A new study on steelhead trout found that salmon hatcheries cause genetic changes. Oregon State University and Oregon Department of Fisheries and Wildlife conducted a research on steelhead trout to find out the differences at the DNA level. It was found that wild and hatchery fish have different DNA.
The changes in their bodies were found to take place very quickly. It is believed these changes are the result of the adaptation of the fish’s new environment. Scientists explained how only one generation of hatchery culture can show genetic changes. For the research, experts used the genes of a type of salmon—steelhead trout—born in hatcheries and compared them to wild steelheads from Oregon’s Hood River.
The study revealed over 700 changed genes in that single generation. Moreover, the changes are believed to be passed on to fish’s offspring. While some of the DNA changes were pointed out, others features still remain a mystery. As the study’s main author, Michael Blouin, stated
‘This pretty much settles the question of whether hatchery fish can be genetically different after just a single generation of domestication”.
The scientist claims a fish hatchery is an environment that enables natural selection pressures. Moreover, he claimed these results are a step forward to finding out which features come under strong selection in the hatchery. Steelhead trout is known to be solitary and defensive about their habitat when they are in the wild. However, in hatcheries they are overcrowded.
Blouin mentioned that in this environment, over one generation, the fish developed traits like improved immune function. He claims the steelhead trout bite each other when they are crowded together. This might lead to the selection for enhanced wound repair abilities.
What’s more, experts didn’t find any proof that hatchery fish are a risk to Oregon’s wild populations. However, when hatchery fish mate in the wild it’s possible they might affect the health of the wild salmon populations. Blouin believes this study may help determine how the fish differ and work to solve this problem.In addition, a better understanding of the DNA traits in hatcheries could change the way fish are raised.
In November, the FDA gave permission for the sale of genetically modified salmon for human consumption, saying the meat hadn’t any issues. Further information about salmon hatcheries that cause genetic changes can be accessed in the current issue of Nature Communications.
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