Take 2: Down on the Farm

Two new studies add yet more weight to the case against industrial-scale salmon farming, especially in waters that support native salmon populations:

In the first, Jennifer Ford and Ransom Myers of Dalhousie University in Nova Scotia have documented systematic declines in wild salmon populations that come into contact with farmed salmon. Their peer-reviewed paper published online in PLoS Biology, compares the survival of wild fish that swim past salmon farms with that of wild salmon and trout that don't encounter salmon pens.

In data from Scotland, Ireland, Atlantic Canada and Pacific Canada, they've found "significant and negative" effects on the population of wild salmon and sea trout that swim past penned fish.

A second and unrelated study, published in the journal Molecular Ecology, finds that farmed salmon are different genetically from wild salmon, and that their genetic traits are infiltrating wild populations when farmed fish escape from the pens.

According to two of the co-authors, "These findings provide support to the claim that hybridization with farmed escapees may alter the gene pool of wild salmon, reduce its fitness and accelerate its decline."

The authors conclude: "This further supports the idea that measures to considerably reduce the number of escaped farmed salmon and their reproduction in the wild are urgently needed."

Food for thought next time you see Atlantic salmon on the menu. Seafood Watch offers abundant better choices.

(Big thanks to Science Daily online for reports on the studies.)