Some Sea Lice With That Farmed Salmon?

| Tue Sep. 27, 2011 6:03 AM EDT
Sea lice devour a a farmed salmon in New Brunswick, Canada.

I've written a lot about "superbugs" from factory-farmed meat, as well as "superweeds" and "superinsencts" from genetically modified crops. Turns out, industrial agriculture is wreaking similar havoc in the sea. What do I mean? Consider the salmon, that noble family of fish, which has evolved over the millennia alongside an ignoble parasite: the sea louse.

Often less than a centimeter long, the sea louse operates like the land louse that bedevil humans: by attaching itself to the skin of the host and then chomping down and sipping its blood. Happily, wild salmon and sea lice populations achieved a rough balance over their time on the planet—wild salmon developed resistance to the point that sea lice can do their thing without causing significant harm.

That was the state of things, anyway, until the emergence of industrial-scale salmon farming in Norway in the 1970s. In industrial salmon production, the fish are stuffed together by the hundreds of thousands in pens open to the coastal sea. These conditions provide a veritable banquet for sea lice—rather than having to scour the sea for their hosts, the parasites find their targets wriggling around en masse in one place. Left to their own devices, the industry discovered, the age-old parasite-host balance is upset, and farm salmon populations succumb to sea lice.

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