2011 Winnebago Lakes Sturgeon Spearing Season Preliminary Wrap-Up Ron Bruch WI DNR Fisheries Supervisor The 2011 season will go into the books as the 4 th 16 day season since we began the harvest cap system in 1999. The others were 2002, 2006, and 2007. Under current rule the season lasts until we hit one of the harvest cap closure triggers or 16 days, whichever comes first. The average season length under the harvest cap system since we went to the 6 hour spearing day (6:30 AM to 12:30 PM) in is 11 days. The shortest season since was a 4 day season in 2008. Our total harvest of 1426 was close to the average annual harvest, since initiating the harvest cap system in 1999, of 1405. Effort as measured by total spearing license sales was definitely up this year at 12,423 from 10,860 in 2010. Spearers are excited in general about the success of the fishery, and the lure of the increased number of trophies in the harvest also brings some additional people into the fishery. There may also be some demographic changes occurring as the next generation of spearers may be entering the fishery. I ll know more about these trends after we examine the license and harvest data and complete our analysis. Effort as measured by shanty counts on the lake told the real story of the 2011 season. We started the season on opening day with counts of 4321 on Lake Winnebago and 372 on the Upriver Lakes. Warm weather, snow melt, and deteriorating travel conditions on the ice of the lakes the first week of season forced a majority of spearers to pull their shacks off the lakes dropping the shanty count by the second Saturday of the season 59% on Lake Winnebago and 81% on the Upriver Lakes. The Upriver Lakes usually drops off anyways since, as a lottery fishery, once tags begin to be filled, spearers often pull their shacks off the lakes. The biggest change we have seen over the last ten years is the percentage of large fish in the harvest. This year the percentage of fish 100 lbs or larger in the harvest was 7.5% on Lake Winnebago and 3.6% on the Upriver Lakes. The percentage of these century mark fish has been steadily increasing over the last 15 years. Spearers ask two questions related to this phenomenon: 1) Why?, and 2) Are we taking too many 100 lbers?. Why? - When we started down the path of updating regulations to better control the harvest and stabilize the adult spawning stock of sturgeon in the Winnebago System our colloquial goal was We want to grow more old ladies. In other words, we saw that our adult female stock was being overharvested primarily due to a high size limit (45 ) along with the lack of a safe harvest cap system, and that we needed to reduce that harvest and increase survival of females. All of the new regulations and laws (22 in total) that were implemented since 1993 appear to have done their job quite well. The other part of the success equation was luck sometimes you just have to get lucky. The timing of implementation of the new regulations and laws could not have been better. As the new regulations began to have an impact on the sturgeon harvest, the size and age structure of the Winnebago sturgeon population was poised to include more older and larger fish with each passing year. This phenomenon was due to the fact that by the mid 1990s we finally were on the back side of a hole in the sturgeon population that had been created by excessive legal and illegal overharvest during the 1930s-1950s. The sturgeon population in numbers and age composition had finally grown past the impact of this overharvest that occurred 50 to 70 years ago. Are we taking too many 100 lbers? At this point the percentage of 100 pound plus fish in the harvest appears to be truly reflective of what is actually in the population. We have been watching the trend of more trophy size fish growing not only in our harvest, but also in the spawning stock both females and males for over 15 years 1
now. I will be looking into this further to see if there is any significant differences in exploitation rate of fish by size, but I will surprised if I find any. Stay tuned. Also remember 5-6 years ago when our sturgeon were so skinny? In the 2004-2006 time period sturgeon food resources were at a low point. Lakefly larvae were at the lowest point we had ever measured going back to the 1960s, and the gizzard shad hatches in the early 2000s were low as well. Sturgeon depend on these two food resources for 86% of their nutrition. Since 2006 both of these food resources have bounced back to high levels and the condition of the sturgeon also bounced back to the fish with shoulders that we see have been seeing the last few years. * * * * * * * * * * * * * * * * * * * I need to recognize some people for their extraordinary efforts to make this season run so smoothly first of all my outstanding crew. These guys are out there everyday doing their thing to make sure registration stations are set up, open, staffed, and supplied. We actually begin preparing for the spearing harvest assessment back in December. This is a huge undertaking that would not be possible without the dedication and hard work on my crew along with other DNR staff who are sturgeon registration regulars every year. On opening weekend there are about 40 regulars including my staff, other DNR folks, and volunteers from the Fish and Wildlife Service that work registration stations with another 16 or so student volunteers from UW-Stevens Point and Oshkosh, and the Fox Valley Technical College. The number of people I schedule to work stations goes down after opening weekend, but it is my crew that hangs in there until the end of the season to make sure spearers have a place to register their fish, and that we collect all the data accurately. To all those that work the registration stations you make this harvest management system work. I want to also thank all the spearers who participate in this great fishery one of the best examples, I believe, of a sustainable fishery anywhere. Because the spearers buy licenses, and become involved in the management program through our Sturgeon Advisory Committee, at public sturgeon meetings, or one on one with me or my crew, we have the critical public involvement necessary to make a successful sturgeon program. As many of you have heard me say before we have two main sturgeon management goals on the Winnebago System: 1) do what we need to do to ensure we maintain a healthy and robust lake sturgeon population in the Winnebago System; and 2) do what we need to do to ensure we maintain the tradition and culture of sturgeon spearing on the System. We would not have the sturgeon program we have if the people that hold this fish near and dear to their hearts did not have a genuine passion for this fish. Finally we ll be busy now taking down our stations, entering and proofing data, putting summaries together, and thinking already about next year. I will be putting together my regular summaries and getting those out as soon as possible; and scheduling a meeting with the Sturgeon Advisory Committee. We ll thoroughly de-brief this season, age all the sturgeon spines, take a look at the data, crunch all the numbers, and determine what we need to do to continue to improve the sturgeon program as we move forward. All of this will take time to complete. In the meantime though, I ve included some initial summaries and charts below for you to peruse until I get the final reports out. Have fun looking these over, and thanks again for your support and involvement in this fantastic fishery. Ron 2
Harvest 3500 3000 2500 2000 1500 1000 500 0 Registered Harvest 1941 1945 300 250 200 150 100 50 0 Winnebago System Sturgeon Spear Harvest 1941-2011 URL Winnebago 1949 1953 1957 1961 1965 1969 1973 1977 2011 Sturgeon Spearing Daily Harvest Winnebago Pool Lakes 1981 1985 1989 1993 1997 2001 2009 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Day of Season Winnebago Upriver Lakes 3
Total Harvest 500 400 300 200 100 0 Winnebago & Upriver Lakes Combined Daily Sturgeon Spear Harvest 2011 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Day of Season >100 lbs <100 lbs Percentage 8% 7% 6% 5% 4% 3% 2% 1% 0% % of Sturgeon 100+ lbs 1955-2011 Winnebago & Upriver Lakes Spear Harvest Winnebago 1975 1970 1965 1960 1955 Upriver Lakes 1985 1980 2010 2000 1995 1990 4
3,000 Lake Sturgeon Spear Harvest 1999-2011 Lake Winnebago & Upriver Lakes 2,500 Upriver Lakes 2,000 Winnebago Harvest 1,500 1,000 500 0 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 Percentage of Harvest 100% 80% 60% 40% 20% 0% 1999 Lake Winnebago Sturgeon Spear Harvest 1999-2011 Sex Ratios 2001 2003 2007 2009 2011 Juv Females Adult Females Males 5
Percentage of Harvest 100% 80% 60% 40% 20% 0% Upriver Lakes Sturgeon Spear Harvest 1999-2011 Sex Ratios Juv Females Adult Females Males 1999 2001 2003 2007 2009 2011 6
STURGEON SPEAR HARVEST - WINNEBAGO LAKES 1999-2011 Harvest Cap System implemented in 1999 Upriver Lakes Lottery started in 2007 LAKE WINNEBAGO Registrati on Station 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 TOTAL Waverly 118 22 100 143 59 30 106 4 117 159 99 200 51 1208 Harrison 122 188 52 362 Fishtale 203 27 144 235 1 29 40 1 680 Stockbridg e 149 20 127 95 42 67 211 16 197 219 470 405 366 2384 Quinney 209 30 110 115 8 118 87 1 99 139 201 221 87 1425 Brotherto wn 197 35 69 33 2 180 38 3 557 Jim & Linda's/Ca lumet Hbr. 367 90 168 30 244 442 181 67 253 192 126 118 70 2348 Wendt's 115 97 711 30 386 748 159 116 266 364 71 98 208 3369 Taycheed ah 15 15 Jerry's 40 35 51 33 39 183 21 11 61 54 22 79 88 717 Payne's 86 8 110 133 121 57 36 6 47 86 124 199 171 1184 Winnebago Totals: 1484 364 1590 847 902 1854 894 225 1040 1213 1235 1508 1093 14249 Winnebago Season Length (Days) 3 2 2 16 10 2 12 16 16 4 8 6 16 UPRIVER LAKES Registrati on Station 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 TOTAL Winnecon ne 351 122 24 99 70 126 141 666 Poygan South (Cty Lndg) 590 79 117 786 Captain's Cove 7 7 Indian Pt. 665 64 99 132 152 116 131 1112 Boom Bay 548 72 67 69 53 70 61 809 Upriver Lakes Totals: 2154 345 313 300 275 312 333 3380 URL Season Length (Days) 2 1 6 4 5 6 10 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 TOTAL System-Wide Harvest Totals: 1484 2518 1590 847 902 1854 1239 225 1353 1513 1510 1820 1426 17629 System-Wide Harvest Caps 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 Juvenile Females 400 400 400 400 400 425 500 500 556 556 350 350 395 Adult Females 400 400 400 400 400 425 500 500 556 556 630 740 790 Males 2150 2150 2150 2150 2150 1300 2000 2000 1000 1000 1000 1000 1200 7
Winneba go 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 Harvest Juvenile Females 345 70 317 176 157 349 159 50 189 193 231 223 158 Adult Females 469 126 608 327 350 684 368 99 439 548 562 726 493 Males 670 169 665 344 395 821 367 76 412 472 442 559 442 Total 1484 364 1590 847 902 1854 894 225 1040 1213 1235 1508 1093 Upriver Lakes 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 Harvest Juvenile Females 576 97 72 85 67 47 51 Adult Females 294 55 51 50 53 75 71 Males 1295 193 190 165 155 190 211 Total 0 2165 0 0 0 0 345 0 313 300 275 312 333 TOTAL Harvest 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 1999-2011 Juvenile Females 345 646 317 176 157 349 256 50 261 278 298 270 209 Adult Females 469 420 608 327 350 684 423 99 490 598 615 801 564 Males 670 1464 665 344 395 821 560 76 602 637 597 749 653 Total 1484 2529 1590 847 902 1854 1239 225 1353 1513 1510 1820 1426 8