Science Magazine —
Two years ago, off the coast of Norway, the blue-hulled Ro Fjell pulled alongside Ocean Farm 1, a steel-netted pen the size of a city block. Attaching a heavy vacuum hose to the pen, the ship’s crew began to pump brawny adult salmon out of the water and into a tank below deck. Later, they offloaded the fish at a shore-based processing facility owned by SalMar, a major salmon aquaculture company.
The 2018 harvest marked the debut of the world’s largest offshore fish pen, 110 meters wide. SalMar’s landmark facility, which dwarfs the typical pens kept in calmer, coastal waters, can hold 1.5 million fish—with 22,000 sensors monitoring their environment and behavior—that are ultimately shipped all over the world. The fish from Ocean Farm 1 were 10% larger than average, thanks to stable, favorable temperatures. And the deep water and strong currents meant they were free of parasitic sea lice.
Just a half-century ago, the trade in Atlantic salmon was a largely regional affair that relied solely on fish caught in the wild. Now, salmon farming has become a global business that generates $18 billion in annual sales. Breeding has been key to the aquaculture boom. Ocean Farm 1’s silvery inhabitants grow roughly twice as fast as their wild ancestors and have been bred for disease resistance and other traits that make them well suited for farm life. Those improvements in salmon are just a start: Advances in genomics are poised to dramatically reshape aquaculture by helping improve a multitude of species and traits.