Jeanine Sumner puts an Atlantic salmon back in the net pen at Marine Harvest Canada’s Sonora Point farm after checking it for sea lice. Salmon farmers are defending the methods they use to manage sea lice.
The farm tech scoops feed pellets and flicks them over the water, getting the attention of thousands of Atlantic salmon beneath the surface.
After a few moments, tech Jeanine Sumner and Paul McManus, the assistant manager at Marine Harvest’s Sonora Point fish farm, draw the net closed, trapping a sample of salmon for a sea lice check. Over the next half-hour, they select 20 salmon at random with a dip net, drop them in a container of water laced with a mild anesthetic and examine them for sea lice. They’re looking for one particular kind of louse – the lepeophtheirus salmonis or “leps” – which can harm salmon by eating through their scales, making them more susceptible to infection. They find seven on all the salmon, and a couple more in the container when they’re finished.