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Ok - thanks to Kevin Casper - Central Region Fisheries Manager - we have some data!

Hey

Here are a few things: Age Length Weight data over time Lake WPG only.

On thing to make sure you explain the fact that we don’t catch very many big fish, hence the drop in average length and weight in the older fish. Big variation in the males

Let me know if you need something different.

KC


Data from ~ 18,000 samples both Male and Female from 2009 to 2017
Remember - the lengths are fork lengths - total lengths will be ~ 10mm more for small fish and ~30mm more for large fish.

Age Avg Fork L(mm) Avg Wt (g)
0 126 20
1 132 31
2 209 105
3 284 267
4 342 453
5 368 558
6 396 701
7 426 871
8 441 1034
9 463 1251
10 512 1643
11 532 1913
12 532 1930
13 541 2146
14 620 2735
15 617 2682
16 667 3133
17 680 3550
18 752 4625

Here is just the length (fork length in mm) at age for just 2017 - both sexes:

Age Fork L (mm)
0 108
1 145
2 221
3 275
4 323
5 315
6 356
7 367
8 396
9 450
10 514
11 606
12 627
13 451
14 629
15 666
16 674

I hope that this is what you are looking for and is helpful.

Derek
 

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Thak you for the interesting information Derek. Based on this information, my conversion calculations show that a 752mm fish LW would measure in at 30.79" with a weight of 10.2 lbs. and that a 27.7" fish would be 16 years of age.

As compared to the growth chart found at http://wildernessnorth.com/wordpress/wp-content/uploads/2014/09/FishGrowthChart.pdf, the lenght and weights are pretty much in line with these results, but age differs significantly with the same 30" fish coming in at almost 1/2 the age for a LW fish. I suspect that the smaller head, sloping forehead, smaller tail, and larger body for a LW fish to be a clear indicator of this younger age.

Funny, but in my experiences, I would have expected average weights to have come in considerably higher for LW fish. I suspect that some football fish and/ or pre spawn fish could still easily come in a 2-3 lbs. heavier. I also wonder if there would be a significant variance between the North and South basin fish or possibly even between different pods of fish, likely based on type and availability of forage.
 

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Good points.

I was the bio on Lake Winnipeg for 7 years (2007-2013). Kevin and I were the team that collected most of the fish in this sample.

I can say that we caught very, very few exceptionally large fish. This means the average size that you see below may not be representative of the true population of large individuals. The large fish were always female and were usually not the oldest fish in the sample. If I can remember correctly, the big females usually topped out at 10 to 12 years. It is the males that often were the very oldest (again these are also very rare in our sample). These very old males were not very big ~ 23 to 25" and were not very heavy.

Here is a break down of males vs females in the 2009-2017 data set:

Females

Age Av Fork L(mm) Avg of Wt (g)
0 138 33
1 127 28
2 210 106
3 286 272
4 346 488
5 378 637
6 415 824
7 449 1012
8 474 1242
9 502 1517
10 541 1862
11 573 2222
12 605 2499
13 620 2805
14 652 3026
15 649 2987
16 667 3133
17 770 4550
18 752 4625

Males

Age Avg Fork L(mm) Avg Wt (g)
0 114 8
1 139 36
2 208 103
3 283 261
4 339 425
5 361 503
6 371 547
7 385 612
8 381 661
9 383 713
10 436 1068
11 374 704
12 394 860
13 379 792
14 426 986
15 473 1308
17 590 2550

Again - remember to add ~ 10mm for small fish and ~ 30mm to large fish to convert from fork length to total length.

Thanks for taking an interest.

Derek
 

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One last note - our largest mesh was 5". (we did experiment with 6" for a while).

This mesh is not ideally suitable to capture the very largest fish present in LK WPG (over 30").

Derek
 

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Looks like a healthy linear trend line...
Actually, Walleye growth almost never looks like this.

There is usually fast growth up to maturity, then a slower growth trajectory as more energy is diverted to annual gonad development...such as this trajectory ...(found this on the web - not sure which lake it is from)



Derek
 
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