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Posts: 714
Location: Rhinelander, WI | I have a new research type question for all us bar room biologist to discuss.
Can over stocking on a lake that has been known to produce trophy musky in the past create a stunted situation for musky?
As I have been going over stocking information I came across some interesting stuff that makes me wonder about two lakes that have recently been labeled as being stunted because of over stocking.
Butternut and North & South Twin
Lets look at the stocking history. Forgive me if I make a math error, I will post the raw numbers at the end.
I’ll look at stocking from 1972(data available on computer only goes back that far) to 85 and from ’85 to the last recored year of stocking as I think it has been said that these lake produced many trophy fish in the late 70s through the 80s but during the 90s saw an extreme drop off of trophy fish that many attribute to high harvest of the big fish in the 70s and 80s and then over stocking to compensate. If I have that wrong please inform me.
Butternut Lake:
From 1972-1984 (12 years) was stocked with 22,249 Fingerlings with stocking every year. That’s an average of 1854 fish per year.
From 1985-1999 (14 years) was stocked with 18,000 fingerling with stocking every year through ’91, then in ’93, ’95, and ’99. That’s an average of 1286 fish per year.
So why did Butternut Lake stop handling the excessive stocking? In the last 14 years the actual fish stocked per year went down. Did catch and release catchup with the lake and that is the reason some now think it is stunted? Or are the fish unable to grow to trophy size?
Twin Lakes
From 1972-1984 was stocked with 31,628 fingerlings with stocking closer to every other year. That’s an average of 2636 fish per year.
From 1985 to 1995 is more difficult because from 1985-1989 they stocked 15,184 fingerlings, and from ’89 to ’95 they stocked 128,600 fry. I don’t know the numbers on how many fry survive, but my guess is the average is still less fish per year than the pre 85 numbers.
Again I ask the same questions. What explains the lakes ability to handle the numbers prior to 1985?
Thanks any incite would be great.
Nail a Pig!
Mike
The actual stocking numbers
Butternut Lake
1 1972 MUSKELLUNGE UNSPECIFIED FINGERLING 15.0 500
2 1973 MUSKELLUNGE UNSPECIFIED FINGERLING 13.0 400
3 1974 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 2,009
4 1975 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 201
5 1975 MUSKELLUNGE UNSPECIFIED FINGERLING 13.0 450
6 1976 MUSKELLUNGE UNSPECIFIED FINGERLING 3.0 2,000
7 1976 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 1,000
8 1977 MUSKELLUNGE UNSPECIFIED FINGERLING 3.0 1,200
9 1977 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 1,300
10 1978 MUSKELLUNGE UNSPECIFIED FINGERLING 12.0 500
11 1978 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 1,233
12 1979 MUSKELLUNGE UNSPECIFIED FINGERLING 4.0 2,500
13 1979 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 1,280
14 1979 MUSKELLUNGE UNSPECIFIED FINGERLING 13.0 664
15 1980 MUSKELLUNGE UNSPECIFIED FINGERLING 10.0 2,000
16 1981 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 500
17 1982 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 1,000
18 1983 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 517
19 1983 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 995
20 1984 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 1,000
21 1984 MUSKELLUNGE UNSPECIFIED FINGERLING 10.0 1,000
22 1985 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 2,500
23 1986 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 2,000
24 1987 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 3,000
25 1988 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 2,000
26 1989 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 1,000
27 1990 MUSKELLUNGE UNSPECIFIED FINGERLING 13.0 1,000
28 1991 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 500
29 1991 MUSKELLUNGE UNSPECIFIED FINGERLING 12.0 1,500
32 1993 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 2,000
34 1995 MUSKELLUNGE UNSPECIFIED FINGERLING 8.6 2,000
36 1999 MUSKELLUNGE UNSPECIFIED LARGE FINGERLING 11.8 500
South Twin
1 1972 MUSKELLUNGE UNSPECIFIED FINGERLING 13.0 1,000
2 1974 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 944
4 1976 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 848
6 1977 MUSKELLUNGE UNSPECIFIED FINGERLING 3.0 1,717
7 1981 MUSKELLUNGE UNSPECIFIED FINGERLING 12.0 600
8 1984 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 500
North Twin
1 1972 MUSKELLUNGE UNSPECIFIED FINGERLING 13.0 1,604
2 1974 MUSKELLUNGE UNSPECIFIED FINGERLING 7.0 2,400
3 1974 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 500
6 1976 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 1,184
8 1977 MUSKELLUNGE UNSPECIFIED FINGERLING 1.0 2,106
9 1977 MUSKELLUNGE UNSPECIFIED FINGERLING 3.0 5,289
10 1977 MUSKELLUNGE UNSPECIFIED FINGERLING 5.0 7,123
11 1979 MUSKELLUNGE UNSPECIFIED FINGERLING 8.0 2,500
13 1981 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 993
16 1982 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 1,844
17 1982 MUSKELLUNGE UNSPECIFIED FINGERLING 13.0 476
23 1985 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 2,500
25 1986 MUSKELLUNGE UNSPECIFIED FINGERLING 12.0 2,500
28 1987 MUSKELLUNGE UNSPECIFIED FINGERLING 12.0 7,500
32 1988 MUSKELLUNGE UNSPECIFIED FINGERLING 9.0 1,284
33 1988 MUSKELLUNGE UNSPECIFIED FINGERLING 10.0 600
34 1988 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 600
36 1989 MUSKELLUNGE UNSPECIFIED FINGERLING 11.0 2,000
37 1989 MUSKELLUNGE UNSPECIFIED FRY 3.0 10,800
46 1993 MUSKELLUNGE UNSPECIFIED FRY .4 37,800
51 1995 MUSKELLUNGE UNSPECIFIED FRY .4 80,000
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| MRoberts question is:
"Can over stocking on a lake that has been known to produce trophy musky in the past create a stunted situation for musky?"
This is a very legitimate and appropriate question for the DNR to provide an answer to since the DNR stocking numbers for these lakes completely dismisses what they are claiming is probably one of the main problems in WI with lack of trophy fish. Nice find.
EJohnson | |
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Posts: 1291
Location: Hayward, Wisconsin | Mike:
I personally think your question leads directly back to "what" was stocked. Research Report #172 (1996) clearly shows that Minocqua strain muskies (Wisconsin River drainage-Woodruff hatchery) were stocked into Butternut Lake (Chippewa River drainage-Spooner hatchery responsibility). This, combined with other "mixed strain" stocking from the Spooner hatchery, to me, defines the problem. I am not discounting possible "overstocking," but I still believe that the fish being stocked to be more of a problem than the numbers.
As for North/South Twin, ask some of the guides up that way that have been arguing with various "decision makers" at the Woodruff hatchery over the past 30 years about stocking the small "hatchery strain" muskies there, as well as several of the other "former" trophy producing waters. They are not happy.
While this post doesn't directly answer the question you posed, it certainly must be considered in the overall picture.
Muskie regards,
Larry Ramsell
Wisconsin Muskellunge Restoration Team
www.WisconsinMuskyRestoration.org | |
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I would say somewhat Yes! on all accounts.
Over stocking the wrong strain,Over spearing of the bigger fish,and yes their was harvest.Their also is a strong catch and release on this lake.
If we could eliminate the wrong strain and spearing, the lake would bounce right back. | |
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Posts: 32886
Location: Rhinelander, Wisconsin | 'The Department has several efforts currently underway to improve its muskellunge management programs. Recent studies have shown that overstocking a lake can result in high populations that grow slowly - presumably because of insufficient food. Also, stocking into lakes that have adequate natural reproduction may not increase the population and may actually depress the number of natural fish. The Department is entering year 5 of a major long-term evaluation of stocking rates. Stocking rates have been systematically adjusted on 118 waters statewide depending on the level of existing natural reproduction, and follow up fish surveys are being conducted. Initial results confirm the recent studies and subsequent changes in stocking practices will be made over the next 5-10 years as the results are finalized'
Mike,
This is a paragraph from a letter sent out by Tim Simonson from the DNR. I talked to a couple of the area biologists about this concept and it's pretty well accepted that stocking too heavily will have the effects described. I think that's as close as you need to be to 'stunting'.
EJ,
Ditto. This was an email from the DNR which directly addressed your comments, I think.
Also, look at the expected survival rates in the 4 strain comparison study in Minnesota, with NO angling allowed, and what would be left of these fish after nature has her way, and anglers have theirs. In that study and more that describe actual survival to full potential, the number that make it is a small fraction of the total stocked. That said, there has been a study recently by the DNR on that subject as Mr. Simonson described, and many lakes are being managed differently now as a result.
That's stunting folks, not stunning... 
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| I certainly agree that over-stocking a lake to the point it is over-populated can have an impact on growth. However I'm not sure that is whats going on with Butternut as well as many other lakes in WI. Butternut was talked about by a DNR employee when we met with him a few months ago. He said that Butternut is full of adult muskies in the 34-40 inch size range that don't seem to grow any larger than this. He felt that this was because of over-stocking it. I have my doubts about this being the reason for small muskies in this lake. The stocking numbers don't seem to support this reasoning. Could it be the fish?
So, rather than taking 500 of these potentially small growing strains of stocked fish from Butternut and dumping them into LCO to see if they grow there and potentially damaging it even further, why not put 500 34-40-inch muskies from a known pure strain, or any strain for that matter, that are known and have been proven to grow large and put them into Butternut and study that instead? Why would I or anyone think that our hatchery fish that are stocked into Butternut that don't seem to grow large there would grow any larger in LCO when we already stock LCO with hatchery fish that even under a 50-inch size limit do not grow? What is the difference between taking fish from Butternut and putting them into LCO, than what we are stocking in LCO already? Why do we want to continue to study the same fish over and over in WI and keep finding out that nearly all of them do not grow no matter where we put them? Study after study over the years already shows this. Why do we want to keep doing basically the same study with the same fish over and over? Why keep studying the same fish?
Why not put muskies from a known pure strain, or any strain for that matter, that are known and proven to grow large into both Butternut and LCO and study that? I think this would still answer the question about over-stocking causing stunted populations and at the same time may provide anglers with an increase in trophy fishing opportunities when the large growing strains reach trophy sizes.
The DNR has recently made the following statement: {"Scientific investigations clearly show that Wisconsin musky populations have the genetic potential to reach trophy sizes. However, the trophy potential of a particular water body is dependent on its size, forage base, angling pressure, angling regulations, and musky population density"}. This satement has been printed in several papers recently and without providing any data to support it or where the public can find any data that supports it. So here are a few questions. Where can the public see the data that supports this statement? Why don't the stocked fish in LCO grow? Does LCO have the size, depth, forage, a 50-inch size limit, and everything else mentioned in this statement needed to produce trophy fish? Why do our hatchery rasied fish that "have the genetic potential to reach trophy sizes" not grow when stocked into LCO, a lake with all the right ingredients to grow trophy fish? Why do our hatchery raised muskies that "have the genetic potential to reach trophy sizes" average only 36.4 inches in length at age 9 when stocked into LCO? Is LCO over-populated with muskies? Has LCO been over-stocked with muskies? Is there any chance at all that the problem with LCO and other lakes in WI just might possibly be the fish itself? Is this a possibility? If not, then why does LCO lack trophy fish? | |
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Posts: 714
Location: Rhinelander, WI | Though Eric makes some great points, I am going to try and keep this thread from being hijacked into the same area the other threads have gone. Though the topics do definitely relate.
Steve, I have read the letter from Tim and understand what he is saying but what I noticed with these two lakes is that they where stocked far heavier, at least Butternut for sure, in the 70s and early 80s when they where producing many trophy fish. Than they have been stocked since 85 and they are now clamed to be over stocked.
Butternut ‘72-‘85 stocked with an average 1.84 fish/acre/year. ’85-’99 stocked with 1.28 fish/acre/year.
N&S Twin ’72-’85 stocked with an average 0.77 fish/acre/year. ’85-’89 stock with 1.11 fish/acre/year. ’89-’95 stocked with an average 6.25 fry/acre/year.
I still don’t know how fry survive compared to fingerling, and it appears when you break the numbers out this way the stocking could be more in the last 14 years on N&S twin, but still not convinced. Also according to the internet records on these lakes the last time Butternut was stocked was 99 and Twin was 95, shouldn’t some big fish be showing up with less fish being added if over stocking was/is a problem.
These lakes have always been stocked extremely heavy, if overstocking is now a problem on them shouldn’t it have been a problem in the early 80’s? I guess that is what I am curious about.
Also is it possible to determine which hatchery the fish came from for the stocking of these lakes?
Nail A Pig!
Mike
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Posts: 2361
| Interesting question and study of the same may actually give some answers. If things brought up by the WMR are correct, and it is possible, then perhaps there has been gene pollution in the lake resulting in the spider lake strain becoming the dominant fish in this lake, and thus failing to grow. If that is the case perhaps the natural reproduction of that strain results in elimination of the incoming fingerlings to the point of decimation. That might be a feasible picture, if if if if.
The sheer numbers of musky in the lake may have been fine when harvest removed large portions of the mature population before the 1980s but, there may have been a "tipping point" event at which time the population exceeded carrying capacity in several high survival stockings and crashed the whole lake and influenced the forage and forage encounters for adult fish at that time, and the population has never been in balance since then.
A single forage element or a couple, ie bullheads and perch for example, were overutilized by several big year clasees of musky and have not recovered since and have caused diminished growth in the bigger end of the population.
I would be interested in the natural reproduction in this lake, is there a lot or some noted? One thing that IS proven, you can only put so much corn in a kettle and muskies in particular are adept at keeping additional corn in check. This has been pretty well proven in Bone Lake stocking once harvest ended.
What is the history of musky in Butternut, were they native to the lake or newbies originally?
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Posts: 32886
Location: Rhinelander, Wisconsin | Another thing to consider:
The fish stocked in Butternut began adulthood in about 1977, in a lower density situation as the other year classes were introduced. The survival, if average, would be about a 200 or less at 1 year from each 3000 or so, if I have my math correct. It is within norms to be in that area, I believe, with post stocking mortality and NO angling pressure on Waconia the expected surviving fish would be about 152 at 6 years out of 3000 stocked. Add angling, spearing, ETC. and do the projections, one might see the effects talked about with adult fish per acre coming into play about the early 90's, figuring in the average mortaility percentage over an additional 10 years and the other variables.
Fry survival is WAY poorer, and there are far more variables. Time of year stocked, size of the fingerling, conditions on that body of water, all play into the situation. | |
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| Mike,
my understanding of fry survival is that almost none survive, although there are instances when conditions allow the fry to survive very well creating a good year class. It's hard to tell unless there are fall netting surveys that indicate survival.
AS for Muskies stunting - It's a very interesting question. For most of my life I was led to believe that the reason for the small fish in BSL/Tigercat/Mud Callahan was because of stunting or lack of forage in those lakes. Yet, when other strains have been stocked there, the occasional Muskie can and does grow to large size. This would indicate it's not stunting in those lakes. My take on it is that Muskies don't necessarily stunt (Not saying they don't ever) but that growth can be limited by 2-4 inches of max growth potential based on lack of food. (again anecdotal, just my opinion) In lakes with an abundance of food, you typically get fatter muskies not longer ones. In lakes that have an overabundance of big Muskies you get thinner ones not shorter ones. A year or two back there was an interesting article in In-fisherman talking about fish in virgin lakes being large but lean. They had many big fish that had to work for their meals. Survival of young was likely very low because of cannibilization by larger fish. This required small fish to grow big fast to become a predator instead of prey.
Regarding Butternut and Twin:
It's hard to believe that Butternut and Twin lakes can be overpopulated with the extreme harvest Worrall and the WDNR contend happens everywhere in Wisconsin. Depending on which day of the week it is we either have fish everywhere or they are all being killed.
Personally I agree with Larry that the problem is the type of Muskie that is stocked. These smaller Muskies are proven to have better survival, are harvested less frequently and can possibly take over a lake limiting the larger muskies. I'm concerned that stopping stocking of these lakes will only allow for slightly better growth of these small fish. Thus when the smaller fish grow from 34 inches to 36 inches - we then say - "Look we were stocking too much". All we did was improve growth two inches. We need to return to the days when Myrl Mcfaul was cathing his 57 inch 53 pound muskie out of North Twin. We need to improve growth by 18 inches not two inches.
I've been watching what the DNR is doing with Bass limits in NW Wisconsin. While the size limit is being increased from 12 to 14 inches on most waters, there are a few lakes that have an over abundance of small bass where the size limit remains at 12 inches. The DNR has recommended leaving the size limit at 12 inches on the lakes with too many small bass. Would it not be best to eliminate size limits completely? shouldn't we target removal of the small 6"-12" bass that overpopulate rather than the large ones we desire? I believe we need drastic change in management philosophies. As far as I can tell, all of the studies on increased size limits only increase the number of fish under the size limits. This is true for ALL species. We need to get to a plan where we protect the fish we want/need in the lake and harvest the ones that are less desirable. That's 100 years away if we have to pass it through the CC, we need the DNR and NRB to step in and get it done.
I've been trying to find examples of lakes where Leech Lake or Great Lakes Muskies stunt when overstocked. While I've had a few suggestions on lakes where they stunt, the "stunting" appears to limit growth to 48 inches on the Leech strain. (No science here, purely anecdotal)
It's very hard to tell when stunting occurs in Wisconsin because of the various strains used. Most of our past studies on growth have assumed that all Muskies are created equal, we now know that is not true. Bone Lake is one lake where growth was supposedly limited by the numbers of fish, at the same time Bone lake has some of the best growth rates in the state, and while the fish were "leaner" they were still well above the state average in terms of weight.
I think we know less about Muskies stunting than we do about strains. As for teh Twin Lakes and Butternut - wouldn't it make more sense to be stocking forage than muskies at this point? Why aren't we stocking Ciscos in Twin and Suckers in Butternut? I hope managing forage is a part of the new management plan the WDNR is working up. The Muskies Inc. clubs do want to help.
There are some lakes over here that have "warm water ciscos" that could thrive in many lakes, as well some deep clear lakes that could support ciscos but don't have them. There are many things we can be doing to improve our fishery, not all of them need to be "studied" for 10 years.
(Tried to stay away from the strain issue here - hope i succeeded)
Bob Benson | |
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Posts: 32886
Location: Rhinelander, Wisconsin | Here are some links to the subject, great reading!
Managing WI Fish Ponds---http://cecommerce.uwex.edu/pdfs/G3693.PDF
MN DNR, Sunfish and bluegill stunting---http://www.dnr.state.mn.us/fish/sunfish/management.html
Warm water fish of Oregon---http://www.dnr.state.mn.us/fish/sunfish/management.html
A MN resource, several papers regarding stunting---http://www.state.mn.us/cgi-bin/portal/mn/jsp/search.do?action=searchtopic&ct=177297594&agency=OT
An article, interesting read---http://www.lakestatefishing.com/article56.html
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Location: WI | I cant say about Butternut, but I can about the Twins, and they are definatly overstocked. 3 years ago a 1 day net survey yielded over 900 muskie. Thats just in one day. For many years now it has been hard to find many muskie in the mid 40's on the Twins. Now in the last couple years there has been a big push to keep a few every year off of these lakes, since they have been doing it the size has started to come back up. A friend of mine who lives and guides on the lake mentioned he had went 3 years without seeing a fish over 45". Last year he caught quite a few over 45". So it looks like these lakes are definatly starting to come back. | |
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| Mike
Good question.
I don't know the answer, but would lean towards answering "yes" - though not in every situation. I would only guess that this is more applicable on smaller bodies of water like the ones in which you refer.
In addition to overstocking, I believe the rising popularity of catch and release beginning around 1979 may have also played a major role in the population dynamics of many lakes. You might want to consider this factor. Let me explain.
I have been fishing a small N. Central WI resort lake for 20 years. The lake (300 acres) was originally stocked over 120 years ago with musky taken from the Flambeau River. There have been no musky stocking in modern times, due to a self sustaing population. Judging by the many photos and wall mounts, this little lake produced occasional monsters, upwards of 54" and 40 lbs.; the last being a thick 53" fish caught in 1985.
The resort maintains catch records for every fish landed and has done so for decades, including the % of fish released. What might be interesting is to test for size distribution and maximums for both pre-CR and post-CR, as there has not been a 50" fish caught in over 20 years and the largest specimen caught nowadays scarcely makes 45" and that might be one fish a year in that size range. Most muskies seen and caught are 32-38" and very few are over 40".
The resort owners became aware of the issue and took the problem seriously, as they began losing musky fishermen to MN and Canada. A fishery scientist was called in to study the problem of the incredible-shrinking-musky and found through a number of years of fish surveys that the muskies were too numerous and, as a result, extremely slow-growing. His recommendation? Heaven forbid...to promote a controlled harvest of smaller (legal) fish and stock suckers as forage. Hardly anyone will kill a musky today, so the lake has not returned to its former glory and may never do so.
Take what the fishery expert who has studied this lake one step further - perhaps inappropriately. Catch and release has helped the number of musky on this little lake, but may have had the consequence of reducing the maximum size potential. In other words, C/R = larger numbers = less preferred forage = slower growing fish. I could be all wrong here and realize that many other factors are probably at play. Perhaps an increase in fishing pressure in the last 30 years or other unknown environmental factors. One thing seems clear though. The problem in this small lake are not with the origin of the fish stocked (they're 100% pure Flambeau River fish) or stocking numbers (there hasn't been any in modern times), but something else altogether. Could this same phenomenon be having an effect on the lakes which you refer?
I will go a little nuts here and say that I think small bodies of water (like the kind typically found in WI) are much more sensitive to the effects of over-population than larger bodies of water (like the kinds getting the attention in MN these days). That makes sense to me.
This summer, I will attempt to collect fish records from the resort as far back as they go. Analysis of this data might be of interest. Maybe there is some stastically significant information there. I can share with you if you'd like.
BrianF. | |
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Posts: 1291
Location: Hayward, Wisconsin | Brian:
In your post, you didn't name the water you were referring to. We believe we know what lake you are referring to, but won't name it. You state that there has "been no musky stocking in modern times..." If we are correct, we recently found some "lost" stocking records that is contrary to that.
What you posted certainly has merit, IF it hasn't been stocked. Drop me an email at: [email protected] and I will tell you what we think the water is. If we are correct, I'll relate to you the information on the stockings there...Larry
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| Larry
You have PM.
Brian | |
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| Mike, I extracted portions of the DRAFT Butternut Lake Fishery Management Plan and pieced it together here in a way that I hope answers some of your questions. In Butternut, a combination of overstocking and natural reproduction has resulted in a dramatic increase in density over the past decade along with a decline in condition factor and growth rate of muskellunge. These changes probably had nothing to do with genetics. Obviously we cannot analyze every fishery problem on a web forum. But it is important for anglers to see, at least once here, that we (DNR) have a scientific and social basis for our opinions and conditional recommendations. Here are the relevant excerpts from the DRAFT plan:
On April 21, 2004, DNR representatives Skip Sommerfeldt and Dave Neuswanger met with 24 local stakeholders who were willing to volunteer their time to help develop a long-term vision for the Butternut Lake fishery. Objectives of the meeting were to prioritize species of interest, and then to identify for those species the relative importance of numbers versus size and catch versus harvest. Attention was then focused on identifying the desired conditions (goals and objectives) that appear in this plan. Time constraints precluded in-depth group visioning for panfish, but goals and objectives for walleye and muskellunge were developed by consensus of local stakeholders in consultation with Skip Sommerfeldt, who served as technical advisor to the group on what was possible. However, no attention was given to methods for achieving goals and objectives (management strategies such as harvest regulations, fish stockings, and habitat preservation or enhancement). It was understood and agreed that professional fishery managers would select the most appropriate strategies once goals and objectives had been developed by local stakeholders and adjusted to incorporate what is known about statewide angler preference and the capacity of Butternut Lake to produce what is desired.
Muskellunge were of medium to high importance to two-thirds of local Butternut Lake stakeholders. (We also know that the Butternut Lake musky fishery is important regionally.) Participants clearly preferred a balance between numbers and size, desiring neither a strictly “numbers” fishery nor a strictly “trophy” fishery. Because Butternut Lake muskellunge have demonstrated the capacity to reproduce naturally and grow to a large size when density is not excessive, it should be possible to achieve an adult population density and size structure that meets local stakeholder desires while providing excitement for local and non-local musky anglers alike.
GOAL 2: A muskellunge population of moderate density with a moderately high proportion of preferred-size fish
Objective 2.1: 0.2 to 0.3 adult muskellunge per acre in population estimates
Objective 2.2: Of all muskellunge 20 inches and longer captured by fyke netting in early spring, 25-50% should be 38 inches or longer (RSD-38 = 25-50%).
Muskellunge Status and Management Strategies:
In 2003, Butternut Lake contained a very high-density population of adult muskellunge (1 per acre), despite the fact that muskellunge have not been stocked since 1999. Natural recruitment has been documented in every survey since 1984. In 2003, the population was characterized by large numbers of 28- to 38-inch muskellunge and few fish longer than 38 inches (RSD38 = 9%; Figure 4). The average muskellunge caught by Wisconsin anglers is 37 inches long. The average fish in Butternut Lake currently is only 33 inches long, despite the lake’s historical reputation for producing large muskellunge.
Our estimates of muskellunge growth rate in Butternut Lake matched the statewide average during 1984-1987 but had fallen dramatically by 1998 despite high overall lake productivity (Figure 5). Condition factor (relative plumpness) of muskellunge also has decreased over time and is low in relation to statewide averages (Figure 6). Both of these observations corroborate our assessment that muskellunge density has increased to the point where prey often preferred by adult muskellunge (large yellow perch and white suckers) are no longer available in sufficient numbers (Table 3). This has repercussions for many other species of importance in Butternut Lake, including walleye and other non-game fishes that comprise a healthy, diverse fish community.
The muskellunge length limit at Butternut Lake has coincided with the statewide minimum length limit, which increased from 30 to 32 inches in 1983 and from 32 to 34 inches in 1995. Because more than half of the excessive number of adult muskellunge in Butternut Lake currently is protected by the 34-inch minimum length limit, we recommend changing the management strategy altogether. In addition to a moratorium on stocking, we recommend reducing the minimum length limit to 28 inches and implementing a voluntary 40- to 45-inch protected length range for muskellunge at Butternut Lake. These steps may help to shift size structure toward Objective 2.2 over time, but a strong catch-and-release ethic among ardent musky anglers may prove difficult to overcome in generating sufficient harvest of 28- to 40-inch fish to reduce adult density to the level of Objective 2.1. Therefore, we recommend experimental removal of up to 500 adult muskellunge (0.5 per acre, 50% of all adults) less than 38 inches long from Butternut Lake in spring of 2006. We propose to capture these fish in early spring fykenets, tag them, and transfer all except extremely plump fish to another lake where muskellunge density is lower than desired. Project approval will hinge upon capturing fish in spring of 2005 in order to obtain a Fish Health Certificate (20-fish sample) and favorable test results for genetic compatibility (50-fish sample) with the receiving water.
We will ask resort owners and the Butternut-Schnur Lake Association to encourage some harvest of 28- to 40-inch muskellunge, and to strongly encourage voluntary release of 40- to 45-inch fish until we determine whether density and size structure objectives have been achieved. Local partners can also help by encouraging participation in our volunteer musky angler diary program, which would aid our evaluation of musky angling success. If 6-8 years of evaluation reveal that the voluntary protected length range fails to allow achievement of Objective 2.2, a mandatory slot length limit will be considered. All parties should support the use of quick-strike rigs rather then single-hook rigs while live-bait fishing for muskellunge in order to minimize delayed mortality of fish caught and released within the voluntary protected length range.
In its 2004 publication, A Health Guide for Eating Fish in Wisconsin, the Department of Natural Resources advised certain people to limit or avoid consumption of muskellunge in order to minimize or avoid risks associated with mercury contaminants. When anglers are encouraged to harvest muskellunge from Butternut Lake, they should also be advised of the health risks.
Lastly, in all publicity regarding this plan, anglers should be reminded that these management strategies are not meant to eliminate muskellunge from Butternut Lake, but rather to restore the moderate-density population of preferred-size fish that once characterized this fishery.
Mike, because the tables and figures in the Plan are not readily “copied and pasted” into this web forum, I have summarized a few key facts from those graphics:
--In four creel surveys conducted between 1990 and 2003, musky angling effort averaged 14 hours per acre, and musky catch rates by anglers fishing specifically for muskellunge averaged 1 fish every 23 hours (Table 1).
--In 1973 we estimated adult muskellunge population density at 0.18 per acre. In 1998 density was 0.66 per acre, and in 2003 it was 1.02 per acre (Table 2). Stocking ceased in 1999. Natural reproduction continues, despite the presence of northern pike.
--Figure 5 shows estimated muskellunge lengths at various ages in relation to Wisconsin statewide averages for fish captured in the mid 1980s, for the stocked 1990 year class, and for the entire sampled population in 1998. Mid 1980s growth was slightly above statewide averages. Growth of the 1990 year class was much slower – 2 to 4 inches shorter at any given age. Growth rate estimates in 1998 were alarmingly slow; mean lengths at various ages had fallen short of statewide averages by 5 to 10 years, coincident with increasing density.
--Condition of Butternut Lake muskellunge (weight at any given length) was somewhat lower than statewide average in 1984. But between 1998 and 2003, Butternut Lake muskies 42 to 44 inches long weighed only 15 to 16 pounds. Statewide averages for fish in that length range are 21 to 24 pounds.
These are the data behind our assessment of increased density, reduced growth rate, and reduced condition factor. These data, and other data on prey density not presented here, all support our conclusion that muskellunge have become overabundant at Butternut Lake through a combination of past overstocking and ongoing natural recruitment. Condition factor and growth rate have suffered as a result. There is no reason to believe that a genetic factor is responsible for the rapid decline in growth rate and condition associated with increased density over the past decade or so.
Dave Neuswanger, Fisheries Supervisor
Upper Chippewa Basin, Wisconsin DNR
May 31, 2005
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Posts: 2091
Location: Stevens Point, WI | Why not introduce stocking of more forage fish such as perch or suckers to possibly increase the size of the overabundance of muskie? Wouldn't that keep more anglers happy with larger numbers of muskie and maybe increased size? Just a weird thought. | |
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| Muskie Medic,
I think stocking of forage is a great idea, and one that we could address immediately. Since the DNR has taken to stocking foreign species (Brown Trout) in Native Muskie waters that are struggling like Round lake in Sawyer County, I'd be interested in seeing if it'd be possible to introduce Ciscos into more waters. It's my understanding that in Wisconsin we do have populations of "warmwater ciscos" in some relatively shallow lakes. I think many of our lakes have "voids" that can be filled with other types of baitfish, allowing us to have more and larger gamefish. Since we are already managing many non-native species of fish at the expense of native fish, I don't think there should be any issues here- but I'm not sure.
I'd have to defer any questions on the problems that may arise on the stocking of ciscos to the experts at the DNR. All I know about cisco's is that Muskies like to eat them.
Bob | |
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Location: Rhinelander, Wisconsin | IMHO, stocking specific species as forage can be a 'slippery slope' approach. The same management problems can exist with the smaller fishes, so one must be concerned with the same possible impacts as stocking other species 'over' what is already there naturally.
If the predator/prey balance is out of whack, it's better to reduce the top end predator numbers than attempt to artificially increase forage numbers for many reasons, not the least of which is cost and effectiveness. | |
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| Is this where the term Maximum Biomass comes in. I thought I read or heard somewhere that an acre of water can only support a certain amount or lbs of fish and species is irrelavent. | |
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Location: Rhinelander, WI | Thanks for the great responses of late. Things are kind of makeing a little more sense to me.
Steve, I understand what you are saying, but I think it pays to be a little carefull and the Predator/prey balance needs to be looked at before those decisions are made.
If the Predator numbers are to high because of some artificial means (to much stocking and natural reproduction combined) then yes by all means it could be lowered, but if the prey numbers are low because of some artificial means (like over harvest of panfish by anglers) then that should equally be looked.
If panfish numbers are low because of man I would hate to see a group try to lower musky numbers. Many people have this as a goal anyway, they don’t need another reason.
I would hate to see mistakes of the past continue with the introduction of non-native species, especially just as prey fish. If biological sound reasons can be made to stock a non-native species then maybe, if it wont do any harm, but that could be a slippery slope as Steve pointed out.
Nail A Pig!
Mike
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Posts: 32886
Location: Rhinelander, Wisconsin | Mike, Agreed, I wouldn't like to see reduced numbers of predators if the harvest of panfish is too high, or another reason exists for reduced prey availabliity. Tough choice sometimes, I bet! | |
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| Bob - 5/31/2005 5:09 PM
Muskie Medic,
I think stocking of forage is a great idea, and one that we could address immediately. Since the DNR has taken to stocking foreign species (Brown Trout) in Native Muskie waters that are struggling like Round lake in Sawyer County, I'd be interested in seeing if it'd be possible to introduce Ciscos into more waters. It's my understanding that in Wisconsin we do have populations of "warmwater ciscos" in some relatively shallow lakes. I think many of our lakes have "voids" that can be filled with other types of baitfish, allowing us to have more and larger gamefish. Since we are already managing many non-native species of fish at the expense of native fish, I don't think there should be any issues here- but I'm not sure.
I'd have to defer any questions on the problems that may arise on the stocking of ciscos to the experts at the DNR. All I know about cisco's is that Muskies like to eat them.
Bob
I think stocking forage is a terrible idea and would always be last on my list as a way to fix a problem. Rarely do lakes have an overabundance of the top of the line predator. That is the exception not the norm. Stocking non reproductive predators like the brown trout tried in some of the clear deep lakes, may impact a prey species but can quickly die out of the eco system if there are untoward effects of the stocking. They do provide an additional sport fish if successful. Stocking prey is a much more expensive process and one that usually is not needed anyway due to the generally low incidence of the top of the line predator. Stocking non native prey such as the warm water ciscos discussed here(Flambeau Flowage orgin?) would have to be studied extensively to see where they fit into the ecosystem. If they actually reproduce there could be several negative results from their stocking, unforseen prior to their placemnt. ie would you want them in a lake if they could wipe out the spring walleye hatch in the fry statge, or if heavy populations competed with a previously successful well fed population of suspended bluegill and crappie? I just don't see forage stocking as anything worth doing, in normal circumstance, much as it might appeal to us as fisherman. | |
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| I think firstsixfeet has an accurate perspective on prey stocking.
There are basically two reasons why fishery management biologists rarely consider prey stocking to be a viable option:
First is our healthy respect for the "Law of Unintended Consequences." A prime example was the stocking of gizzard shad into most small impoundments (<500 acres) in the lower Midwest back when the bass fishing industry was pressuring biologists to produce more big bass (late 1960s, early 1970s). It was felt that bass would grow faster and get bigger if they had more to eat than crayfish and bluegills. Gizzard shad were introduced virtually everywhere. The impact on bass was mixed and not relevant here. But the impacts on BLUEGILL and sometimes crappie (in SMALL impoundments) were devastating. South of Interstate 80, gizzard shad often became the dominant fish in the community, sometimes reaching standing crops of 500 pounds per acre! These shad can selectively "pick" large zooplankton, but they can also "pump filter feed" zooplankton in a way that removes most of the large water fleas and other critters that bluegill and crappie need to grow fast and attain desirable sizes. Panfish fisheries were ruined in many cases, and benefits to bass often were mixed and temporary. In a few of the worst cases, gizzard shad became so abundant that even young bass could not find zooplankton to eat at a critical life stage. Bass recruitment and density declined dramatically in those cases. (NOTE: These impacts are not the same on larger reservoirs.) To consider stocking ciscoes or smelt or other non-indigenous prey to some of our systems to enhance predator growth rates would be to ignore the valuable lessons of the past and place other important fisheries (e.g. perch, bluegill, crappie) at risk. We must remember that when asked "If you could fish for only one species [or group of similar species] in Wisconsin, what would you fish for?" 31% of Wisconsin anglers responded "PANFISH". So all such strategies must be considered in light of other goals and objectives for each water -- something that requires further development in Wisconsin.
Second is logistics. If the proposal is to supplement prey by stocking more of an existing species, like perch or suckers, the benefit:cost ratio is unacceptably low. Our natural ecosystems will produce as many of these critters as nutrient levels and other factors will allow. If there aren't enough of these fish to feed existing predators, then predator density is too high. Stocking more adult perch or suckers will not likely produce more young unless prey densities are extraordinarily low. It's not usually how many eggs are laid, but how many larvae and fingerlings survive, that govern year-class strength in fish. That survival depends on temperature, prey availability, and a myriad of other factors. The only way to ensure greater availability of perch and suckers to large predators would be to stock them in such numbers, as adults, that it would consume all our time and resources to supplement just a handful of lakes. It's just not a practical option.
Are there alternatives to prey stocking? Yes. We can manage prey by carefully managing predators. Maintaining optimal numbers and sizes of predators should maintain the healthy prey populations needed for satisfactory predator growth. We manage for BALANCE. To do so, we may need more than minimum length limits in our toolbox for muskellunge.
We may need slot length limits in some situations (more on that another time), and we need to manage entire ecosystems, not just one or two fish species. | |
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| Gentlemen:
Here is my summary of the musky records kept by a resort on a 300 a. "resort" lake in N. Central Wisconsin dating back to 1940. Most fish before the mid-1970's were killed. A very high percentage today (around 90-95%) are released; though most of the larger specimens {>45"} are killed. I think this lake is fairly representative of many of the smaller lakes in N. Central Wisconsin.
Before looking at the data, I had theorized that catch and release might have something to do with the absence of occasional supertankers in the present day fish population. Now, I think this may be due to a number of factors; one possibility being the introduction of genetically inferior fish in supplemental stocking during the 1950's (but that is a different story and one highly debated on other threads).
So, what does this data tell us?
1) There has been a FAVORABLE CHANGE in the number of 'nice fish' being caught. Today, a higher % of nice fish {>40"} are consistently caught than ever before.
2) There has been NO CHANGE in the average size fish caught. Adjusting the calculation for the legal length limit changes, there is no difference between the size of the average fish caught today vs. 20, 30, or 40 years ago.
3) There has been NO CHANGE in the average maximum size of fish caught annually since 1940. The average size of the maximum fish caught in each decade has been around 46 inches - give or take a half inch or so; even during the boom "big fish years" of the 1950's. While the max size was counted, I did not take into consideration the number of large fish caught within that year. Clearly, there has been a drop-off in that department.
Really big fish have never been numerous in this lake. Still, only one 50" fish has been caught since 1983, when that used to be a more common occurence. That is what is bothersome here. Where did those "rogues" go in the last 20 years?
Ideas???
BrianF.
Total # Avg. Size % >40" %>45" Max Size
1940 16 36 0% 0% 38
1942 21 36 10% 0% 44
1942 21 37 10% 0% 43
1943 20 38 15% 0% 42
1944 14 38 14% 0% 44
1945 25 38 12% 4% 47
1946 26 37 4% 4% 47
1947 50 36 2% 0% 42
1948 20 37 10% 0% 41
1949 23 38 9% 4% 46
1950 32 37 6% 0% 42
1951 30 38 13% 3% 45
1952 30 38 13% 3% 46
1953 26 36 4% 0% 40
1954 25 37 8% 0% 43
1955 40 38 3% 3% 55
1956 44 38 7% 2% 51
1957 47 37 4% 2% 46
1958 42 38 21% 2% 45
1959 43 38 16% 0% 43
1960 54 36 2% 0% 43
1961 75 37 9% 0% 44
1962 63 38 10% 5% 50
1963 42 37 10% 5% 50
1964 48 37 10% 2% 46
1965 54 37 4% 0% 44
1966 60 37 7% 3% 48
1967 53 38 9% 2% 48
1968 55 37 7% 2% 47
1969 44 37 5% 2% 46
1970 44 37 7% 0% 44
1971 40 37 5% 3% 46
1972 45 37 7% 2% 49
1973 55 37 11% 2% 54
1974 54 36 2% 0% 40
1975 60 37 5% 0% 44
1976 51 38 16% 4% 51
1977 56 36 9% 0% 44
1978 64 36 2% 0% 40
1979 75 37 13% 0% 44
1980 54 37 4% 2% 45
1981 55 38 15% 4% 45
1982 73 39 22% 4% 52
1983 55 37 11% 2% 45
1984 78 37 19% 1% 49
1985 102 36 9% 1% 45
1986 88 36 8% 0% 43
1987 113 36 7% 0% 44
1988 84 37 8% 0% 41
1989 93 37 6% 0% 44
1990 84 36 8% 1% 45
1991 92 37 9% 0% 42
1992 138 37 12% 1% 47
1993 104 37 17% 2% 46
1994 99 37 14% 0% 44
1995 78 37 23% 1% 46
1996 146 38 29% 5% 50
1997 165 38 27% 2% 46
1998 109 37 21% 2% 46
1999 130 37 24% 1% 48
2000 60 37 20% 5% 47
2001 59 37 25% 2% 45
2002 72 37 22% 4% 46
3802 37 13% 2% Avg = 45"
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| Again something I mentioned in the past . This is why slot limits are needed and why it will work . You want bigger fish slots are way to achieve it and slots are the most cost effective way of doing it.
Think slot limits...........Don Pfeiffer | |
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Is it possible for a Muskies to Stunt.