I'm not a fish ecologist (you noticed?), so maybe there are things about this story I don't get. I'm looking for an explanation, which I assume a knowledgeable ecologist could give me. It seems that a decades long program to restore the endangered and almost extinct greenback cutthroat trout (Colorado's official state fish) has run afoul of a discovery that the restocking was being done with a closely related subspecies native to the other side of the mountain, the Colorado river cutthroat.
The first thing I don't understand is this sentence in the (otherwise excellent) Rocky Mountain News article:
The greenback, named for the brilliant crimson slashes behind its jaw, became Colorado's state fish in 1994. (Kevin Vaughan, Rocky Mountain News)
Correct me if I'm wrong, but isn't crimson red not green? But that's a minor matter and not what I'm really wondering about.
The back story is this. By the 1930s overfishing and mine pollution had apparently killed off the greenback cutthroats. In 1937 it was declared extinct. But in the 1950s nine small "relic" populations of the fish were discovered in tributaries of the Colorado River. In the 1970s (the Rocky Mountain News article says 1973 but another article from the AP cites the date as 1978) the greenback cutthroat was added to the endangered species list. To restore the species in its native range, egg and sperm from these nine relic groups were used in hatcheries to make new fish and they were then released into the native habitats.
It turns out that five of the nine relic populations were the non-endangered Colorado river cutthroats, so some of the restocking is being done with the wrong fish. The two fish are so much alike -- apparently almost identical in appearance -- that the mistake was only discovered with the use of sophisticated DNA analysis. Instead of 142 miles of waterway with the "right" fish, there are now only 11 miles of waterway. So much of the effort in the restocking program has been wasted. The new findings, published in the journal Molecular Ecology (no cite given in the news articles I read) have caused consternation in some quarters. My question is: Why?
I am not making a know-nothing argument about endangered species. I see the value of biological diversity and I support the Endangered Species Act. But if you can't tell the difference between fish from one side of the mountain and the other except by recently available DNA technology, what is the issue here? At any other time these would have been (and were) considered the same species. We expect the genetics of two geographically isolated populations to differ, but this is true for fish of the same species in southern Minnesota versus norther Minnesota, too.
Since this is the subject of a scientific publication and two reasonably lengthy news articles, it seems there is some underlying issue here I don't understand. Can someone help me?
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I can't answer your big question, but crimson is red, and the greenback was so named because the red behind its jaw emphasizes the green of its back - making the green back look more prominent and distinct.
Or so I've been told.
This has been a problem with augmentation of fish populations in the past, the robust redhorse in North Carolina is a good example. Back before DNA technology things like this were just a risk of translocating animals, but today analysis to determine the possibility of cryptic species should always be taken seriously before mixing populations...
Oops, forgot about the question you directly asked: we care about two seemingly identical fish for several reasons. One is genetic diversity, if one species goes extinct under a given set of conditions then the sister may have alleles/adaptations that allow it to survive and continuing filling its ecological role. Just because we can't distinguish the species with our current knowledge does not mean that they have identical behaviors/roles in their environments, I'm not sure how well-studied the cutthroats are, but it is never safe to assume that we observe about an animal is the same as what other members of its species/community perceive. I study mammal conservation, so I'm not that up on my fish ecology, but cryptic species are definitely an important point of debate in conservation biology/policy.
And crimson is most definitely red. Strange.
Revere,
You're in luck! Not only am I a fish ecologist, I also work in the endangered species arena.
First, notice that both populations here are cutthroat trout. They were so-named due to the distinctive "cut markings" on their anterior ventral side (their "throat"). So when you see "named for the brilliant crimson slashes behind its jaw", that refers to these cut markings. The greenback is distinct from other cutthroat populations because of its....well, green back. IOW, green on the back with crimson markings on the underside.
Anyways, on to the main issue. It's important to note that cutthroat trout are a very wide-ranging and diverse species, with many populations that are classified as sub-species. Because they inhabit primarily inland mountainous regions, there are a lot of populations that are isolated from each other, and have been so for a long time. Oftentimes you'll see cutthroat referred to in terms of which side of a mountain range they are found in (e.g. westslope cutthroat trout).
That brings us to the endangered species act. Although it is the endangered SPECIES act, it contains what is known as the "distinct population segment" policy. This applies only to vertebrates, and it basically says that distinct populations of a species (they don't even have to be sub-species) are eligible for protection under the ESA.
So, if we put the DPS policy together with the evolutionary history of cutthroat trout, you end up with a lot of distinct populations (because they've been isolated for long periods of time) that can be ESA protected.
As Anne-Marie points out in her comment, the value lies in the likelihood that these distinct populations have some unique alleles, specially evolved for these habitats, that if lost are gone forever.
I hope that helps.
Jason F-IYO should we be even tinkering at all with natural selection even if we are the cause. We are part of a somewhat natural process ourselves and one day, we too might be selected for elimination. Our processes even though evolved and affecting the other species of the planet, doesnt that still make it natural?
If the Greenies are gone for good, didnt it mean that their population wasnt robust enough and was susceptible to that elimination?
I get into this a lot with the ecologists. Obviously we dont want cyanide from mines leaking into streams but it does. It also does naturally. Both kill fish, and us if we drink the water. But isnt a part of the natural process. If you take humans out of the question as to what ecology is, we are just another species tapping into resources.
Thoughts?
Anne-Marie, Jason: Yes, this helps. I am not quite sure when genetic variation between individuals becomes genetic diversity, but I see the overall point you are making. I guess it is a matter of degree, since the reductio ab absurdum endpoint is to consider every individual a potential endangered species. Where that line is drawn is a matter of judgment at the moment and I don't have a quarrel with how it is curently done (I don't have the expertise) but I was quite curious as to the underlying thinking, which is much as I surmised, although you provided details about the fish I didn't know.
Many thanks.
> isnt a part of the natural process.
Rate of change makes a difference.
Poison, combustion, nuclear fission, climate change, extinction, all natural.
Rates thereof due to human activity are far faster than the rates of change any species is able to handle.
The difference is that intelligence is able to produce rates of change far greater than those produced by other species; the open question is whether intelligence can manage what it can produce.
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In reply to a reporter's question "What do you think of Western Civilization?" Gandhi replied "I think it would be a good idea!"
M. Kruger,
If we were to apply that logic, we wouldn't bother doing anything to restore damaged ecosystems or endangered species. If I went out into a lake and dropped a charge of dynamite, killing everything in the lake, using the rationale you described that's "natural". Likewise, pollution from power plants is "natural". In fact, under what you describe, there is no such thing as "non-natural".
Revere,
That's why they're called a "distinct POPULATION segment". The population itself has to be distinct to qualify. Factors such as uniqueness of morphology, life history, and genetics all come into play when establishing a DPS.
The "distinct population segment" is important with salmon in the northwest and the endangered species act. Although the same species of salmon spawn in different streams, they through natural selection develop slight genetic differences that allow them to better adapt to their own spawning sites.
These differences progress that salmon of the same species can not survive if they are introduced into a different spawning stream. I don't know if this is an issue with cutthroat trout, but pacific salmon and cutthroat trout are closely related (in the same genus Oncorhynchus).
M. Randolph Kruger what you are asking is a question of ethics. Yes in a broad sense people are part of the ecology, but we can act in ways that no other living organism can. Because of our intelligence the normal ecological constraints that apply to all other organisms don't apply to humanity.
Mr Kruger would you intentional kill a puppy? Animals kill other animals all the time for many reasons. Its a normal part of ecology, and after all people are just another type of animal. Maybe people should be aware of ecology but not blindly follow it.
Jason, Joseph: Thanks.
Jason F-But thats what I mean. If we are to believe that humanity is killing the planet, arent we just delaying the inevitable? We are going to have another 1.5 souls on the planet in 50 years unless something dramatic happens. Those souls will tap an already tapped out resource pool. Oil in particular. I remember from college watching one and a few celled bacteria once the food source was gone, start to eat each other. I dont share the idea of "end of days" but end of some really screwed up ones. The notion of humanity tapping everything out until its like the dino's, nothing larger than "x" body weight survived. They went because the food supply was gone and the temp was too cold or so they say. Re: Non-natural, yes thats what I meant. With the advent of another 1.5 billion we either have to leave or face really, really bad times in the next 50. We leave in space ships or we leave via starvation, bugs, what have you. Natural selection?
Joseph-Of course not. But it might get to that. I see wars now for natural resources. Thats what Iraq is for the first part and security in the second. Without those resources the EU and US are non-entities. We would be struggling along looking for energy sources without it. Is it ethical?.... Depends on who you talk to. I for one just dont know. it would seem that if you are biblical in any way then yeah you are right. It also seems that having been indoctrinated into that, that we should be good stewards of the earth. But so far all I have seen is a lot of absolutely crazy stuff that puts us on an uneven playing field and thats not good either. That brings it up the eco-chain if we are just another species, again... Survival of the fittest. That generally means the most intelligent and strongest make the rules.
Again your thoughts guys.
Mr Kruger- Cyanide is naturally released into watercourses? I think you probably mean ARD (acid rock drainage containing metals and low ph) which may occur in runoff from sulphide bearing ore outcrops naturally or from mine rock dumps and tailings ponds.
Cyanide, used in dissolving gold from ore can, if not treated properly (PDF) prior to release into mine tailings ponds, enter receiving water environments through overflows, dam seepages or groundwater.
ARD has a greater and more longlived impact on receiving water quality. Cyanides will naturally form stable compounds or degrade. With ARD only wetlands or ocean can mitigate the effects naturally, but metals and low ph have a devastating affect on fish and their food in freshwater streams and lakes.
ARD may occur at coal mines or metal mines, typically at historic workings. Current operations use acid/base accounting to determine risks at the planning stage and then operational methods to prevent ARD during and following mine operations.
M. Kruger
The point is, humanity doesn't have to "kill the planet". We are able to make choices.
Jason-Okay. I understand that we can make some choices but each choice we have made since the inception of the EPA has been to create huge bureacracy and make it harder and harder for us to do business. So we become "ecologically correct" and the rest of the world kicks our asses economically because of it. Then the backlash occurs as it did from Carter to Reagan as people lose jobs and incentives.
Then they dump the regulations just about entirely and I dont agree even as a Republican with that. We can act more responsibly of course, but in the same breath we are adding 1.5 billion people and maybe 2/3rds of that in my lifetime. The taxation upon the eco system IMO wont take it, and most of those people will not be in the US or EU. So you have big polluters, developing a lot more polluters who will multiply at least 2.5 more in 150 years. I doubt we can sustain that number under any condition and that means the world eco system will come under attack. Follow my thinking here? Something is going to give and its going to be the eco system first and then very shortly thereafter humans.
Krugerq you sort of wring yourself with your own figures. You agree that we don't have eight billion people yet. However, the best estimates for population growth forty years ago said we would be at eight billion by the year 2000. Yea, we have a lot of people now though I ask you were those two billion people that we should have had went? There wasn't a war, plague, or famine that killed them. Developed nations like ours and like the vast majority of europe simply decided not to have that many kids. The fact that we can predict a steady state population in the 8-10 billion is a huge tribute to world society in general. The goal is ofcourse to work out the details to support that many with as much of our flora and fauna as possible for future generations. And considering the green revolution we can do it, (though it would help if we all became vegetarians). As per your fossil fuels all running out and it being the end of times scenario I seem to recall them predicting the same thing back when copper was a limiting resource. The moral of the story is not to give up on precious aspects of biology because you can plausibly develop a pessimestic scenario where the restoration efforts would be inconsequential.