A genetic analysis of Piscine orthoreovirus shows how it was repeatedly transported from Norwegian salmon farms to aquaculture operations around the world—and on to wild Pacific salmon.
Farmed salmon, like any farmed animals that live in close quarters, are highly vulnerable to infectious diseases. On Atlantic salmon farms in the Pacific Ocean, one virus—Piscine orthoreovirus (PRV)—is so common that one can expect that by the end of a farm’s 18-month production cycle, practically every fish will be infected. Read more in Hakai.