that salmon lice alone can reduce entire stocks of wild salmon,” she says.

“Since it’s communicated as a fact that such a reduction occurs, efforts should be placed into finding out if this is actually the case, and to include other possible explanatory models.”

In an equivalent report about the genetic influences from escaped farmed salmon on wild salmon populations, scientist Céleste Jacq says: “To date no published studies have attempted to identify whether the natural selection of Norwegian wild salmon is changed as a result of interactions with farmed salmon."

"We require knowledge about different local salmon populations, their size, how large an area they cover, and how important local adaptation is before we can reach a conclusion about whether escaped farmed salmon influences precisely these factors.”

Scientist, Lill-Heidi Johansen, was the project manager of an interdisciplinary team of scientists from Nofima, the Norwegian Veterinary Institute and the Institute of Marine Research whose report shed light on what we know about pathogen transfer between farmed and wild fish.

Their main conclusion is that there is little, or no, documented evidence of pathogen transmission between farmed and wild fish, even though in some cases it is established as probable that such transmission occurs. There is also a general lack of knowledge concerning naturally occurring pathogens in wild fish populations.

This research was commissioned by the Fishery and Aquaculture Industry Research Fund (FHF). The Norwegian Institute for Nature Research (NINA) also tendered and conducted evaluations concerning salmon lice and genetic interactions. Links to these reports are published on the FHF website.

Link to the reports:

Summary of the report “A review of the factual basis of interactions between farmed and wild salmon as it applies to salmon lice” published in norwegian in April 2011. An english version of the report as a whole will be published in August/September 2011.

Evaluering av faktagrunnlaget om påvirkning mellom oppdretts- og villaks: Lakselus

A review of genetic influences from escaped farmed Atlantic salmon on wild Atlantic salmon populations

Smitte mellom oppdrettsfisk og villfisk – hva vet vi?