McKenzie River Rainbow

Wild McKenzie River Rainbow

This is a very short piece about a very complex topic.  My intention is to put a few ideas out there for people to consider, and present a little information that will keep people’s brains wrapped around the challenge of managing wild fish in a world where hatchery fish are still very popular, and are, at the very least, part of the psyche of the modern industrialized world.

Here is an example of the sort of statement I have often heard.

“There’s no such thing as a wild rainbow in the McKenzie anymore.”

Let me try to answer this one.

Here are some key definitions central to this discussion, quoted from the ODFW 2005 Native Fish Status Report.  I have added a short comment behind each definition

Hatchery-Produced Fish: a fish incubated or reared under artificial conditions for at least a portion of its life. (Jay’s note:  hatch box fish, fish produced by placing fertilized eggs in a gravel spawning channel, and unfed fry released into streams are all classified as hatchery fish.)

Naturally Produced: fish that reproduce and complete their full life cycle in natural habitats.  (Jay’s note:  ODFW does not formally use the term wild fish anymore.  I think this was a word-choice intended to avoid the ambiguity and acrimony associated with the wild-fish versus hatchery-fish advocates.  Solution?  Avoid use of the word “wild.”

Native Fish: indigenous to Oregon, not introduced. This includes both naturally-produced and hatchery-produced fish. (Jay’s note:  brook, brown, and lake trout are not native to Oregon.  Bull trout, rainbow, cutthroat, Chinook salmon, and so on, are native.

Indigenous: means descended from a population believed to have been present in the same geographical area prior to the year 1800 or from a natural colonization of another indigenous population.  (Jay’s note:  in order to be considered indigenous, a McKenzie trout must be descended from the stock of rainbow present before non-indigenous peoples started messing around with fish by moving them around and culturing them in hatcheries, or by a natural colonization by another un-messed-with population

Population: a group of fish originating and reproducing in a particular time which do not interbreed to any substantial degree with any other group reproducing in a different area, or in the same area at a different time. (Jay’s note:  some formal definitions of salmon, steelhead, and trout populations used by ODFW probably reflect lack of information, rather than genetic analyses that demonstrate reproductive isolation.)

In the vast majority of situations, the terms native and indigenous may be used in the same sentence when referring to a naturally produced fish.  Here’s an example: native, indigenous Rogue River spring Chinook salmon.

Rarely, a native salmonid population could be non-indigenous. Here’s an example: Cascade lakes rainbow.  These rainbow are native to Oregon, may be naturally produced, but may not be indigenous to the lakes where they are present, as the lakes were barren of trout before rainbow were originally introduced by back- and horse-packing.  At the moment, I cannot recall other instances of native salmonids that are not indigenous in Oregon, especially in rivers.  Anyone want to help out here?

Here’s a really interesting twist:  a trout could be a native, indigenous, naturally produced fish, or it could be a native, indigenous, hatchery-produced fish.

Huh?  Yep.  An Elk River hatchery Chinook is native, indigenous (derived from Elk River Chinook, and raised in a hatchery.  So here in one river we have naturally- and hatchery-produced, native, indigenous Chinook.

Now let’s get back tour topic question.

Are native, indigenous, naturally produced rainbow trout still present in the McKenzie? In my opinion, the answer is – absolutely – yes. Genetic studies of upper Willamette basin rainbow trout indicate that rainbow in the McKenzie, Middle fork Willamette, and areas above the Calapooya are very different from the domesticated trout that have been stocked here for many decades.  These naturally produced, native, indigenous trout are also very different from O. mykiss we find today in Cascade tributaries downstream from Harrisburg (i.e., Calapooya, Santiam, Molalla, and so on) where native, indigenous winter steelhead populations are present.  Remember, the McKenzie does not support native anadromous winter or summer steelhead populations.

The good news in all this is that there are indeed naturally produced, native, indigenous rainbow trout in the upper Willamette basin, including the McKenzie.  To me, this translates to:  “like dude, there really are wild rainbow in the McKenzie!”

JN

6 thoughts on “McKenzie River Rainbow

  1. You should talk with Jeff & Kelly @ Springfield ODFW regarding this. The first batch of genetic samples they submitted summer 2009 from lower McKenzie fish found no indications of crossbreeding with known hatchery trout stocks.

    1. Scott: Thanks, and yes, that is my understanding also. I wanted to make the point that there are indeed still wild rainbow (the term wild still works for me, rather than saying naturally produced, native, indigenous) in the McKenzie. I also wanted to wait until the official report is published (released to the public) before going into specifics, to make sure that I get the facts straight.

      Expect future posts to provide more detail regarding biology of the wild McKenzie trout and the fishery management challenges ODFW faces.

      Really appreciate your efforts to get information out for people to consider.

      JN

  2. Thanks for this thoughtful discussion! One other issue that has come up in relation to wild fish in the McKenzie is that protecting the McKenzie redside is being characterized as a “social” rather than a biological issue. The pro-hatchery folks are suggesting that there are adequate reserves in the tribs, and that this issue should be characterized in terms of “sharing” the resource. That argument seems disingenuous at best, but I’d be interested in hearing your biological opinion.

    Thanks,

    Dave Vázquez

    1. David: Thanks for your comment and question. Please allow me to give only a short response here, and stay tuned for further discussion regarding McKenzie River management. As you know, questions can be framed in a certain way that limits the answers.

      What does one mean by “protect the McKenzie redside”. Does this mean protecting the ability of “Upper Willamette” O. mykiss to sustain highly productive, naturally produced (wild) trout for the next century? What does protecting McKenzie redsides mean in a ” whole-Upper-Willamette-basin” context versus a context that dissects Upper Willamette redsides into several groups that could represent distinct breeding populations? What genetic data are available to guide definition of Upper Willamette trout populations? if genetic data are limited, could we apply professional judgment that could guide delineation of Upper Willamette redside populations?

      There are more aspects of the issue that merit discussion and i will try to address these over the coming weeks.

      Many well intentioned people are characterizing the discussion about stocking hatchery trout in the McKenzie as either social or biological. I think that a management decision regarding the hatchery trout program in the McKenzie requires a thorough consideration of both biology and social information – and then reaching a policy decision that has been informed by both.

      Thanks again for your continuing interest and patience.

      JN

  3. Thanks for the helpful information, Jay. Your conclusion agrees with the tentative conclusion that the McKenzie FlyFishers Fishery Committtee has reached. I insert the word “tentative”, because the only genetic data that we are aware of was generated by the ODFW in their recent genetic sampling of the upper Willamette watershed. We have seen a graph depicting the preliminary results, but a report on the study has not yet been completed, and we have not been able to examine the data or the methodology in detail.

    Are you aware of any other data that speaks to this issue? And any thoughts on the apparent barrier to reproductive interaction between upper Willamette rainbows and those below the Harrisburg area? I’ve heard ODFW biologists refer to the possibility that Ceratomyxa shasta infestation in that area may be the barrier, but I’m not sure what evidence there may be to support the idea, especially since it would have had to be in place for a long time.

    1. Arlen: thanks also for keeping us up on the theories and information. I do not want to delve into some of the points you raise quite yet. I, too, am waiting for the genetic sampling report to be released and believe it will be very useful. There are other possible explanations for the differentiation of Upper and Lower Willamette basin O. mykiss. I will go into some of those after we can all see the report. In the meantime, I think we are on pretty firm ground in our belief that the McKenzie River still supports a native, indigenous, naturally produced rainbow (redside). Viva wild trout!

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