WISCONSIN
COOPERATIVE FISHERY
RESEARCH UNIT
SUMMARY OF ACTIVITIES JULY 2015 - JUNE 2016
The Wisconsin Cooperative Fishery Research Unit has been
an integral part of fisheries and aquatic science research and
education in the College of Natural Resources at the
University of Wisconsin-Stevens Point since 1971. The
cooperators in this partnership include the U.S. Geological
Survey, the Wisconsin Department of Natural Resources and
the University of Wisconsin-Stevens Point.
The three-fold mission of the Unit is to: 1) conduct
scientifically-valid research addressing the research needs of
our cooperators, 2) train graduate students to become future
professionals and 3) provide extension services and
continuing education opportunities to resource professionals.
Our research endeavors encompass a wide range of topics
including population dynamics and demographics,
conservation of genetic resources, propagation and stocking
success, fish movement and passage strategies, and fish
habitat assessment.
Wisconsin Cooperative Fishery Research Unit studies have
met and continue to meet the needs of the U.S. Geological
Survey, the Wisconsin Department of Natural Resources, the
University of Wisconsin-Stevens Point, the U.S. Fish and
Wildlife Service, other agencies, and the public.
Wisconsin Cooperative Fishery
Research Unit
Wisconsin Cooperative Fishery Research Unit
www.coopunits.org
MISSION STATEMENT
PERSONNEL AND COOPERATORS
COORDINATING COMMITTEE
MICHAEL TOME
Eastern Units Supervisor
Cooperative Research Units
U.S. Geological Survey
U.S. Department of the Interior
12201 Sunrise Valley Drive, MS 303
Reston, VA 20192
(703) 648-4860
GREG PILS
Acting Director
Bureau of Integrated Science Services
WI Department of Natural Resources
125 South Webster
PO Box 7921
Madison, WI 53707
(608) 267-9753
CHRISTINE THOMAS
Dean
College of Natural Resources
University of Wisconsin–Stevens Point
800 Reserve Street
Stevens Point, WI 54481
(715) 346-4617
ANDREA MUSCH
Program Assistant
WI Cooperative Fishery Research Unit
College of Natural Resources
University of Wisconsin-Stevens Point
(715) 346-2178
KEITH TURNQUIST
Molecular Conservation Genetics Lab
WI Cooperative Fishery Research Unit
College of Natural Resources
University of Wisconsin-Stevens Point
(715) 346-3873
DAN DEMBKOWSKI
Research Scientist
Fish Propagation Science Center
WI Cooperative Fishery Research Unit
College of Natural Resources
University of Wisconsin-Stevens Point
(715) 346-4350
USGS STAFF
DAN ISERMANN
Unit Leader
WI Cooperative Fishery Research Unit
U.S. Geological Survey
College of Natural Resources
University of Wisconsin-Stevens Point
(715) 346-3221
UNIVERSITY STAFF
JEFF DIMICK
Research Scientist
Aquatic Biomonitoring Lab
WI Cooperative Fishery Research Unit
College of Natural Resources
University of Wisconsin-Stevens Point
(715) 346-3868
JANICE KERNS
Research Scientist
Fisheries Analysis Center
WI Cooperative Fishery Research Unit
College of Natural Resources
University of Wisconsin-Stevens Point
(715) 346-2502
WES LARSON
Assistant Unit Leader
WI Cooperative Fishery Research Unit
U.S. Geological Survey
College of Natural Resources
University of Wisconsin-Stevens Point
(715) 346-3150
CURRENT M.S. STUDENTS GRADUATED M.S. STUDENTS
Nick Rydell Zach Snobl
Josh Schulze Hadley Boehm
Jason Gostiaux
Eric Wegleitner
Jenna Ruzich
RESEARCH ASSISTANTS AND TECHNICIANS
UNDERGRADUATE RESEARCH TECHNICIANS
Justin Howard
Brad Erdman
Matt Krause
Logan Sikora
Brandon Maahs
Zach Witzel
Jacob Steckmesser
Zach Mohr
Shae Flood
Andrew Zabel
Taylor Beaman
Drew Wallace
Sam Schaick
Alex Catalano
Kaitlyn Duhm
Ben Breaker
Tim Gander
Autumn Neilson
Kate Carpenter
WISCONSIN DEPARTMENT OF NATURAL RESOURCES
Jennifer Bergman, Fisheries Biologist
Wisconsin Rapids Field Unit
Dave Boyarski, NR Region Team Supervisor
Sturgeon Bay Service Center
Tom Cichosz, Treaty Data Coordinator
DNR Central Office-Madison
Mike Donofrio, NR Region Team Supervisor
Peshtigo Service Center
Brad Eggold, NR Region Team Supervisor
Great Lakes Water Institute-Milwaukee
Lawrence Eslinger, Fisheries Biologist
Woodruff Treaty Fisheries Assessment Team
Steve Fajfer, NR Operations Supervisor
Wild Rose Hatchery-Wild Rose
Kevin Gauthier, Water Resources Management Specialist
Woodruff Service Center-Woodruff
David Giehtbrock, Section Chief
Fish Culture Section, Madison
Steve Gilbert, Fisheries Biologist
Woodruff Service Center
Scott Hansen, Fisheries Biologist
Sturgeon Bay Service Center
Joe Hennessy, Fisheries Biologist
DNR Science Operations Center-Madison
Ben Heussner, Fisheries Biologist
Kettle Moraine Southern Unit State Forest-Eagle
Steve Hewett, Section Chief
DNR Central Office-Madison
Pradeep Hirethota, Fisheries Biologist
Great Lakes Water Institute-Milwaukee
Steve Hogler, Fisheries Biologist
Green Bay Service Center-Green Bay
Jeff Kampa, NR Region Team Supervisor
Spooner Service Center-Spooner
Ryan Koenigs, Fisheries Biologist
Oshkosh Service Center-Oshkosh
John Kubisiak, Fisheries Biologist
Rhinelander Service Center-Rhinelander
Nick Legler, Fisheries Biologist
Sturgeon Bay Service Center-Sturgeon Bay
John Lyons, NR Program Supervisor
DNR Science Operations Center-Madison
Ryan Marty, Program and Policy Analyst
DNR Central Office-Madison
Tom Meronek, Fisheries Biologist
Wisconsin Rapids Field Unit
Matt Mitro, NR Research Scientist
DNR Science Operations Center-Madison
Adam Nickel, Fisheries Biologist
Oshkosh Service Center-Oshkosh
Al Niebur, Fisheries Biologist
Shawano-Shawano
Nathan Nye, Fisheries Biologist
Lake Wissota State Park-Chippewa Falls
Timothy Parks, Research Scientist
Spooner Service Center
Luke Roffler, Fisheries Biologist
Richard Bong State Rec Area-Kansasville
David Rowe, NR Region Team Supervisor
Fitchburg Service Center-Fitchburg
Andrew Rypel, NR Research Scientist
DNR Science Operations Center-Madison
Greg Sass, NR Program Supervisor
WI Limnology Boulder Junction
Dave Seibel, Fisheries Biologist
Antigo Service Center-Antigo
Tim Simonson, NR Staff Specialist
DNR Central Office-Madison
Lori Tate, Fisheries Biologist
DNR Central Office-Madison
Scott Van Egeren, Water Resources Management Specialist
DNR Central Office-Madison
Max Wolter, Fisheries Biologist
Hayward Service Center-Hayward
PERSONNEL AND COOPERATORS (CONTINUED)
FEDERAL AGENCY
Chuck Bronte, US Fish and Wildlife Service
Fisheries Biologist-Green Bay, Wisconsin
Rob Elliott, US Fish and Wildlife Service
Fisheries Biologist-Green Bay, Wisconsin
Mark Luehring, Great Lakes Indian Fish and Wildlife
Commission Inland Fisheries Biologist
Darrin Simpkins, US Fish and Wildlife Service
Fisheries Biologist-Green Bay, Wisconsin
Ted Treska, Sea Lamprey Information Systems Manager
Great Lakes Fishery Commission-Ann Arbor, Michigan
Mike Quist, Assistant Unit Leader
ID Cooperative Fish and Wildlife Research Unit
PERSONNEL AND COOPERATORS (CONTINUED)
UW-STEVENS POINT COOPERATORS
Ron Crunkilton
Professor Water Resources
Bill DeVita
Wisconsin Environmental Analysis Laboratory
Bill Fisher
Assistant Professor Water Resources
Kyle Herrman
Assistant Professor Water Resources
George Kraft
Professor Water Resources
Paul McGinley
Assistant Professor Water Resources
Joshua Raabe
Assistant Professor Water Resources
Jason Riddle
Assistant Professor Wildlife Ecology
Kevin Russell
Associate Professor Wildlife Ecology
Brian Sloss
Associate Dean of Outreach, Extension and Extramural
Grants
Justin VanDeHey
Assistant Professor Fisheries and Water Resources
OTHER UNIVERSITY COOPERATORS
Steve Carpenter
UW-Madison, Center for Limnology
Rob Colombo
Eastern Illinois University
Derek Crane
Coastal Carolina University
Patrick Forsythe
University of Wisconsin-Green Bay
John Janssen
University of Wisconsin - Milwaukee
Kevin Kapuscinski
Lake Superior State University
Loren Miller
University of Minnesota
Derek Ogle
Northland College
Kim Scribner
Michigan State University
Trent Sutton
University of Alaska - Fairbanks
Chris Wilson
Trent University, Canada, Ontario Ministry of Natural
Resources, Peterborough, Ontario
Amy Welsh
West Virginia University
Jake Vander Zanden
UW-Madison, Center for Limnology
OTHER COOPERATORS
John Ackerson
Missouri Department of Conservation
Eric Altena
Minnesota Department of Natural Resources
Ed Baker
Michigan Department of Natural Resources
Brian Blackwell
South Dakota Game, Fish and Parks
Randall Claramunt
Michigan Department of Natural Resources
Dave Carrofino
Michigan Department of Natural Resources
Patrick Hanchin
Michigan Department of Natural Resources
Jon Hansen
MN Department of Natural Resources
Gretchen Hansen
MN Department of Natural Resources
Andrew Jansen
Iowa Department of Natural Resources
Ken Kansas
Fisheries Branch, Manitoba Water Stewardship
Darren Kramer
Michigan Department of Natural Resources
Dale Logsdon
Minnesota Department of Natural Resources
Joshua Pyatskowit
Menominee Indian Tribe of Wisconsin
Jeremy Pyatskowit
Menominee Indian Tribe of Wisconsin
Jeff Reed
Minnesota Department of Natural Resources
Troy Zorn
Michigan Department of Natural Resources
Rich Zweifel
Ohio Department of Natural Resources
WISCONSIN COOPERATIVE FISHERY RESEARCH UNIT—
COMPLETED GRADUATE THESES
HABITAT USE OF SUB-ADULT LAKE
STURGEON IN THE LOWER WOLF RIVER,
WISCONSIN
RESEARCH ASSISTANT: ZACH SNOBL, M.S
PRINCIPAL INVESTIGATOR: DAN ISERMANN
FUNDING SOURCE: WISCONSIN DEPARTMENT OF
NATURAL RESOURCES
Habitat use and movement of sub-adult Lake Sturgeon
is largely unknown for most systems. Establishing patterns of
habitat use and movement at this life stage could assist
managers in capturing sub-adult fish, which would provide a
better understanding of recruitment. Sampling sub-adult
sturgeon can provide a more immediate and accurate method
for assessing the effectiveness of management actions on Lake
Sturgeon recruitment. This monitoring is especially important
for exploited populations, where changes to harvest
management could be implemented if recruitment declines and
increases can be detected before cohorts reach adulthood.
The Lake Winnebago System Lake Sturgeon
population supports an annual spear fishery with average annual
harvests of approximately 1,400 fish from a population of
adults that is estimated at approximately 42,000 fish. Little
information on sub-adult Lake Sturgeon in the Lake Winnebago
System is available and standardized sampling has not targeted
these fish in the past. Fishery managers are interested in
determining habitat use of sub-adult Lake Sturgeon to aid in
developing recruitment surveys to better understand the
population at this life stage.
While sub-adult Lake Sturgeon likely occupy multiple
habitats in the Lake Winnebago System, the first phase of this
research focused on sub-adult Lake Sturgeon in the lower Wolf
River. The objectives of my study were to determine if: 1)
numbers of sub-adult Lake Sturgeon in the lower Wolf River
are sufficient to justify sampling this portion of the Lake
Winnebago system as part of a basin-wide recruitment survey;
2) linear home range or movements of sub-adult Lake Sturgeon
in the lower Wolf River varies in relation to season, sex, or total
length (TL) category (small < 96.0 cm TL; large ≥ 96.0 cm TL)
and 3) sub-adult Lake Sturgeon selectively occupy certain
habitats in the lower Wolf River in terms of substrate and
channel morphology.
A total of eighteen sub-adult Lake Sturgeon were
captured on the lower Wolf River during fall 2013 and 2014
using various sampling techniques. A total of 618.5 hours were
invested in attempting to capture these fish. Sub-adult Lake
Sturgeon were surgically implanted with radio-transmitters and
released back into the river near capture locations. Relocation
of fish was attempted every two weeks over the two years of the
study, except for winter, when relocation attempts occurred
once per month. Latitude, longitude, and substrate type were
recorded at each relocation. Data collected were used to
determine overall, annual, and seasonal linear home range sizes
for each fish.
Side-scan sonar was used to collect images of the
lower Wolf River that were uploaded into ArcGIS™.
Substrates were identified with color-coded polygons that
corresponded to different substrate types to create a substrate
map of the entire study area. This map was used in conjunction
with fish relocations to determine substrate use.
Linear home ranges did not differ in relation to sex or
TL category, but did vary among seasons. The majority of
movement for sub-adult Lake Sturgeon occurred in spring,
which is similar to trends observed in previous studies of adult
fish. Additionally, fish usually exhibited limited movement
during winter (linear home range < 0.5 rkm). Selection ratios
indicated that sub-adult Lake Sturgeon were not selecting for
any substrate or channel morphology type.
Although some sub-adult Lake Sturgeon do occupy the
lower Wolf River, I conclude that sufficient numbers of sub-
adult Lake Sturgeon do not reside in the river to justify
extensive sampling as part of a recruitment index survey. This
information is important because sampling effort is typically
limited by cost and logistics and my study suggests this effort
may be better expended in other locations within the system.
However, additional work is needed to determine where the
largest concentration of sub-adult Lake Sturgeon reside within
the Winnebago System, as there is still interest in developing a
method for sampling sub-adult Lake Sturgeon to monitor
recruitment trends before fish reach adulthood.
COMPLETED GRADUATE THESES (CONTINUED)
IDENTIFYING RECRUITMENT BOTTLENECKS IN
NORTHERN WISCONSIN WALLEYE
POPULATIONS
RESEARCH ASSISTANT: HADLEY BOEHM, M.S
PRINCIPAL INVESTIGATOR: DAN ISERMANN
FUNDING SOURCE: WISCONSIN DEPARTMENT OF
NATURAL RESOURCES
Walleye Sander vitreus recruitment (measured as age-
0 catch-per-effort in fall electrofishing) has declined in many
northern Wisconsin lakes and the reasons for these declines are
not known. Recruitment declines are a significant management
concern for the Wisconsin Department of Natural Resources, as
many of these walleye populations did support popular
fisheries. Understanding mechanisms and timing associated
with walleye recruitment bottlenecks during the first year of life
is important in developing management solutions, as changes to
harvest regulations or stocking strategies may be warranted
depending on when and where bottlenecks occur. Therefore, the
objectives of my research were to: 1) develop sampling
protocols for collecting larval and post-larval walleyes before
electrofishing for age-0 walleye occurs in fall; 2) identify
timing of recruitment bottlenecks for age-0 walleyes in two
northern Wisconsin walleye lakes with a declining recruitment
history (D-NR) relative to trends observed in two lakes with
sustained recruitment histories (S-NR); and 3) evaluate
differences in abiotic and biotic variables between lakes with
the two different recruitment histories. In 2014 and 2015, I
sampled Kawaguesaga and Sawyer lakes (D-NR) and Escanaba
and Big Arbor Vitae lakes (S-NR). Adult walleye were
captured in spring using nighttime electrofishing, egg mats
were used to verify spawning, towed ichthyoplankton nets,
quatrefoil light traps, beach seines, micro-mesh gillnets, and
electrofishing were used to capture age-0 walleye throughout
their first year of life. Water quality data, zooplankton samples,
and panfish diet information were also collected. Age-0
walleyes were not captured in D-NR lakes after the early larval
stage, while age-0 walleyes were captured at multiple life
stages during both years on S-NR lakes. These results suggests
a recruitment bottleneck for age-0 walleye occurs at or before
the larval stage in D-NR lakes. Panfish were not major
predators of larval walleyes on any lake in either year. I
compared biotic and abiotic metrics between recruitment
histories using repeated-measures analysis of variance.
Temperature and dissolved oxygen were similar for all lakes,
although D-NR lakes were slightly clearer. Mean total length
(TL) of adult walleyes was significantly greater on D-NR lakes
than S-NR lakes. Larval yellow perch TL, mean coefficient of
variation in May daily water temperature, average density and
TL of calanoid and cycolopoid copepods, nauplii, and Daphnia
spp., walleye egg density, and Secchi depth did not differ
significantly between S-NR and D-NR lakes. Continued
research should focus on further collection of some abiotic and
biotic metrics on these and other lakes to determine if the
trends observed in age-0 walleye abundance occur in other D-
NR and S-NR lakes. This expanded sampling might also
provide more information on the factors for responsible for
potential recruitment bottlenecks. My results suggest that
temporal trends in relative abundance of walleyes during their
first year of life can be monitored using a combination of
ichthyoplankton nets towed at night during mid to late May
(i.e., 1-3 weeks after peak walleye spawning), 0.64-cm mesh
gill nets set in mid to late July, and fall electrofishing. Future
studies might also include experimental stocking of walleye fry
to determine if this strategy can be used to circumvent
recruitment bottlenecks that occur at or before the larval stage.
WISCONSIN COOPERATIVE FISHERY RESEARCH UNIT—
CONTINUING GRADUATE RESEARCH
MOVEMENTS OF LAKE STURGEON AFTER
UPSTREAM PASSAGE ABOVE TWO DAMS ON
THE MENOMINEE RIVER
RESEARCH ASSISTANT: JOSH SCHULZE, M.S.
CANDIDATE
PRINCIPAL INVESTIGATOR: DAN ISERMANN
FUNDING SOURCE: GREAT LAKES FISH AND WILDLIFE
RESTORATION ACT, U.S. FISH AND WILDLIFE SERVICE
JULY 2014 - DECEMBER 2016
Currently, hydroelectric dams prevent lake sturgeon entering
the lower Menominee River from Green Bay from reaching
high-quality spawning locations and juvenile fish habitat
available upstream. Fish passage through the lower two dams
on the Menominee River began in 2014 and fishery managers
with the Wisconsin and Michigan Departments of Natural
Resources (DNR) need to determine the numbers and
characteristics of lake sturgeon that should be allowed to pass
in order to maximize recruitment potential and the return of
fish back downstream. Our proposed research will use acoustic
telemetry to describe movement of lake sturgeon passed
upstream in the Menominee River and will provide fishery
managers around the Great Lakes with information that can be
used to formulate passage strategies and possibly help design
passage facilities for lake sturgeon. Our research objectives are
to determine: 1) if adult lake sturgeon passed upstream return
downstream to the lower Menominee River or Green Bay
within 1 or 2 years of passage; 2) if adult lake sturgeon have
the opportunity to spawn at least once above Park Mill Dam
within 1-2 years after passage; 3) if spawning opportunity,
downstream return rates, and use of the downstream fishway at
Park Mill Dam are related to timing of passage, time elapsed
since passage occurred, month of year, flow or temperature
conditions, or in relation to fish attributes such as sex, length,
and maturation status and 4) if the number, length, and sex of
fish passed upstream and timing of passage can be
manipulated to maximize the number of eggs deposited above
Park Mill dam by fish that were passed upstream.
EFFECTS OF 2, 4-D HERBICIDE TREATMENTS
USED TO CONTROL EURASIAN WATERMILFOIL
ON FISH AND ZOOPLANKTON IN NORTHERN
WISCONSIN LAKES
RESEARCH ASSISTANT: NICK RYDELL, M.S CANDIDATE
PRINCIPAL INVESTIGATOR: DAN ISERMANN
FUNDING SOURCE: WISCONSIN DEPARTMENT OF
NATURAL RESOURCES
JULY 1, 2014 - JUNE 30, 2018
Eurasian watermilfoil Myriophyllum spicatum (EWM) is one of
the most problematic aquatic invasive species in North America
because it can outcompete native macrophytes (Madsen et al.
1991), negatively affect fish and wildlife, and interferes with
recreational activities (Smith and Barko 1990). Application of
herbicides is commonly used as a means to control or eradicate
EWM (Sorsa et al. 1988; Parsons et al. 2001). Specifically, 2, 4-
Dichlorophenoxyacetic acid (2, 4-D) based herbicides are
widely used for controlling EWM in Wisconsin and other
states, but little is known regarding the effects of these
herbicide treatments on fish and zooplankton communities
outside of a laboratory setting. One previous study indicated
that application of 2, 4-D herbicides did not affect fish diversity
or biomass in two Minnesota lakes (Kovalenko et al. 2010), but
application of these herbicides remains an important concern
for the Wisconsin Department of Natural Resources (WDNR),
which issues the permits required for herbicide application in
Wisconsin lakes. Consequently, the objectives of our study are
to determine if: 1) 2, 4-D herbicide treatments used to control
EWM affect the abundance, diversity, and size structure of fish
at different life history stages; 2) herbicide treatments affect
feeding, survival, growth, and reproductive investment of
selected fish species, and 2) if herbicide treatments affect
diversity, abundance, and size of zooplankton. Our working
hypotheses are that 2, 4-D herbicide treatments will not reduce
fish diversity, but will reduce abundance and survival which
will eventually influence the size structure of fish populations in
WISCONSIN COOPERATIVE FISHERY RESEARCH UNIT—
CONTINUING GRADUATE RESEARCH
IDENTIFYING RECRUITMENT BOTTLENECKS IN
NORTHERN WISCONSIN WALLEYE
POPULATIONS
RESEARCH ASSISTANT: JASON GOSTIAUX, M.S.
CANDIDATE
PRINCIPAL INVESTIGATOR: DAN ISERMANN
FUNDING SOURCE: WISCONSIN DEPARTMENT OF
NATURAL RESOURCES
JANUARY 2016 - DECEMBER 2018
treated lakes through reduced recruitment. Furthermore, we
hypothesize that herbicide treatments will not affect gonadal
investment and fecundity, but will reduce survival, foraging
success, and growth of larval fish. Lastly, we hypothesize that
herbicide treatments will not affect zooplankton diversity, but
will result in increased abundance and size structure of
zooplankton because of reductions in larval fish predation.
Walleye recruitment has declined in several northern Wisconsin
lakes for unknown reasons and our goal is to identify the timing
and potential causes of recruitment bottlenecks for age-0
walleyes in northern Wisconsin lakes. In the first phase of this
project, we identified a recruitment bottleneck for age-0 walleye
occurring at or before the larval stage in two lakes where
walleye recruitment has declined dramatically over the last
decade. We also determined that abundance of age-0 walleyes
can be monitored during the first year of life using a
combination of towing ichthyoplankton nets at night during mid
to late May, micromesh gill nets set in July, and electrofishing
in fall. Our plans for the next phase of this project, has
expanded to include 12 lakes in northern Wisconsin. Our
objectives will be to determine if: 1) larval walleyes are not
present in declining NR lakes; 2) differences in limnological
conditions and zooplankton communities observed between
sustained and declining NR lakes during Phase I are consistent
at a broader spatial scale; and 3) stocked walleye fry persist in
lakes with declining NR. To achieve these objectives, we will
expand our sampling to additional lakes in the northwest
portion of the state, while continuing to sample the 4 lakes that
were included in Phase I. Our plan would be to add 1-2
sustained NR lakes and 3 declining NR lakes in the northwest
portion of the state. Our revised sampling regime on each lake
will include: two night larval towing events on each lake in the
last two weeks of May, 1-2 nights of small mesh gillnet
sampling in mid to late July, and fall electrofishing for age-0
walleyes. We will also collect limnological data and
zooplankton during late May-June. Sampling would occur in
2016 and 2017. Because we have collected no larval walleye in
the two declining NR lakes, we propose to stock OTC marked
walleye declining NR lakes to see if fry survive to fall; stocking
would occur in spring 2017. Otoliths from any age-0 walleye
collected from these lakes would be examined for OTC marks.
SALMONID ABUNDANCE AND OUTMIGRATION
IN WISCONSIN TRIBUTARIES TO LAKE
MICHIGAN
RESEARCH ASSISTANT: ERIC WEGLEITNER, M.S.
CANDIDATE
PRINCIPAL INVESTIGATOR: DAN ISERMANN
FUNDING SOURCE: WISCONSIN DEPARTMENT OF
NATURAL RESOURCES
JANUARY 2016 - DECEMBER 2018
Introduced salmonids (i.e., chinook and Coho salmon, rainbow
and brown trout) support important recreational fisheries within
the Lake Michigan ecosystem. These fisheries are primarily
supported by stocking. However, some natural reproduction is
known to occur within some tributary systems. Specifically,
anadromous rainbow trout (i.e., steelhead) stocked into Lake
WISCONSIN COOPERATIVE FISHERY RESEARCH UNIT—
CONTINUING GRADUATE RESEARCH
GENETIC ASSESSMENT OF SEVEN FISH
SPECIES ABOVE AND BELOW THE WISCONSIN
RIVER DAM AT PRAIRIE DU SAC
RESEARCH ASSISTANT: JENNA RUZICH, M.S.
CANDIDATE
PRINCIPAL INVESTIGATOR: WES LARSON
FUNDING SOURCE: ALLIANT ENERGY
JULY 2016 - JUNE 2018
Downstream fish movement at Prairie du Sac is possible, and
therefore some downstream transfer of genetic material from
Lake Wisconsin to the lower Wisconsin River likely occurs.
However, by blocking upstream migration of fish from the
lower Wisconsin River into Lake Wisconsin, the dam prevents
the transfer of genetic material from fish populations that reside
below the dam to populations of the same species that reside
above the dam. Therefore, conservation of genetic diversity is of
great concern to species that remain present above and below
Prairie du Sac Dam because a reduction in genetic diversity can
Michigan are known to exhibit an adfluvial life history,
migrating up tributaries for spawning. Wild offspring have been
encountered in some of these tributaries, but it is not known
whether these fish successfully outmigrate from these streams
into larger tributaries or Lake Michigan. The primary objectives
of our research are to determine if: 1) abundance of wild age-0
salmonids (primarily steelhead) varies among selected streams
in relation to available habitat; 2) wild age-0 salmonids
successfully outmigrate from Wisconsin tributaries into Lake
Michigan or into larger tributaries and 3) potential bottlenecks
related to stream temperature or annual flow regimes prevent
successful outmigration from some streams. We will also
compare mark-recapture methods used to estimate wild age-0
salmonid abundance to determine if a single sampling event
following stocking of marked fish yields similar estimates to
estimates derived from multiple sampling events.
lead to a reduction in the ability to adapt to selective pressures.
Previous studies have examined genetic differences in various
fish species across fragmented river systems. Typically,
evidence of genetic differentiation in artificially fragmented
populations with one-way gene flow has been detected in short
lived species with short generation times. Fish with long
generation times, on the other hand, often show few genetic
differences across large areas (e.g. lake sturgeon). These results
illustrate the importance of investigating genetic differentiation
in multiple species with variable life histories and generation
times to assess fragmentation and inform management.
Fish passage has been established as an acceptable form of
management to maintain connectivity between populations of
fish and ensure that the genetic structure and diversity present
before dam construction is preserved. The goal of this project is
to obtain baseline genetic data on multiple species sampled
above and below the Prairie du Sac Dam and use these data to
inform passage strategies that will help to protect the genetic
integrity of fish populations in this region. The specific
objective of this project is to determine if the genetic diversity
and structure of lake sturgeon (Acipenser fulvescens), quillback
carpsucker (Carpiodes cyprinus), smallmouth bass
(Micropterus dolomieu), shorthead redhorse (Moxostoma
macrolepidotum), flathead catfish (Pylodictis olivaris), sauger
(Sander canadensis), and walleye (Sander vitreus) populations
are different above and below the Prairie du Sac Dam. The
intended outcome of this project will be to provide data that will
allow managers to make more informed decisions regarding
passage of different species on the Wisconsin River.
Wisconsin Cooperative Fishery Research Unit—
Fisheries Analysis Center
CO-DIRECTORS: DANIEL ISERMANN AND JANICE KERNS
WDNR LIAISONS: JOE HENNESY, MATT MITRO, AND STEVE HEWETT
MISSION
The Fisheries Analysis Center (FAC) is a research collaboration involving the Wisconsin Department of Natural Resources and the
Wisconsin Cooperative Fishery Research Unit. The FAC is funded by the WDNR Bureau of Fisheries Management and was created
to serve three primary functions 1) analysis of fish population dynamics and demographics as they relate to fisheries management
and environmental variability 2) development, implementation, and evaluation of methods for estimating the age and growth of fish
and 3) provide technical training for fisheries professionals and students.
WDNR FUNDED PROJECTS
Dynamics and demographics of Cisco populations
in Wisconsin lakes
Principal Investigators: Daniel Isermann, John Lyons, Jeff
Kampa, Connie Isermann
Project Summary: Cisco Coregonus artedi are native to many
water bodies in Wisconsin. Cisco are important to food web
dynamics because they serve as primary prey for large,
economically-important piscivores such as walleyes and
muskellunge and because they influence lower trophic levels
through planktivory. Despite their importance, a comprehensive
evaluation of the dynamics and demographics of cisco
populations in Wisconsin has not been conducted. Describing
cisco population characteristics across a broad spatial scale will
provide a better understanding of how abiotic and biotic
variables affect cisco in Wisconsin. Our objective is to
determine if abiotic and biotic variables affect growth rates,
recruitment patterns, and the age and size structure of cisco
populations in Wisconsin. This is a collaborative project with
Wisconsin DNR and we are currently processing cisco that
were collected during the 2013 and 2014 sampling season.
Assessment of walleye population characteristics
in Stevens Point Flowage using passive integrated
transponders
Principal Investigators: Daniel Isermann, Janice Kerns, Jacob
Thompson, and Tom Meronek
Project Summary: The Wisconsin River supports some of
Wisconsin’s most prominent walleye fisheries, but information
on these populations is often lacking because of other sampling
responsibilities. Our objectives are to use mark-recapture of
walleyes implanted with passive integrated transponders (PITs)
to develop population models that will allow us to estimate
abundance, growth, and mortality metrics for walleyes in
Stevens Point Flowage. Our larger goal is to determine whether
this approach will be useful for other populations where annual
sampling does not occur and sacrifice of fish for otoliths is not
desirable.
FISHERIES ANALYSIS CENTER (CONTINUED)
Assessment of Walleye stocks in Green Bay
Principal Investigators: Daniel Isermann, Steve Hogler, Troy
Zorn, and Connie Isermann
Project Summary: Green Bay currently supports one of the
most economically-important recreational fisheries for walleyes
Sander vitreus in North America, attracting anglers from across
the continent. Walleyes spawn in many locations within Green
Bay and its tributaries, but the contributions of these different
locations or regions to the overall fishery have not been
determined. The first phase of the research focused on
determining if otolith microchemistry can be used to identify
larval walleye originating from different locations within Green
Bay. We have submitted a full proposal to Wisconsin Sea Grant
to secure funding for this portion of the project. Our additional
objectives are to use biological data and mark-recapture
information to determine if growth, fecundity, and condition of
spawning walleyes vary among tributaries and if fish repeatedly
return to the same river during spawning. We are currently
processing ovary and otolith samples collected by WICFRU
and WDNR staff during spring of 2015.
Electrofishing catchability of juvenile
muskellunge in northern Wisconsin lakes
Principal Investigator: Janice Kerns, Daniel Isermann, and
Tim Simonson
Funding Source: Hugh C. Becker Committee of Twin Cities
Chapter of Muskies, Inc. and donations from Musky Clubs
Alliance of Wisconsin
Project Summary: To assess the effectiveness of muskellunge
stocking, biologists conduct electrofishing surveys in fall to
estimate catch per effort (CPE) and relative contribution of
stocked fish. Inherent assumptions of this sampling are that
wild and stocked fish have equal probability of capture and that
changes in CPE reflect changes in actual abundance. However,
capture rates of age-0 muskellunge tend to be low for both wild
and stocked fish, making it difficult to determine if
electrofishing catch is a meaningful predictor of actual
abundance. The goal of our study was to determine the
effectiveness of electrofishing for capturing individual age-0
muskellunge by determining locations of stocked fish released
into two lakes in northern Wisconsin. All stocked fish received
a fin clip and at least 40 fish per lake were inserted with radio
transmitters. All fish were released at a single boat ramp on
each lake, which followed standard Wisconsin Department of
Natural Resources (DNR) protocols. Stocked muskellunge with
transmitters were tracked weekly for one month after release.
Fish were also sampled weekly using standard Wisconsin DNR
electrofishing methods that included a single boat following
single line transect around the shoreline of each lake.
Comparing known locations of radio-tagged fish to the area
sampled by the electrofishing boat revealed that most of the
sampling effort was expended outside the area where stocked
fish were located. Our initial results suggest that the majority
of hatchery fish remained in the vicinity of the release location,
with fish moving a max distance of 0.4 – 0.7 km on average
away from the release location within four weeks of being
stocked. Based on these results, biologists will be able to
improve sampling protocols to evaluate muskellunge stocking
success by stratifying sampling effort so that more time is spent
sampling where the fish are located.
Statewide evaluation of calcified structures used
to estimate ages of largemouth bass and northern
pike
Principal Investigator: Daniel Isermann, Eric Wegleitner,
Connie Isermann, and Tom Meronek
Project Summary: This project is a continuation of the
Wisconsin DNR Fish Age Task Group’s efforts to develop
statewide protocols for estimating the age of species of
management interest and is similar to the efforts we have
completed for bluegills and walleyes. Our objective is to
provide guidance to biologists regarding selection and
preparation of calcified structures. At this point we have
processed and aged scales from more than 200 largemouth bass
collected from 7 lakes statewide. We are currently processing
northern pike collected during spring 2015. Our initial results
suggest that dorsal spines are more effective for replicating
otolith ages than scales, if a correction factor is employed.
FISHERIES ANALYSIS CENTER (CONTINUED)
Evaluation of car counters and trail cameras for
estimating angler effort on Wisconsin lakes
Principal Investigators: Janice Kerns, Daniel Isermann,
Jonathan Hansen, and Joseph Hennessy
Project Summary: Angler effort can affect the quality and
long-term sustainability of fished. Angler effort is typically
estimated using creel surveys, although surveys are rarely
conducted on most lakes due to costs and logistics. When creel
surveys are possible, small sample sizes (few interviews) may
lead to large variance and poor confidence intervals associated
with estimates of effort. The objective of this study was to
determine if use of low-cost remote vehicle counters can be
used to estimating trends in angler effort. During the spring of
2015, vehicle counters (n = 40) were buried at boat ramps
throughout the state of Wisconsin. We compared vehicle
counter results to boat ramp use determined from trail cameras
deployed at 14 study lakes. Linear regression was used to
evaluate relationships among estimates of boat ramp use (i.e.,
effort). Vehicle counters explained on average 77% of the
variation in the number of boats using each lake. This suggests
vehicle counters can be used to remotely monitor trends in
angler effort on some water bodies. Vehicle counters could
provide more accurate estimates of temporal trends in angler
effort through continuous monitoring at many lakes compared
to sporadic counts conducted during traditional creel surveys.
Predicting abundance of adult muskellunge in
northern Wisconsin Principal Investigators: Janice Kerns, Daniel Isermann, Tim
Simonson, Joseph Hennessy, and Tom Cichosz
Project Summary: Most Wisconsin muskellunge Esox
masquinongy populations occur within the Ceded Territory of
northern Wisconsin, where mixed fisheries consisting of a
recreational hook-and-line fishery and a tribal spearing fishery
occur. Safe harvest levels for each population are based on
estimates of adult muskellunge abundance. Estimates of adult
muskellunge abundance used to establish safe harvest levels are
obtained from mark-recapture surveys that are conducted on a
few lakes over a two year interval. These estimates are
considered valid estimates of abundance for up to two years
after the initial marking of fish. If a recent population estimate
is not available for an individual lake, a linear regression model
is used to predict adult abundance from lake surface area using
existing population estimates from all lakes. A similar approach
is used to predict abundance of walleyes, but the amount of
variation in adult abundance that is explained by lake surface
area is much higher for walleyes than for muskellunge.
Therefore, the objective of our study is to determine if
alternative models can be used to explain greater variation in
the abundance of adult muskellunge within northern Wisconsin
lakes than the current linear model that relies solely on lake
surface area as a predictor variable.
FISHERIES ANALYSIS CENTER (CONTINUED)
Comparison of lake sturgeon growth rates
estimated from fin rays and mark-recapture
Principal Investigators: Janice Kerns, Daniel Dembkowski,
Dan Isermann, Michael Donofrio, and Edward Baker
Project Summary: Pectoral fin rays are commonly used as a
non-lethal method for estimating age of lake sturgeon
Acipenser fulvescens. While fin rays generally underestimate
age of older lake sturgeon, fin rays could provide useful
estimates of growth rate for younger fish within a population.
Our objective was to determine if lake sturgeon growth rates
estimated from fin rays were similar to growth rates observed
from recaptures of lake sturgeon tagged with passive integrated
transponders (PITs). Lake sturgeon were sampled in 2012-2013
via electrofishing on the Menominee River, where the
Wisconsin and Michigan Departments of Natural Resources
maintain a long-term PIT tagging program. Parameters from a
von Bertalanffy growth model were used to describe growth
rates estimated from fin rays (range of fin ray ages = 4 to 34).
For recaptured fish, growth rates were quantified as change in
length during time at large. Preliminary results suggest growth
rates estimated from fin rays (mean = 1.18 in/yr) are
substantially higher than rates observed from PIT tag recoveries
(mean = 0.47 in/yr). This difference is consistent with
underestimating lake sturgeon age from fin rays. Differences in
growth rates between the two methods were inversely related to
lake sturgeon total length, suggesting that fin ray growth
estimates were more reliable for larger (≥ 50 in), older lake
sturgeon, only because these fish were growing very slowly.
Fin rays are probably not useful for estimating growth rates of
lake sturgeon and we suggest that continued use of mark-
recapture with PITs offers the best method for describing
growth and survival in most lake sturgeon populations.
Largemouth bass population dynamics and
management
Principal Investigators:
Daniel Isermann, Jonathan
Hansen, and Kaitlin Schnell
Project Summary: We are
continuing to address the
potential effects of harvest
regulations on largemouth
bass populations by adding
simulations for three
additional lakes to the work
that was completed by Kaitlin Schnell. We did this to ensure
that some relatively high-density lakes were included in this
analysis, as densities of bass in the original four lakes were not
as high as expected. We are currently processing otoliths from
these samples. We also continue to collect age-0 largemouth
bass in August seine hauls on 12-14 lakes across the state. This
sampling represents an effort to better understand annual
variations in bass recruitment and hatch timing. Otoliths are
removed from these fish and daily rings are used to estimate
hatch dates. This represents a continuation of the work that was
initiated by Craig Kelling. We are also implanting passive
integrated transponders into largemouth bass in Big Arbor
Vitae Lake in northern Wisconsin. This tagging program has
been implemented to gain a better understanding of the long-
term population dynamics in northern Wisconsin lakes without
removing otoliths on a regular basis. Additionally, we are
working on a comparison of calcified structures to determine
whether scales or dorsal spines can be used to replicate otolith
ages of largemouth bass.
FISHERIES ANALYSIS CENTER (CONTINUED)
OTHER SERVICES PROVIDED
Dr. Isermann presented a research seminar at the annual
summer gathering of Illinois Natural History Survey personnel
affiliated with Kaskaskia and Sam Parr Biological Stations.
Dr. Isermann and Dr. Mike Quist (Idaho CFWRU) team taught
a population dynamics workshop for Idaho Fish and Game
personnel.
Dr. Isermann and Dr. Quist continue to work on a book focused
on age and growth methods and analyses for freshwater
fisheries biologists that will eventually be published through
the American Fisheries Society. First round of revisions for all
chapters has been largely completed. Janice Kerns is a co-
author for one of the chapters.
Dr. Isermann and Dr. Gretchen Hansen (WDNR) conducted a
webinar sponsored by the USGS National Climate Change and
Wildlife Science Center entitled “What’s the deal with
Wisconsin’s Walleye? What we know, what we don’t know,
and what we can do about it”.
FAC students and staff provided extensive assistance on an
evaluation of muskellunge stocking being conducted by
WDNR and the Fisheries Propagation Science Center at UW-
Stevens Point. These efforts included fin-clipping and tagging
muskellunge at Wild Rose Fish Hatchery as well as conducting
electrofishing surveys on several Wisconsin lakes to capture
stocked fish.
FAC students and staff removed otoliths and assigned ages to
more than 400 panfish collected from northern Wisconsin lakes
as part of an ongoing WDNR evaluation of changes to panfish
harvest regulations occurring within the state.
Assisted WDNR personnel with collection and transfer of adult
lake sturgeon on the Wolf River as part of a continued effort to
validate the use of ultrasound for determining sex and
maturation stage.
Dr. Isermann assisted Scott Hansen (WDNR) and Ted Treska
(USFWS) in implementing an age-correction protocol for lake
whitefish in Lake Michigan.
FAC students and staff implanted 30 acoustic transmitters into
lake whitefish in Green Bay and the Menominee River as a
NON-WDNR PROJECTS
Population characteristics and movements of
smallmouth bass in the Menominee River Principal Investigators: Daniel Isermann, Michael Donofrio,
and Joshua Raabe
Funding Source: WE Energies Mitigation and Enhancement
Fund
Project Summary: Our primary goal is to use mark-recapture
population assessments to describe population characteristics
and movements of smallmouth bass in multiple segments of the
Menominee River to determine if current harvest regulations are
sufficient to maintain the quality of these fisheries. Our
secondary goal is to use acoustic telemetry to determine if
seasonal movements could result in increased vulnerability to
angling or suggest that future fish passage is warranted.
Specifically, our objectives are to determine if: 1) smallmouth
bass population characteristics (i.e., abundance, size and age
structure, growth, mortality) vary among impoundments; 2)
current harvest regulations are sufficient to maintain or
maximize opportunities to catch trophy smallmouth bass (≥ 18
inches total length); 3) the majority of smallmouth bass make
fall movements to deeper, slower habitats more prevalent in the
lower portions of an impoundment and 4) the majority of
smallmouth bass make spring movements to the tailwater
sections of specific impoundments. Additionally, our work will
allow us to determine if smallmouth bass exhibit site fidelity for
specific spawning areas within the Menominee River.
Safe operating space for walleye: adapting inland
recreational fisheries Principal Investigators: Steve Carpenter, Jake Vander Zanden,
Daniel Isermann, and multiple WDNR personnel
Funding Source: National Climate Change and Wildlife
Science Center—USGS
Project Summary: Climate change affects inland recreational
fisheries by influencing lake thermal structure, water clarity,
habitat, and other factors that influence economically valuable
sport fishes. The Safe Operating Space (SOS) for a given
fishery is the range of biophysical and social conditions that
allows for self-sustaining populations of target species.
Walleye, a socially and economically important sportfish across
much of North America, is undergoing declines due to
recruitment failures in many lakes throughout their range.
Studies of the SOS for Walleye suggest that many factors are
involved, including warming and changes in thermal structure,
loss of habitat, increasing clarity (perhaps due to drought), and
biotic interactions with other fish species. We propose research
to identify mechanisms behind recruitment failures that will
help inform rehabilitation of Walleye recruitment and
populations. In a whole-lake experiment we will remove
centrarchid fish species. In parallel, we will conduct a structured
comparison of lakes with contrasting habitat and centrarchid
densities to evaluate the effects of water clarity, growing degree
days, and predation mortality on young-of-year growth and
survivorship of Walleye. Results of these studies, in
combination with simulation modeling and additional analyses
of long-term data from lakes in Northern Wisconsin, will
sharpen our understanding of the SOS for Walleye and inform a
new vision for recreational fisheries management in a changing
climate. Members of the research team work closely with
fisheries managers, which will foster a regular exchange of
information. Results will also be communicated to managers
through regular management workshops, as well as technical
papers in the scientific literature.
FISHERIES ANALYSIS CENTER (CONTINUED)
SUBMITTED GRANTS TO SUPPORT WDNR RESEARCH
Evaluation of muskellunge habitat use and suitability in
Green Bay and tributaries
Principal Investigators: Daniel Isermann
Funding Source: Fox River/Green Bay NRDA Trustee
Council
Status: Proposal submitted
Brook trout movements in the west branch of the Wolf
River, Wisconsin
Principal Investigators: Daniel Isermann
Funding Source: Menominee Indian Tribe of Wisconsin-
Joshua Pyatskowit
Status: Selected for funding
Contribution and movements of lake whitefish in
northwestern Lake Michigan
Principal Investigators: Daniel Isermann, Scott Hansen,
David Caroffino, Randall Claramunt, Thomas Binder, Wesley
Larson, Justin VanDeHey, Christopher Vandergoot, Ted
Treska, Charles Krueger
Funding Source: Great Lakes Fishery Trust and Great Lakes
Fish and wildlife Restoration Act
Status: In Review
Mixed stock assessment and movements of Green Bay
walleyes
Principal Investigators: Daniel Isermann, Steve Hogler, Troy
Zorn, Todd Hayden, Christopher Vandergoot, Janice Kerns,
Charles Kruger
Funding Source: Great Lakes Fishery Trust and Great Lakes
Fish and wildlife Restoration Act
Status: In Review
AWARDS
Josh Schulze
2016 University of Wisconsin-Stevens Point College of
Natural Resources Outstanding Research Assistant.
Josh Schulze
2016 University of Wisconsin-Stevens Point-Graduate
Council Award for exceptional contributions to the profes-
sion, research and instruction
Josh Schulze
Best Student Poster Oregon Chapter of the American Fish-
eries Society Meeting
Hadley Boehm
Best Student Paper Wisconsin Chapter of the American
Fisheries Society Meeting
pilot project. Subsequent locations of these fish provided
interesting information on the movements of lake whitefish and
this information is being used to secure additional funding to
study whitefish movements.
FAC staff provided technical assistance with age and growth
estimation to numerous WDNR staff and provided OTC mark
detection for walleye stocking evaluations occurring in several
Wisconsin lakes. Staff also provided OTC mark detection for
Minnesota Department of Natural Resources and the Iowa
Department of Natural Resources.
Dr. Isermann continues to serve as an associate editor for the
North American Journal of Fisheries Management.
FISHERIES ANALYSIS CENTER (CONTINUED)
ADDITIONAL ACCOMPLISHMENTS
Publications Haglund, J.M, D.A. Isermann, and G. Sass. In Review.
Evaluation of trophy harvest regulations for Walleyes in
Escanaba Lake, Wisconsin. North American Journal of
Fisheries Management.
Andvik, R.T., B.L. Sloss, J.A. VanDeHey, R.M. Claramunt,
S.P. Hansen, and D.A. Isermann. In Press. Mixed stock
analysis of Lake Michigan's lake whitefish commercial
fishery. Journal of Great Lakes Research.
Richter, J.T., B.L. Sloss, and D.A. Isermann. In Press.
Validation of side-scan sonar for quantifying Walleye
spawning habitat availability in the littoral zone of northern
Wisconsin lakes. North American Journal of Fisheries
Management.
Faust, M.D., M.J. Hansen, D.A. Isermann, and M.A. Luehring.
2015. Muskellunge growth potential in northern
Wisconsin: implications for trophy management. North
American Journal of Fisheries Management 35:765-774.
Kelling, C.J., D.A. Isermann, B.L. Sloss, and K.N. Turnquist.
2016. Diet overlap and predation between largemouth bass
and walleye in Wisconsin lakes using DNA barcoding to
improve taxonomic resolution. North American Journal of
Fisheries Management 36:3, 621-629.
Hansen, J.F., G.G. Sass, J.W. Gaeta, G.H. Hansen, D.A.
Isermann, J. Lyons, and M.J. Vander Zanden. 2015.
Largemouth bass management in Wisconsin: intra- and
inter-specific implications of abundance increases. Pages
193-206 in M.D. Tringali, J. M. Long, T.W. Birdsong, and
M.S. Allen, editors. Black bass diversity: multidisciplinary
science for conservation. American Fisheries Society,
Symposium 82, Bethesda, Maryland.
Wilson-Rothering, A.E., S.V. Marquenski, D. Isermann, A.
Thruman, K.L. Toohey-Kurth, and T.L. Goldberg. 2015.
Seroprevalence and inter-epidemic persistence of viral
hemorrhagic septicemia virus in freshwater drum
(Aplodinotus grunniens) from Lake Winnebago,
Wisconsin, USA. Journal of Clinical Microbiology
53:2889-2894.
2015 Top 5 Most Read Article in North American Journal of
Fisheries Management: Mosel, K. J., D. A. Isermann,
and J. F. Hansen. 2015. Evaluation of daily creel and
minimum length limits for black crappies and yellow
perch in Wisconsin. North American Journal of
Fisheries Management 35:1-13.
Presentations
Kerns, J., D. Isermann, and T. Simonson. 2016. Electrofishing
catchability of juvenile muskellunge in northern Wisconsin
lakes. Hugh C. Becker Symposium - Muskies, Inc.,
Minnetonka, Minnesota.
Kerns, J., D. Isermann, T. Simonson, J. Hennessy, and T.
Cichosz. March 2016. Predicting abundance of adult
muskellunge in northern Wisconsin lakes. Hugh C. Becker
Symposium, Muskies, Inc. Minnetonka, Minnesota.
Schulze, J.C., D.A. Isermann, M. Donofrio, S. Cooke, R.
Elliott, E. Baker, and B. Sloss. March 2016. Lake sturgeon
movements after passage upstream of two hydroelectric
dams on the Menominee River, Wisconsin-Michigan.
Oregon Chapter of the American Fisheries Society
Meeting. Seaside, Oregon.
Boehm, H., D. Isermann, and G. Hansen. February 2016.
Identifying recruitment bottlenecks for age-0 walleye in
northern Wisconsin lakes. Wisconsin Chapter of the
American Fisheries Society Annual Meeting. LaCrosse,
Wisconsin.
Isermann, D.A., and S. Hogler. February 2016. Walleye stock
characteristics in Green Bay. Wisconsin Chapter of the
American Fisheries Society Annual Meeting. LaCrosse,
Wisconsin.
Kerns, J., D. Isermann, and T. Simonson. February 2016.
Electrofishing catchability of juvenile muskellunge in
northern Wisconsin lakes. Annual Meeting of the
Wisconsin Chapter of American Fisheries Society.
LaCrosse, Wisconsin.
Ogle, D.H. and D.A. Isermann. February 2016. Modified von
Bertalanffy growth function to estimate the age to reach a
critical length. Wisconsin Chapter of the American
Fisheries Society Meeting. LaCrosse, Wisconsin.
Rydell, N., D. Isermann, and J. VanDeHey. February 2016.
Effects of 2, 4-D herbicide treatments used to control
Eurasian Watermilfoil on fish and zooplankton in Northern
Wisconsin Lakes. Wisconsin Chapter of the American
Fisheries Society Meeting. LaCrosse, Wisconsin.
Schulze, J.C., D.A. Isermann, M. Donofrio, S. Cooke, R.
Elliott, E. Baker, and B. Sloss. February 2016. Lake
sturgeon movements after passage upstream of two
hydroelectric dams on the Menominee River, Wisconsin-
Michigan. Wisconsin Chapter of the American Fisheries
Society Annual Meeting. LaCrosse, Wisconsin.
Schulze, J. C., D. A. Isermann, and M. Donofrio. February
2016. Smallmouth bass population characteristics and
movements in the Menominee River, Wisconsin. American
Fisheries Society Annual Meeting – Minnesota Chapter.
Duluth, Minnesota.
Boehm, H., D. Isermann, and G. Hansen. January 2016.
Identifying recruitment bottlenecks for age-0 walleye in
northern Wisconsin lakes. Midwest Fish and Wildlife
Conference. Grand Rapids, Michigan.
Kerns, J., D. Dembkowski, D. Isermann, M. Donofrio, and E.
Baker. October 2015. Comparison of lake sturgeon growth
rates estimated from fin rays and mark-recapture. North
American Sturgeon and Paddlefish Society. Oshkosh,
Wisconsin.
Schulze, J. C., D.A. Isermann, M. Donofrio, S. Cooke, R.
Elliott, E. Baker, B. Sloss. October 2015. Lake sturgeon
movements after passage upstream of two hydroelectric
dams on the Menominee River, Wisconsin-Michigan.
Oshkosh, Wisconsin.
Snobl, Z., R. Koenigs, D. Isermann, B. Sloss, and J. Raabe.
Habitat use and movement of sub-adult lake sturgeon in the
Lower Wolf River, Wisconsin. North American Sturgeon
and Paddlefish Society. Oshkosh, Wisconsin.
Boehm, H., D. Isermann, and G. Hansen. July 2015. Identifying
recruitment bottlenecks for age-0 walleye in northern
Wisconsin lakes. North Central Division of the American
Fisheries Society – Walleye Technical Committee Meeting,
Brookings, South Dakota.
Kerns, J., D. Isermann, T. Simonson, J. Hennessy, and T.
Cichosz. July 2015. Evaluation of methods used to estimate
population metrics for adult muskellunge in northern
Wisconsin lakes. North Central Division of the American
Fisheries Society – Walleye Technical Committee Meeting,
Brookings, South Dakota.
Posters Boehm, H., and D. Isermann. February 2016. Evaluation of
sampling techniques for capturing age-0 walleyes in
northern Wisconsin lakes. Wisconsin AFS Annual Meeting.
LaCrosse, Wisconsin.
Kerns, J., D. Isermann, and J. Hansen. February 2016.
Evaluation of vehicle counters for monitoring angler effort
on small freshwater lakes. Annual Meeting of the
FISHERIES ANALYSIS CENTER (CONTINUED)
Wisconsin Chapter of American Fisheries Society.
LaCrosse, Wisconsin.
Rydell, N., D. Isermann, and J. VanDeHey. February 2016.
Comparison of two larval fish sampling gears on northern
Wisconsin lakes. Wisconsin Chapter of the American
Fisheries Society Annual Meeting. LaCrosse, Wisconsin.
Schulze, J.C., D.A. Isermann, M. Donofrio, and A. Schiller.
February 2016. Smallmouth bass movements in the
Menominee River, Wisconsin-Michigan. Wisconsin
Chapter of the American Fisheries Society Meeting.
LaCrosse, Wisconsin.
Wegleitner, E. and D. Isermann. February 2016. On the screen
or through the scope: is there a difference when estimating
ages of largemouth bass and walleyes from sectioned
otoliths and dorsal spines? Wisconsin Chapter of the
American Fisheries Society Meeting. LaCrosse, Wisconsin.
Witzel, Z. J., and D. A. Isermann. 2016. Relative precision of
northern pike ages estimated from multiple calcified
structures: preliminary results from an ongoing statewide
evaluation. Annual Meeting of the Wisconsin Chapter of
American Fisheries Society. LaCrosse, Wisconsin.
Schulze, J. C., D. A. Isermann, M. Donofrio, S. Cooke, R.
Elliot, E. Baker, and B. Sloss. February 2015. Lake
sturgeon movements after passage upstream of two
hydroelectric dams on the Menominee River, Wisconsin-
Michigan. American Fisheries Society – Minnesota
Chapter. Duluth, Minnesota.
Boehm, H., and D. Isermann. January 2016. Evaluation of
sampling techniques for capturing age-0 walleyes in
northern Wisconsin lakes. Midwest Fish and Wildlife
Conference. Grand Rapids, Michigan.
ADDITIONAL ACCOMPLISHMENTS (CONTINUED)
Wisconsin Cooperative Fishery Research Unit—
Molecular Conservation Genetics Lab
DIRECTORS: WES LARSON AND BRIAN SLOSS
LAB MANAGER: KEITH TURNQUIST
MISSION
The mission of the Molecular Conservation Genetics Lab (MCGL) is to employ genetic techniques and conservation principles to
assist the management of our natural resources. The MCGL specializes in the application of molecular genetic techniques to address
key issues in conservation biology, resource management, and ecological studies.
CONTINUING PROJECTS
Effectiveness of shoreline Walleye propagation
Principal Investigator: Keith Turnquist, Doug Welch, Luke
Roffler, and Brian Sloss
Funding: Walleyes for Tomorrow
Objective: To identify the origin of young of year walleye
collected from Lake Geneva, Wisconsin originated from
shoreside larval hatcheries (aka walleye wagons), WDNR
hatchery facilities, or naturally reproduction.
American Hazelnuts genetic structure assessment Principal Investigator: Keith Turnquist and Mike Demchik
Objective: Determine the genetic structure of American
hazelnuts in populations throughout the upper Midwest. Investigating the relationship between gill lice
prevalence and genetic diversity in brook trout across
Wisconsin Principal Investigator: Wes Larson
Funding: WDNR
Objective: Determine whether gill lice prevalence is correlated
with genetic diversity at neutral markers and at a gene involved
in immune response in populations of brook trout across
Wisconsin.
Assessing neutral and adaptive differentiation in cisco
populations across Wisconsin using RAD-sequencing Principal Investigator: Wes Larson
Funding: WDNR
Objectives: (1) Determine the spatial structure of cisco
populations across Wisconsin; (2) investigate adaptive
differentiation between cisco population in Wisconsin with
particular emphasis on differences between dwarf and normal
morphotypes; (3) investigate whether metrics of genetic
diversity and differentiation are correlated with stock
characteristics and/or environmental variables.
Developing species-diagnostic assays for salmon using
mitochondrial sequencing Principal Investigator: Chris Habicht
Funding: Alaska Department of Fish and Game
Objective: Sequence seven loci from the mitochondrial genome
in seven species of salmon to construct species specific assays.
Species identification of egg samples to investigate
Asian carp reproduction
Principal Investigator: Mike Weber
Funding: Iowa State University
Objective: Use DNA barcoding to conduct species
identification on egg samples taken from the Mississippi River
to investigate Asian carp reproduction.
Genetic heritage of naturally produced lake trout in
Lake Michigan Principal Investigator: Brian Sloss
Funding: Great Lakes Fishery Trust
Objective: Determine if a subset of microsatellite markers
designed for salmonids can reliably delineate strain of origin
for the seven primary lake trout strains stocked into Lake
Michigan, and to determine if the same subset of genetic
makers and reference data are capable of diagnosing the genetic
heritage of interstrain crosses.
MOLECULAR CONSERVATION GENETICS LAB (CONTINUED)
Development of eDNA Techniques for Detection of
Endangered Purple Cat’s Paw Pearlymussel and
Snuffbox
Principal Investigator: Keith Turnquist, Brian Sloss, Tim
Strakosh, and Darrin Simpkins
Funding: US Fish and Wildlife Service
Objective: The goal of this study is to initiate the development
of eDNA techniques for detection of presence/absence of the
endangered unionid mussels: purple cat’s paw pearlymussel
Epioblasma obliquata obliquata and snuffbox Epioblasma
triquetra. Our specific objectives are to: 1) develop a set of
species-specific PCR and qPCR markers for the two species
and other extant species in Epioblasma (n = 11 total extant
species per Musselp Database; http://mussel-project.
uwsp.edu); 2) determine the critical threshold detection limit of
qPCR for the developed markers using known amounts of
DNA; and 3) determine the realized detection probabilities by
testing water samples collected from known areas where the
two target species occur and areas where they are not thought to
occur using the developed qPCR molecular markers.
Wisconsin walleye state and private hatchery
assessment Principal Investigator: Brian Sloss, Keith Turnquist, and
David Giehtbrock
Funding: WDNR
Objectives: (1) Develop a set of easily quantified and
measurable genetic metrics and brood source identification
practices all hatcheries (State, Private, and Tribal) must meet to
be compliant with stock-based management; (2) Determine if
hatcheries (State, Private, and Tribal) met the developed
genetic metrics necessary for stock-based management in 2014
production year.
Growth potential and genetic diversity of yellow perch
in South Dakota
Principal Investigator: Justin VanDeHey
Objective: (1) Determine if differences exist in protein coding
regions of yellow perch DNA among populations in South
Dakota waters by 30 June 2017; (2) To relate yellow perch
genetic structure to perch growth and mortality rates by 30 June
2017; (3) To compare relative survival and growth of age-0
yellow perch from two distinct population types by 30 June
2017.
Using parentage analysis to investigate the spawning
and recruitment dynamics of walleye in a small
northern lake Principal Investigator: Wes Larson
Funding: WDNR
Objective: Build a pedigree for walleye in a small lake in
northern Wisconsin to investigate spawning and recruitment
dynamics.
Evaluating the potential of DNA mixture models to
infer individual counts from fish and wildlife genetic
samples Principal Investigator: Suresh Sethi, Wes Larson, and Mark
Henderson
Funding: USGS
Objective: Pilot study to determine the utility of a novel statis-
tical model to infer the number of individuals contributing to a
mixed-DNA sample such as those collected from eDNA, stom-
achs, or wildlife traps.
MOLECULAR CONSERVATION GENETICS LAB (CONTINUED)
COMPLETED PROJECTS
Genetic diversity of Wisconsin Spring Pond Brook Trout
Principal Investigator: Bob Tabbert and Brian Sloss
Funding: International Fly Fishing Federation
Objective: To determine if genetic differences exist between
spring pond brook trout and other northern Wisconsin brook
trout populations
Chippewa River Lake Sturgeon genetic analysis
Principal Investigator: Brian Sloss, Heath Benike, and
Joseph Gerbyshak
Objective: Determine the genetic diversity and genetic
structure of lake sturgeon in the Chippewa and Flambeau River
systems.
Origin assessment of Menominee River lake sturgeon
Principal Investigator: Dan Isermann and Mike Donofrio
Funding: WDNR
Objective: Determine the genetic stock origin of Lake
Sturgeon (Acipenser fulvescens) collected from the mouth of
the Menominee River.
Delineation of natural boundaries of muskellunge in
the Great Lakes and the effects of supplementation on
genetic integrity of remnant stocks
Principal Investigator: Brian Sloss
Funding: Great Lakes Fishery Commission
Objective: Our objectives are to: (1) build on existing genetic
data to determine if significant genetic structure exists among
muskellunge spawning aggregates across the Great Lakes and
their tributaries; (2) determine if significant admixture is present
in Great Lakes muskellunge populations consistent with
introgression between stocked and resident Great Lakes
muskellunge; (3) determine if levels of admixture vary in
relation to several measures of direct and relative stocking
intensity (as measured by various life-history weighted stocking
indices); and (4) determine if the genetic structure of non-
admixed Great Lakes muskellunge populations is consistent with
a genetic stock model that can be described in terms of genetic
stock identification and degree of stock isolation.
Use of real-time polymerase chain reaction for the
identification of larval walleye and yellow perch
Principal Investigator: Keith Turnquist, Hadley Boehm, Dan
Isermann, and Brian Sloss
Objectives: (1) Determine efficacy of a qPCR assay for
diagnostic identification of walleye (Sander vitreus) and yellow
perch (Perca flavescens); (2) Determine if the qPCR assay is
effective for identifying larval walleye and yellow perch in
panfish diets and from the water column.
Wisconsin Cooperative Fishery Research Unit—
Fisheries Propagation Science Center
RESEARCH SCIENTIST: DAN DEMBKOWSKI
FPSC MISSION
Coordinate propagation system technical and scientific support to ensure the Wisconsin State Fish Hatchery system operates on
best available scientific and technical principles and standards.
GRADUATE RESEARCH
Conservation of genetic resources is a challenging issue and
represents a vital component of fisheries management in
Wisconsin. Walleye Sander vitreus are an ecologically
important top predator and one of the most sought after sport
fishes in Wisconsin. Maintaining the genetic diversity of
walleye populations is important for sustainability and is an
explicit goal of Wisconsin’s walleye management plan. This
maintenance of genetic diversity is especially important within
the propagation program. Long-term sustainability of managed
fish species requires an understanding of potential genetic
hazards associated with the use of propagated fish. Propagation
programs commonly face four genetic hazards when using
propagated fish that may threaten the genetic integrity of native
populations: extinction, loss of within-population genetic
variation, loss of between population genetic variation, and
artificial selection. With an increase in production of extended
growth walleye fingerlings (6-8” in length) from state and
private hatcheries, the Wisconsin Department of Natural
Resources (WDNR) has requested assistance to better
understand the genetic implications of their current propagation
methods. A critical evaluation of current practices within
Wisconsin’s Walleye propagation program is necessary to
understand how these practices relate to the overall goal of
ensuring long-term sustainability of Walleye populations in
Wisconsin. Therefore, the objectives of our research are to (1)
compare the genetic diversity within Wisconsin’s feral walleye
broodstock with genetic diversity levels in other wild, naturally
recruiting, Wisconsin walleye populations and, (2) determine if
levels of inbreeding, effective population size, and the
probability of spawning related individuals differ between fish
collected with different gears (electrofishing and fyke netting)
and varying levels of sampling effort. Upon completion of these
objectives, we propose to develop a walleye genetic broodstock
management plan based on best management practices, sound
genetic principles, and logistical considerations.
DEVELOPMENT OF A GENETIC BROODSTOCK
MANAGEMENT PLAN FOR WISCONSIN’S
WALLEYE PROPAGATION PROGRAM
RESEARCH ASSISTANT: MICHAEL VASKE, M.S
CANDIDATE
PRINCIPAL INVESTIGATOR: JUSTIN VANDEHEY AND
BRIAN SLOSS
FUNDING SOURCE: WI DEPARTMENT OF NATURAL
RESOURCES
JULY 1 2014 - JUNE 30, 2016
FISHERIES PROPAGATION SCIENCE CENTER (CONTINUED)
RESEARCH
Growth, condition and short-term survival of age-0
muskellunge reared using two different techniques
Principal Investigator: Justin VanDeHey and Tim Simonson
Funding: Wisconsin Department of Natural Resources
Objective: Determine if growth, and condition differed
between pre-stocking age-0 Muskellunge reared solely on
natural prey (minnow only; MO) with those reared intensively
on pellets and finished extensively on minnows (minnow
finished; MF) and determine relative survival of stocked
Muskellunge reared using the two techniques in 23 Wisconsin
lakes during 2013 and 2014.
Influence of habitat additions on growth, condition,
and survival of extensively-reared juvenile
muskellunge Principal Investigator: Dan Dembkowski
Funding Source: Wisconsin Department of Natural Resources
Objectives: Determine if growth, condition, and relative
survival of juvenile muskellunge differ between rearing ponds
with and without structural habitat additions.
Influence of rearing tank substrate on performance of
lake sturgeon in Wisconsin’s streamside rearing
facilities Principal Investigator: Dan Dembkowski
Funding Source: Wisconsin Department of Natural Resources
Objectives: Determine if size-at-stocking, condition, relative
survival, and fish health metrics of lake sturgeon differ between
raceways with and without natural substrate additions.
Walleye production in outdoor rearing ponds Principal Investigator: Dan Dembkowski
Funding Source: Wisconsin Department of Natural Resources
Objectives: Determine the influence of biotic (e.g., density,
prey resources) and abiotic (e.g., water temperature, pH,
dissolved oxygen) on growth, survival, and yield of walleye fry
in earthen outdoor rearing ponds.
External Funding Sought
Worked hand-in-hand with Dan Isermann and cooperators from
WDNR management and propagation sections to develop the
following proposals:
Return-to-creel, movement, and predation of stocked brown
trout in Green Bay Project leaders: Dan Dembkowski, Dan Isermann, Tammie
Paoli (WDNR), Janice Kerns, and Keith Turnquist
Objectives:
To determine if differences in return-to-creel exist between
brown trout stocked offshore versus inshore,
To determine if brown trout stocked at offshore locations
move into tributary streams within 3-6 months after
stocking,
To determine if brown trout stocked inshore remain in
tributary streams for 3-6 months after stocking, and
To determine the impact of walleye predation on stocked
brown trout at inshore stocking locations.
Funding agencies considered: Great Lakes Fisheries
Commission, Great Lakes Fishery Trust
Movement of muskellunge in Green Bay related to stocking
strategy
Project leaders: Dan Dembkowski, Dan Isermann, Steve
Hogler (WDNR), Steve Fajfer (WDNR), Janice Kerns
Objectives:
To estimate post-stocking mortality and dispersal rates of
juvenile muskellunge stocked into the Fox and
Menominee rivers within 3-6 months after stocking,
To determine if juvenile muskellunge move out of
tributaries and into lower Green Bay within 3-6 months
after stocking, and
To determine if adult muskellunge in lower Green Bay
return to spawn in the tributary where they were
stocked.
Funding agencies considered: Great Lakes Fisheries
Commission, Great Lakes Fishery Trust, Great Lakes Fish and
Wildlife Restoration Act
Wisconsin Cooperative Fishery Research Unit—
Aquatic Biomonitoring Lab
RESEARCH SCIENTIST: JEFF DIMICK
MISSION
The Aquatic Biomonitoring Lab (ABL) provides aquatic macroinvertebrate sample processing to the Wisconsin Department of
Natural Resources and other regional resource management agencies, partnering in their assessments of water quality and
environmental condition at sampled locations. The ABL also provides expertise and technical support to the College of Natural
Resources and offers opportunities for undergraduate students to develop professional skills in a real-world laboratory setting.
WDNR SUPPORT
Aquatic macroinvertebrate biomonitoring sample processing
450 total WDNR samples
26 Hester-Dendy samples from non-wadeable
rivers, assessing ecological condition
424 qualitative kicknet samples from wadeable
streams
Expert advice and review of protocols and practices
Provide taxonomy validation to SWIMS
Work with SWIMS to improve data reporting
WDNR Streams and Rivers Technical Team Meeting
WDNR Endangered Resources Insect Species Team
WDNR Endangered Resources Odonate Species Team
PARTICIPATION
NON-WDNR PROJECT COOPERATORS
Aquatic macroinvertebrate biomonitoring sample processing
USGS Wisconsin District, Milwaukee
Metropolitan Sewerage District
Ho-Chunk Nation
Madison Metropolitan Sewerage District
Discovery Farms
Mayfly collaboration with Dr. Tom Klubertanz, UW-Rock
County
Manuscript review Mayflies of Wisconsin, UW-Extension
publishing
Manuscript review, New records of mayflies from Kenora
District and Northwestern Ontario, Canada, Dr. Tom L.
Klubertanz
Manuscript review, Key to Plecoptera larvae from Wisconsin,
Dr. Tom Klubertanz
Chironomidae collaboration with Dr. Will Bouchard, Minnesota
Pollution Control Agency
Caddisfly collaboration with Dr. Kurt L. Schmude, UW-
Superior and Jim Snitgen, Oneida Nation
Provided insight to USEPA Region 5 development of Regional
Monitoring Network-Biological Sampling Methods for
Wadeable Streams
Provided insight to UWFWS development of Lake Michigan
harbor monitoring project
Provided insight to Fort McCoy development of bioassessment
project
Hosted laboratory tour for Wisconsin Public Health Lab
Network
UNIVERSITY SUPPORT PROVIDED
Employ 10 undergraduate students:
Haley Bodoh Macayla Greider
Mekayla Gronholm Rebecca Grover
Madison Hodge Andrew Kohlmann
Alison Kuhne Ryan Masek
Cadie Olson Hunter Slaght
Provided materials for CNR Advising and Recruitment pro-
grams
Provided materials for Golden Sands RC&D outreach program
Mentored two undergraduate student research projects
Development of Jr taxonomist, Kaira Kamke
DISCOVERIES
Allocladius (Diptera: Chironomidae: Orthocladiinae)
Gymnometriocnemus (Diptera: Chironomidae: Orthocladiinae)
Polypedilum (s.s.) nubeculosum (Diptera: Chironomidae: Chironominae)