Genetically Modified Salmon Can Breed with Wild Fish and Thrive

Fast-growing, genetically modified salmon can interbreed with wild brown trout and produce offspring that grow rapidly and out-compete other wild salmon in streams, according to a new study. Researchers from Memorial University in Newfoundland, Canada, found that so-called “Frankenfish” — which are close to being approved for sale in the United States — can easily interbreed with brown trout in the wild, creating offspring that aggressively compete for food with salmon. In settings that simulated real streams, the offspring of the genetically modified (GM) salmon and brown trout were so aggressive that they suppressed the growth of GM salmon by 82 percent and wild salmon by 54 percent. “These findings suggest that complex competitive interactions associated with transgenesis and hybridization could have substantial ecological consequences for wild Atlantic salmon should they ever come into contact [with GM salmon] in nature,” the researchers wrote in the Proceedings of the Royal Society B. The creator of the GM salmon, Aqua Bounty, said the risks were minimal since all the GM salmon will be female, sterile, and produced in tanks on land.