The Laser Battle Against Blood-Sucking Parasites of the Deep

Back and forth he walks across the polished hardwood floors of a barge anchored in a fjord off the southwestern coast of Norway. The barge sits alongside one of the world's largest salmon farms. It's November and the sky is cloudless, the mountains are snow-capped, the water is a clear sapphire blue. The control room has the feel of a W Hotel lobby with its elegant lighting and spare Scandinavian design. On one wall are huge monitors streaming video from nine underwater cages nearby. Aarskog scans the footage--masses of salmon swimming in circles like glittering cyclones--and mutters what I take to be Norwegian profanities.