Workers position their boats at a Cooke Aquaculture salmon farm near Blacks Harbour, New Brunswick, Canada. A surge of parasitic sea lice is disrupting salmon farms around the world, infesting salmon farms in the U.S., Canada, Scotland, Norway and Chile.

A sea louse with an extruding attached. The tiny lice attach themselves to salmon and feed on them, killing or rendering them unsuitable for dinner tables.

Atlantic salmon brood stock circle a tank at Oak Bay Fish Hatchery in Oak Haven, New Brunswick. Scientists are working to defeat sea lice using numerous methods including the breeding for genetic resistance.

Aan Atlantic salmon leaps in a Cooke Aquaculture farm pen near Eastport, Maine.

Workers gather Atlantic salmon before putting them into a tank aboard a ship for a treatment with hydrogen peroxide at a Cooke Aquaculture salmon farm near Blacks Harbour, New Brunswick., Canada.