Posted by: bushbear
Hatchery role in Snake River sockeye recovery - 11/26/14 10:12 PM
Interesting study on the recovery of Snake River sockeye and the quick adaptation of hatchery fish to wild production.....
http://www.sciencedaily.com/releases/2014/11/141125140834.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Ftop_news%2Ftop_environment+%28ScienceDaily%3A+Top+Environment+News%29
Posted by: eyeFISH
Re: Hatchery role in Snake River sockeye recovery - 11/27/14 03:06 PM
This program has a few KEY elements going for it.
1) A strong gene pool specifically adapted to Redfish Lake and the Sawtooth Valley Basin
2) Relative lack of competition for wild fish to utilize the available spawning/rearing habitat
While wild-born fish are producing adult recruits at 3-10 times the rate of hatchery fish, the hatchery can make up the relative deficit on volume... in absolute terms, 20 times the number of offspring that could be produced n the wild.
Hatchery-origin adults can continue to be placed into the spawning habitat and still gain a net positive until density dependent factors start to figure significantly into the equation. Once this happens, the hatchery fish can begin to be progressively culled from the escapement to maximize natural production from the gravel.
At that point, recovery has been achieved.