2011 Winnebago Lakes Sturgeon Spearing Season? Season Synopsis

The 2011 season went into the books as the 4th 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 2005 is 11 days. The shortest season since 2005 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 now. 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.

Ron Bruch, WI DNR Fisheries Supervisor