Wisconsin
Cooperative Fishery
Research Unit
Annual Report
October 2008 - September 2009
COOPERATING AGENCIES
United States Geological Survey
University of Wisconsin-Stevens Point
Wisconsin Department of Natural Resources
MISSION STATEMENT
of the
Wisconsin Cooperative Fishery Research Unit
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 WisconsinStevens Point since 1971. The cooperators of this partnership include the U.S. Geological Survey,
the Wisconsin Department of Natural Resources, and the University of Wisconsin-Stevens Point.
The Unit objectives are to conduct world-class fisheries and aquatic science research of interest to
cooperators, educate and train students at the Master’s degree level in fisheries and aquatic sciences, and provide extension services and continuing education in fisheries and aquatic resource
management. Areas of study that have been emphasized by the Unit during the past 30 years include: fish biology; fisheries management; conservation genetics; fish habitat analysis, design, and
modeling; stock identification and assessment; Great Lakes fisheries; limnology; integrated landwater linkages; aquatic toxicology; and aquatic entomology. The Unit has a special interest in understanding how ecosystem processes are altered by anthropogenic activities having conducted several multidisciplinary projects assessing linkages between aquatic and terrestrial environments, and
how to conserve genetic resources across landscapes. 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, the U.S. Forest Service, the Great Lakes Fishery Commission, other agencies, and
the public.
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TABLE OF CONTENTS
PERSONNEL AND COOPERATORS
Unit Coordinating Committee ............................................................................................. 1
Cooperating Unit Staff
Permanent ............................................................................................................... 1
Graduate Degree Candidates................................................................................... 2
Research Associates ................................................................................................ 2
University of Wisconsin-Stevens Point Faculty Cooperators ............................................. 3
Wisconsin Department of Natural Resources Cooperators ................................................. 3
Federal Agency Cooperators ............................................................................................... 4
Other University Cooperators ............................................................................................. 4
Other Cooperators ............................................................................................................... 4
PROJECTS
Continuing Projects
Delineation of muskellunge genetic structure in northern Wisconsin ................................ 6
Factors influencing genetic diversity of walleye, Sander vitreus, populations in northern
Wisconsin lakes ...................................................................................................... 7
Estimating strain contribution for lake trout naturally produced at Lake Michigan’s midlake reef complex .................................................................................................... 8
Fish community dynamics in Escanaba Lake, Wisconsin ................................................... 9
Genetic structure of non-game fish species: implications for fisheries management........ 10
Mixed stock analysis of Lake Michigan’s lake whitefish commercial fishery and historical
integrity of resolved genetic stocks ....................................................................... 11
Development of multidimensional littoral zone habitat fingerprints and quantifying structural habitat in lakes .............................................................................................. 12
Completed Projects
Cooper’s hawk genetic structure and parentage assessment ............................................. 14
Genetic concerns and paddlefish propagation ................................................................... 15
Genetic structure of Wisconsin’s naturally recruiting walleye populations ...................... 16
Influences of riparian vegetation on trout stream temperatures in the North Central Hardwoods Forest Ecoregion of Wisconsin ................................................................. 17
Propagation practices and genetic resources in lake sturgeon rehabilitation ..................... 18
iii
Spawning strategies and impacts on the maintenance of genetic diversity in lake sturgeon
propagation .............................................................................................................. 19
PUBLICATIONS
Peer Reviewed .................................................................................................................... 20
Theses ................................................................................................................................. 20
PRESENTATIONS
Scientific Meeting .............................................................................................................. 21
Workshops .......................................................................................................................... 22
Guest Lectures .................................................................................................................... 23
Courses ............................................................................................................................... 23
PROFFESSIONAL SERVICE .................................................................................................. 23
SCHOLARSHIPS AND AWARDS ........................................................................................... 24
iv
PERSONNEL AND COOPERATORS
UNIT 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
Jack Sullivan
Director
Bureau of Integrated Science Services
Wisconsin 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
COOPERATIVE UNIT STAFF
Permanent
Michael Bozek, Unit Leader
Brian Sloss, Assistant Unit Leader
Andrea Musch, Unit Program Assistant
Project Staff Support
Ryan Franckowiak, Conservation Genetics Lab Manager
JoAnna Griffin, Database Manager
David Giehtbrock, Assistant Coordinator – Statewide Propagation Program
GRADUATE DEGREE CANDIDATES
Current Students
Ryan Andvik
Matthew Waterhouse
Lacie Westbrook
Patrick Wherley
Justin Haglund
Students
Field Analysis Complete
Thesis in Progress
Benjamin Mann
Edward Murphy
Meaghan Proctor
Sara Schmidt
Brandon Spude
RESEARCH ASSOCIATES
Ben Kissinger
Matthew Koehler
Rebecca Pawlak
Hilary Meyer
2
Graduated (M.S.)
Benjamin Cross
Jeremy Hammen
Luke Roffler
UNIVERSITY OF WISCONSIN – STEVENS POINT FACULTY
COOPERATORS
Eric Anderson
James Cook
Tim Ginnett
Anna Haines
Christopher Hartleb
Paul McGinley
Dan Isermann
Robert Rosenfield
Stanley Szczytko
Les Werner
Eric Wild
Professor
Professor
Associate Professor
Associate Professor
Assistant Professor
Assistant Professor
Assistant Professor
Professor
Professor
Associate Professor
Associate Professor
Wildlife
Forestry
Wildlife
Human Dimensions
Biology
Water Resources
Water Resources
Biology
Water Resources
Forestry
Biology
WISCONSIN DEPARTMENT OF NATURAL RESOURCES
COOPERATORS
Steve Avelallemant
Ron Bruch
Mike Donofrio
Brad Eggold
Steve Fajfer
Steve Gilbert
Scott Hansen
Jen Hauxwell
Gene Hatzenbeler
Steve Hogler
Martin Jennings
Al Kaas
Jeff Kampa
Matt Mitro
Heidi Nelson
Randy Piette
Paul Peeters
Rori Paloski
Dennis Pratt
David Rowe
David Sample
Rebecca Schroeder
Gregor Schuurman
Tim Simonson
Michael Staggs
Regional Fisheries Coordinator - Northern Region
Basin Team Supervisor - Upper Fox River Team
Fisheries Team Supervisor - Northeast Region
Basin Supervisor - South Lake Michigan Fisheries Team
Operations Supervisor - Wild Rose Hatchery
Fisheries Biologist - Northern Region
Fisheries Biologist - Central Office
Research Scientist - Bureau of Integrated Science Services
Research Technician - Central Office
Fisheries Biologist - Lake Shore Team
Research Scientist - Bureau of Integrated Science Services
Coordinator - Statewide Fish Propagation Program
Research Scientist - Spooner Hatchery
Research Scientist - Central Office
Conservation Biologist - Central Office
Research Technician - Bureau of Integrated Science Services
Fisheries Team Supervisor - Sturgeon Bay Fisheries Team
Conservation Biologist - Central Office
Fisheries Biologist - Superior Station
Fisheries Biologist - Northeast Region
Research Scientist - Bureau of Integrated Science Services
Section Chief, Ecosystem Diversity and Conservation
Conservation Biologist - Central Office
Fisheries Lake Sampling Coordinator
Director – Bureau of Fisheries and Habitat Protection
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FEDERAL AGENCY COOPERATORS
Cathy Carnes
Rob Elliott
Rob Klumb
Greg Moyer
Kevin Pope
Dave Potter
Chris Ribic
Wendylee Stott
US Fish and Wildlife Service, New Franken, Wisconsin
US Fish and Wildlife Service, Green Bay, Wisconsin
US Fish and Wildlife Service, Pierre, South Dakota
US Fish and Wildlife Service, Warm Springs, Georgia
NE Cooperative Fish and Wildlife Research Unit, USGS
US Fish and Wildlife Service, Fort Snelling, Minnesota
WI Cooperative Wildlife Research Unit, USGS
US Geological Survey, Great Lakes Science Center
OTHER UNIVERSITY COOPERATORS
Neil Billington
Paula Eterovick
John Ferrell
Ed Heist
John Janssen
Emily Latch
Loren Miller
Michael Romano
Trent Sutton
Chris Wilson
Troy State University
Pontifical Catholic University of Minas Gerais, Brazil
SUNY - College of Environmental Science and Forestry
Southern Illinois University
University of Wisconsin - Milwaukee
University of Wisconsin - Milwaukee
University of Minnesota
Western Illinois University
University of Alaska-Fairbanks
Trent University, Canada
Ontario Ministry of Natural Resources, Peterborough, Ontario
OTHER COOPERATORS
Jennifer Anderson
Ed Baker
Randall Claramunt
Dwayne Etter
J. Marty Holtgren
Jennifer Meece
Marc White
Marshfield Clinic
Michigan Department of Natural Resources
Michigan Department of Natural Resources
Michigan Department of Natural Resources
Little River Band of Ottawa Indians
Marshfield Clinic
Riveredge Nature Center, Inc.
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CONTINUING
PROJECTS
5
Delineation of muskellunge genetic structure
in northern Wisconsin
Research Assistant:
Ed Murphy M.S. Candidate
Brandon Spude, M.S. Candidate
Principal Investigator:
Brian Sloss
Funding Source:
Wisconsin Department of
Natural Resources
The muskellunge (Esox masquinongy) is a prized sportfish throughout its native range. Wisconsin contains >700 muskellunge populations providing a diverse array of angling experiences from highdensity action waters to low-density trophy fisheries. The Wisconsin Department of Natural Resources’ (WDNR) muskellunge management goals include maximizing angling opportunities while preserving genetic integrity. Historically, the WDNR has managed
musky populations through regulations, such as daily bag limits and
length limits, and a prolific stocking program. However, supplemental muskellunge stocking can have strong impacts on the genetic integrity of a population. The use of stocks when managing
native populations minimizes risks to genetic integrity including
outbreeding depression and introgression. Currently, the WDNR
delineates genetic management units based on watershed boundaries and genetic data. The available genetic data showed low variation and little genetic structure resulting in a more-or-less default
watershed delineation. To develop a more precise management approach, we used microsatellite genotyping and non-lethal sampling
to identify genetic structure among naturally recruiting muskellunge populations in Wisconsin. The WDNR provided non-lethal
fin clips from 39 naturally recruiting populations (n ≈ 50/
population) across the native range of muskellunge in Wisconsin.
Microsatellite genotyping was conducted using a suite of 14 loci
developed in our lab. Genetic stock identification showed an eastwest split among populations not stocked since 1990. Two contemporary management units, the upper Chippewa River and the Lake
Superior, failed to resolve suggesting historical genetic boundaries
and contemporary watershed boundaries are not congruent for these
two units. Further delineation and resolution of stock boundaries
within the state will provide for more accurate and efficient management of Wisconsin’s muskellunge resource.
6
Factors influencing genetic diversity of walleye, Sander vitreus,
populations in Northern Wisconsin lakes
Research Assistant:
Matthew Waterhouse, M.S.
Candidate
Principal Investigator:
Brian Sloss
Funding Source:
Wisconsin Department of
Natural Resources
The Wisconsin Department of Natural Resource’s walleye (Sander
vitreus) management goals include ensuring the population viability
and genetic integrity of naturally recruiting walleye populations.
Walleye show both broad-scale genetic (i.e., regional) and finescale genetic structure (i.e., watersheds). Supplemental stocking,
stocking fish into systems where some level of natural recruitment
occurs, is commonly employed in the management of Wisconsin
walleye. Supplemental stocking can adversely affect the overall
broad- and fine-scale genetic structure, population levels of genetic
diversity, and lower the overall effective population size resulting
in increased inbreeding and genetic drift. Previous genetic research
has identified low effective population size (Ne) to census population size (Nc) ratios (approximately 3-5%) suggesting inbreeding
and genetic drift should be considered important in conserving the
genetic diversity of walleye populations. Additionally, significant
inbreeding has been observed in a number of walleye populations
thought to have healthy census populations. The first objective of
this research is to determine if previously observed genetic indications of inbreeding in some naturally reproducing walleye populations were the consequence of sampling a small number of spawning locations (and thus, a high number of related individuals) or
accurate estimates of inbreeding. The second objective is to determine if a relation exists between measures of walleye genetic diversity and observed patterns of recruitment and management activities. Previously identified walleye populations that exhibited significant inbreeding coefficients were originally sampled using fykenets during the spawning run. In many instances, the number of
nets sampled were small suggesting a potential sampling bias.
Therefore, the first objective will be addressed by re-sampling the
previously studied populations using shoreline electrofishing to obtain a larger more spatially representative genetic sample. Samples
(n = 50) will be surveyed for genetic variation at 13 microsatellite
loci and estimates of inbreeding and within population genetic differentiation (the Wahlund effect) will be performed. The second
objective will be addressed by determining the genetic diversity of
walleye populations across a gradient of management practices and
recruitment levels (Npops = 14). Genetic diversity in the adult
spawning population and the subsequent fall’s young of year will
be surveyed. Estimates of Ne, heterozygosity, mean number of alleles/locus, and allelic richness will be used to examined trends and
relations among the diversity estimates and known recruitment and
management practices. This research may provide insight into the
impacts of supplemental stocking, natural recruitment variability,
and spatial dynamics on the overall integrity of walleye populations.
7
Estimating strain contribution for lake trout
naturally produced at
Lake Michigan’s midlake reef complex
Research Assistant:
Meaghan Proctor, M.S. Candidate
Principal Investigator:
Brian Sloss
Funding Source:
Great Lakes Fishery Commission
Historically, lake trout (Salvelinus namaycush) were abundant in
Lake Michigan and supported a large commercial fishery. But the
introduction of sea lamprey (Petromyzon marinus) combined with
over-harvest of lake trout and habitat degradation contributed to the
lake trout’s extirpation from Lake Michigan during the 1950s.
Since then, a restoration program has been developed which relies
on stocking of multiple strains developed from either native Lake
Michigan lake trout collected prior to extirpation or strains that occupy a habitat similar to native lake trout. The most commonly
used strains are Seneca Lake (SLW), Lewis Lake (LLW), Green
Lake (GLW), and Marquette (SMD). Despite intensive stocking,
restoration efforts have shown limited success primarily attributed
to minimal natural reproduction. Genetic assessment of lake trout
eggs and sac fry has been used to determine the strains of lake trout
that are most successfully spawning and hatching under natural
conditions. Management agencies can subsequently focus their efforts on stocking the successful strains. Our objective was to determine the strain of origin for eggs and sac fry produced in the Fall
2006 on the Mid-Lake Reef Complex of Lake Michigan. We used
seven microsatellite genetic markers and known genetic diversity
from the four most common strains stocked in Lake Michigan.
Data was analyzed using individual assignment tests, admixture and
mixed stock analysis, and hybrid detection methods. Simulations
were performed on all measures to assess the usefulness of various
algorithms for predicting F1 and Fx hybrids. The level of genetic
diversity among the four strains at seven microsatellite markers appeared to allow moderate confidence in the assignment of lake trout
to a single strain and limited accuracy in predicting F1 or Fx strain
hybrids.
8
Fish community dynamics in Escanaba
Lake, Wisconsin
Research Assistant:
Justin Haglund
Principal Investigator:
Michael Bozek
Funding Source:
Wisconsin Department of
Natural Resources
Fish population size, size structure, reproduction, and recruitment,
are highly dynamic and often fluctuate widely across years. Such
population variability, in combination with intensive harvest from
state and tribal users greatly increases the risk of overexploitation
and possible fishery collapse. Regulations offer opportunities not
only to prevent population collapse, but to maximize different desirable fish population characteristics such as size structure (i.e.,
larger fish), abundance, and catch rates, among others that offer a
wide array of angling opportunities. Studying the effects of regulation changes insure that desirable outcomes are achieved and elucidate under which conditions particular regulations should be implemented. The most effective way to measure the effects of natural
population variability and regulation changes relative to exploitation is by studying them for a long period of time. There are at
least eight different regulations that are applied to the management
of walleye in northern Wisconsin with the intent of creating diverse
fishing opportunities. Unfortunately, many of those regulations
have not been evaluated. The Wisconsin Department of Natural
Resources (then the Wisconsin Conservation Commission) established the Northern Highlands Fishery Research Area (NHFRA) in
1946 and the population size of walleye in Escanaba Lake has been
estimated there annually since 1953. Until 2000, harvest of walleye
was unlimited (no bag or size limits) and the population fluctuated
annually. In 2000, as part of an overall exploitation study, a 28
inch minimum size limit was established to effectively reduce harvest to near zero and to help create a trophy walleye fishery. The
objective of this study is to evaluate how walleye and other species
of fish have responded (e.g., abundance, growth) to the implementation of the 28 inch minimum size limit using the long term data
set available at Escanaba Lake.
9
Genetic structure of
non-game fish species:
Implications for fisheries management
Research Assistant:
Lacie Westbrook, M.S. Candidate
Principal Investigator:
Brian Sloss
Funding Source:
Wisconsin Department of
Natural Resources
Fish propagation can interfere with underlying patterns of genetic
diversity including disrupting the genetic integrity of populations
and confounding efforts to identify historical stock boundaries. In
Wisconsin, genetic structure of walleye (Sander vitreus) and muskellunge (Esox masquinongy) is mostly consistent with major watersheds; however, a major disjunction occurs in the head waters of
the Chippewa River watershed. Populations of both species from
this region are generally more similar to populations in the Upper
Wisconsin River watershed. This pattern may be the exclusive result of natural zoogeographic processes, or it may be influenced by
stocking. Knowing the cause of the disjunction is central to management of walleye and muskellunge on a stock basis. A comparison of spatial patterns of genetic variation between these highly
managed species and species without a significant history of human
-mediated movement can be used to evaluate the alternative hypotheses. The objective of this study is to determine if the genetic
structure of two non-propagated fish species, rock bass
(Ambloplites rupestris) and logperch (Percina caprodes), show
concordant patterns of genetic diversity with walleye and muskellunge. Spatial relations will be determined using ten to fourteen
microsatellite loci with fifteen populations (50 fish/population)
from each species. If observed spatial relations in walleye and
muskellunge are natural, a similar pattern will be observed in rock
bass and log perch. However, if the spatial patterns are different, it
can be inferred stocking has had an impact on the genetic diversity
of walleye and muskellunge.
10
Mixed-stock analysis
of Lake Michigan’s
lake whitefish commercial fishery and
historical integrity of
resolved genetic stocks
Research Assistant:
Ryan Andvik, M.S. Candidate
Principal Investigator:
Brian Sloss
Funding Source:
Great Lakes Fishery Commission
The commercial importance of lake whitefish (Coregonus clupeaformis) in Lake Michigan has resulted in increased demand for effective allocation of harvest. Six genetic stocks of lake whitefish
have been identified in Lake Michigan providing a framework for
stock based management on the commercial fishery. However, better understanding of proportional stock harvest is required to properly implement such a regime. The objective of this research is to
use multi locus microsatellite data and mixed stock analysis (MSA)
to identify the proportional stock harvest of lake whitefish sampled
from the 2009 and 2010 Lake Michigan commercial harvest. Genetic samples (n equals150/sample) will be collected during spring,
summer and fall (pre spawn) in 2009 and 2010 from two primary
locations, Big Bay de Noc (MI) and North Moonlight Bay (WI),
and from six randomly chosen (season and location) landing sites
throughout Lake Michigan (total samples equals18). Samples will
be genotyped at 11 microsatellite loci consistent with a reference
dataset of 12 known spawning aggregates used to delineate the six
primary genetic stocks. Mixed stock analysis of the commercial
harvest will be performed using a conditional maximum likelihood
estimate of genetic mixture implemented in ONCOR. Previous
work has shown the efficacy of MSA for this reference database.
Findings from research will aid in more efficient management of
Lake Michigan’s commercial harvest of lake whitefish.
11
Development of
multidimensional
littoral zone habitat
fingerprints and
quantifying structural habitat in
lakes
Research Assistant:
Sara Schmidt, M.S. Candidate
Principal Investigator:
Michael Bozek
Funding Source:
Wisconsin Department of
Natural Resources
Littoral zones can be structurally diverse within and among lakes
providing a wide array of habitat for aquatic organisms. However,
little work has been done to assess littoral zone structure, develop
guidelines on sampling intensity, and integrate findings into generalized management applications. In particular, research is lacking
on the level of structural complexity in littoral zones, on how typologies can provide management frameworks, and in understanding the functional relation between habitat diversity and biotic diversity. The objectives of this study are to measure structural habitat in littoral zones, provide guidelines for sampling intensity, create littoral zone habitat fingerprints of lakes, and explore applications of fingerprints for general lake and fisheries management, littoral zone protection, and littoral zone habitat classification. Littoral zone habitat was quantified in twelve moderate-sized (40-160
ha) north temperate lakes using quadrats placed along 100 transects
in 2007 and 50 transects in 2008 from shore to 3m depth. Water
depth, substrate composition, and macrophyte composition were
visually estimated in square meter quadrats along transects in each
lake using snorkel gear. Coarse woody structure abundance and
branching complexity was measured within 10m on both sides of
transects. Multi-dimensional ordinations of habitat features, or fingerprints, were developed to display the variation in habitat occurring within and among lakes. Results show that fingerprints provide objective habitat information and reveal patterns that can aid in
identifying common, rare, simple, complex, and diverse habitat typologies. Also, Kolmogorov-Smirnov tests were used to compare
goodness of fit for subsamples of randomly selected transects and
quadrats versus the entire data set to assess sampling intensity requirements. Simple linear regressions were used to investigate the
relationship between physical lake characteristics (surface area,
shoreline distance, maximum depth, and mean depth) and sampling
intensity necessary to adequately sample littoral zone habitats. Results indicate a minimum of 45-70 transects and all corresponding
quadrats or 278 quadrats randomly placed along 50 transects were
necessary to sample littoral zone habitats. Mean depth appears to
be a reasonable predictor of transect sampling intensity. Other lake
characteristics were not found to be significantly related to sampling intensity requirements for quadrats or transects.
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COMPLETED
PROJECTS
13
Cooper’s hawk genetic
structure and parentage assessment
Principal Investigator:
Brian Sloss
Michael Bozek
Bob Rosenfield
Laura Rosenfield
Ryan Franckowiak
Funding Source:
USGS
University of WisconsinStevens Point
The Cooper’s hawk (Accipiter cooperii) is a medium sized raptor
found primarily in deciduous forests across North America. Three
discrete populations are thought to occur in Wisconsin, North Dakota, and British Columbia. Migration and suspected gene flow
across this range was expected to result in fairly low amounts of
divergence between populations. Morphological/ morphometric
assessment of hawks from the three populations showed population
divergence and differentiation consistent with an east-west cline.
Determining if the differences are the result of genetic divergence
or the result of non-genetic, environmental influences will provide
key information for the management and conservation of this species. To this end, we are conducting genetic research on numerous
aspects of the Cooper’s hawk’s biology. Key issues addressed in
this research include: 1) the phylogeography of Cooper’s hawk
across North America in conjunction with an east-west morphological cline, and 2) parentage assessment of a suspected multiple
brood male bird from North Dakota.
14
Genetic concerns and
paddlefish propagation
Principal Investigators:
Brian Sloss
Rob Klumb
Funding Source:
US Fish and Wildlife Service
The biology of the paddlefish (Polyodon spathula), like sturgeon, is
not conducive to high levels of exploitation. Nevertheless, a number of small, tightly regulated yet highly popular paddlefish fisheries occur throughout its range. Numerous anthropogenic and biological changes in big river ecosystems over the past 100+ years
(i.e., channelization, fragmentation, and introduction of exotics)
coupled with current exploitation poses serious threats to the longterm viability of the species as a whole. Because the Missouri
River forms a geopolitical boundary, an extensive propagation and
management program exists as a cooperative effort between South
Dakota Department of Game, Fish and Parks, Nebraska Game and
Parks Commission, and U.S. Fish and Wildlife Service. This program is concerned with various factors including genetic implications of propagating cultured fish such as the source of broodfish,
mating strategy, and the genetic diversity represented in broodfish
and progeny. Our objective is to analyze the genetic diversity of
broodfish, the sources of broodfish, and two additional populations
of paddlefish from the Upper Missouri River to determine the efficacy of propagation practices. We sampled paddlefish from Lake
Francis Case, Lewis and Clark Lake, broodfish used by the Gavins
Point National Fish Hatchery in 2005 and 2006, and resulting progeny. All fish were genotyped at five microsatellite loci. Standard
genetic diversity measures were calculated and comparisons were
made across sample years and between sample sites. Diversity was
assessed temporally from broodfish to fry to stocked fish to examine bias in survival due to hatchery conditions. This study will allow more efficient propagation of paddlefish in the Upper Missouri
River system thus, improving our efforts to conserve this unique
resource.
15
Genetic structure of
Wisconsin’s naturally
recruiting walleye
populations
Research Assistant:
Jeremy Hammen
Principal Investigators:
Brian Sloss
Michael Bozek
Funding Source:
Wisconsin Department of
Natural Resources
Genetic diversity has been recognized as a vital component of fish management in Wisconsin. An explicit goal of the state’s walleye management plan has been to preserve the genetic integrity of naturally recruiting
walleye populations. A prerequisite to achieving this goal is understanding the distribution of genetic diversity within and among the State’s
walleye populations. My objectives were to 1) to determine whether
there is significant genetic structure among Wisconsin’s naturally recruiting walleye populations, and 2) if this resolved genetic structure was consistent with contemporary fisheries management zones employed for Wisconsin’s walleye. Genetic diversity for these walleye populations was
measured at 10 microsatellite loci and genetic structure was delineated
through a process known as genetic stock identification (GSI). Genetic
stock identification is a series of hierarchical tests consisting of genic differentiation, genetic distance, AMOVA, and pairwise FST comparisons to
identify putative genetic units. Genetic diversity levels throughout the
sampled populations were high (Ho = 0.7144, HE = 0.7677) and comparable to other walleye studies (Wirth et al. 1999; Borer et al. 1999; Eldridge
et al. 2002; Cena et al. 2006; Franckowiak et al. 2009) using a similar
suite of microsatellite loci. Results however showed current fisheries
management units were not consistent with this genetic structure. Delineation of genetic units using GSI identified 21 significant genetic units
among the 26 sampled populations suggesting populations are primarily
maintaining localized gene pools. Iterative analyses examining the ratio
of among-group variance to within-group variance was performed to
identify higher level genetic units (i.e., putative stocks). Eight putative
genetic units, mostly consistent with geographic location of the populations and not with current watershed regions, were identified using the
ratio comparing among-group variance to within-group variance. Significant inbreeding coefficients were observed in half the sampled walleye
populations. No relation was observed between inbreeding and population size or effective population size. A trend was observed where inbreeding predominately occurred in walleye populations from large systems; 81.5% (9/13) of all systems with a surface area > 500 ha showed
significant inbreeding whereas 31.3% (4/13) of populations with a surface
area of < 500 ha showed significant inbreeding. Several factors could
account for these data including the preferential sampling in large systems
of a single walleye spawning area, coupled with known philopatry of
walleye, resulting in biased sampling of cohorts and/or related individuals. Current management strategies should be re-evaluated in light of
these findings to better define management zones that can effectively conserve the genetic integrity of naturally recruiting walleye populations.
This re-evaluation should weigh the cost of increasing the number of genetic units managed with the short- and long-term impacts on the genetic
integrity of Wisconsin’s walleye populations. A primary conflict between
genetic structure and geographical location were the populations located
in the Upper Chippewa River basin were more genetically similar to
populations found in the Upper Wisconsin River basin. Geographical
(glacial recession and stream capture) and anthropogenic (stocking across
basin boundaries) are both reasonable explanations for this disruptive pattern. This issue requires further research to determine the biological reality of the resolved structure with strong implications for future management.
16
Influences of riparian
vegetation on trout
stream temperatures
in the North Central
Hardwoods Forest
Ecoregion of Wisconsin
Research Assistant:
Benjamin Cross
Principal Investigator:
Michael Bozek
Funding Source:
Wisconsin Department of
Natural Resources
Brook trout distribution and abundance throughout Wisconsin has been
reduced compared to historical levels. Much of this reduction is believed
to be due to land use changes that have increased summer stream temperatures which reduce the length of stream thermally suitable for brook
trout (Salvelinus fontinalis). Brook trout prefer temperatures ranging
from 10 to 19°C, and 22.3°C is considered suitable when maximum
weekly average temperatures (MWAT) are attained. Trees in the riparian
area reduce stream temperatures by adding shade to the stream and altering the microclimate to promote cooler stream temperatures. Managing
riparian vegetation offers potential for mitigating increased stream temperatures caused by poor land use and other factors thereby providing an
opportunity to increase the amount of stream with suitable temperatures
for brook trout. This study assessed the potential for forested riparian
areas to create thermally suitable stream segments for brook trout in central Wisconsin’s North Central Hardwoods Forest Ecoregion. Temporal
thermal profiles were created for twelve streams, six in 2007 and six in
2008, throughout central Wisconsin for the MWAT time period. Five of
the twelve streams monitored became thermally unsuitable for brook trout
with study stream temperatures ranging from 13.3 to 23.6°C during the
MWAT period. Using a stream heat budget temperature model (Stream
Segment Temperature Model), stream temperatures were modeled for the
MWAT period under varying levels of riparian vegetation stream shading
(0, 25, 50, and 75%). Modeling results were then compared to the temporal thermal profiles in order to assess the influence of stream shading on
the length of stream thermally suitable for brook trout. Shading modeled
at the 0% level predicted average equilibrium stream temperatures of
25.7°C and decreased the length of thermally suitable stream for brook
trout by as much as 91.5%, (4.31 km, on Unnamed 17-5 / Cunningham
Creek in Clark County). On the other hand, shading modeled at the 75%
level predicted average equilibrium stream temperatures of 20.9°C and
increased the suitable length of stream by as much as 128.63%, (4.96 km,
on Sucker Creek in Waushara County). Multiple regression analysis
found upstream temperature, segment length, stream width, and width to
depth ratio to be positively related to downstream temperature, whereas
change in flow per distance, stream slope, riparian vegetation shade, sand
substrate, and upstream flow were inversely related. Analysis of covariance found stream reaches with riparian trees to be significantly cooler
compared to grass-vegetated reaches. Forested riparian areas had stream
temperatures 0.74°C colder than grass vegetated riparian areas at the
downstream end of stream reaches during the MWAT period and 0.93°C
colder during the maximum daily average temperature (MDAT) period.
Estimated marginal means (i.e., least squared means) for change in stream
temperature per km predicted a decrease of 0.54°C/km under forested
riparian areas compared to an increase of 1.23°C/km under grassvegetated riparian areas during the MDAT period. In summary riparian
forests are clearly important for maintaining thermal conditions suitable
for brook trout and provide an opportunity to increase the amount of thermally suitable brook trout water in central Wisconsin.
17
Propagation practices
and genetic resources
in lake sturgeon rehabilitation
Research Assistant:
Luke Roffler
Principal Investigators:
Bradley Eggold
Steve Holger
Steve Fajfer
Brian Sloss
Ed Baker
Marty Holtgren
Robert Elliott
Marc White
Funding Sources:
Great Lakes Fishery Trust and
Wisconsin Department of
Natural Resources
Over the past two centuries, lake sturgeon Acipenser fulvescens populations have suffered massive declines, throughout North America. Lake
sturgeon once numbered 11 million in the Lake Michigan basin alone,
but contemporary estimates place their current count at less than 10% of
this historic abundance. This population decline has been attributed to the
combined effects of water quality degradation, habitat fragmentation and
alteration in the form of dam construction, and overexploitation. In response to these declines, the Wisconsin Department of Natural Resources
(WDNR) began collecting lake sturgeon eggs in 1978 at the Fox and
Wolf Rivers (Winnebago and Outagamie counties, Wisconsin) of the
Lake Winnebago system for artificial rearing at the Wild Rose State Fish
Hatchery (Waushara County, Wisconsin). Such efforts continue today,
with on-site manual fertilization by hatchery personnel typically combining the eggs of one female with the mixed-milt from two to five males,
after which all sturgeon progeny are reared together in communal hatchery ponds. The WDNR and Michigan Department of Natural Resources
(MDNR) began rearing lake sturgeon at stream-side rearing facilities
(SRFs) in 2006 and 2007, respectively. These facilities are located on the
banks of four target streams, allowing the young sturgeon to imprint and
one day potentially reestablish a spawning run in the stream. The spawning and rearing techniques used at the SRFs differ -greatly from WDNR
traditional hatchery methods, with the female’s eggs split into five
roughly equal lots which are fertilized by a single male per lot, after
which female-based families are reared separately. The SRF spawning
and rearing methods are designed to maximize genetic diversity and effective number of breeders (Nb) by minimizing the reproductive variance
of broodstock within each cross in the facility. To determine the most genetically appropriate method for lake sturgeon artificial rearing, comparison were made between the diversity produced at Wild Rose and the
SRFs. The objectives of this study were to identify the presence and extent of sperm competition in mixed-milt crosses, characterize the genetic
diversity present in each broodstock population, and evaluate the relative
reproductive contributions of male broodstock to each cross at the facilities. Significant paternal bias was observed in two of three experimental
mixed-milt crosses. This indicates that sperm competition was present in
mixed-milt crosses of lake sturgeon and has the potential to significantly
bias the genetic character of the resulting progeny towards the most successful males. Broodstock populations at Wild Rose and the SRFs were
found to be genetically representative of their respective source populations, even during years characterized by difficult adult capture or facility
problems that resulted in relatively small numbers of total broodstock.
Significant paternal bias was detected in the final stock at the SRFs, by
larval stage at Wild Rose, and in natural larval mortalities in the SRFs.
This indicates that survival at the larvalstage in the SRFs may be responsible for biased parental contribution at later stages. These data suggest
that significant genetic gains can be made by furthering attempts to equalize reproductive contributions of male broodstock. This could be accomplished by hatching egg lots in separate containers and combining into
female-based families for rearing only after hatch. Together with allowing
progeny to imprint, these data suggest that stream-side rearing holds great
promise for the re-establishment of genetically representative lake sturgeon spawning runs in the target streams.
18
Spawning strategies
and impacts on the
maintenance of genetic
diversity in lake sturgeon propagation
Principal Investigators:
Brian Sloss
Funding Source:
Wisconsin Department of
Natural Resources
Sustainable propagation and rehabilitation of lake sturgeon populations relies on the implementation of sound genetic principles in any
broodstock management program. A central issue with genetic considerations of hatchery production is the mode and strategy of crossing males to females. Key questions in lake sturgeon propagation
include: (1) how many adults need to provide gametes to ensure a reasonable level of genetic diversity; (2) what gamete fertilization strategy will produce the most diverse offspring; and (3) what are the segregation patterns of the standard mitochondrial and microsatellite
markers used in lake sturgeon genetics analysis. Of central concern
for lake sturgeon is a phenomenon known as sperm competition.
When milt from multiple males is mixed prior to fertilizing the eggs
from a female, the possibility exists that not all males will equally fertilize the same number of eggs. This disproportionate fertilization,
sperm competition, is a major impediment to maximizing the effective population size and, subsequently, the genetic resources of lake
sturgeon hatchery products. We are assessing the genetic contribution of three mixed milt families compared to a priori expectations of
20% fertilization by all males. The results of this study will be used
to adapt the State of Wisconsin’s standard protocols for fertilization.
19
PUBLICATIONS
PEER REVIEW
Jennings, C.A., B.L. Sloss, B.A. LaSee, G.J. Burtle, and G.R. Moyer. ACCEPTED. Care, Handling, and Examination of Sampled Organisms and Related Tissues. In: A. Zale, D. Parrish,
and T. Sutton, eds. Fisheries Techniques 3rd Edition. American Fisheries Society. Bethesda,
Maryland.
Sloss, B.L., R. Klumb, and E.J. Heist. IN PRESS. Genetic Conservation and Paddlefish
Propagation. AFS-Sponsored Book on Paddlefish Biology and Management.
Stott, W., J.A. VanDeHey, and B.L. Sloss. IN PRESS. Genetic diversity of lake whitefish in
Lakes Michigan and Huron; sampling, standardization, and research priorities. Journal of
Great Lakes Research.
VanDeHey, J.A., B.L. Sloss, P.J. Peeters, and T.M. Sutton. IN PRESS. Determining the efficacy of
microsatellite DNA-based mixed-stock analysis of Lake Michigan’s lake whitefish commercial fishery. Journal of Great Lakes Research.
Jennings, M.J., G.R. Hatzenbeler, M.A. Bozek, and C.E. Edwards. 2009. Natural and human influences on fish species richness in small north temperate lakes: Implications for bioassessment. Journal of Freshwater Ecology 24:7-18.
Franckowiak, R.P., B.L. Sloss, M.A. Bozek, and S.P. Newman. 2009. Temporal effective size
estimates of a managed walleye Sander vitreus population and implications for geneticbased management. Journal of Fish Biology 74:1-18.
Rosenfield, R.N., S.J. Taft, W.E. Stout, T.G. Driscoll, D.L. Evans, and M.A. Bozek. 2009. Low
prevalence of Trichomonas gallinae in urban and migratory cooper’s hawks in north central
North America. Wilson Journal of Ornithology 121: 641-644.
Moyer, G.R., B.L. Sloss, B.R. Kreiser, and K.A. Feldheims. 2009. Isolation and characterization
of microsatellite loci for alligator gar (Atractosteus spatula) and their variability in two
other species (Lepisosteus oculatus and L. osseus) of Lepisosteidae. Molecular Ecology
Resources 9: 963-966.
VanDeHey, J.A., B.L. Sloss, P.J. Peeters, and T.M. Sutton. 2009. Genetic stock structure of lake
whitefish in Lake Michigan. Canadian Journal of Fisheries and Aquatic Sciences 66:382393.
THESES
Cross, B.K. 2009. Influences of riparian vegetation on trout stream temperatures in the North
Central Hardwoods Forest Ecoregion of Wisconsin. M.S. Thesis. University of WisconsinStevens Point. 126 p.
Hammen, J.L. 2009. Genetic structure of Wisconsin’s naturally recruiting walleye populations.
M.S. Thesis. University of Wisconsin-Stevens Point. 102 p.
Roffler, L.S. 2009. Propagation practices and genetic resources in lake sturgeon rehabilitation.
M.S. Thesis. University of Wisconsin-Stevens Point. 93 p.
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PRESENTATIONS
SCIENTIFIC MEETING
Proctor, M.E., B.L. Sloss. May 2009. Assessing our abilities to distinguish among lake trout
hatchery strains and their potential to hybrid offspring on Lake Michigan’s mid-lake reef
complex. 52nd Annual Conference on Great Lakes Research. Toledo, Ohio.
Schmidt, S.M., and M.A. Bozek. April 2009. Development of multi-dimensional littoral zone
habitat fingerprints for classification and management of lakes. 22nd Annual National Conference Enhancing the States’ Lake Management Programs. Chicago, Illinois.
Sloss, B.L., R.P. Franckowiak, E. Heist, and R. Klumb. February 2009. Management of genetic
diversity in paddlefish (Polyodon spathula) populations and propagation. Aquaculture
America 2009. Seattle, Washington.
Cross, B.K., M.A. Bozek, and M. Mitro. February 2009. Central Wisconsin trout stream temperature changes related to riparian vegetation. Joint meeting of the Minnesota, Wisconsin, and
Ontario American Fisheries Society Chapters. Duluth, Minnesota.
Franckowiak, R.P., B.L. Sloss, and M.A. Bozek. February 2009. Walleye exploitation,
population demography, and the effective population size. Joint meeting of the Minnesota,
Wisconsin, and Ontario American Fisheries Society Chapters. Duluth, Minnesota.
Schmidt, S.M., and M.A. Bozek. February 2009. Assessment of littoral zone habitats for
classification and management of lakes. Joint meeting of the Minnesota, Wisconsin, and
Ontario American Fisheries Society Chapters. Duluth, Minnesota.
Spude, B.T, B.L. Sloss, E. Murphy, and M. Jennings. February 2009. Muskellunge genetic
stock structure in northern Wisconsin and implications for management. Joint meeting of
the Minnesota, Wisconsin, and Ontario American Fisheries Society Chapters. Duluth, Minnesota.
Cross, B.K., M.A. Bozek, and M. Mitro. December 2008. Influences of riparian vegetation on
trout stream temperatures. 69th Annual Midwest Fish and Wildlife Conference Columbus,
Ohio.
Franckowiak, R.P., B.L. Sloss, M.A. Bozek, and S.P. Newman. December 2008. Walleye
exploitation and the effective population size. 69th Annual Midwest Fish and Wildlife Conference Columbus, Ohio.
Proctor, M.E., B.L. Sloss. May 2009. Assessing our abilities to distinguish among lake trout
hatchery strains and their potential to hybrid offspring on Lake Michigan’s mid-lake reef
complex. 52nd Annual Conference on Great Lakes Research. Toledo, Ohio.
Schmidt, S.M., and M.A. Bozek. April 2009. Development of multi-dimensional littoral zone
habitat fingerprints for classification and management of lakes. 22nd Annual National Conference Enhancing the States’ Lake Management Programs. Chicago, Illinois.
Sloss, B.L., R.P. Franckowiak, E. Heist, and R. Klumb. February 2009. Management of genetic
diversity in paddlefish (Polyodon spathula) populations and propagation. Aquaculture
America 2009. Seattle, Washington.
Cross, B.K., M.A. Bozek, and M. Mitro. February 2009. Central Wisconsin trout stream temperature changes related to riparian vegetation. Joint meeting of the Minnesota, Wisconsin, and
Ontario American Fisheries Society Chapters. Duluth, Minnesota.
Franckowiak, R.P., B.L. Sloss, and M.A. Bozek. February 2009. Walleye exploitation,
population demography, and the effective population size. Joint meeting of the Minnesota,
Wisconsin, and Ontario American Fisheries Society Chapters. Duluth, Minnesota.
21
Schmidt, S.M., and M.A. Bozek. February 2009. Assessment of littoral zone habitats for
classification and management of lakes. Joint meeting of the Minnesota, Wisconsin, and
Ontario American Fisheries Society Chapters. Duluth, Minnesota.
Spude, B.T, B.L. Sloss, E. Murphy, and M. Jennings. February 2009. Muskellunge genetic
stock structure in northern Wisconsin and implications for management. Joint meeting of
the Minnesota, Wisconsin, and Ontario American Fisheries Society Chapters. Duluth, Minnesota.
Cross, B.K., M.A. Bozek, and M. Mitro. December 2008. Influences of riparian vegetation on
trout stream temperatures. 69th Annual Midwest Fish and Wildlife Conference Columbus,
Ohio.
Franckowiak, R.P., B.L. Sloss, M.A. Bozek, and S.P. Newman. December 2008. Walleye
exploitation and the effective population size. 69th Annual Midwest Fish and Wildlife Conference Columbus, Ohio.
Hammen, J.J., B.L. Sloss, and M.A. Bozek. December 2008. Genetic spatial analysis of naturally
recruiting walleye populations in Wisconsin. 69th Annual Midwest Fish and Wildlife Conference Columbus, Ohio.
Proctor, M.E., B.L. Sloss, J.J. Janssen, and M. Rise. December 2008. Efficacy of assignment
methods for determining the origin of lake trout produced on Lake Michigan’s mid-lake reef
complex. 69th Annual Midwest Fish and Wildlife Conference Columbus, Ohio.
Roffler, L.S., B.L. Sloss, B. Eggold, T. Burzynski, R. Burch, and E. Baker. December 2008. Genetic resources in lake sturgeon restoration using stream-side rearing facilities. 69th Annual
Midwest Fish and Wildlife Conference Columbus, Ohio.
Schmidt, S.M., and M.A. Bozek. December 2008. Development of multi-dimensional littoral
zone habitat fingerprints for management of lakes. 69th Annual Midwest Fish and Wildlife
Conference Columbus, Ohio.
Spude, B.T., B.L. Sloss, E. Murphy, and M. Jennings. December 2008. Wisconsin muskellunge
genetic stock structure and management implications. 69th Annual Midwest Fish and Wildlife Conference Columbus, Ohio.
Stoffregen, J.R., M.A. Bozek, K.J. Kohler, and A. Janicke. December 2008. A synopsis of littoral
zone habitat in lakes of the upper mid-western United States relative to fish species
associations. 69th Annual Midwest Fish and Wildlife Conference Columbus, Ohio.
Bozek, M.A., B.M. Mann, and M.G. Newbrey. November 2008. Use and partitioning of complex
coarse woody habitats by fish in the littoral zone of a north temperate lake. 28th International Symposium of the North American Lake Management Society Lake Louise, Canada.
Schmidt, S.M., and M.A. Bozek. November 2008. Development of multi-dimensional littoral
zone habitat fingerprints for classification and management of lakes. 28th International
Symposium of the North American Lake Management Society Lake Louise, Canada.
WORKSHOPS
Sloss, B.L., and R.P. Franckowiak. July 2009. Fisheries Conservation Genetics Workshop.
American Fisheries Society North Central Division Technical Committee Meeting. Lacrosse, Wisconsin.
Sloss, B.L. March 2009. Muskie genetics. 8th Intermediate and Advanced Muskie School.
Waunakee, Wisconsin.
Sloss, B.L. and G. Moyer. January 2009. Conservation genetics workshop with special
emphasis on endangered species issues. Presented to USFWS region 3. Chicago,
Illinois.
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GUEST LECTURES
BOZEK
Forecasting the effects of land use on the recruitment of coarse woody structure and the creation of
sustainable sources of fish habitat in north temperate lakes; Departmental invited seminar to the
Department of Fish, Wildlife and Conservation Ecology, New Mexico State University.
SLOSS
NRES/Water 324 – Invasive and exotic species; University of Wisconsin-Stevens Point
NRES 462/662 – Adaptive resource management; University of Wisconsin-Stevens Point
WL 840 – Metapopulations and other advanced topics; University of Wisconsin-Madison
Genetic structure and stock-based management of Lake Michigan lake whitefish; Departmental invited seminar to the Department of Biological Sciences, Western Illinois University
COURSES
BOZEK
SLOSS
Fish Habitat Analysis, Design, and Modeling
Ecological Genetics
PROFESSIONAL SERVICE
BOZEK
Member, Resolutions Committee - American Fisheries Society
Member, Graduate Committee - University of Wisconsin-Stevens Point, College of Natural
Resources
Member, Steering Committee - North American Black Bass Coalition
SLOSS
Associate Editor - North American Journal of Fisheries Management
Chair, Genetics and Biodiversity Tech Committee - North Central Division of the American
Fisheries Society 2002-Present
Member, Lake Michigan Lake Sturgeon Technical Committee
Member, Graduate Committee - University of Wisconsin-Stevens Point, College of Natural
Resources
Member, Institutional Animal Care and Use Committee - University of Wisconsin-Stevens Point
Member, University Professional Development Council - University of Wisconsin-Stevens Point
Peer Reviewer - North American Journal of Fisheries Management
Peer Reviewer - Environmental Biology of Fishes
Peer Reviewer - Journal of Great Lakes Research
Peer Reviewer - Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative
23
SCHOLARSHIPS AND AWARDS
Benjamin Cross
University of Wisconsin-Stevens Point UPDC Research Grant
Ben Kissinger
Salmon Unlimited Scholarship
Meaghan Proctor
University of Wisconsin-Stevens Point UPDC Travel Grant
University of Wisconsin-Stevens Point UPDC Research Grant
Midwest Fish and Wildlife Conference – Best student paper award 2nd
place
Sara Schmidt
Best Student Paper Award, Honorable Mention – North American Lake
Management Society Annual Meeting, Lake Louise, Canada.
University of Wisconsin-Stevens Point UPDC Travel Grant
University of Wisconsin-Stevens Point UPDC Research Grant
Amanda Smith
Musky Club Alliance Scholarship
Midwest Fish and Wildlife Conference – Best student poster award 2nd
place
Brandon Spude
University of Wisconsin-Stevens Point UPDC Travel Grant
University of Wisconsin-Stevens Point UPDC Research Grant
Salmon Unlimited Scholarship
Worth Fisheries Research Scholarship
Andrew West
Musky Club Alliance Scholarship
24