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| Where did the pic of Larry w/ the frozen fish go? |
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Posts: 8772
| SV - 4/12/2011 6:53 PM
Where did the pic of Larry w/ the frozen fish go?
Left it in the freezer too long, it evaporated away to nothing...  |
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Posts: 574
Location: Elk Grove Village, IL & Phillips, WI | Look in the report on the first post. |
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Location: Green Bay, WI | fins355 - 4/12/2011 2:20 PM
...SNIP
Molds are used in forensic science and criminal investigations and in general science extensively.
When done properly they are about as good as a fingerprint, an EXACT duplicate of what was molded.
Kevin Hockley's mold appears to be very well done which one would expect from a museum taxidermist.
DougP
Wow Doug, I had no idea how involved that process was. It does sort of suggest that the fish that went into the molding process, is the exact same one that came out.
So I wonder if anyone has actually asked the taxidermist's opinion about the stated size of O'Brien's fish? Surely someone must have, but I probably missed it somewhere. Larry probably knows, I'll bet...
TB |
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| Tom, I don't see how examining the skin mount, or asking for a taxidermist's "word on it" could have been any more beneficial for the purpose of this report. I think this short report contains everything he needs, and should put the fishing world on notice that you should not trust a persons word over hard scientific evidence.
In my mind, if something like this can happen onshore with lots of people present and fish in hand, where does that leave the status of the line class and released records. My thinking is that they will all eventually be dominated by the best/worst liars, even more so than the weight divisions. |
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Location: Green Bay, WI | I cannot argue with most of that, I guess...
It is a shame though, this "pursuit of records" mentality. Not that all record holders go out and consciously pursue a World Record specimen, but it seems as though some do...at least in the Musky world. I have no issue with a person who is in search of the largest fish of a particular species--more power to them, especially if they should be good enough (and lucky enough) to catch it. But it sort of just illustrates another ugly vice that many humans seem to have: Greed.
How else can you explain conscious efforts, perpetuated ad infinitum, to misrepresent something like this for one's own gain? I hate World Records. I don't even see why we need them, to be honest. Never have, never will.
Having said that however, if I were wealthy and had the means to not need to work, I'd launch on a 20-year mission in search of the World Record musky. I'd travel to the "best" big fish spots, talk to the "best" local anglers, see the sights that these places have to offer. And I might even wet a line now and then!
At the very least, I'd have a reason to go fishing and remind myself how nice it would be to not have to work...
TB |
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| Agreed, especially the having to work part! I think the research provided was not only beneficial in finding the record (or rather not finding it), but more importantly determining the optimum size the species can acheat... I mean achieve:)
I would think that as a man of science and muskie researcher for MI, this no 70lb muskie revelation is of particular interest to you. It will be interesting to see how biologists and fisheries personnel interpret this new found information. |
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Location: Green Bay, WI | On the contrary...I feel quite strongly that muskies can reach weights of 70 pounds, given the right ecosystem (like Green Bay, for example). Combine good genetics, an unlimited forage base, no natural predators and a HUGE expanse of water to hide in, and I think we could see a true blue 70-pound fish come from the bay system. In fact, there are many people who believe that Ryan Dempsey's April 2005 fish (caught out-of-season while walleye fishing) was that record fish. If you run the numbers, it's certainly feasible.
I don't want to hi-jack this thread, so I'll stop here. But if you want to read more about the potential of the fish we have here, skip on over to the Research forum, and search for some topics I posted in. There's one in particular about growth rates using the current growth model (which I and many others feel to be under-estimating the true potential), that will open your eyes a bit. Don't let the calculus in there scare you though, lol.
Back on point... While I am quite convinced of the weight potential of these fish here, I am not entirely convinced of the potential of reaching 62, 63 or even 64 inches in length. That remains to be seen here; and anywhere really. If you look at my math in that thread, it does go into how long the fish keep growing in length, but there was an article by Minnesota Fish Biologist Rod Ramsell a few years back, where he talked about the point (age) at which the fish--especially females--stop devoting much energy into somatic growth, and start shunting it into gonadal growth. I'd like to find the paper because I don't have it any longer, but it was a very interesting article. But the take-home message is that I don't believe it will take a 60" fish to break 70 pounds...not here in the Green Bay system, anyway. It will be VERY interesting to see what this population does after a few generations of fish have passed though. We're still on the first generation, for the vast majority of stocked fish, and of course we're not at all sure how/where/if they are reproducing to any great degree.
But that's a discussion for another thread though.
TB
EDIT: Here's the thread if you care to review it:
http://muskie.outdoorsfirst.com/board/forums/thread-view.asp?tid=50...
Edited by tcbetka 4/13/2011 1:11 PM
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Location: Hayward, Wisconsin | Tom:
Thanks for posting that link...somehow I missed that thread. I see the age of the Williamson fish from Georgian Bay was corrected by bytor. According to recent correspondence with Dr. Casselman, the O'Brien fish, also from Georgian Bay, was the oldest female he has handled and he is confident now it was 30 years old...Also, he noted that he had a MALE from the St. Lawrence River that was also 30 years old!! And he noted, that it had "scars" from several encounters of being caught/handled.
As for the Green Bay giants/spawners showing up in the fall, several tracking studies from Quebec (Ottawa River); NY/SE ONTARIO (St. Lawrence River); ON (Stoney Lake), have shown that muskies return to their "spawning areas" in the late fall, where they overwinter, which likely explains your GB situation.
Edited by Larry Ramsell 4/13/2011 1:47 PM
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Location: Green Bay, WI | Right...I've read a few of those same studies, I think; and I believe this is now why the DNR plans to stock (when the stocking is re-started; I'm not sure when this is planned) in several other areas of the bay system. If we have lots of water to support muskellunge, then I say we take advantage of as much of it as possible to reduce angling pressure on some of these fish.
TB |
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| The O'Brien fish doesn't appear to jibe very well with the von Bertalanffy growth model. It was supposedly 30 years old and yet only 54".  |
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Location: Green Bay, WI | Well, that VbL model was for Green Bay fish...while O'Brien's fish was from Georgian Bay. There is a different curve for that population. I have it someplace, or at least a more recent one, and I could dig it up tonight if I get the time.
I haven't checked his fish against the curve, but my guess is that 58" would fit better than the 54" does.
TB |
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| So if the 54" length doesn't fit the curve, how does that affect the reported age? |
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Location: Green Bay, WI | Well, if the cleithrum was aged at 30 years, then I'd say it doesn't! I've never aged a cleithrum before, but my understanding is that it's quite sensitive and accurate, unlike scales which have annuli that get pretty rough and ratty as the fish ages past 9-10 or so. The annuli also get closer together, making it harder to interpret distinctions between them--and also making it more difficult to back-calculate annular growth rates from the data.
I am not entirely sure to what age the cleithra are felt to be accurate though, now that I think about it. I am certain that they are more useful for older fish, but I am not sure *how* old they are useful to. But Dr. Casselman apparently was able to determine the age of the O'Brien musky out to 30...so maybe age isn't a significant limitation like it is with scales.
TB |
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| With muskies, length is a product of age. At this point, from what we now know about the length of O'Brien's fish, I would say the age is also suspect. |
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Location: Eau Claire, WI | Huh. I thought I had heard Cassleman say that weight is a product of age while length basically stops many years before. You may pick up fractions of an inch over time later in the life cycle but the weight goes up until a point where the body deteriorates with age as any body will.
I think I have it on a VHS tape somewhere. It came from a presentation he made in Eau Claire when we hosted a Muskies Inc. Board Meeting.
Can anyone help me out with a confirmation?
Jono
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Posts: 280
| Jono, I think length is certainly a product of age, at least to a certain point when length may cease to a large degree and weight may continue.
You wouldn't expect to see a 50" fish in 5yrs. Age must be reached for a certain length to be viable.
DougP
Edited by fins355 4/13/2011 5:10 PM
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| weight diminishes after Peak life period,like most living matter
Fish dont continuously grow till death,some attain great lengths some dont,just like all living matter
actually I covered it in a piece I wrote about "Muskies limitations" which Sean Lansdman and many others important biologist concur to limitations of most if not all species and living matter
marc |
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Location: Green Bay, WI | Actually, I believe that I have read that fish continue growing until they die, basically. I am not sure of the reference though, so I'd have to look it up again--but it's less likely to be true for very old fish, as Marc alluded. But the thing is that they apparently devote different amounts of energy into somatic growth, versus gonadal growth. I sent Rod Ramsell an email this afternoon, asking for a copy of that paper. If I can get one from him, I'll summarize it here for everyone--unless he points me to a publicly available version, and then I'll link to it.
Two other points of interest though:
1) Different fish have different growth potentials. The von Bertalanffy growth curve for the female fish in Green Bay shows the estimated length at a given age for the average female fish. This means of course that there are fish that grow faster than the average, and there are fish that grow slower. That's the definition of the term 'average,' for the most part. So the O'Brien fish could have been a slow-growing older fish, and Dr. Casselman's age assessment could be right on the money. I'd wager that he's forgotten more about the biology of muskies than most of us will ever know, so I for one am giving him the benefit of the doubt on the age assessment for that fish. I find it HIGHLY unlikely that he would have falsified his age estimate to support a misrepresented fish. His credentials are beyond reproach as far as I am concerned, so if he says the fish was 30 years old...it was 30 years old. Enough said.
2) The other thing is that, if you differentiate the von Bertalanffy grow curve with respect to time, you'll get the average rate of change of length per unit of time. In other words, you'll get the growth rate. From one of my posts in that other thread (for the Green Bay fish, using the original model developed by Kapuscinski et al), you get these values:
dLt / dt = 12.72mm per year; t = 14.33 years
dLt / dt = 1 mm per year; t = 29.29 years
So the average female fish in that population (at least according to that model) are growing at about one-half inch (12.7mm) per year at 14.33 years old, and only 1 mm/year when they are 29 years old. Now, given that the model was based on an immature population, this might all change. In fact the model has since been updated, but I don't have a copy of the new equation--so I don't know how different these growth rates would be now. Also, don't forget that the female fish in Georgian Bay have a different growth model, so you cannot compare the average growth rate of those fish to the average growth rate of the fish in Green Bay, unless you use the appropriate model for that population.
Incidentally, according to the model, the average female muskellunge would be 47.1" at 10 years of age, as can be seen in that other thread. So Doug's statement certainly bears out in the Green Bay population.
TB
Edited by tcbetka 4/13/2011 6:00 PM
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Location: Hayward, Wisconsin | Tom:
What would the growth curve look like for a 54 inch fish KNOWN to be 10 years old? Bet that would be a dandy. Happened in Wisconsin...with Minnesota fish! |
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Location: Green Bay, WI | What a freak! That thing had a pituitary disorder; or else someone was hand feeding the thing Ciscoes laced with Growth Hormone, lol!
Sheesh...
TB |
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Location: Hayward, Wisconsin | Actually not Tom. It was only the largest (38 pounds) of several 10 year olds that were over 50 inches! And this was in a lake the WDNR said had a low forage base (no cisco's) and an over population of stunted northern pike!! |
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Location: Green Bay, WI | That girl was on a diet at only 38 pounds! Either that or there's not much fat on a stunted pike...
TB |
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| John Casselman says the average maximum length for Georgian Bay is 52.8" and the ultimate maximum length is 58.5". According to him big waters consistently produce thick-bodied muskie with slow, steady growth rates over a long lifespan. Besides girth, length is the most important factor determining weight, and length comes with age. O'Brien's fish was a female, 58 inches in length (147.3 cm) and 30 years of age.
So, the true length of O'Brien's at 54" suggests the fish wasn't 30 years old and that it was just slightly above the average maximum length for Georgian Bay. Being it came from Georgian Bay also suggests it had a slow, steady growth rate.
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Location: Green Bay, WI | Don't forget that there is a confidence interval built around that average maximum length value--probably a 95% interval. In other words, if the average maximum length is 52.8 inches, then the biologists will have calculated an interval around that value, such that an "average" fish can be expected to fall within it 95% of the time--or with a 95% (0.95) probability. So the probability that an average fish wouldn't fall within the interval is 0.05, or 5%.
I am recovering from surgery and not getting around very well quite yet, so I haven't gotten a chance to dig through my library and find the reference with the von Bertalanffy models for the various water bodies. So without the actual equation, I cannot say how long the average 30 year-old female fish would be expected to be. But we may find that, since 58.5" is the average ultimate length (AUL), a length of 54" is well within the interval outlined by the model. I will try to dig this up within the next day. EDIT: This AUL might actually be the top of the 99% CI, I am currently researching this.
Another possibility with these calculated lengths, because they are obtained from equations built on models from gathered data, is that the data is incomplete...or just plain wrong. In fact this is exactly what we've argued in Green Bay, because the vast majority of the fish used to build the model, were stocked in 1989 or later--obviously within one generation, in terms of a musky's lifespan. However since there have been muskies in Georgian Bay for many, many years, I would expect the growth model for that population to be about as accurate as we are going to get. If you want some background on these growth models, here is a link that gives some basic info on the fellow who developed the concept:
http://en.wikipedia.org/wiki/Ludwig_von_Bertalanffy
While it's been a number of years since I've studied the background theory of this general model, I do seem to recall that it is most accurate when applied to a stable population. This would seem to make sense I suppose, given that the complete size structure may not be fully represented in samples gathered otherwise. And while this could very well be the case with the early Green Bay models, I wouldn't expect it to be so with the model from Georgian Bay. Note that I am not criticizing the Green Bay data in any way however--it's just that I feel the data gathered there thus far is from an immature population. The accuracy of the model will only improve here, as more fish are added...especially large fish.
TB
EDIT: By the way, the 95% CI for female fish in Green Bay in the Kapuscinski (et al) model was 46.2" - 60.4". Not exactly going out on a limb in terms of pinning down how large the fish could ultimately get, but I believe the model may have been since revised--so that interval might have tightened somewhat.
Edited by tcbetka 4/14/2011 3:47 PM
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| 54" is much closer to the average maximum length of 52.8" than it is to the ultimate maximum length of 58.5" therefore the probability of the fish being less than 30 years old is much greater than it being 30 years old. If 54" falls within the interval outlined by the model I don't feel it has much value. John Casselman hasn't even aged any other muskies at 30 years old. I'm not saying it's impossible for the fish to be 30 years old, just highly unlikely. |
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Location: Green Bay, WI | OK, one thing I just found, is that just as the average maximum length (AML) has a confidence interval around it, as does the average ultimate length (AUL). They are both mean values, as their names state. Therefore each could have a confidence interval calculated for it. Now I just need to find the relationship between the AUL and the top of the confidence interval (either 95% or 99%) for the AML. I thought that there was one, but now I am not sure and I haven't found it just yet. But I did find my reference, so I just need to spend some time digging through the papers, and I should be able to find the published model for the Georgian Bay population.
By the way, the reference that I am using is the compilation of manuscripts from the 2005 MI Muskellunge Symposium. So if you can lay your hands on a copy, you will probably have all the Georgian Bay data as well.
TB |
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| It just seems to me that a muskie reaching 30 years of age in a body of water having a maximum ultimate size of 58.5" should be longer than 54". The odds are either it was aged wrong or it was 58". |
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Location: Rhinelander, Wisconsin | 'It just seems to me that a muskie reaching 30 years of age in a body of water having a maximum ultimate size of 58.5" should be longer than 54". '
Not necessarily. Getting old doesn't necessarily equate to getting big; that depends on each fish and everything that's happened to that fish in it's lifetime.
Although I am getting old, and WAS recently growing allot. Now I'm shrinking. Not as fast as I grew, but there you have it. |
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| Guest - 4/14/2011 4:32 PM
It just seems to me that a muskie reaching 30 years of age in a body of water having a maximum ultimate size of 58.5" should be longer than 54". The odds are either it was aged wrong or it was 58".
Or maybe every fish in the system doesn't reach the maximum ultimate size in 30 years, if at all... |
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