And it affected the development of sea salmon, which started to grow faster and migrate earlier. This was concluded by a group of Norwegian scientists, who measured the growth rate of 6,926 salmon caught in the country’s rivers (this is done by analyzing the scales of the animal) over seven years (1). The fish that had received genes from the captive salmon were the ones that exhibited the changes. It is not the first time that farmed salmon have escaped sea farms and created problems: in July 2021, a study (2) revealed that they spread PRV-1, a virus that attacks the kidneys and liver of fish, in Norway, Iceland, Denmark, USA, Chile and Canada.

Source: Captive salmon transferred genes to wild fish – Magic Mistura を