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Location: Rhinelander, WI | The post on the information and links thread got me thinking, I didn’t want to hijack that thread so I started this one.
Is it not the case, muskies that spawn over shallow dead weeds do have problems competing with pike? Because, pike traditionally spawn in the same areas earlier in the season, thus when the muskies hatch the baby pike have already had a few days/weeks to grow and are ready to eat the baby musky as they come out of the eggs.
Also is it not proven that Mississippi River musky spawn deeper? Thus, giving the musky fry a extra level of defense from the bigger pike fry. They are not instantly in harms way.
IF, you could get them to reproduce naturally, wouldn’t common sense dictate the deeper spawners have a better chance of competing with pike?
Nail A Pig!
Mike
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Location: Northwest Chicago Burbs | What I HAVE HEARD, though I have no proof of this in my hands, is that the Leech Lake fish tend to spawn in the same areas as the WI strain fish, when put in the waters of NW WI.
And yes, they do compete.
Edited by Slamr 11/9/2005 9:47 AM
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Location: The desert | Yes they do compete, but my line of thinking as that they are also in competition of other fish or wildlife as well. Everything competes from plants to animals. That would be a great research topic to investigate to see the effects of competition between the Esox genus. |
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Location: Rhinelander, Wisconsin | I should have a study linked for you on this issue tomorrow. |
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| Mike, there is no doubt that northern pike fingerlings can and do eat muskellunge fry wherever the two species have used the same spawning area. This phenomenon was documented long ago by Wisconsin DNR researchers. The question scientists still need to answer, however, is "How significant (or insignificant, as the case may be) is this source of mortality in relation to all the other known sources of mortality of young muskellunge during their first year or two of life?"
This is a very important question, yet it has not been answered due to the high expense of determining with confidence the relative contribution of various factors causing mortality of young muskellunge in a wide variety of habitats with different fish community types. Many of my colleagues and I suspect that northern pike can, under some conditions, repress the recruitment (I'll define as survival to 20") of muskellunge, not so much because of what happens on or near the spawning ground, but rather because of what happens all year in the relatively shallow nursery habitat (weedbeds or shallow woody cover) that young muskies and their predators cohabitate throughout the year.
In the weedbeds or flooded terrestrial vegetation, young muskies have several predators year round, including northern pike up to 24-26" (bigger ones tend to spend mid-summer in deeper, cooler water if available), sub-adult and adult muskellunge (unabashed cannibals), and largemouth bass of all sizes. Largemouths often are overlooked as potential predators on muskellunge, yet researchers in Ohio and Illinois have demonstrated that largemouth bass predation is a major factor limiting the recruitment of muskellunge in bass-dominated fish communities. Unpublished data for small lakes in the Chequamegon-Nicolet National Forest suggest that musky recruitment is very low whenever we capture largemouth bass at rates exceeding 40 per hour in fall electrofishing samples. Keep in mind that largemouth bass populations are on the rise in many Northern Region waters, probably in response to favorable weather conditions and increased protections afforded to bass starting ~1998 (14" statewide length limit and a seasonal harvest restriction).
There is no doubt that muskellunge need high-quality habitats in order to reproduce and survive to adulthood. But once the eggs have been laid on suitable substrate, assuming reasonable weather conditions, the ultimate recruitment of muskellunge is likely to be governed by what happens in each body of water throughout the year, not just in the week or two following hatching when young northern pike fingerlings may eat some young musky fry. Young muskies must "run the gauntlet" if you will, all year and well into the next year, until they are large enough to avoid predation by most potential predators. Because young muskies have a habit of dispersing rather evenly into suitable nursery habitats, they are subject to year-round predation by whatever northern pike, muskellunge, and largemouth bass may be using those habitats at any given time. I strongly suspect that predation by these fishes throughout the year is the real limiting factor to muskellunge recruitment. The better the habitat for muskies, and the more alternative prey (perch, suckers, bluegills, etc.) available to the predators, the better the odds for survival of young muskies. I wish we knew more, and sometimes I wish it was not quite so complicated; but that's what makes it so interesting!
All this has implications, of course, for the ongoing debate over the alleged superiority of Leech Lake strain fish. Proponents of stocking this strain into the native range of muskellunge in Wisconsin believe it will recruit better than native stocks in waters with northern pike because the Leech Lake fish generally spawn over offshore reefs when available, away from the shallow, near-shore habitats selected by spawning pike. That may, in fact, confer a brief (couple weeks???) advantage to young musky fry upon hatching in waters like Leech Lake. But once they disperse into traditional nursery areas, young Leech Lake strain muskies may be just as vulnerable as any other strain of muskellunge to predation by sub-adult and adult northern pike, muskellunge, and largemouth bass. There is so much we do not yet know. I wish the proponents of stocking Leech Lake fish into the native range of muskellunge in Wisconsin would acknowledge that uncertainty and stop trying to justify a genetically ill-advised stock-transfer proposal on the basis of one known pike-musky interaction that may or may not prove to be important in the final analysis.
Good question, Mike. I appreciate the opportunity to share my opinions about what we know and what we don't.
Dave Neuswanger
Fisheries Team Leader, Upper Chippwa Basin
Wisconsin DNR, Hayward |
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| Mr. Neuswanger,
Genetically Ill-advised? Was wondering if you could explain that statement. Has there been any determination yet that the Leech Lake/Mississippi Strain would cause genetic harm if stocked in Wiscsonsin waters that have no known native musky stocks? Correct me if I'm wrong, but the material I have read has indicated that greater than 85% of Wisconsin waters are dependent on stocking to maintain (i.e. no natural reproduction) viable musky populations. That would lead me to believe that in a vast number of waters, the current musky stocks were never native to that water to begin with and a switch to LL/MS strain would be nothing more than switching the source of fish in a put and take environment. It seems by your statement you have already made the conclusion that stocking the LL would be the wrong course of action without any scientific support.
And again, through my reading, I don't think that Leech Lake is the only location where it is proven that the LL/MS strain has successfully reproduced in a water with a substantial Northern Pike population. The recent nettings done at Nancy Lake have proven that reproduction occurred, even with the limited stocking done on that water.
Now I will grant you that I agree that many other factors play into whether reproduction success will occur (water quality, predation by other species and availablity of spawning areas). However, if there is proof that a certain strain can and has successfully coexisted with a competing species, I would be in favor of using that strain over one that has not shown results.
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Location: Rhinelander, Wisconsin | Thanks for the information, sir, we appreciate it. I have the report 'Lake Characterstics Influencing Spawning Success Of Muskellunge In Northern Wisconsin Lakes' ready to go, I'll make an album of the sheets I scanned for everyone to read and link it here.
http://muskie.outdoorsfirst.com/board/photos/photo-thumbnails.asp?a...
Click on the first photo, then click 'next' to get the next page. |
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| Please refer to this material as well:
http://muskie.outdoorsfirst.com/board/forums/thread-view.asp?tid=22...
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Location: Rhinelander, Wisconsin | I know that there are many locations in Wisconsin where NR occurs with Northern Pike available in numbers, but have no idea what that means when compared to say, the Chippewa Flowage. Dave, I have a question. I know of a 230 acre lake here in N Wisconsin LOADED with pike. It hasn't been stocked with muskies in decades, but was once from what I can find, and is not considered 'natural range'. I caught three pike last winter in one evening over 36" there on tip ups, and one was 42". An average day spinnerbaiting the pads will yield a limit of nice pike and Largemouth.
There is a strong population of Muskies there. Two were caught that were over 50" this summer, I saw pictures of both and know the anglers who CPR'd the fish. My best there was low 40's, but I only started fishing it for muskies last year, before that I fished it primarily for panfish.
I have had 5 fish days there with muskies running from YOY to about 38" very common , at least that's what I catch and see in numbers. Some days we would see 25 fish in that size range to the occasional big girl.
Is this an indication that natural reproduction can and does occur in some waterbodies by WI strain fish, with a representative sample reaching 50" side by side with a strong population of Pike? Is this an anomoly, the norm, or are there too many variables to have either as a clear indication? Is there a big difference between adaptation to pike here in the North to the waters in the NW? Sorry, I guess that's several questions...  |
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Location: Mauston, Wisconsin | Steve-I agree, it seems that each body of water needs to be accessed based on it's own unique characteristic's, i.e., there is no magic bullet. Yes, there are big spotted ones out there. But I've also seen a couple of really huge barred strain muskies (almost scary, imagine a fish with a +12" wide head & girth to go with it) in Canada. These fish make 50"rs look small. I don't think it's a matter of what we can stock in Wisconsin, but what the regional DNR biologist feels is right for the specific body of water. I'm looking forward to the next 10 years as we definitely have some up and coming fisheries and also well established fisheries with huge potential in Wisconsin. I think preditation works both ways, once the muskie reaches a sufficient size, the pike better watch out! Where I fish here in Central Wisconsin the biggest problem is the # of large fish kept and/or the number killed by other species fisherman through miss handling. I personnally know of two 50" class fish that were kept this year in a ~ 2 mile stretch of the WI River.
Have fun!
Al
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| MuskyMonk, you ask a few challenging but legitimate questions that deserve an answer. Here’s what I know…
MONK: Genetically Ill-advised? Was wondering if you could explain that statement.
DAVE: Sure. Fishery biologists all over North America have become increasingly aware that combining fish from two distinctly different stocks (often called strains) can cause what the population geneticists call “outbreeding depression.” This has been documented in salmonids, largemouth bass, and many other species. I believe I have addressed the phenomenon elsewhere on this site (please check previous threads for details), but I’ll summarize briefly here. In a nutshell, if sufficient numbers of adult fish from two distinctly different stocks mate successfully, their second-generation progeny (grandchildren in a way) and subsequent generations may no longer possess the co-adapted gene complexes that may have existed and conferred a fitness advantage to the original stocks in their native waters. This phenomenon is difficult to describe without the benefit of illustrations, so I’ll ask you to trust that this is a real phenomenon and a legitimate concern, even though it has not yet been documented in muskellunge because of the sampling effort required to do so.
MONK: Has there been any determination yet that the Leech Lake/Mississippi Strain would cause genetic harm if stocked in Wisconsin waters that have no known native musky stocks?
DAVE: Obviously if there is no existing muskellunge population in a Wisconsin water, the stocking of this exotic strain would cause no genetic harm UNLESS it could emigrate from the stocked system into native musky waters OR it could be moved illegally (e.g., in live wells) to nearby waters by well-intentioned but misguided proponents of the exotic strain. This may seem like a long shot, but we suspect this is one mechanism for the expansion of northern pike into many waters where pike did not exist previously. The WDNR is allowing some limited stocking of Leech Lake strain fish into select waters south of the native range because we previously identified those waters as “universal receptor” lakes where native fish populations could not be harmed.
The basic premise of your question deserves some attention. Proponents of stocking the Leech Lake strain of muskellunge into the native range of muskellunge in Wisconsin have tried their best to make “Mississippi River strain” synonymous with “Leech Lake strain.” Some of these proponents would have you believe that these “Mississippi River strain” fish WERE the native fish in much of Wisconsin before we (WDNR) somehow replaced them with inferior products of our hatchery system. In reality, all our North Country muskellunge had a common ancestor that “wintered” the last Ice Age in a lower Mississippi River refugium, but when they expanded north with the retreating glaciers there was divergence in stock structure based upon adaptations to local climates, habitats, and fish species assemblages. We’re not sure how many truly different “stocks” exist today. That’s one reason why the UW-Stevens Point study will be so important. But we’re quite certain that Wisconsin fish were different from Leech Lake strain fish before Europeans settled the area. So let’s call fish from Leech Lake the “Leech Lake strain” and not the “Mississippi River strain” in order to avoid creating the misperception that these fish existed almost everywhere in the Mississippi River watershed in MN and WI.
MONK: Correct me if I'm wrong, but the material I have read has indicated that greater than 85% of Wisconsin waters are dependent on stocking to maintain (i.e. no natural reproduction) viable musky populations.
DAVE: Actually, only 149 of Wisconsin’s 711 musky waters (~21%) are known to be totally dependent upon stocking due to the lack of natural reproduction. Details can be found on the musky page of WDNR’s website.
MONK: And again, through my reading, I don't think that Leech Lake is the only location where it is proven that the LL/MS strain has successfully reproduced in a water with a substantial Northern Pike population. The recent nettings done at Nancy Lake have proven that reproduction occurred, even with the limited stocking done on that water.
DAVE: I encourage you to obtain DNR biologists’ DIRECT interpretation of their data. I was not there, but some very good biologists were. What they actually found was a remnant population of Leech Lake strain fish, capturing only 6 fish in 78 net lifts. Compare this with the Wisconsin average of 1 adult musky per net lift and it begins to put things into perspective. Critics say the researchers did not sample long enough, but they are wrong. Our biologists sampled several days over a range of spawning temperatures and suspended their netting efforts only after capturing large females with free-flowing eggs. Everyone who has spent two weeks freezing on the bow of a net boat every spring knows that you capture male fish during at least a two-week period leading up to the time when females have ripe eggs and are ready to spawn. If you don’t catch lots of males and some immature females during that time period, they just aren’t there. This was the case at Nancy Lake in spring 2005. Two of the six fish captured during this solid effort did not exhibit evidence of fin clips and therefore may have been produced naturally unless their fins regenerated so perfectly that the clips were undetectable. It happens. Regardless, reporting that 33% of the muskies captured were the result of natural reproduction is a bit like reporting that 50% of your eyes are watering. If there had been significant natural reproduction in Nancy Lake, our researchers would have caught some smaller adult and sub-adult fish. For experienced biologists, there is no uncertainty about this.
MONK: Now I will grant you that I agree that many other factors play into whether reproduction success will occur (water quality, predation by other species and availability of spawning areas). However, if there is proof that a certain strain can and has successfully coexisted with a competing species, I would be in favor of using that strain over one that has not shown results.
DAVE: I appreciate your open-minded acknowledgment that factors in addition to genetics may play an important role here. Thank you for your polite questions. I hope my answers are helpful.
Dave Neuswanger
Fisheries Team Leader, Upper Chippewa Basin
Wisconsin DNR, Hayward
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Location: Ogden, Ut | wow; good stuff
S. |
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Location: Rhinelander, WI | Great stuff, thank you for all the great responses.
If there is merit to the Riverine (evolved in presence of pike) and Lacustrine (evolved without pike) theory of musky evolution, is it possible that Northern Wisconsin has it’s own two distinct strains? Similar, yet different than the Leech Lake and Schopak strains. Please forgive my spelling if I screwed any of those words up, but I think you all understand what I am trying to say.
How widely is THIS two-strain theory accepted by fishery biologists across the U.S. and Canada? If it is accepted there are obvious questions on what caused the two different strains, pike or some other factors.
With the work Dr. Sloss is performing, will he be able to distinguish if these two types of musky exist? Is it even something that is being looked into?
Nail A Pig!
Mike
Edited by MRoberts 11/10/2005 10:31 AM
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| The concept that the netting was aborted too early and as a result missed the 'run' was addressed in several communications we had with the biologists in charge of that project. MuskieFIRST spoke with the person managing this study and with others involved in fyke netting activities across the muskie's range, including other states. We were told that if very few or no males are captured early in the process and few or no mature but smaller females are captured later, and that free flowing spawning is observed upon handling (which Mr. Benson Sr. posted elsewhere was definitely happening) that signals the end of the spawing 'run' of a limited population, not the beginning. Several nets were moved during the study to maximise capture potential, with 9 deployed for almost three times the average timeframe usually devoted to a fyke netting project, and placed where earlier studies had captured LL fish from Nancy with good success.
The goal of this study was to determine if Nancy Lake could be used as a brood stock lake to acquire material for the hatchery production of LL muskies for stocking in the St. Croix basin. It was determined that less than one fish per day and few representative males/females would cause the necessity to 'hold' fish for a day or more, not an acceptable process, and that the numbers were not sufficient to eliminate concern over inbreeding depression. it was determined that the material would be purchased from the Minnesota DNR. This is significant because the LL fish WILL be acquired and introduced, just not from the Nancy Lake stock. It's really a shame that the population didn't reproduce well in Nancy, they displayed what we all agree LL fish can do under the correct conditions, they grew quickly and reached trophy size in Nancy. It will be interesting to see how those fish do in Wissota and in the St. Croix area, I think everyone has high hopes!
The survey indicated a comparitively small population of LL fish, all adults, were present, but that those fish did not represent a population large enough to use for brood stock purposes. There was nothing else inferred, and no other survey conclusions offered or for that matter drawn as best as we could tell. To attempt to infer any other purpose for this material, or draw any other conclusions including a superior adaptation to Northern Pike populations, appears to not be the intent of the survey. If we learn any more pertinent factual information or data, we will indeed forward it to this discussion immediately. |
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| MROBERTS: If there is merit to the Riverine (evolved in presence of pike) and Lacustrine (evolved without pike) theory of musky evolution, is it possible that Northern Wisconsin has its own two distinct strains? Similar, yet different than the Leech Lake and Shoepac strains?
How widely is THIS two-strain theory accepted by fishery biologists across the U.S. and Canada? If it is accepted there are obvious questions on what caused the two different strains, pike or some other factors.
With the work Dr. Sloss is performing, will he be able to distinguish if these two types of musky exist? Is it even something that is being looked into?
DAVE: Mike, I'm really not an expert in this area. Someone like Michael Butler or Dr. Martin Jennings could answer this question much better. What I CAN tell you is that it is likely that we will find MANY groups of muskies based upon the things we can now measure genetically. I hear no discussion among my colleagues to the effect that there are only two basic types -- river and lake. Also, I am not at all certain that the differences we find among Wisconsin muskellunge populations will be great enough (as they ARE with Leech and Shoepac strains) that we will actually be classifying them as distinct stocks; but there COULD be some. This has all kinds of implications for broodstock selection in the future. If fish from two sources are TOO different genetically, we risk outbreeding depression by crossing them. If we breed fish that are too similar genetically, we risk inbreeding depression. There's an optimal point of diversity within a known stock that we are hoping to tap in our selection of broodstock. Of course, we need Dr. Sloss' genetic stock characterization study (underway now) to begin to understand what we really have in northern Wisconsin. We'll know a lot more in just a couple years.
Dave Neuswanger
Fisheries Team Leader, Upper Chippewa Basin
Wisconsin DNR, Hayward |
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Location: Rhinelander, WI | Thanks again Dave, very interesting stuff. I really appreciated you coming into this public forum and answering these questions.
Nail A Pig!
Mike
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