Studying Genetic differences between wild and domesticated Salmon

 Scientists from the Alaska Fisheries Science Center, Alaska Department of Fish and Game, and Texas Christian University recently looked at the genetic differences between Pacific salmon raised in hatcheries and wild salmon in Alaska.  Salmon are raised in hatcheries in order to supplement wild populations.  The issue with hatcheries is that it can cause domestication selection, which causes the fish to adapt to the conditions of the hatchery.  These conditions do not line up with the ones out in the wild.  The concern is that hatchery salmon released out into the wild may interbreed with wild salmon and pass on unfit traits.  For example, hatchery salmon tend to lack predator avoidance behavior, which is critical out in the wild.  The study found that hatchery salmon are differing genetically from wild salmon populations.  The study lays important groundwork for genomic sequencing in salmon for future studies.  This will help to prevent substantial divergence between hatchery and wild salmon.

I never considered the potential for genetic differences to affect wild fish population through the introduction of hatchery fish.  This study reminds me of how with certain animals living in zoos and aquariums, they can't survive out in the wild because they've been raised to get food from humans.  With human care, animals raised in captivity would die out in the wild.  However that relates to learned behavior of the animal.  What's fascinating with this study is that it's the genetic code of the animals affecting their fitness to survive out in the wild.  I hope that further research can be done to prevent significant genetic differences between hatchery fish and salmon out in the wild.

Article Link: https://www.fisheries.noaa.gov/feature-story/cracking-code-scientists-use-dna-examine-differences-between-hatchery-and-wild-chinook

Article on Genomic Sequencing: https://www.cdc.gov/pulsenet/pathogens/wgs.html

Chinook Salmon: A Decline in Genetic Diversity

Over the past years, the genetic modification of salmon for commercial use has been steadily decreasing as less salmon is being caught along the Pacific Northwest. Apart from their general population decline, the past 7000 years has shown a 2/3 decrease in genetic diversity, compared to bones of the same Salmon found in Native American archaeological sites. Such a loss in diversity is detrimental to such a valuable and rich food source. Genetic diversity allows for the different characteristics in the salmon we eat, and helps to control GMO salmon from the natural Chinook Salmon. A possible cause for such a low diversity comes from the numerous man made structures that hinder the natural process for many Chinook Salmon. Dams cover off many potential spawning habitats from ocean Chinook Salmon, thus creating some inbreeding for the fish already located in the rivers and oceans.

Genetic Diversity helps to create more variations in offspring and allows for natural adaptations to occur. Without a growing population the Salmon can be susceptible to a loss in genetic diversity and thus a loss in adaptation and variation. Conservations have been made restore the flow of diversity back into the Salmon, but the damage may be far from repairable.

Link to Pacific Northwest Salmon
Pacific Northwest Salmon (Chinook Salmon)

Link to other Pacific Northwest Salmon
Chinook Salmon Populations