04-12-2010, 03:12 PM
[quote pookiebar]Jacks in the wild are unsuccessful at spawning. Due to their small size they typically run and die without spawning. In the past hatcheries would use their sperm, stupid idea, and now they don't. Hopefully the jacks will all be gone from the system in time, because a high number of jacks actually indicates a system that is under stress.[/quote]
Not to be a jerk, but where did you get your data?
I think you have been given some bad information. First, the gene that causes males to come back a year early (as a Jack) is the same gene that causes females to stay an extra year in the ocean. The Idaho Fish and Game has purposly spawned jacks and extra salt females to spread out the run ( [url "http://www.fws.gov/pacific/fisheries/hatcheryreview/Reports/snakeriver/DW--008Dworshak%20NFH%20Spring%20Chinook%20HGMP.pdf"]http://www.fws.gov/pacific/fisheries/hatcheryreview/Reports/snakeriver/DW--008Dworshak%20NFH%20Spring%20Chinook%20HGMP.pdf[/url] ). It is a genetic trait that has allowed salmon to fill in the gaps (so to speak) caused by low water/poor survival years and one time natural disasters, such as slides and ash saturation after large fires. This process continues at Dworshack and Rapid River hatcheries.
Additionally, jacks do spawn in the wild. Their viability has been observed to be between 6% and 10%, which parallels ( although a little lower) 4 year old and 5 year old ( 2 and 3 salt) fish.
Jack numbers have nothing to do with stress, but instead is a genetic factor. See the following website...( [url "http://www.nature.com/hdy/journal/v89/n4/abs/6800141a.html"]http://www.nature.com/hdy/journal/v89/n4/abs/6800141a.html[/url] ) Having jacks extirpated from a river system would (in essence) chlorinate the gene pool, and reduce wild salmon's chances of restoration in the long term.
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Not to be a jerk, but where did you get your data?
I think you have been given some bad information. First, the gene that causes males to come back a year early (as a Jack) is the same gene that causes females to stay an extra year in the ocean. The Idaho Fish and Game has purposly spawned jacks and extra salt females to spread out the run ( [url "http://www.fws.gov/pacific/fisheries/hatcheryreview/Reports/snakeriver/DW--008Dworshak%20NFH%20Spring%20Chinook%20HGMP.pdf"]http://www.fws.gov/pacific/fisheries/hatcheryreview/Reports/snakeriver/DW--008Dworshak%20NFH%20Spring%20Chinook%20HGMP.pdf[/url] ). It is a genetic trait that has allowed salmon to fill in the gaps (so to speak) caused by low water/poor survival years and one time natural disasters, such as slides and ash saturation after large fires. This process continues at Dworshack and Rapid River hatcheries.
Additionally, jacks do spawn in the wild. Their viability has been observed to be between 6% and 10%, which parallels ( although a little lower) 4 year old and 5 year old ( 2 and 3 salt) fish.
Jack numbers have nothing to do with stress, but instead is a genetic factor. See the following website...( [url "http://www.nature.com/hdy/journal/v89/n4/abs/6800141a.html"]http://www.nature.com/hdy/journal/v89/n4/abs/6800141a.html[/url] ) Having jacks extirpated from a river system would (in essence) chlorinate the gene pool, and reduce wild salmon's chances of restoration in the long term.
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