Do Salmon Return to the Steam Where They Were Born to Spawn?
Tracking natal origins of salmon using isotopes…[and other stuff] posted by randomstriker at 4:33 AM on June 8 [+] [!] This is a paper about comparing two stable isotopes in salmon earbones to mixtures in rocks near various streams, not a paper about injecting salmon with long-lived emitters so they can be detected years later from far away.
It’s not invariant. It’s not absolutely one hundred point zero zero percent. A few get lost. But most do. That’s how hatcheries maintain their stock, for example; the fry are released in a special stream at the hatchery, and when they become adults they return to the hatchery. I’ve seen big round tanks full of adult salmon at the salmon hatchery at the Warm Springs Indian Reservation. The few that do get lost serve the species because they help mix the genes around.
With Salmon I think that they grow up in the stream, thus the thing to do would be to tag them as they leave the stream after they have grown and the mortality rate has dropped. They have to have been born there and you can then easily see if they return to the same place. IANANS (I Am Not A Natural Scientist) But that makes sense to me.
