Riainbow or steelhead?

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

  1. Zen Piscator

    Zen Piscator Supporting wild steelhead, gravel to gravel.

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    Our local (Walla Walla area) steelhead display amazing size variation. This hen and buck were taken in the same pool within 1 hour of each other.
    [​IMG]

    Both hatchery fish, I would be inclinded to think the smaller fish is from a different hatchery than the larger male. The big male is 38.5 inches while the hen was 21 inches. He outweighed her by 17lbs. Here is another photo of him:
    [​IMG]
    We kept the female to try to indentify what exactly she was. Her eggs were underdevloped for march, furthermore she was chrome and her flesh was deep orange. I showed photos of the fish and eggs to a local biologist who concluded she still had at least a month, likely longer, before she would spawn. I think both these fish have been to the ocean. The buck for likely 3 years while the hen had probably not spent more than several months in the salt. She was also probably smaller heading out that he was, destined to be a much smaller fish. Curt, is there any reason for such size variations? I would assume the buck is B-run headed for the clearwater but it is possible that it just spent more time out in the salt than average. Thoughts?
     

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  2. Josh

    Josh dead in the water

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    That's a meaty fish there Zen. Good work.
     
  3. Smalma

    Smalma Active Member

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    Richard -
    I would say that there is very high probability that those O. mykiss you caught last week were indeed rainbows. For as long as I have fished the North Fork (more than 30 years) have caught the occassional resident rainbow (confirmed a number from scale readings - 18 inch fish would 6 or so years old and had spawned a couple times). With the more restrictive regulations in place during the summer season -CnR for all non-hatchery game fish - for nearly a decade the numbers of those rainbows seem to have increased.

    The first couple of sea-run trips each year I seem to catch severl of those rainbows (after that they are rare - not so easily fooled with the standard cutthroat presentations). They typcially are between 12 and 18 inches long but have encounterd a couple that would measure more than 20 inches (the size of smaller Deer Creek steelhead). In fact I believe that there are now enough resident rainbows that if one were to target them (and I have done so) catch a handful is very doable. One thing I have noticed is that when targeting cutts I catch fewer rainbows that I would otherwise - the two species most often can be found using different habitat niches. Did fish cutts last week and found that they are all ready being "pushed around" by the pinks. Found decent numbers of cutts (including several nice fish) but found tehm in scattered concentrations - they seem to collect in areas not frequent by holding or traveling pinks


    Zen -
    While we anglers typically characterize individual steelhead populations as being one of large fish or small fish the reality is that most populations while having a "typcial" size or age structure while more often or not have other exceptional individuals. While we all treasure and are pleased to see that occasssional "oversized" fish those fish at the other end of the spectrum (size wise) should also be in the population. That other end of the distribution are just as rare and should be cherished as well as part of the diversity of the over all population.

    One of my home waters (the Sauk) is noted for its large steelhead and over the years I have had the opportunity to visit with more than a few its exceptional fish; a handful over 40 inches. But I have caught that occassional fish that would need a sizeable sinker or two to weight even 5#s. The biologist and conservationists in me find those fish at each end of the spectrum equally exciting and cause for celebration of the population diversity.

    Tight lines
    Curt
     
  4. fishintom

    fishintom Member

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    Great thread Curt,

    This is one of the most interesting posts I've read since I joined this forum....

    -Tom
     
  5. David Dalan

    David Dalan 69°19'15.35" N 18°44'22.74" E

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    The flexibility of life history options is one of the things that has always fascinated me about trout/char. Rainbow/Steelhead, Brookies/Sea-run brookies, Browns/Sea trout, Cuts/SRC...the list goes on. I always wondered if there were any anadromous hostories for the rarer trout. I assume during the last ice age, anadromy was the only means of getting so wide spread, but was there ever a sea-run Gila/Apache (having access to the colorado river drainage) or are they a much later development descending from a more widely travelled ancestor?

    Fun stuff!
     
  6. Zen Piscator

    Zen Piscator Supporting wild steelhead, gravel to gravel.

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    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.
     
  7. Smalma

    Smalma Active Member

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    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
     
  8. David Dalan

    David Dalan 69°19'15.35" N 18°44'22.74" E

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    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 :)
     
  9. Zen Piscator

    Zen Piscator Supporting wild steelhead, gravel to gravel.

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    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.
     
  10. David Dalan

    David Dalan 69°19'15.35" N 18°44'22.74" E

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    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.
     
  11. Gary Thompson

    Gary Thompson dirty dog

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    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.
     
  12. yuhina

    yuhina Tropical member

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    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..."
     
  13. bhudda

    bhudda heffe'

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    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
     
  14. spanishfly

    spanishfly Steelberg

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    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.
     
  15. Rasheed

    Rasheed New Member

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    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?