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Author Topic: Fishing for Native Steelhead  (Read 46772 times)

Offline snowpack

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Re: Fishing for Native Steelhead
« Reply #210 on: February 28, 2014, 12:57:31 PM »
So if steelhead are just searun rainbows, I am pretty sure steelhead would never go extinct unless we killed all the rainbows in the world. We may have some low numbers in WA Rivers but as long as we have rainbows we will have steelhead.
Kind of.  On the whole, extinction is unlikely; because as you pointed out they are rainbow trout.  The issue for the fish groups is distinct population segments and basin/river specific genetics.  The fish have a certain percent that stray into other rivers and change up the genetics from time to time naturally--some of it makes a better suited fish and they carry on, some are less suited and die off.  The stray rate/genetic change is kind of slow going, so it could take a while for fish at one end of a coast to recolonize and then have strong runs all the way to the other end of that coast.  The fastest way to get a fish population back for a specific area would likely be to use the fish that have already gone through a few thousand years of living in that specific river.  One of the issues going around now is whether or not to use wild fish for hatchery donors.  Although I think most any steelhead would with enough time eventually get to that same point.  Example being that an out of basin steelhead can be used at a hatchery and can successfully make it back up river--so it already shows it has most of the characteristics to survive.  Some places the difference might be run timing or number of years in salt water that make or break the long term survival.

Online Bullkllr

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Re: Fishing for Native Steelhead
« Reply #211 on: February 28, 2014, 04:09:13 PM »
So if steelhead are just searun rainbows, I am pretty sure steelhead would never go extinct unless we killed all the rainbows in the world. We may have some low numbers in WA Rivers but as long as we have rainbows we will have steelhead.
Kind of.  On the whole, extinction is unlikely; because as you pointed out they are rainbow trout.  The issue for the fish groups is distinct population segments and basin/river specific genetics.  The fish have a certain percent that stray into other rivers and change up the genetics from time to time naturally--some of it makes a better suited fish and they carry on, some are less suited and die off.  The stray rate/genetic change is kind of slow going, so it could take a while for fish at one end of a coast to recolonize and then have strong runs all the way to the other end of that coast.  The fastest way to get a fish population back for a specific area would likely be to use the fish that have already gone through a few thousand years of living in that specific river.  One of the issues going around now is whether or not to use wild fish for hatchery donors.  Although I think most any steelhead would with enough time eventually get to that same point.  Example being that an out of basin steelhead can be used at a hatchery and can successfully make it back up river--so it already shows it has most of the characteristics to survive.  Some places the difference might be run timing or number of years in salt water that make or break the long term survival.
Nice post.
So in other words, it probably wouldn't work very well to try to rebuild a steelhead run by planting a bunch of resident rainbow. If it did work, it would take so many generations that none of us would likely see the results.

I found this read on the topic somewhat interesting: http://mag.audubon.org/articles/blog/fishy-date-steelhead-and-rainbow-trout-mingle-northwest Exerpt: "But Christie’s team found “there’s very little genes being contribute by these hatchery fish"

To "Example being that an out of basin steelhead can be used at a hatchery and can successfully make it back up river--so it already shows it has most of the characteristics to survive.  Some places the difference might be run timing or number of years in salt water that make or break the long term survival." I would add spawning success/adult recruitment; as most hatchery fish are notoriously poor at producing more returning adults (in the short-term, at least) even if they do spawn in the wild. I know you're thinking long term over generations and I'm sure there would be some adaptation- but who knows how many generations that may take? One reason the WDFW still uses Chamber Creek winter stock (besides early run-timing) is that they're such bad spawners the thought is they may not impact wild fish as much as more "productive" hatchery stock might.
« Last Edit: February 28, 2014, 04:36:03 PM by Bullkllr »
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Offline snowpack

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Re: Fishing for Native Steelhead
« Reply #212 on: February 28, 2014, 07:06:50 PM »
yeah, bullkllr I'd imagine if you started with an empty river and tried to just let it happen naturally it would take a while.  You'd have to have neighboring rivers with enough of a population that you could get at least one buck and one hen to stray into the empty river and successfully spawn.  Then the smolt need to survive and return.  Additionally, you would want more strays to occasionally spawn from time to time so that inbreeding doesn't leave them all susceptible to something like a disease that would wipe them all out.  The time from egg to return to spawn varies, but I think Chambers fish are like 4-5 years (2 in rearing ponds then some go to sea for 2-3 years, some hang out in the river for a year then go to sea for a couple years).  wild fish seem to add a year or two at sea.  So, to get returns built up just from strays, probably be a few fish generations.  If there were resident rainbows that might help speed things up a little--you would only need one stray hen.  (I think the steelhead hen with the male resident bow is usually how the mixing works best.) 

 


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