Responding to collapsing wild-fish stocks worldwide, the World Bank has hotly promoted "aquaculture" — essentially, large-scale, industrial fish farms.

Photo: Simon Bisson via Flickr

The Bank has directed serious resources at promoting fish farming. Such projects make up a significant chunk of its "portfolio of over US$1.2 billion in fisheries, aquaculture, coastal and aquatic environmental management and related projects serving coastal and fishing communities."

Grist thanks its sponsors. Become one.

Yet the idea of cramming thousands of genetically identical fish into a small space may prove as problematic as its land-based analogue: the confined-animal feedlot operation (CAFO). CAFOs must have once seemed a brilliant idea: They rationalized meat production, saving vast amounts of land through concentration.

We now know that those land savings are spectral: land once used to house grazing animals has been taken over by millions of acres of input-intensive feed crops (corn and soy). The environmental horrors of CAFOs are now well-documented — and yet the model lurches on, stronger than ever.

Fish farming, too, is starting to reveal environmental liabilities. A new peer-reviewed study by Canadian researchers shows that salmon farms are severely depleting wild-salmon stocks, causing survival rates to fall by as much as half each generation. According to the study, the problem is worse than scientists had previously assumed.

The effect of salmon farming on wild stocks has been well-known for a while. As the researchers put it (quoted in the Globe & Mail):

Grist thanks its sponsors. Become one.

Studies have clearly shown that escaped farm salmon breed with wild populations to the detriment of the wild stocks, and that diseases and parasites are passed from farm to wild salmon.

This study is the first to document how these processes affect populations. And the news is dire. As one scientist who studies salmon told the Globe & Mail, "Frankly, [the extent of devastation] is surprising to me. It’s a stronger result than I would have anticipated."

So to stock our supermarkets with flavorless, nutritionally suspect farmed salmon, we’re sacrificing entire populations of glorious wild salmon. Sounds like another one of industrial agriculture’s fool’s bargains.

Reader support helps sustain our work. Donate today to keep our climate news free. All donations DOUBLED!