Back to All Media

Oct 21, 2016

Study backs triploid salmon

According to a recent study, triploid Atlantic salmon do not pose a significant threat to wild populations, and should be viewed as an effective measure to prevent escaped farmed fish from interbreeding with wild salmon. A large issue that continues to plague the salmon farming industry in the Atlantic Ocean is escapees. If escapees enter freshwater, and manage to interbreed with native fish, genetic introgression occurs which can have severe negative effects on genetic diversity and fitness of wild populations. Interbreeding has been documented in Norway, Ireland, and most recently, Newfoundland. To prevent this from happening, farmers have been looking at growing sterile triploid salmon. However, until now, ecological impacts on local populations were still considered to be a significant problem. Scientists at the Institute of Marine Research (IMR) in Norway have shown that triploids have been getting a bad rap for no reason. A recent study published in the journal Biological Invasions titled “Genetic screening of farmed Atlantic salmon escapees demonstrates that triploid fish display reduced migration to freshwater” by Glover et al. determined that triploid salmon are not motivated to migrate to spawning grounds. The researchers tested nearly 4,000 escapees in 17 Norwegian rivers, and only 7 (0.18%) were triploid – a 10-fold lower than the frequency of triploids in farms. Read the article.