ABOVE: Researchers dissect wild Pacific salmon tissues for molecular analysis and viral genomic sequencing.
AMY ROMER
Pacific salmon (Oncorhynchus spp.) are important to the fishing industry, Indigenous peoples, and endangered local populations of killer whales (Orcinus orca), but several salmon species have declined to the point of near extinction. To meet the demand for fish consumption, farmed salmon have become common, but aquaculture is a known spreader of diseases that infect wild populations. In a study published May 26 in Science Advances, researchers demonstrate that piscine orthoreovirus (PRV)—different strains of which cause anemia, jaundice, cardiomyopathy, and death in fish—was likely transmitted to wild Pacific salmon from farmed Atlantic salmon (Salmo salar) in the late 1980s.
“The paper shows convincingly that there’s repeated exchange or transmission between wild and domesticated species,” says Martin Krkosek, an ecologist at the University of Toronto who was not involved in the work. “We’ve suffered through the ...