Goodbye to cutthroat trout?

Posted Jun. 9th, 2014 by Melynda Harrison

In Montana, we pride ourselves on clean rivers and abundant angling opportunities, but we may soon say goodbye to a local favorite—westslope cutthroat trout.

As the planet heats up due to global warming, a lot of species are having a tough time. One of those species is the westslope cutthroat trout whose native streams are getting warmer and warmer.

Close-up of Yellowstone cutthroat trout

Iconic Yellowstone cutthroat trout are mixing with introduced rainbow trout, creating a new, muddled species.

Rainbow trout were introduced to area lakes and rivers by government fishery managers to give anglers more fish to catch.

Historically, rainbow trout have stayed at lower elevations where the water is warmer, while cutthroat stuck to the cold waters higher up. But now that those cold, cutthroat-laden waters are warming up and rainbows are invading.

When the two species get together they mate and make hybrid babies—mixing up the gene pool in the process.

The study led by ecologists with the U.S. Geological Survey and published in the journal Nature Climate Change, provides what the researchers believe is the first empirical evidence of how global warming is promoting invasive hybridization.


It’s an upstream swim against global warming to keep cutthroat trout alive as a species.

Why does all this matter? A fish is a fish, right? Not quite.

“The hybrid offspring have greatly reduced fitness,” said Clint Muhlfeld, a biologist with the U.S. Geological Survey. Fitness is “their ability to produce offspring and have those offspring survive.”

The threat from introduced rainbow trout was held at bay for decades, until the climate changed, he says. “So essentially, hybridization was a time bomb waiting to go off under the right environmental conditions.”

It’s bad for biodiversity and it’s bad for Montana. Trout fishing brings tens of millions of dollars to the state. A lot of those anglers want to catch native cutthroat, but that may not be an option for long.

Do we have to say goodbye to cutthroat trout?

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There are 14 comments on this post…
  1. Steven C. AmstrupOn Jun. 23rd, 2014

    As a sometime fly fisherman, and a full time conservationist, I have been chagrinned at the dialogue stimulated by the recently discovered hybridization threat to cutthroat trout. The debate about whether we should have introduced Rainbow Trout over much of the west is now moot. Because there is uncertainty about ultimate effects, of this long-ago action, on native cutthroat trout, there still is room for debate regarding what managers may be able to do to preserve native stocks. In contrast, there is no debate about whether humans are warming the world. Likewise, the human caused rise in the earth’s temperature has not slowed-it is still keeping pace with the rise in the atmospheric greenhouse gas (GHG) concentration. And, without mitigating the rise in greenhouse gas concentrations, there can be no “global cooling.”

    Planetary physics require that the earth’s heat content can only increase as GHG concentrations rise. Short wave radiation from the sun warms the earth. In turn, earth maintains its energy balance by returning that solar energy back to space in the form of long wave radiation. If it did not re-radiate the sun’s energy into space, the earth soon would become a ball of molten rock or hot gas. Greenhouse gases, like CO2 prevent a too rapid return of the Sun’s heat into space, making life on earth (unlike Mars which has a very thin atmosphere) possible, but growing concentrations of those gases prolong heat retention and make the earth ever warmer. In a stable atmosphere, such as we have had for most of the last million years, the amount of heat coming in from the sun is balanced, after a temporary residence in our lower atmosphere, by the amount of heat leaving the top of our atmosphere (TOA). For decades, scientists have used satellite sensors to monitor the earth’s energy balance by measuring the difference between incoming and outgoing energy at the TOA. Ever since monitoring began, there has been a growing difference, with less energy leaving the atmosphere than entering. This growing difference is in lock step with the rise of atmospheric GHGs. So, we know that the earth’s heat content is continuing to increase.

    When people say the earth’s temperature has not risen significantly for a few years they are focusing only on atmospheric or air temperatures. That makes sense because air temperatures are what we feel as we go about our lives. Focusing only on air temperatures, however, ignores the changes occurring in the earth’s main heat reservoir—the ocean.

    Natural variations in the climate and weather periodically alter the proportion of incoming heat that goes into the ocean or the air. During recent years, a higher proportion of the earth’s heat has gone into the ocean and less into the air. Because the air temperatures are most obvious to us, we sense this as a slower rise in temperature-a pause if you will. But, the heat is still with us. At the same time there may have been a deceleration of the rise in air temperature, various ocean layers have been heating rapidly. The growing TOA temperature differential tells us there has been no recent slowdown in global warming. And, as TOA measurements confirm, the total energy content of the earth has continued to grow. In a sense we are lucky to have had “mother nature” provide a respite from rising air temperature. Because air temperatures play a major role in sea-ice melt and the warming of fresh water systems; the cutthroats and the polar bears also may have benefited by a temporary slowing of air temperature rise. Nonetheless, the natural variations in weather and climate, which we always have had, are continuing, and in the long run air temperatures will catch up. A similar “warming pause” occurred in the 1950s and 1960s, and was followed by a rapid multi-decadal warming.

    There no uncertainty that the earth’s temperature must continue to rise along with GHGs. But how much of recent temperature trends is due to this chronic climate forcing? Because of the natural chaos in the climate system, a particular weather or climate pattern can, at any one point, be dramatically influenced by natural variation. It is well established in dozens of scientific papers, however, that none of these sources of natural variation can explain the chronic and steady global temperature rise observed over the last century. Variation in sunspot activity for example, has been shown to explain no more than a few percentage points of recent changes in the earth’s heat content. One need only consult recent IPCC reports, or the pages of refereed science journals to verify this.

    The only “global cooling,” outside the minds of those denying man’s influence on our climate, is the long-term trend determined by cycles in solar energy reaching the earth. Incident solar energy has been on a downward trend and the earth has been cooling for most of the last 8000 years. This cooling, is part of the natural changes in the earth’s orbit around the sun. These are the same changes that have led to the cycle of continental glaciations and interglacial periods throughout the last million years. In the last 100+ years, as the combustion of fossil fuels dramatically escalated, man has reversed that slow cooling trend.

    Because the current warming is man-caused and not part of the natural cycle of warming and cooling that has occurred over the past million years, we will see global cooling again only after humans alter their GHG emissions path. Numerous publications point out that we still have time to avert climate disaster by changing our uses of fossil fuels. A major catastrophe, such as eruption of the Yellowstone super volcano, could override our current path. That would, of course, also alter the situation for cutthroat trout and most of the rest of us. I for one do not wish to bet my future on that sort of “salvation.” Rather, I would like to see all of us recognize risks of our current lifestyle, and move toward a sustainable way of living.

    • Portrait of Daniel J. Cox

      Daniel J. CoxOn Jun. 23rd, 2014

      Steve, thanks so much for your insight based on many, many years of great science.

  2. DougOn Jun. 17th, 2014

    Dan: Wow! What an interesting response! Let’s see if I can sum it up…I’m a selfish, over 60 guy who is wrongly informed and unconcerned about my children’s future because all I care about is my quality of life until I die. In other words, I’m uninformed and selfish. Amazing! Actually, I’m under 60, relatively well informed and very, very concerned about my children’s future. Until now, our discussion has been civil and enjoyable. Now that you’ve lowered yourself to insulting me, I think it’s time to stop chatting. What a shame…

    • Portrait of Daniel J. Cox

      Daniel J. CoxOn Jun. 17th, 2014

      Doug, Not sure where you got the insulting part, maybe it was my guess at your age and my second guess that you don’t like the government taking too much of your money? If that’s insulting then I apologize but these are two factors many climate deniers have in common. Either way, you accuse me of not responding to your so called facts. Yet, you’ve given no proof of any of your “facts” being true. In my last post I supplied information that is current and produced by scientists who have been studying the climate changes for decades. You respond back with your comment that I’ve insulted you and you no longer want to play ball so to speak. That’s often the response a person gives when backed in to a corner. I’m all ears if what you outlined in one of your earlier posts is true. All I’m asking is to give me some proof. Without it I’ll stand by the people I respect and have faith in based on their long term studies known as science. No insult intended. I appreciate the dialogue. On lighter note, what cameras do you shoot?

  3. DougOn Jun. 16th, 2014

    Dan: Gosh, my comment about my friend in Idaho was only meant to bring a little levity into a serious discussion. But, since you do not seem to be in the mood to laugh…

    Well, you continue to make the 97% (now 99%) “of all scientists agree” statement. My goodness, I’ve seen everything from 35% to 97% quoted, depending on what I’m reading. But, if I remember correctly, it was 99% when Galileo made his observations about the solar system. And we all know how that turned out.

    Your presuppositions about government (generally good and helpful) and industry (generally bad and in need of constraint) are interesting. That certainly hasn’t been my experience. I’d much rather deal with B & H Photo than my local tax office when I want and deserve a refund, if you get my drift.

    Anyway, here’s my main point, for what it’s worth, and then I guess we can agree to disagree and get back to discussing photography which is why I’d begun frequenting your site in the first place.

    Please notice, in my comments, that I have never suggested that we have not had any global warming over the last 100 years (or cooling since both have been documented). However, what’s in dispute is what has caused these global warming cycles. The supposition that humans, and fossil fuels in particular, are the primary cause of the global warming cycles for the last 100+ years is simply not beyond debate. That’s what’s at issue. And it is at issue. And it is being debated. And it’s a crucial point because all sorts of draconian measures regarding fossil fuels and industry are being suggested by activists and governments based on the “settled science” that humans are the primary cause of global warming. And these actions must be taken now, “before it’s too late.” When I was a kid, there was a book out about a certain “Chicken Little.” I’m sure you remember it. It comes to mind now. Forgive me, but when I see the activist industry, and it is an industry, aligning with progressive governments around the world to pass treaties (meaning higher taxes) and redistribute monies, I grow suspicious. There are literally trillions, not billions, of dollars at stake here. (A lot more money, by the way, than the fossil fuel industry will ever see.) And some of those taxpayer dollars are mine. I have a vested interest, in other words, on the wisdom of moving quickly given what we “know.”

    The other thing is, Dan, I’ve noticed that you have yet to respond specifically to some of the facts I’ve presented. For example, the fact that there has been no measurable global warming since 2002, the fact that the incidences of “killer” tornadoes and hurricanes have decreased markedly during that same time, the fact that sun spot activity is being widely discussed by scientists at places like MIT as the primary cause of our earth’s warming/cooling cycles, and the fact that reputable scientists (not activists or politicians) are now discussing global cooling all lead me to question the big “push” to do something “before it’s too late.”

    You know, it was almost ten years ago when Al Gore made his worldwide tour claiming that in ten years catastrophic results would occur if we didn’t “do something.” Well, here we are almost nine years later. Temperatures aren’t higher. They’re flat. Catastrophic weather hasn’t increased. On the contrary. But one thing has changed. Al Gore’s 120+ million dollars richer. And, by the way, he’s still flying around in a fossil fuel jet preaching the same mantra. I guess he’ll have to extend his prediction to twenty years. My point is, to suggest that global warming has not become an industry with a vested interest in perpetuating its “facts” is a bit silly, it seems to me. Just look at the billions and billions wasted by the USA on so-called green industry initiatives over the last 5 years or so. Taxpayers have lost enormous amounts of money and government cronies have continued to get richer at our expense.

    So no, Dan, I don’t agree that it is “settled science” that human beings are the primary cause of global warming. Nor do I believe that global warming is on a non-stop upward trend, but rather that it’s cyclical like it always has been. Interestingly, 55% of Americans don’t buy into the man-made global warming mantra either despite the relentless propaganda that has been unleashed over the last 10 years. There’s simply too much evidence that there’s more to the story than this, in my mind.

    Thanks for the discussion and for allowing me to voice my opinion. I appreciate it. Now, back to photography.

    Your trip to Italy looks like it was amazing. My wife and I were able to spend a few days in Italy about ten years ago and fell in love with it. We particularly enjoyed Venice’s back streets. We can’t wait to go back someday and hope we will be able to.

    • Portrait of Daniel J. Cox

      Daniel J. CoxOn Jun. 16th, 2014

      Doug, good to see you’re still around. You’re obviously a sharp guy and you seem to have lots of facts but virtually none that I can tell are substantiated. You call them facts I’ve not responded to. I call them hearsay until you provide proof. Yes, we do know the outcome of Galileo’s observations regarding the solar system. Thankfully, had he been wrong, life as we know it would not have been effected like it will if we’re wrong about Climate Change. You seem to be at ease wagering high stakes on your assumption global warming won’t be a problem. The way I look at it is simple. Virtually all of us insure our health, our home, our cars and many other things, spending money to make certain we’ve protected ourselves from loss as best we can. Why not insure our planet by cleaning up the air our water, our atmosphere, our food supply etc.? What’s the downside to making sure people have a healthy planet to live on, one that is comfortable, clean and gives us all quality of life? Too costly, I’m guessing you’re going to say. I’m also guessing you’re most likely beyond 60 years in age and are convinced the government will be after to much of your money for a problem you most likely won’t experience. Hell, I don’t have kids but I pay a boat load of taxes making certain the ones growing up in our little town are educated. I couldn’t get out of paying those taxes if I wanted to but quite frankly it doesn’t bother me. I look at it as a good investment for all of society. I’m not just thinking about myself and how much money my government is trying to extract from my yearly income.

      The Keelling Curve

      In conclusion, I would love to hear your thoughts on the Keeling Curve. I’m assuming you’re aware of this long term study that shows the drastic change in our atmosphere’s temperature that continues to rise? This is a substantiated graph based on science. In case this is new to you, feel free to click on the link above to be taken to more information. And finally, just because a person has to use the current technology, jets using fossil fuels, in their efforts to educate people on the issues of global warming, does not make them a bad person. Maybe Al Gore would be using solar powered airplanes had it not been for the Reagan administrations dismantling of Jimmy Carter’s solar power program. But of course that would have been more government intrusion and now the Germans and Chinese lead the world in solar panel production.

  4. Maresa Pryor-LuzierOn Jun. 13th, 2014

    Daniel and Doug, I find your conversation interesting. I too, do not agree with Doug since, it is fact that certain areas in the world have warmed 2-3 degrees and more… I remembered when I visited Puerto Rico a few years ago and the biologist were saying because of temperatures rising only a couple of degrees on top of the mountain ranges that they are losing amphibians and possibly orchids now. It’s not an answer of when, it has already begun, and the cutthroat is probably another specie that is now feeling the effects of climate change. I’m sure this will bring up more conversations on introducing species for outdoor sports. Can it really be done without any consequences down the road. Definitely, food for thought.

    • Portrait of Daniel J. Cox

      Daniel J. CoxOn Jun. 13th, 2014

      Thanks for your input Maresa. It’s a great conversation to have. I appreciate you taking the time to add your voice.

  5. DougOn Jun. 12th, 2014

    Hi Dan: I appreciate your openness to discussion. There’s no need for me to provide you with links because good information is readily available. For example, you could Google “global warming myths” and find a number of reputable information sources that provide facts rarely discussed by the mainstream press. The reality of cyclical climate change can apparently be documented for the last 1000 years, for example, long before the industrial revolution. And there has been no actual increase in storm/tornado occurrences or intensity contrary to what’s often anecdotally discussed. In fact, we’ve had fewer hurricanes in North America in recent years, etc. And, as I mentioned, there has not been any increase in earth surface temperature readings since 2002 and no increase in atmospheric temperatures prior to that. Good grief, some scientists are now discussing global cooling as being the new reality. The notion that scientists agree about this is also misrepresented. There is plenty of disagreement among scientists of repute and their opinions are all over the Web, too. Last, but not least, I think if you “follow the money” it’s pretty evident that this has become a highly profitable “industry” and government particularly seems to love using this so-called “settled science” to increase regulations and taxes. On a happier note, my best friend told me yesterday that Cutthroat Trout are doing great in Idaho where he lives. That was nice to hear.

    • Portrait of Daniel J. Cox

      Daniel J. CoxOn Jun. 12th, 2014

      So how does your buddy from Idaho know about the cutthroat trout? I’m guessing he’s more than just a fisherman that’s caught them on a fishing rod? Maybe he’s one of the authorities on “global warming myths”? I’m a firm believer in science and virtaully all your “global warming myths” have been disproven by 99% of all scientists that study and specialize in climate change. Furthermore, more power to “Climate Change” being a “highly profitable industry” which is a small fraction of the billions and billions of dollars the fossil fuel industry currently rakes in on a daily basis. I hope Climate Change dwarfs the money we see being made from Fossil fuels. That would give some new blood a chance to become wealthy, like so many deniers of Climate Change all ready are. Too much government? I don’t care for it either but when was the last time any industry in Idaho or anywhere else, made certain the waste water, they’re pouring in to the river your buddy fishes in, is clean enough to drink and fish to live in? It doesn’t happen without somebody/government or environmental watch dogs breathing down industries neck. There are a few instance in history where a well managed corporation has done the right thing, for the sake of share holders and humanity, such as Apple. But they are few and far between.

  6. DougOn Jun. 9th, 2014

    Dan: I really would encourage you to investigate this further. There is simply no scientific consensus on “man-made” global warming anymore. There is plenty of debate going on and it is widespread within the scientific community. And it is a simple fact that the earth’s temperatures have been level since 1998. And that there have always been warming/cooling patterns over time. And that our ability even to measure earth’s temperature is fraught with difficulty, etc. To relegate to the fringe reputable scientists such as Richard Lindzen of MIT who are openly questioning the “man-made” global warming mantra is hardly fair or accurate it would seem to me. And he is far from alone.

    • Portrait of Daniel J. Cox

      Daniel J. CoxOn Jun. 10th, 2014

      Doug, I hope you are right but based on my studies of the issue and the folks I know, your opinion that Global Warming has finally been proven to be false is not what I’m hearing. Maybe you can post more info here on the Blog that we can all read. I’m going to see if a good friend of mine from Polar Bears International would like to joint the discussion. Thanks for your interest and adding your voice. Though we may not agree on all issue, I appreciate listening to all sides.

  7. DougOn Jun. 9th, 2014

    Melynda: I hate to be the bearer of good news, but the earth hasn’t warmed since 1998. In fact, after 15 years of flat temperatures, it appears we might now be entering a cooling cycle that is completely consistent with the warming/cooling cycles that have always been present and are well documented. And, apparently, sun spot activity might be the key factor in all this, something over which we have no control. Far from being settled science, global warming is a hotly debated topic among scientists as any Google search will demonstrate. So, although I think it’s a shame about the Cutthroat Trout, to assign the blame to global warming seems a bit fishy to me. And, yes, pun intended.

    • Portrait of Daniel J. Cox

      Daniel J. CoxOn Jun. 9th, 2014

      Doug, there is no longer any debate on global warming other than from a minuscule number of scientists on the fringe. Virtually all scientists agree it is now in full swing and the only debate left is what sort of significant changes we’re all going to endure. Which includes our beloved cutthroat trout. I hope I’m wrong and your right. I’m happy to eat my words if our climate goes back to what we experienced in the middle part of last century and before.

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