This should settle it... Steelhead = Rainbows

Discussion in 'Steelhead' started by windtickler, Oct 20, 2006.

  1. I must've gotten this link from the board here:
    http://www.nytimes.com/2006/10/17/s...gin&adxnnlx=1161121848-0wSIcQctEu20L0udSBIM/Q

    Of course I haven't read the Russian studies, so this really is going on faith:

    In Kamchatka, wild trout (or real trout) are abundant, fierce and incredibly adaptable, their genes undiluted by hatcheries.

    After years of studying these fish, Russian biologists have established a surprising fact. A river’s stock of resident rainbow trout and its stock of sea-run steelheads are not just different forms of the same species. They are members of the same population.

    In 2004, Maltsev and other scientists observed them spawning together, small-river trout on redds with heavy, sea-run fish. DNA analysis confirms rainbow trout can form one complex population, from mountain headwaters to the high seas.
     
  2. This should setttle it...Steelhed = Rainbows

    same thing has been documented around the pacific northwest
     
  3. This should setttle it...Steelhed = Rainbows

    Yet it is an argument I seen endlessly recycled here and other places. For instance whethere there are steelhead in the Cedar. Sometimes it's just nice to have a reference.
     
  4. This should settle it...Steelhead = Rainbows

    Recently, I was told that Steelhead are classified as salmon. Was the "expert" at Salmon Day's incorrect?
     
  5. This should settle it...Steelhead = Rainbows

    Definately a mistake/misunderstanding there somewhere.
     
  6. If this is true, Im not arguing for or against, then what prompts certain fish to go to the ocean and others to stay in their respective river systems?
     
  7. This should settle it...Steelhead = Rainbows

    Steelhead and Pacific salmon are all classified in the same genus. So, in a sense they are 'salmon,' or at least 'Pacific salmon,' since Atlantic salmon are more distantly related and classified in a different genus. That being said, if you are going to call steelhead 'salmon,' then you would need to call rainbow trout, cutthroat trout, golden trout, etc. 'salmon,' too. Unless 'salmon' was not being used as a taxonomic term, but rather as some sort of general term for a trout relative that has an anadromous life history, in which case steelhead would be 'salmon' and rainbows (even if they were from the same clutch of eggs) would NOT be 'salmon.'

    Clear?
    Dick
     
  8. This should settle it...Steelhead = Rainbows

    I believe they are salmonoids, whereas brookies, mackinaws, and dollies are char.
     
  9. you mean, why did the rainbow cross the saline/freshwater barrier?
     
  10. Just think of the oceans and seas as really BIG lakes and it all makes sense. Where do the resident fish usually spawn? In streams that are tribs to their home lake or stream. Same goes for the salty ones.
     
  11. iagree
    Simple statement that sums a steelhead up.

    Chris
     
  12. "Originally Posted by bigskeels73
    If this is true, Im not arguing for or against, then what prompts certain fish to go to the ocean and others to stay in their respective river systems?"

    I asked this question of a guide who also holds a degree in fisheries biology. He explained to me that the fish go where they have the best chance to get food. In nutrient-poor rivers like we have around Seattle, if the fish can get to the ocean, they evolve to take advantage of that and become sea-run. If it is to the fish's advantage to stay in the stream (good food, difficult access to the sea), they evolve to stay there. There is no cut-off line where it is more advantagous to go or stay, rather it overlaps somewhere upstream, so in areas like Kamchatka where the local and anadromous fish mix, clearly the advantage of each life cycle is approximatly the same. DISCLAIMER: I am not a fisheries biologist, just paraphrasing someone who claimed to be....

    Rich
     
  13. You have to keep in mind that oceans differ from "really big lakes" in one important aspect--salt water. This would mean that your regular run of the mill rainbow is biologically equiped to survive in salt water, unless I'm mistaken. Rainbows and steelhead are members of the same populations in rivers that host both sea run and resident fish, but are the fish in rivers which don't host anadromous populations equally equiped to survive in salt water? Is this ability common to other populations of, say landlocked rainbows?

    It does make a lot of sense that these fish are members of the same population because they aren't distinct species which means that they are capible of breeding. It would seem to me though that evolutionarily, anadromous and resident rainbows are on their way towards distinct speciation because of the fact that resident fish would be less physically equiped to compete for mates which would limit interbreeding between residnet and anadromous fish. It isn't suprising either that they would find this in Kamachtaka where the size of the resident rainbows are probably more comprable to the size of the sea runs--at least the steelhead on the smaller end of the spectrum.
     
  14. YES! For instance on the Cowichan River in B.C. there is a large population of huge brown trout. In recent years more and more anglers have been catching chromer browns near or in the mouth of the river. This would seem to indicate that some have adapted to going to sea or are at least flirting with the idea. Same thing in Argentina. These browns as far as I know all came from non-anadromous fish populations.

    Also, I read in a fish biology book that any trout or char can be placed in a tank whose water is slowly (months) turned saline and survive. It appears all of these fish have the ability to adapt.
     
  15. Take into consideration the fact that all of our brown trout came from Europe and the British Isles (i.e. 'German-brown' and 'Loch Leven Brown'). Many of these populations did (and do) in fact go to sea. A nearly perfect Pacific Northwest analog of the searun brown, or 'sea-trout' is the searun cutthroat. They head to the estuaries and inshore waters but not really out into the open ocean.

    There are examples of searun brook trout as well and, as far as I know, the only example of Salmo spp., Oncorhynchus spp. or Salvelinus spp. (excepting the inland forms like Goldens or Apaches) that have not been documented going to sea are lake trout.

    An interesting trend that biologists picked up on long ago is that incidences or proportion of anadromy increase with latitude...surely related to productivity in streams. For example, rainbow trout in California than in British Columbia. Nutrients. This all changes, of course, when you're looking at a stream like the Kenai in AK where there are literally tons of marine nutrients brought into the freshwater environment by 40+lb swimming bags of protein.
     
  16. lets see to answer some comments/questions:

    steelhead and rainbow trout are different life history expressions of the same species. they are also members of the same genus (Oncorhynchus) that contains all species of pacific salmon as well as cutthroat trout- this genus is collectively known as the 'salmon' because the true 'trout' is refers to the genus salmo which contains atlantic salmon and brown trout.

    in order for a rainbow trout to use marine environments they must go through physiological changes which allow them to maintain biologically sustainable osmotic balance. this process has many constraints, chiefly temperature and size of fish, and is less common for o. mykiss above about 10 C and for older individuals.

    -T
     
  17. I was under the impression that latitude has little to with it. Geography and chemistry surely matter more. I can see what these scientists meant as far as sunlight is concerned but it is far too general. Some rivers and lakes into the far north are fertile beyond belief even without anadromous fish. I was told that the latest science has the fish load linked directly to the presence of phosphites that are essential to the development of bugs and small crustaceans. This is why spring creeks and chalk streams are so full of bugs, because these essential minerals are present to an extreme. The same can be said for all rivers and lakes in some form or another.

    Also, I read a book years ago about the brown trout plants in Argentina and they were non-anadromous. Also, I have speant much time with a master guide on the Cowichan by the name of Iam Muirhead and he said that the browns there were non-anadromous as well. Anyway, I ain't trying to argue here just that I ain't talking out my anus. I have read all the books I can get my hands on and have researched all of this for most of my life.
     
  18. There are a lot of things that I want to comment on in this post, but I don't really have the time right now. I do have two comments to be made.

    I like what Richard said about being in the same genus, then actually they are ‘salmon’ in a sense. Salmon and trout are just common names that we give to the fish. It used to be a life history kind of thing, but even that doesn’t really make much sense because there is Atlantic salmon, and there life history pattern is more similar to a steelheads, they don’t always die after they spawn. Steelhead/rainbows were just recently (1989) brought into the same genus as the Pacific salmon (Oncorhynchus) we have, before that they were known as Salmo gairdneri. So as you can see the whole taxonomic classifications are changing as well. Researchers have found that they are genetically closer to the Pacific salmon, so that is why they were brought over, same with cutthroat trout. I actually know quite a few fisheries biologist that think that the whole common name thing is just a joke, it doesn’t really have anything to do with anything, just what people originally thought was going on. Some of these are pushing for a common name change, so all Oncorhynchus species will be known as salmon, all Salmo will be trout, and all Salvelinus will be char. I think they have a good argument, but this would confuse a lot of people, then again, I know some people that still call rainbow/steelhead Salmo gairdneri until they realize it is now Oncorhynchus mykiss. If you think about it, things just really don’t make much sense if you try to make meaning of common names. Most of the things that are char, we call trout (brook, bull, lake). So I wouldn’t really get too hung up on it.

    My second comment is for windtickler, I think what you meant to say is the genus Oncorhynchus, not salmonoids.

    A good reference if you are interested in learning about this is Thomas Quinn's book The Behavior and Ecology of Pacific Salmon & Trout. For being a reference/textbook it is a really easy read, and pretty cheap. Quinn is a really knowledgeable guy, and it is a great book for anyone interested in salmon and trout. On a different note, you guys are on the surface of touching into my research topic for my thesis, but instead of looking at O. mykiss (rainbow/steelhead), I am looking at O. clarki clarki (coastal cutthroat/sea-run coastal cutthroat). If anyone is now interested in why SRC go to sea a good resource is an article by T.G. Northcote in the Sea-Run Cutthroat Trout Symposium from 1995. The article is titled Why Sea-Run? An Exploration into Migratory/Residency Spectrum of Coastal Cutthroat Trout.

    Sly
    (Hope this isn't to wordy)
     
  19. That sounds good. How could I get it though?
     
  20. I agree with most of what you said, but just because something hasn't been documented much, that doesn't necessarily make it true. It is kind of like saying a null hypothesis is true, when in reality all you can really say is that you didn’t reject it. It is believed that SRC don’t really use the open water like the rest of the genus Oncorhynchus, but then again, there have been some cases where SRC have been caught far off shore. I have read a couple papers from research done in California that have found SRC far off shore. It all kind of depends on the circumstances. SRC research is a pretty new thing, I mean some of the best stock information for SRC in Washington is from the Stilly, and that has only been going on for a couple years. Oh, and I am not arguing, I am actually agreeing with what you said, just wanted to make the one addition.

    Sly
     

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