03-19-2008, 02:49 PM
Wyobraz -- that seems very near to the findings at Fish Lake. Remember, an average divides the total growth over a period of time. It doesn't necessarily mean that the growth actually happened that way. They may average 1-2 pounds per year, but they might have actually gained 4 pounds in 1 year, and none in the next -- thus an average of 2 per year. Gain 10 pounds in 3 years, then none in the next 7 and you still have a yearly average of 1 pound per year.
Once a lake trout of 24" completely converts to a fish diet, it will grow very fast for a period of time. It will eventually reach a size where it will not be able to sustain that growth rate. Fisheries managers ideally would like to keep fish in that maximum growth rate area. That is where the fishery is at it's best.
Tightline -- slow down. You're taking things too literally. I have not said anywhere that "genetics don't matter". Obviously genetics are an important part. But they are not the limiting factor in the majority of Utah's fisheries. Again, look at the fish in question. That small lake trout had the genetics to grow large. Why didn't it? Because it didn't switch to a piscivorus diet. It's genetics were there. But it didn't grow large.
Look at the Lahontan Cutthroat. Historically they grew to huge sizes. They were then thought to be lost until a population was found in the Pilot range. Those Lahontans in that small creek were very small (10"?) and had been so for over 100 years of breeding. Were the genetics to grow large lost? When those same 10" fish were put in larger ponds they quickly started growing cutthroat over 10 pounds! We do not know how large those fish have the potential to grow at this time -- but it is very obvious that it was environment that forced them to 10" in the streams of the Pilot range, and not genetics. The genetics are still there.
Genetics are important -- I've never said otherwise. But, when it comes down to it, it is usually not genetics that are the limiting factor in fish growth and size.
You mention selective breeding. This can be accomplished in an aquarium where you can control which fish is fertilizing the eggs. In a natural environment (like Flaming Gorge) you cannot control this selective breeding. The genetics of the large fish are being mixed along with the small fish. There is no way to selectively breed out the size (or other characterisitics) in a natural environment.
jacksonlaker -- Look at their environment. They head out to the ocean and begin a vicious feeding frenzy off rich oceanic food sources that provide an environment of FAST growth rates. Perfect example of what I'm talking about. It's not how long the fish lives, it's how well it takes advantage of it's environment and how fast it grows. It's no different than a Steelhead. Steelhead are rainbow trout. Genetically identical. So, why do steelhead get so much bigger than an average rainbow? It's not genetics, it's environment. Steelhead are an ocean going salmonid that take advantage of a richer food source -- or a better growing environment.
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Once a lake trout of 24" completely converts to a fish diet, it will grow very fast for a period of time. It will eventually reach a size where it will not be able to sustain that growth rate. Fisheries managers ideally would like to keep fish in that maximum growth rate area. That is where the fishery is at it's best.
Tightline -- slow down. You're taking things too literally. I have not said anywhere that "genetics don't matter". Obviously genetics are an important part. But they are not the limiting factor in the majority of Utah's fisheries. Again, look at the fish in question. That small lake trout had the genetics to grow large. Why didn't it? Because it didn't switch to a piscivorus diet. It's genetics were there. But it didn't grow large.
Look at the Lahontan Cutthroat. Historically they grew to huge sizes. They were then thought to be lost until a population was found in the Pilot range. Those Lahontans in that small creek were very small (10"?) and had been so for over 100 years of breeding. Were the genetics to grow large lost? When those same 10" fish were put in larger ponds they quickly started growing cutthroat over 10 pounds! We do not know how large those fish have the potential to grow at this time -- but it is very obvious that it was environment that forced them to 10" in the streams of the Pilot range, and not genetics. The genetics are still there.
Genetics are important -- I've never said otherwise. But, when it comes down to it, it is usually not genetics that are the limiting factor in fish growth and size.
You mention selective breeding. This can be accomplished in an aquarium where you can control which fish is fertilizing the eggs. In a natural environment (like Flaming Gorge) you cannot control this selective breeding. The genetics of the large fish are being mixed along with the small fish. There is no way to selectively breed out the size (or other characterisitics) in a natural environment.
jacksonlaker -- Look at their environment. They head out to the ocean and begin a vicious feeding frenzy off rich oceanic food sources that provide an environment of FAST growth rates. Perfect example of what I'm talking about. It's not how long the fish lives, it's how well it takes advantage of it's environment and how fast it grows. It's no different than a Steelhead. Steelhead are rainbow trout. Genetically identical. So, why do steelhead get so much bigger than an average rainbow? It's not genetics, it's environment. Steelhead are an ocean going salmonid that take advantage of a richer food source -- or a better growing environment.
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