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Location: Eagan, MN | I've often referred to a bass study conducted in Texas that showed how the relative aggressiveness in bass is passed along to off-spring and thought there may be interest in some of the details of the research.
Years ago, Dr. Gary Garrett, at the Heart of the Hills Research Station in east/central Texas, started studying aggression in northern largemouth bass. His research showed that an aggressive female northern bass bred with an aggressive male northern bass would produce aggressive offspring that anglers could catch easily. The research also proved that difficult-to-catch northern male bass bred to difficult-to-catch northern female bass produced off-spring that anglers had a very difficult time catching.
Biologists in Alabama went even further and found that by continuing to breed aggressive bass with aggressive bass, the offspring become even more and more aggressive. These super-aggressive northern largemouth bass, bred selectively for aggression for 15 years, were called "Gorilla bass." They have a much faster growth rates than average northern bass, and bite much more readily.
Interestingly, the researchers found that stocking just a few Gorilla bass into an already existing bass population increases the catch rate of bass in that pond. The Gorilla bass begin to out-compete with the native bass for food. The native bass learn that they need to feed more aggressively, or they won't get much to eat. Pretty soon, the entire fish population was feeding more aggressively.
Would these bass study results apply to a population of muskies?? Could decades of 'trophy only harvest' cull the more aggressive muskies from the population, leaving the more timid fish whose off-spring is more difficult to catch as well? Essentially, the reverse effect as what the above biologists were attempting to accomplish with bass?
It's an intesting question, at least for me.
Brian
Edited by BrianF. 10/3/2014 12:03 PM
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| If we were harvesting all of our fish, than yes - the aggressive fish and their genes would eventually be removed from the system. When you introduce selective harvest into the mix, and the prevalence of catch and release fishing, it becomes a lot more complicated. We're still catching the more aggressive fish more often than the timid fish, but we're putting them back.
I also believe that the fish we care catching over and over again, and likely the most aggressive fish in the system. (i.e. the stupid ones) The more timid and less catchable fish are likely the ones that follow and turn off, or come in 3 feet behind and under our lures.
It's an interesting bit of research. I'm not sure it's possible to incorporate that into our breeding and stocking programs, but we could, theoretically at least, breed and stock meaner muskies that are more apt to eat anything that swims by.
It also makes me wonder about the differences in lakes that we all see. Some lakes have a great topwater bite. Some not so much. Some lakes it seems like the fish either eat or don't. Some lakes you can raise a fish once and you'll never see it again. On other lakes you can get the same fish to follow 3-4 times in a row.
The real question is how much of that is conditioning, and how much is just the nature of the fish in that body of water.
Another thing to consider with your earlier example of seeing your spots dry up is the possibility that those fish were harvested by other anglers, or eventually fell victim to delayed mortality.
In the end, I don't know there's a lot we can do as individual anglers that we're not already doing.
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Location: Smith Creek | We didn't always selectively harvest. Up until 1980 or so almost everything over 30" was kept.
Edited by Flambeauski 10/3/2014 2:48 PM
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Location: Rhinelander, Wisconsin | Brian,
The overall numbers of any one year class fall off at a pretty high percentage each year (as high as 30% is cited in the literature, if I remember correctly) due to all mortality possibilities.
I have seen it postulated that as the year class reaches it's last few years that the more aggressive fish have already succumbed to angling mortality or death due to 'stupid moves', leaving the less aggressive to acquire maximum size structure of the year class. Doesn't mean they won't hit a lure, just means you might have to do a little more to stimulate them into a strike response, which is different than feeding by a long shot.
There are not a ton of muskie studies to begin with so I am not sure there's anything to support the postulation. |
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| Steve, perhaps the affects of that are offset by the fact that the more aggressive fish are better feeders and are more apt to score a meal, therefore allowing them to grow faster and larger than the more timid fish.
It also stands to reason that the more aggressive fish may very well be more aggressive breeders, and pass along their genes more often than the more timid fish. All in all I would think aggression in feeding and breeding behavior would be conducive to survival for any predator, muskies included.
Which brings us back to the original question of how much angling pressure is affecting the behavior of muskies on the heavily fished lakes. I am not aware of any studies past or present as it relates to this. |
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Location: Rhinelander, Wisconsin | I don't think so addict, it's not like feeding opportunities in most cases are so limited that fish less likely to display a strike response will weaken in any way, and 'competition' is based more upon numbers than actual physical aggression.
Muskies do not selectively breed with a single partner, either, and are 'broadcast spawners' so competition for a female isn't a big deal, sometimes 3 or four males are seen beating on the sides of a female.
The idea is the more aggressive fish have been weeded out by harvest, post CPR mortality,etc. Not sure one can logically apply the opposite to Muskies.
Lions, maybe. Not the Detroit kind, though. |
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Location: oswego, il | I am not a scientist but if it can be done with bass it probably could be done with muskies. Many dog breeds for example did not exist before the year 1800. They were created for all sorts of reasons including ability and temperament. Could be interesting. Could sell alot more fishing licenses based on increased fishing success. |
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Location: Rhinelander, Wisconsin | One of the big issues with trying to 'engineer' any muskie population is NR...if it's a lake with out any, nothing to lose...sort of. If it's one with a natural, healthy population, from what we've seen here, stocking other strains over the natural population results in little or no NR of the stocked fish and no evidence of mixing genetics at all. Dr. Brian Sloss's work, if I have this correct, indicated basically a 'two tier' muskie population in the stocked natural muskie lakes that pretty well just passes on when the stocked fish die out.
It's all discussed right here in this forum back a couple years ago during the 'it's the fish' wild debate.
Secondarily, no one particular strain comes to mind as being significantly more aggressive than any other.
There have also been some BIG failures in the bass world trying to 'improve' the fisheries with bigger, more aggressive fish, crashing some of the populations altogether. What happens in a controlled experiment may not work well at all in the natural environment, and 'messing around' with Muskie populations is also wildly expensive. |
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Location: Smith Creek | If we could find a way to block the muskie's leptin receptors we could make them think they're hungry all time, and grow some extremely obese muskies in the process.
How about it, science? |
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Location: Rhinelander, Wisconsin | Someone must have done that to me... |
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Location: oswego, il | I just ate a salad. Explains the lack of interest in my genes.:-) |
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| ToddM - 10/6/2014 12:20 PM
I just ate a salad. Explains the lack of interest in my genes.:-)
Maybe it's the blue dishwashing gloves? Just sayin'... |
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Location: Eagan, MN | in addition to Garrett's research, a number of other scientists later joined forces to study the phenomenon of the vulnerability of largemouth bass to angling. They found that vulnerability to angling is indeed a heritable trait. Their results indicated that "recreational angling has the potential to alter the gene pool of wild fish populations, which may indirectly affect population characteristics...as well as directly affecting angling success rates."
I'm not suggesting that the musky community push for a genetic breeding program as discuss above, but only that this may have implications for fisheries management policies in areas that care about trophy potential. Folks may say that CPR rates are so high as to negate the unintended effects of sport angling on the relative catch ability of fish, but I think that musky populations are so low, and fishing pressure on some bodies of water so high, that the largest specimens in the population are still quite vulnerable to angling. Eventually, some percentage of the targeted top end fish get harvested or perish from either immediate or delayed mortality.
Mother Nature takes care of herself, and I suspect that is happening in the population of muskies where generations of trophy angling has occurred. In heavily pressured bodies of water, the biggest of the big are getting that way due to their genetic and inherited predisposition NOT to bite artificial lures. They are becoming less catchable over time if you believe the inverse of the bass study is true. And I suspect it is.
Last thought... I fish heavily pressured Lake Vermilion, which is my home water. I've been fishing the lake for 15 years. While the DNR test nettings show the musky population to be as strong as ever, many folks believe the fishery is in decline. I simply feel the adult fish we target there are just getting more difficult to catch. While the DNR test nettings show 1:3 fish (west end) or 1:6 fish (east end) are 50" or larger, my creel doesn't come anywhere near that percentage for most of the year. Those biggies are plain hard to catch! And, I think the reason has to do with our own angling efforts.
Brian |
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Location: Rhinelander, Wisconsin | 'In heavily pressured bodies of water, the biggest of the big are getting that way due to their genetic and inherited predisposition NOT to bite artificial lures'
That could be challenged. It may not be a 'predisposition' at all. I believe what we are seeing in many cases is adaptation to what literally has become part of the environment for most of the muskies in any heavily pressured system; lures in the water.
Pressured muskies are harder to catch, but one might seriously question that the drop in angling success per angling hour is a result of genetics or 'inherited predispositions'. How would one explain that happening in the short time frame since introduction, especially in the case of the 'new' muskie waters in MN?
In some cases where 'new reservoir syndrome' made the first few years of angling easy and pressure subsequently made things tougher, a portion of the original stocked year class may still be present. If CPR approaches 90%, and the percentage that die as a result of angling caused mortality are out of the picture, one may find there are other dynamics at play.
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| I am of the opinion that Genetics are not a likely cause of this in MN. MN didn’t start stocking fish until the 60s, but for most of the well known lakes the stocking didn’t really hit stride until the 1990s. In terms of giant specimens, that is typically a fish that is 12-15+ years of age. So while that fish might do the “deed” each year, how many of its offspring have hit maturity and then produced successful offspring themselves to give a few generations of traits within the system? My guess is even with strong natural reproduction, the answer is very few. On most lakes where the Musky are stocked in MN, the natural success rate is VERY low to non-existent according to the MNDNR.
This leads me to believe that while it can’t be known for certain, there are enough factors that seem to point away from Genetics that it is not a likely cause.
I think the fish adapt to changes in their environment. Seeing how my local water (Minnetonka) has evolved over just the past two seasons via weather trends, invasives (Zebra Mussels), as well as intense angling pressure leads me to believe that while the fish may not be “smart”, they do adapt to their environment. To Steve’s point, our lures have become a part of their environment.
Of course we really cannot know what the causation ACTUALLY is. Is the bite tough due to the type of weather we’ve had? Is it due to invasives? Is it due to poor angling technique? Is it due to pressure? How do you eliminate the various causes to draw a meaningful conclusion over a large sample?
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Location: Eagan, MN | Steve/Brad, I 'get it' that the MN musky fishery might be considered so fledgling that genetics are not yet a factor in terms of vulnerability to angling. I think that is a fair point. If, for the sake of this discussion, we consider the MN musky fishery to be first generation, then what I wonder is if the aggressive gen 1.0 'biters' that have been caught over the last decade haven't had their numbers reduced somewhat by harvest or angler-induced mortality, such that there is a larger percentage of 'non-biters' that carry on their non-aggressive genes to gen 2.0 and gen 3.0 and so forth. Yes, this is probably not an issue for a put/take fishery that is sustained only through stocking.
Using Vermilion as an example, which now has natural reproduction going on, lots of 50"+ gen 1.0 fish have been CPR'd successfully. However, I know for a fact that many very large specimens have been harvested and some have died via mis-handling or other unintended consequences of angling. Over the course of 20 or even 30 years that gen 1.0 fish would otherwise live out their lives naturally, the angler-induced mortality imposed on fish that are aggressive by nature - pre-disposed by genetics if you will - begins to add-up. The less aggressive fish survive in greater numbers to carry on their genes to gen 2.0, 3.0, and so forth. That is what the bass studies tell me MAY be happening in the musky world.
Just another reason seek out and go where other anglers don't.
Brian
Edited by BrianF. 10/7/2014 5:03 PM
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| they eat or they die , they are a efficient predator that takes advantage of meal sizes they prefer and they don't feed daily, may even go weeks without eating after a large meal.... They are a very dumb creature, passing on genes? Yes! - eat or die that's what they pass on... |
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| I dont think they are dumb for fish. One of the few fish that can actually "think" to some degree. Ive seen instances where they are more than mere robots or genetically programmed. Smart? No! but to be an apex predator, one must be of more intelligence than the prey as luck wont get you to giant size. |
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Location: Hayward, Wisconsin | In theory they could go all season without eating...one lived seven months in the Shed Aquarium in Chicago without eating! |
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Location: Eagan, MN | If 'dumb' = will bite lures, then the research shows that there are indeed dumb fish. Fish that will bite the same presentation over and over. However, the research also shows the opposite: there are 'smart' fish. These 'smart' fish are the ones that are avoiding our angling efforts, getting larger, and passing on their genes to their off-spring, who also show the same characteristics. What's bothersome to me is that the researchers also found in their population of study fish individuals that were uncatchable by angling and wouldn't even strike live bait! Guess you could call those fish 'brainiacs'. ha I find that fascinating and think there are fish in the wild population that are equally difficult to catch - or not. |
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Location: Eagan, MN | Larry, I pm'd you. Brian |
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| I'd agree that there are different behaviors present among muskies. Some of that is likely due to conditioning taking place. As to whether it's affecting the characteristics of the overall population genetically, I have some doubt about that. If we were harvesting fish and losing great numbers of them to delayed mortality, I could see it over many generations. I think that the "aggressive" fish that are harvested at a large size have already had many seasons to propagate, so their genes are already out there. Furthermore, a 'learned behavior" does not necessarily exist in the genetic makeup of that fish, so those that "learn" to avoid lures are not creating offspring that are any less likely to be catchable.
Adaptation is not evolution.
If your argument is that the easy to catch fish are slowly being taken out of the gene pool due to harvest and delayed mortality, I'd have to ask how many and how often and to what extent that really alters the makeup of the entire population. I suspect that it's not very much at all.
Edited by esoxaddict 10/8/2014 12:24 PM
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Location: Eagan, MN | Learned behavior and genetic pre-disposition to aggressiveness are two different things. We're only talking about genetic pre-disposition to aggressive feeding here. And, consider that a fish genetically pre-disposed to being aggressive can and are caught from when they are little tykes to the time they are giants. Each encounter has some degree of risk to them in terms of mortality. An immature, non-spawning feisty 28"er that is pre-disposed to aggressive feeding is as likely to be culled from the potential gene pool by a poor release result as a mature, annually spawning 48"er. The common thread is their, apparently inherited, pre-disposition to aggressive feeding and increased propensity to bite angler offerings. That they learn avoidance behavior - or not - is another matter.
I just think in today's time, if you are able to catch a giant in a heavily pressured body of water, you have really done something. Quite an accomplishment for an angler. If you are able to find unpressure bodies of water, and can exploit the population that lives there, enjoy it while it lasts...and don't tell a soul.
Edited by BrianF. 10/8/2014 2:01 PM
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Location: Rhinelander, Wisconsin | I'd argue vehemently with the entire premise. |
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| What's a giant muskie in MN 55" +? Very few giant muskies = Very few caught, the funny thing is ML and Vermilion (two pressured lakes) kick out the most, why? because the most live in those waters... there are 14lb+ walleyes swimming around MN too, very few caught - Are muskies "smarter" than walleyes? I highly doubt it ....consistently catching trophy10 lb + walleyes is no easy task....Trophy muskie is 50" right? to me trophy muskies are easier to pinpoint than trophy walleye's....but both are very obtainable goals on the right water (heck maybe 4-5 a day, when all conditions are right)....we are talking about fish, they don't live by the rules of the land... Watch them on a small lake like I do 40+ days a year, when a muskie chooses to eat your lure, it has nothing to do with them being "smart" ...the same fish that shows extreme caution three days in a row, may go crazy the 4th day and crush the same bait it saw the previous 3 days, seen it often ....they are all catchable under the right conditions....or they never eat and die - that sounds like one of the really "intelligent" ones.
Edited by IAJustin 10/9/2014 1:56 PM
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Location: Black Creek, WI | So... if IAustin is correct... then all it takes to catch the biggest fish in the lake is to be in the right place at the right time. Just stay on them until they decide to feed. Sounds easier than it is.
IAustin's statement....they are all catchable under the right conditions.... is what I think BrianF is getting at. Do these conditions change based on Angling Effects and its impact on the resident fish population? Whether its conditioning, selective harvest/delayed mortality of aggressive behavior genetics, or some other influence... the question being asked is why does a lake seemingly get more difficult to achieve success as angling pressure increases? The windows of "the right conditions" seem to get smaller and less frequent.... and as an angler... our quest is to find ways to open those windows on a more frequent basis.
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| jlong - 10/10/2014 9:22 AM
So... if IAustin is correct... then all it takes to catch the biggest fish in the lake is to be in the right place at the right time. Just stay on them until they decide to feed. Sounds easier than it is.
Moose and Hennepen come to mind 
Edited by IAJustin 10/10/2014 10:08 AM
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Location: Rhinelander, Wisconsin | mnmusky - 10/8/2014 7:05 AM
I dont think they are dumb for fish. One of the few fish that can actually "think" to some degree. Ive seen instances where they are more than mere robots or genetically programmed. Smart? No! but to be an apex predator, one must be of more intelligence than the prey as luck wont get you to giant size.
No. They do not 'think'. They are quite dumb, actually. And 'luck' is exactly how any fish makes it to maximum size.
Look up anthropomorphize.
'So... if IAustin is correct... then all it takes to catch the biggest fish in the lake is to be in the right place at the right time. Just stay on them until they decide to feed. Sounds easier than it is. '
Actually it IS that easy. And that difficult. Knowing where that fish is and presenting a lure to it until you catch it is the challenge...and the more of them there are, the easier it is. |
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| ^ just Google "can fish think" and read a few hits..of course we humans can't prove this one way or the other so "faith" in your experiences or beliefs must sway one to believe one way or another. That's what I think anyway until proven wrong. |
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Location: Eagan, MN | Read this...Genetic Effects of Harvest on Wild Animal Populations by Fred W. Allendorf, Phillip R. England, Gordon Luikart,Peter A. Ritchie, and Nils Ryman...and tell me if they would agree that 'luck' is exactly how fish attain maximum size. I'm sure luck plays some part, but so do many other variables, including apparently angler exploitation. After researching the issue scientifically this team of researchers state the following, "Many resource managers have been reluctant to accept the potential for harvest to cause genetic change, and many are doubtful that any such changes are harmful. However, intense and prolonged mortality caused by exploitation will inevitably result in genetic change. Harvest need not be selective to cause genetic change..."
When I hear stories from a waitress at a restaurant on the shores of Lake Vermilion who tells me that one of her customers caught and harvested a musky bigger than the angler's 6 year old son - and produced a photo showing the harvested fish next to the boy as photographic proof of the claim - and the next day catching an even larger fish from the same spot and also harvesting that fish - a part of me thinks, "Hmmmm, that kind of harvest could someday impact this fishery." Seems to me that the research is backing this up, but maybe I haven't seen all the research or understand the results correctly.
Brian
Edited by BrianF. 10/15/2014 8:28 PM
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