Riainbow or steelhead?

Discussion in 'Steelhead' started by Smalma, Sep 3, 2007.

  1. Curt, I agree that its wonderful to see the size differences in steelhead. However, can you enlighten me as to why it would behoove a fish to stay stay smaller than it otherwise could. I know larger fish carry more eggs. What are some of the advantages smaller steelhead have as far as suvival/reproduction is concerned?

    I resized those photos for easier viewing btw.
     
  2. Zen -
    Typcially you see variability in any of the traits seen in a population (size, run timing, spawn timing etc) to cover a variety of survival situations. Some potential areas where a smaller fish may have a survival advantage include:

    Better access to smaller tributaries and over some barriers. A smallish fish often is better equiped to wiggle its way through series of cascades, boulder drops.

    Spawning gravel size can also be a factor though it often works in the other direction with very large substrate needing a large female to turn the gravel.

    Retruning earlier may allow a youger fish to escape some high sea mortaltiy. This often is a fact for the males where size isn't an issue for its feccundity (aren't most of us glad size doesn't matter!).

    A fish that smolts at an advance age may return earlier. A 6 o 7 year smolt that all ready reached maturity and spawned one or more times would likely return earlier than a fish that needs several years to reach maturity.

    Another potential advantage at returning as a younger/smaller fish would be a shorter generation time. Fish programed to return as 4 years old rather at 5 years would produce 5 generations over 20 years compared to 4 generations for the later maturing fish.

    Bottom line there are a number of factors that operate under the natural selection process the push and pulls a populations and its traits in a variety of directions. The result is a diverse population that is equiped to survive in a variety of conditions. A life strategy that tends to make little sense during normal conditions may preform spectacularly well in some rare condition that occurs only one every decade or two. That success seems to be enough to insure that at least some fish continue to express that strategy even during the "normal" times.

    An example of this may be the expression of extremely late spawning that we see on my home waters where some winter steelhead are still spawning in July. Given the resulting late timing of fry emergence and short first year growing season that doesn't seem to make much sense. But if is but in the context of the run-off seen in the region one can see where such a strategy may occassional be a big advantage. On years with very large snow packs the basin experience what are essentially summer floods caused by large and rapid snow melt. During those rare years that this occurs those "normal time spawners whose eggs are still in the gravel during those events would be at risk while those very late fish's eggs would not yet be in the gravel duirng those events.

    In short our steelhead are complex critters that resist being put in neat boxes that facilitate our understanding of them. Frankly I'm glad that is the case and for me at least part of the enjoyment of the steelhead game is speculating as to why they do what they do.

    Tight lines
    Curt
     
  3. OK cool steelhead behavior # 234.

    Columbia drainge summer runs will often reside in fresh water over a year after returning as an adult. For example the adult returns in July of one year, remains in the river trough winter, spring, the next fall and then moves to the headwaters to spawn in April/May of year 2. I know this behavior occurs as a matter of fact.

    What is interesting (Curt I suspect you have some good insight...by the way I'm new...nice to meet ya) is this idea of steelhead not feeding (or feeding) in fresh water. I have long held that steelhead feed in fresh water more than people think. I often find crayfish in the stomachs of steelhead in the pit of winter (Jan, Feb). While salmon certainly are moving on to dying once they reacclimate to fresh water, steelhead are (after all) just big ole rainbows. Perfectly suited to feeding and living in rivers.

    This behavior seems to give the fish few obvious advantages. Maybe they got in late and are better off waiting? What I want to know, is what do YOU think :)
     
  4. David,
    I have found alot of food in steelheads stomachs over the years but NONE of it has been digested. Have you seen evidence that they do indeed digest food before they spawn? Steelhead will feed heavily in the fresh on my local eastern washington water but I don't believe they get any nutritional benifit from it. I know that kelts will often hang in the walla walla river for up to 6 months after spawning before heading out to the ocean but I cannot recall ever hearing of fish that spend over 1 year in the fresh before dropping their eggs/milt. I would love to here more of what you had to say on this topic. IE what river system and how you found out this data. Please pm me if u dont wanna share everything on the fourm. Anyways thanks for the imput, interesting thought.

    Curt,
    Amazing response, the generation thing is really cool. Thanks for being smart, I'm learning alot.
     
  5. Andy,

    I certainly cannot confirm digestion in the remains I have exmained. The crayfish, caddis, etc were dismemebered and appeared to be crushed. This could just be the side effect of being chomped, swallowed and compressed in the gut. I gues I am more inferring that they could be getting nutrients from food since some appear to spend a long time as adults in fresh water (the over a year fish).

    I do not know if the research was published or not but the fish that were tracked as being in the river "over a season" actually took up residence in and around John Day damn and the Dalles. Some fish literally seemed to be living in the fish ladder. I believe it was a radio tag study of migrating adults trapped in the lower columbia.

    I was told this tidbit about 10-15 years ago so, espeically since I cannot drum up a publication, it should probably be taken with a grain of salt :)

    I don't think it affects how anyone could target these fish, or open up new fishing opportunities so it's more of a curiosity than anything else.
     
  6. This is very interesting.
    I grew up fishing the Rogue river system and would catch steel head with worms at many different times of the year when I was targeting trout. In the same run as the feeding trout.
    Some were fresh from the sea others were spent and returning to the sea. I never caught a ripe hen with worms or a pre spawn buck.
    All the pre spawn steel head were caught on roe, spinners or flies. Not in the feeding lanes.
    When using roe, I was targeting salmon.
    Very good info, really puts some things together.
     
  7. Curt,

    Thanks again for the detailed information.
    Referring to size differences in males and reproductive strategies, I would like to mention a very nice scientific paper ( Coho salmon) just came out in 2006 in a top journal - The American Naturalist. Attached the free link. http://www.journals.uchicago.edu/AN/journal/issues/v167n5/40931/40931.web.pdf
    The introduction has a very nice review without too much academic jargon... maybe some people here will be interested...
    Sincerely,
    Mark

    "...In salmonids generally and in coho salmon (Oncorhynchus kisutch) specifically, male age at maturity is linked to reproductive tactic. Males that mature early typically sneak matings; conversely, older males usually fight to gain access to females (Gross 1985; Sandercock 1991). There are also distinct phenotypic differences: early-maturing males are small and cryptically colored and have poorly developed kypes (hooked jaws), while older males are much larger and more brightly colored and have well-developed kypes (Sandercock 1991). Furthermore, individual coho that grow best in freshwater are most likely to mature early and use the sneaking tactic (Garrison 1971; Hager and Noble 1976). One can envision switch points that are related to growth performance in freshwater; on either side of such switch points, fitness might be maximized by different life histories (e.g., maturing early and sneaking matings vs. maturing late and fighting; Gross 1996). For coho, growth performance in freshwater can be described either by length at the smolt transformation (the transformation that occurs to prepare salmonids for the migration from freshwater to saltwater; e.g., Gross 1996) or by a measure of intrinsic growth potential (i.e., the rate at which parr grow toward the maximum smolt length; see Snover et al. 2005). Interestingly, exceptional growth performance in freshwater may decrease growth potential at sea because the behaviors that confer feeding advantages to individuals in freshwater may not be effective in saltwater (Jonsson and Jonsson 1993; Snover et al. 2005). Since the behavior-environment interaction is abruptly altered when salmonids migrate from freshwater to saltwater, reproductive tactics and their links to switch points should also be considered in the context of growth potential at sea...
     For coho salmon and probably other salmonids as well, age at maturity will probably vary in response to genotype-by-environment interactions that occur in both freshwater and saltwater. Variation in age at maturity occurs both between and within coho populations (Sandercock 1991). Variability between populations is driven by environmental differences that occur over the geographic range of the species and genetic differences that are perpetuated by the homing instinct (Silverstein and Hershberger 1995; Quinn et al. 2001b). Variability within populations is driven by environmental effects on the relative performance, in terms of growth, survival, and fecundity, of different phenotypes (Watters et al. 2003). To our knowledge, long-term longitudinal studies that track the genetic and environmental histories of individual coho and relate these histories to age at maturity and reproductive success are not available..."
     
  8. these are some pics of bows from the sauk ,methow, and a smolt from the nooksack. the one on my arm is from the sauk in july. the methow fish was caught in oct during the open season 2 yrs ago. and the smolt is pete's(greyghost) in april i believe. chrome bright...
    rezzie's i believe from the white tips? im no expert, but they tasted like steelhead:)
    seriously kidding!!
    bhudda
     
  9. Great post Kurt.

    I can vouch for the Westslope’s on the main Snoqualmie. A couple weeks back while targeting SRC’s. A buddy and I came across a run here we witnessed a fish feeding aggressively along a seam. We watched him feed for a couple minutes before I suggested my buddy tie on a dry and target him. First cast and wham! Nice trout about 13” but to my surprise a Westslope cutt. I won’t give specifics but believe it may have come from the Tolt run mentioned earlier.
     
  10. I read somewhere that an anadromous bull trout will venture into multiple streams in search of food. Is this the same for the O. mykiss?
     
  11. When I took Ethology at the UW back in 1974, one of the things the Sociobiologist were interested in was Game Theory. These papers considered life as a game with the rules being mortality and fecundity tables and the winners being reproductively successful. Game theory showed that the sucessful life histories were evolutionarily stable. But what really caught my attention was how in some cases, if the life history functions were laid out in a certain way, you could find that more than one life history choice could be evoluntionarily stable. It was like being slapped awake during this class. I immediately saw how this applied to our anandromous salmonids. You could fiddle with the functions until you got some indiviuals breeding early and some later in life and approximate the percentages seen in our jacking percentages. But the observations of a lowly fisheries student weren't considered very important to those in the zoology department.

    I've been having trouble finding references lately to any of those Game Theory papers. I think they are largely unknown to fisheries scientists, but they should be. Can you be of any help, Curt?
     
  12. Great threat Curt.... but with all of your fish knowledge I figured you would be able to spell Rainbow....:rofl:

    This makes me think how useful it would be to have some basic life history/id/fishing ethics on the main wff page. I know when I first started I was looking for a good place to find this information on the internet. While the info was there it was difficult to find. I would think that it would go well with the tide charts and river flows that are there now. I think this would be a great resource for those that don't want to hurt the resource, but just don't know better.

    If I were to write some content, would there be anyone interested in doing some edit/review work for me?

    Thanks,
    Ned
     
  13. When I was a kid I noticed that there was quite a variance in size of the Walla Walla Steelhead. That buck is quite large for the Walla Walla if I remember correctly. The little one is pretty small for even a small steelhead.

    Keith
     
  14. Paul -
    Game theory would be a great way to look how behavior stategies would dovetail together to produce the best over strategy for long term survival. Have not seen those theories applied directly though I don't see way it would not provide some interesting insights (some of us had begun thing is similar direction).

    Typically folks tend to focus in the survival/strategies at the individual fish level when in reality a more global view by looking at the population as a whole would be productivity in understanding what is needed for long term species survival. A strategy that makes little sense for an individual may be key at the species level.

    In addition looking at even a larger scale level would be very important. Inter-species interactions and partition of the habitats between species (ecoystem interactions if youy will) recieve far too little attention.

    Ned -
    Given my notorious poor spelling ( a lfie long problem) and my clumsy fingers it is amazing that my posts are not even more filled with typos/miss spellings. I try to keep those to a minimum (clearly wiht mixed success) but hope they are not too distracting from the info I attempt to pass along.

    Tight lines
    Curt
     
  15. FWIW Keith I know of fish that size in the lower Snake tibs and WW basin on a rare occasion. I mean this as an aside, as obviously Andy finds them often enough :)

    I have no way of proving it, but I suspect the vast majority of large clipped fish (i.e. over 15 lbs) are likely B-Run strays. I can't back that up, but given the fairly consistent size difference between A-Run Snake/Clearwater fish and B-Run Clearwater fish I think it is a reasonable conclusion. Also, steelhead stray plenty (as do most anadromous fish), for example the Descutes (many/most clipped fish caught are A-run Snake fish) and John Day (I think they still plant 0 hatchery fish...but plenty are caught there).

    Now if I could just bump into a pig like that this year...
     
  16. Did you know that back in the 50's that the Walla Walla had summer run steelhead. We use to catch them. Pretty and Bright. But then came irrigation and they dried up the Walla Walla in the summer from Milton-Freewater on down. End of the Summer Runs. Sad but most folks don't even know that the Walla Walla at one time had a run of summer runs. We were less conscience of the enviroment when I was growing up in the 50's. Irrigation came first.

    Keith
     
  17. Keith -
    Believe you'll find that the Walla Walla steelhead are still consider to be summer steelhead (entering the Columbia during the summer). It is just now that they are forced to remain in the Columbia waiting for favorable flows to enter their home waters.

    Tight lines
    Curt
     
  18. Sad isn't it that some really good summer run fishing was destroyed. I we use to go up the South Fork and catch Summer Runs in July and August. I'll have to ask Andy because I've haven't fished the Walla Walla in years, but when do they come in now I'm wondering.

    We also had winter runs that came into the river in December through March. But, these were either very late winter runs or summer runs that we caught in the the summer. But that was back in the fifties. (I was a gear fisherman back then - confession is good for the soul :) )

    Keith
     
  19. To the best of my knowledge the Walla Walla has always been "summer run" only. The fish that eventually spawn in the WW arrive in feshwater (the Columbia) starting in May. While it is academic for the most part I don't think Winter fish "offically" exist upstream of the Klickitat. I think fish entering the rivers after Nov 1 are considered winter run fish.

    Again, it's kind of academic and I am not calling you a liar :)

    It makes a lot of sense that with higher flows in the 50's, many fish would arrive early (June-Aug) and then a bigger push would show up with the winter high water (Nov-Dec). Now the early push is much smaller, but fish can still be found in the summer if you know where to look.
     
  20. The farm I was raised on was out by Umapine. We had an irrigation canal flow right through our place. In the early fifties when they turned the water off on the canal it would be full of trout and a few steelhead. We'd catch them by hand and cook them. Then they put in a screen to keep the trout and steelhead out.

    David maybe we can do some fishing sometime when I'm down Walla Walla way visiting relatives.
    Have you ever fished with Andy?

    Keith
     

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