Author Archives: BillKoehne

Flexible Classification of Wisconsin Lakes for Improved Fisheries Conservation and Management

Successful fisheries management practices developed for one ecosystem can often be used in similar ecosystems. We developed a flexible lake classification framework in collaboration with ~100 fisheries biologists for improved fisheries conservation management in Wisconsin, USA. In total, 5,950 lakes were classified into 15 lake classes using a two tiered approach. In tier-one, lakes were clustered into “simple” and “complex” sportfish assemblages. In tier-two, lakes were further clustered using accumulated degree days, water clarity, and special cases. We focus on temperature and clarity because these factors often drive fisheries change over time — thus a lake’s class can change over time. Lake class assignments were refined through a vetting process where fisheries biologists with expert knowledge provided feedback. Relative abundance, size-structure, and growth rates of fishes varied significantly across classes. Biologists are encouraged to utilize class interquartile ranges in fisheries metrics to make
improved fisheries assessments. We highlight hard-won lessons from our effort including: (1) the importance of co-developing classification frameworks alongside fisheries biologists; and (2) encouraging frameworks where lakes can shift classes and fisheries expectations over time due to factors like climate change and eutrophication.

Expanded Assessment of Recruitment Bottlenecks for Age-0 Walleye Sander Vitreus in Northern Wisconsin – Thesis

A Thesis Submitted in partial fulfillment of the requirements of the degree
MASTER OF SCIENCE IN NATURAL RESOURCES (FISHERIES)
College of Natural Resources UNIVERSITY OF WISCONSIN
Stevens Point, Wisconsin

Many northern Wisconsin lakes that historically supported naturally-recruiting walleye Sander vitreus populations have shown declines in recruitment over the last 10-15 years. Previous research conducted on four northern Wisconsin lakes suggested a recruitment bottleneck was occurring before mid-July in lakes with declining walleye natural recruitment. Effective management of walleye populations involves understanding these recruitment bottlenecks, as potential management solutions may vary in relation to when and why this recruitment failure is occurring. To further assess these recruitment bottlenecks, I expanded on the previous assessment to determine if: 1) timing of a recruitment bottleneck for age-0 walleyes was consistent among lakes with declining
recruitment; 2) abiotic and biotic metrics differed between lakes with declining (D-NR) and sustained (S-NR) walleye recruitment, with a specific focus on the abundance of edible zooplankton and 3) catch-per-effort (CPE) of larval and post-larval walleyes can be used to predict the presence, absence, and relative strength of walleye year-classes indexed by standard fall electrofishing conducted by the Wisconsin Department of Natural Resources and the Great Lakes Indian Fish and Wildlife Commission.

Changes To The Fox River Locks?

Here is an article ran in today’s Milwaukee Journal Sentinel on concerns over potential changes to the Fox River locks and the formation of the Winnebago System Fisheries Preservation Alliance.

2017-18 Winnebago System Walleye Report

Attached is the 2017 Winnebago Walleye Report. The report covers a variety of topics including 2017 spring water level and walleye hatch results, 2017 spring adult spawning stock results, walleye exploitation and reward tag study results, a walleye population outlook, and a regulation change discussion update.

Walleye anglers have enjoyed some productive walleye fishing on the Winnebago System over the last few months, particularly in May and June. Many anglers have also been wondering how the 2018 walleye hatch will stack up after the historical spring weather events that swept through the area (you may remember the 30 inch snow event in April). DNR staff and a host of local volunteers completed the first round of the Annual Lake Winnebago Bottom Trawl Assessment last week.

Preliminary results indicated a measurable 2018 walleye hatch (5.7 young of year/trawl), but we will have to wait until the September and October trawling rounds are completed for official results. The survey is also vital for evaluating the year class strength of other sport and forage fish species in Lake Winnebago. Stay tuned for the annual trawling report once the survey concludes in fall. I hope you enjoy the walleye report and good luck with your summer fishing adventures. We are committed to service excellence.

Visit our survey at http://dnr.wi.gov/customersurvey to evaluate how I did. Adam D. Nickel Phone: (920) 424-3059 adam.nickel@wisconsin.gov

Click here for 2017-18 Winnebago System Walleye Report

The Sauger Project – WFT

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DNR seeks input on Winnebago Walleye Management Plan

We wanted to bring it to your attention that the Department will be holding public meetings regarding the Winnebago Walleye Management Plan.  The plan originated in 1991 and we having been working to update the plan over the last few years.  There were four public meetings held in 2010 to provide a Winnebago walleye population status update and solicit comments from the public regarding current issues.

The comments received from the 2010 meetings were used to help guide updating the plan.  In addition, several meetings were held with the Winnebago Fisheries Advisory Council and they were directly involved with updating the plan since 2013.

The Department will be holding 3 public meetings to now seek further public input regarding the updated Winnebago Walleye Management Plan (attached).  Please see the press release below for more information on meeting dates and locations.  I hope to see you there.

DNR seeks input on Winnebago Walleye Management Plan

By Northeast Region March 12, 2018

Contact(s): Adam Nickel, DNR fisheries biologist, 920-424-3059; Ed Culhane, DNR communications, 715-781-1683

OSHKOSH, Wis. – The Department of Natural Resources has scheduled three public meetings on a proposed update to the Winnebago Walleye Management Plan. The meetings will also offer the public an update on the status of the Winnebago System walleye population.

Each meeting will be held from 6:30 to 8:30 p.m., with the first occurring Monday, March 19, at the JP Coughlin Center, 625 E. County Road Y, Oshkosh. The second public meeting is set for Wednesday, March 21, at the Engler Center for the Performing Arts, 530 W. Main St., Chilton, and the third is set for Wednesday, March 28, at the Mosquito Hill Nature Center, N3880 Rogers Road, New London.

The Winnebago system is well known both for its healthy, self-sustaining walleye population and the decades-long history of public input in support of fisheries management. This is the first major update to the plan since it originated in 1991. Winnebago System waters include lakes Poygan, Winneconne, Butte des Morts and Winnebago and all their tributaries, including the Wolf and upper Fox rivers, from their mouths upstream to the first dam.

We are committed to service excellence.

Visit our survey at http://dnr.wi.gov/customersurvey to evaluate how I did.

 

Adam D. Nickel

Senior Fisheries Biologist – Bureau of Fisheries Management

Winnebago System Gamefish Biologist

Calumet and eastern Outagamie Counties

Wisconsin Department of Natural Resources

625 E County Road Y, Suite 700

Oshkosh, WI 54901

Phone: (920) 424-3059

Fax: (920) 424-4404

adam.nickel@wisconsin.gov

dnr.wi.gov

2016 Lake Winnebago Bottom Trawling Assessment Report

2016 Lake Winnebago Bottom Trawling Assessment Report
Adam Nickel, Winnebago System Gamefish Biologist, January 2017

The 2016 Winnebago bottom trawling survey results are in and it was a great year to be on the boat as the survey revealed strong year classes for crappie, walleye, and forage base species. Over 36 volunteers (a mix of new and veteran) boarded the Calumet in 2016 and donated over 400 volunteer hours of labor. The bottom trawl assessment is the most critical fisheries assessment conducted on the Winnebago System and simply could not be conducted without the help of our dedicated volunteer base.

The objectives of the trawling assessment are to:
1) provide critical information on year class strength of game and nongame fish species,
2) monitor trends in the forage base,
3) monitor general population trends of game and nongame fish species. The survey also provides volunteers with a hands-on experience with
conducting survey work on the system.

Full report details are here

Walleye Movement in the Winnebago System (2011-2013)

I attended the Berlin chapter meeting last night and had some interesting conversation. Today I called Adam Nickle our Fisheries Biologist. The attached PDF document is a report on a walleye tracking study DNR conducted with WFT funding. WFT purchased the sonic tags. Much of the Berlin conversation centered around lack of walleye using the Fox River as a spawning area.

As you can see from the text, the Winnebago System has 35 listening devices installed. These are used to track sturgeon primarily but are also used to track walleye, flathead catfish and musky. The System is so large and dynamic that this system has been very beneficial to understand how important fish species move around on an annual basis.

Walleye Movement in the Winnebago System (2011-2013)

 

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