The numbers behind CPR and "Keeping a Trophy"

[Shawn Kellett]

I posted this on another site but thought you guys may be interested in the real numbers.

Let me break this down like a fraction for everyone.

Test lake: Minnetonka, 15,000 surface acres, 2500 litoral acres.

MN DNR managed adult population: 1250 fish

(MN Lakes are managed for .5 adult muskies per litoral acre. )

Average number of fish over 50" (DNR state wide estimate): 3%

Stocking efforts by the DNR: 2500-3000 fingerlings bi annually (or equivalent).

Total number of 50" fish in the lake +/-: 38 fish

Now let's assume that every year 1% of the population goes from 49" to 50" every year: +12 fish

Lets also assume that every year 20% of the 50" fish die of old age (this is a metro lake where growth rates indicate 50" fish are older then other lakes in MN): -7 fish

Now let's assume that only 10 people keep their "Trophy" every year: -10 fish

Year 1: 38+12-7-10=33 fish

Year 2: 33+12-6-10=29 fish

Year 3: 29+12-5-10=26 fish

Year 4: 26+12-5-10=23 fish

year 5: 23+12-5-10=20 fish

Year 6: 20+12-4-10=18 fish

Year 7: 18+12-4-10=16 fish

Year 8: 16+12-3-10=15 fish

Year 9: 15+12-3-10=14 fish

Year 10: 14+12-3-10=13 fish

So in 10 years with this mentality we would experience a 2/3 decrease in the number of 50" fish on a 15,000 acre lake. I intentionally was generous as far as how minimal harvest would be (it's probably higher in reality and will be if we have the "it's ok to keep a trophy" mentality), especially on a lake in a multi-million person population.

Now how about the total number of trophies vs. the number of resident muskie anglers.

The DNR stocks roughly 30,000 muskies each year. With about a 10% survival rate for fingerlings we're looking at roughly 3,000 adult muskies per year class.

3000 fish annually

Lets assume that there is 1/4 this number of fish from natural reproduction in the existing lakes (it's a VERY high figure but work with me)

750 fish annually

Let's take a 20 year time frame as 20 is pretty much the upper limit of a muskies life expectancy: (3000+750) x20=75,000 adult fish in the designated muskie lakes in MN

Now taking our 3% number that would equal to 2250 50"+ fish in MN. (And I haven't boated on in how many years?!?!?!?! )

Now take the estimated number of resident people who fish muskies in MN: 225,000.

(Boy the math worked out easier then I thought it would)

1 50" muskie for every 100 muskie anglers in the state.

This doesn't include all of the people who come from out of state to fish muskies. Let's say that the state gets 25,000 people that come to MN to fish muskies from out of state (I don't know the real number, but 10% seems reasonable).

Total fishing pressure: 1 50"+ fish per 111 anglers

[Shawn Kellett]

I just reread it and didn't factor in delayed mortality. Take off roughly another 5% onto each number for delayed mortality.

[Scottie Thomas]

THANK YOU for posting, amazing stuff! CRAZY to think really how few muskies there really are in a lake!

[DHanson]

Nice math skills there Shawn. Just my opinion, but I think there are probably 500- 1000 50"+ fish in Mille Lacs alone. At 132,000 acres there are fish out there that never see a lure. I know it may seem ridiculous to think that with all the pressure on the lake, but we all know everyone is fishing the same areas of the lake. There are areas of the lake that never get fished for skies. Then factor in Vermilion, Leech, and Lake of the Woods (US side), that's got to be another 1000-1500 or more. I think there are a few more 50" fish out there than 3%. Obviously I am just guessing here and I really have no clue. Also 38 seems like a small number for Minnetonka. How many a year does that Turgeon guy catch over 50 a year out there?

[Shawn Kellett]

These are averages that the DNR uses in their muskie management. True, some lakes may have 3+/-, but you also have to take into account that most of our stocked lakes have a strong year class on top since many of these fish were the first ones in the system and didn't have to compete to get big. The 3% signifies a mature system, which is what lakes like Minnetonka and Vermillion are becoming. If you look at all the "hot lakes" with a large number of large fish and no fishing pressure they are almost always stocked lakes (or 1000 miles away on some logging road).

I'm not sure how many 50's Bob got this year although he does catch a lot of fish that's for sure. Also, I've seen a lot of other peoples (not Bob's) 50"ers and I roll my eyes. Trust me, in my position I see them all the time. So I'm not convinced that all the reported 50's truely are.

I do believe that we are recycling these fish at such a rate that it would scare people. I know of over 1000 fish that we caught out of Minnetonka this past year between 25 people +/-. Now take into account that Tonka is managed by the DNR for 1250 fish +/-. We're catching these fish multiple time a year, every year for up to 10-20 years.

Let's say on tonka we catch a fish 2x each year (I believe this is very low but work with me). If we start catching it when they're 4 years old (low 30's) and it takes 15 years to get to 50". That means over the next 11 years we would catch that fish 22 times by the time it get's to 50".

I personally believe the catch rate is closer to 4-5x a year in the metro. I've just seen too many pic's of the same fish over and over to have much doubt.

Yes you can probably shoot some minor holes in the math, but I'm doing this to flesh out how rare these fish are and how we must practice responsible C&R if we want to maintain our fishery.

[DHanson]

I've often wondered myself how many times over the same fish has been caught throughout the year or even in it's entire life. I have had experienced guys tell me that a particular fish will become bait shy once it has been caught. But if you think about it, those fish have to eat and so they will be fooled again whether it's on a different lure or not. Catch and release and proper fish handling is extremely important if this sport is going to exist in the future.

[TheHawgTrough]

That means over the next 11 years we would catch that fish 22 times by the time it get's to 50".

So... No wonder those 50 inchers are so hard to catch on Tonka. 4-5x a year would put it at more like 40-50+ times, up to 75+ in their old age. Never realized how often these fish get caught...

[MUSKYMAN1011]

Everyone has the Right to Keep a Trophy.

Despite what some of the Zealots of MI say.

[Shawn Kellett]

I gotta think that as the fish gets a little older they may become a little more hook-shy, but who knows. All I know is that they haven't been too dumb when I've been coming around lately...

I just remember one fish we caught in the PMTT on Tonka a few years back. It had a very distinct tail. About a month later a guy showed me a fish pic at our meeting and it was the same fish! I said you caught it X right? He just looked at me dumbfounded! Funny, we measured it as a 42 and he measured it as a 44". He beat me in our clubs fish contest by 2" that year and I've never let him forget it. I think he's bought me a 6-pack over that one .

[Shawn Kellett]

People also have the right to run up credit cards and declare bankruptcy too. Personally I like having good credit and big muskies.

[50inchpig]

Locally, MI is an awesome organization. 100% proud to be a member. Proud to share a goal with the other guys I see each month and on the water in between.

Nationally/Internationally, it's understandable but laughable at the same time that MI is depicted as a highly organized political organization with extreme opinions since internationally, we can't agree on hardly anything. To say one angler or group speaks for the organization as a whole would be false. Alot of good guys express opinions and get ripped by the other side, all within the organization.

And it's always easy to pile on.....

[MUSKYMAN1011]

People also have the right to run up credit cards and declare bankruptcy too. Personally I like having good credit and big muskies.

I guess your name isn't Rick Wagoner, Bob Nardelli or

Alan Mullally is it?

[Black_Bay]

You didn't account for the fact that male muskies probably aren't going to make it to 50".

[JRedig]

I'd be curious to see something similar figured out for how many times a 50+ inch fish gets caught in it's life time on a lake like 'Tonka. Granted I realize the impossibilities in figuring that out...

[b1gf1sh1]

Quote:

Everyone has the Right to Keep a Trophy.

if everyone did there would be no muskies, let alone trophies.

it's a good thing what MI and Our DNR Fisheries are doing. keep up the education Shawn. it can only help. that goes for any others out there too with something intelligent to say. i know i ain't afraid to throw my two cents in. ... or 2 million cents, whatever it takes. or is that ''sense''?

[Shawn Kellett]

Hanson, Mille Lac is an entity onto it's own. There isn't really a growth rate study that works on Mille Lac for any species that jives with any other lake. I know that the historic average in my boat for Mille Lac has been around 10% being 50" or better.

I do think that the population numbers are pretty low. If you look at what's been stocked and the limited natural reproduction that exists there can't be nearly as many fish as people think.

The numbers I posted are averages. Certain lakes may be above or below those numbers by a few %. But a change from 3% to 5% for say Tonka would only increase the number of 50's by a handful or two. That's not to say that there aren't that many again or more 48-49" fish (which 1/2 the people call 50's anyway). It data also includes male fish (one reason wy there's so few 50's).

For those that are interested in getting better data concerning population estimates, release rates, growth rates etc and live in the metro, it would behoove you to join one of you're local MI chapters. The TC Chapter (mine) has tagged all the fish we stocked this year and plan on tagging fish for the next few years. Over the next 5-10 years we're going to need catch data from anglers like you all to turn in their information to the DNR. Who knows what the real numbers for the metro are and how they vary from say Leech or Vermilion. We'll have more info to come as the fish get to the size where we'll start to catch them (2-3 years).

[ikatcher]

honest question, do you musky guys really think the same musky can be caught that many times? i consider my self a casual musky fisherman and have caught about 20. i'm not sure any of them had ever had hooks in them before. do the tears in their mouths heal after time? i would think if a fish were caught that many times they would be pretty tore up. especially the ones hooked close to the boat.

[Nick Kuhn]

honest question, do you musky guys really think the same musky can be caught that many times? i consider my self a casual musky fisherman and have caught about 20. i'm not sure any of them had ever had hooks in them before. do the tears in their mouths heal after time? i would think if a fish were caught that many times they would be pretty tore up. especially the ones hooked close to the boat.

Tagged fish have been caught 3 times in the same season. Certainly hook wounds can heal. An ideal hookset would leave little more than a lip piercing. If a couple of months go by between the times it's caught, any minor damage would be fully healed. Like people not every wound leaves a scar on a fish.

[JRedig]

honest question, do you musky guys really think the same musky can be caught that many times? i consider my self a casual musky fisherman and have caught about 20. i'm not sure any of them had ever had hooks in them before. do the tears in their mouths heal after time? i would think if a fish were caught that many times they would be pretty tore up. especially the ones hooked close to the boat.

Myself and a friend caught the same fish 3 times in two weeks this year. I caught it twice, 1 week apart. He got it 3 days later. They definitely heal, i'm just not sure how fast.

[ikatcher]

i'll buy that, again i'm no expert. i am only goin on the few i've caught. the ones that were hooked close to the boat just go nuts and have had some pretty good sized tears in their snouts.thanks for the replies guys!

[TheHawgTrough]

We once caught the same fish trolling through an area within a hour or two of the first time it was caught... Definitely didn't fight as well the second time around, but goes to show you they don't wait long before going on the feed bag again.

[DHanson]

I agree Shawn Mille Lacs is kind've a mystery. I mean they only stock like 3000 fingerlings every other year in a 132,000 acre lake. I think the natural reproduction success rate is minimal at best out there. What I don't get is how every guide boat had a 10+ fish night almost every night for an enire month just a few years ago. I was on the lake one night and the boat next to me had 12 and the other had 11 and the night was young. I think some are dieing at probably a 5-10% rate for experienced fishermen and 20%-50% for inexperienced fishermen. I think Mille Lacs is still loaded with skies. The unreal amount of forage in the lake has the fish scattered around the lake. At least I hope that's the case. I know there were 2 days on the north end this last year where the muskies were just loaded up there and then they were gone. We were able to put some fish in the boat with a 5 fish weekend with 2 others lost. We even had a double and I messed that one up . It was a big fish too.....argggggg.

[BigStick]

DHanson - The answer to your question: COWGIRL and Networking.

[Nick Kuhn]

DHanson - There's probably more natural production than would be expected. Also one thing holds true, the fewer put in the higher the survival rate due to lower intraspecific competition. Any fry that do hatch probably have a considerably better chance of survival than say the small WI lakes maintained by natural reproduction.

Another factor is the 100,000 acres of void in Mille Lacs. There is simply a lot of water fish cannot call home for extended periods of time.

I am surprised though that MN stocks so few fish. Wisconsin has had to back off it's stocking from 1 fish per acre to 1/2 fish per acre, but that's still a lot more than 1/2 per litoral acre. I am excited to see the WI vs Leech strain comparison, but I believe first netting for that will be in 2011 so we have to wait a while. Interesting though that at stocking WI strain fish were larger, the opposite of anticipated (fish raised in the same hatchery under the same conditions):

Code:

Year | Lake Name       | Species     | Strain               | # Stocked | Avg Length (Inches)
2006 | SAND LAKE       | MUSKELLUNGE | LEECH LAKE           | 154       | 11.60
2006 | SAND LAKE       | MUSKELLUNGE | UPPER CHIPPEWA RIVER | 154       | 12.40
2006 | DES MOINES LAKE | MUSKELLUNGE | LEECH LAKE           | 115       | 11.50
2006 | DES MOINES LAKE | MUSKELLUNGE | UPPER CHIPPEWA RIVER | 115       | 12.40

Lousy way to format but it'll have to do.

[Shawn Kellett]

Vahn, another thing to consider concerning natural reproduction in Mille Lac is the lack of hammer handle pike, largemouth bass, and stunted sunfish. All 3 of these hammer the small muskies as they try to get to the 16-20" mark. Once they get to that point they're pretty much going to avoid 95% of the predators.

As far as muskies healing, the ones in my fish tank can regrow fins and heal wounds in a matter of a week or two. I'd imagine that larger fish with larger fat reserves can probably heal over quicker. Just think about how scared up a fish gets during spawn. By the middle of June (in the metro) you rarely see any scars on them.