Fish and Fisheries

Great Lakes fisheries are under stress, and new management approaches must be found to cope with these difficult challenges. The list of needed research encompasses fish biology and population dynamics, habitat and ecosystem health, toxic chemical contaminants, the potential effects of climate change, socioeconomic impacts and conflict resolution. Recent Wisconsin Sea Grant-supported fisheries research has focused on the lake trout fishery and food web dynamics in Lake Superior, and the decline of yellow perch and smelt fisheries in Lake Michigan.


Great Lakes Fishes Poster
Our popular fish poster is a great way to hang your love of fish on your wall.  Read more...


Researchers Find That Dioxin Exposure Can Impact Fish Noses and Reproductive Tracts
A Wisconsin Sea Grant-funded researcher discovered dioxin could have a negative impact on the nose tissue and sexual development of rainbow trout and zebrafish. Read more...

Wisconsin Fish

Fish Identification Tool
Trying to identify a Wisconsin fish?  We have just the tool for the job.  You can search for a fish by name or identify one by its appearance. You can now download an Android app or an iOS app.

Fish Species
More than 170 species of fish inhabit the Great Lakes, their tributaries and connecting waterways. Read more...

Eat Wisconsin Fish
Health experts agree that everyone should eat two servings of fish a week. It’s easy to make at least one of these weekly servings from a Wisconsin fish farm or the Great Lakes! Read more...

Savory Recipes
Looking for some new recipes using local fish? 

Download the Wisconsin Fish ID Mobile App!
Carry 174 Wisconsin fish in your pocket!  Download the mobile app and you can identify Wisconsin fish wherever you go, no Internet connection required. Read more...

Fish Anatomy
View a gallery of the anatomical features of fish.  Learn about general anatomy, body forms, color patterns, fins, mouths, and scales. You can now download an Android app or an iOS app. Read more...

Fish Glossary
Don't know the difference between your caudal peduncle and your mandibular pores? You can sort it all out here. You can now download an Android app and an iOS app is coming soon. Read more...

Trap Nets

Net maps, coordinates and depths

 The 2017 trap net season has started.

Manitowoc-Two Rivers Trap net maps:

There are currently 0 trap nets in the Manitowoc/Two Rivers area (6/30/17).
Trap nets were pulled on 6/30/17.

Be aware of nets! Sheboygan nets will be between 43 40' 55" and 43 34' 39" between June 29 and Labor Day.

Trap Nets in the Great Lakes
Whitefish trap nets are back in the water for the 2017 season. Entanglement in commercial fishing nets can be extremely dangerous. Learn how to steer clear of them and keep yourself and your gear out of the nets. Read more...

Ghost Nets

Ghost nets - Don't get trapped!
Ghost nets are lost fishing nets that can continue to catch fish and become entangled in fishing gear and boat propellers. Boaters and anglers can learn more about what to do what caught in a ghost net or other commercial fishing gear. Read more...

Report a Ghost Net
Report a suspected ghost net to the Great Lakes Indian Fish and Wildlife Commission or a local Department of Natural Resources office.

Report online:

Fish Smart - Tips for Success

Selecting Lure Colors for Successful Fishing
What does a fish see when a lure zips by? Find out more about the optical properties of water, how color changes at different depths and make smarter decisions when selecting lures in this new UW Sea Grant Institute Fact Sheet. Read more...

Viral Hemorrhagic Septicemia (VHS)

VHS in the Great Lakes

Lake Michigan Fisheries Forum

In 2012, the Lake Michigan Fisheries Forum (LMFF) changed from an advisory group to a forum devoted to raising awareness of Lake Michigan fisheries issues and providing an opportunity for discussion and feedback.  

The LMFF is a citizen-based group, and its charge is to review and provide input into the fishery goals, objectives and management plans for Lake Michigan. Members will assist fisheries managers in charting the future course of fisheries management by providing feedback to the Wisconsin Department of Natural Resources (DNR) Lake Michigan Fisheries Team.

Anglers, commercial fishers and anyone else with an interest in Lake Michigan's fisheries are encouraged to join.

The LMFF is facilitated by Titus Seilheimer, UW-Sea Grant, and is independent of the DNR. Representatives from major sport fishing clubs on Lake Michigan and Green Bay, commercial fishers, the Conservation Congress and the University of Wisconsin System are formal members of the forum. Meetings are open to the public.

See the LMFF page on the DNR’s website for more information.

Older Fisheries Forum Recommendations and Notes
A list of all official recommendations and notes from Fishery Forum meetings in PDF format. Read more...


Avoid the Trap: What Anglers Should Know about Commercial Fishing Nets
A fishermen's guide to avoiding trap nets and gill nets in the Great Lakes -- and what to do if you get caught in a drifting net. Read more...

A Cold Shoot on Lake Superior
Shooting video on Lake Superior can be challenging. Take a look at this short (1:43 minutes) video taken during the filming of a video about "ghost nets." Read more...

Titus Seilheimer: Fisheries Outreach Specialist
Titus Seilheimer tells us about his work as the fisheries outreach specialist for the University of Wisconsin Sea Grant Institute. Read more...

What Will Round Gobies Do to Great Lakes Streams?
Using funding provided by University of Wisconsin Sea Grant, UW-Madison ecologist Jake Vander Zanden and UW graduate student Matt Kornis set out to discover just what kind of impact round gobies might be having on streams and rivers. Read more...

Sturgeon Spearing on Lake Winnebago
Sturgeon spearing has its roots in the customs of many of the Native Americans who lived in the Great Lakes region long before Europeans arrived. The tradition continues today. Read more...

Spawning Sturgeon, Wolf River, Wis.
Sturgeon spawning is a yearly event triggered by water temperature—about 54 degrees Fahrenheit—and it in turn triggers a migration of spectators, researchers, wardens and volunteer guards. Read more...

Recent Changes in Great Lakes Fisheries
The fisheries specialist at UW Sea Grant, Dr. Phil Moy, explains recent changes in the Great Lakes, which species are at greatest risk, and the threat posed by Asian carp. Read more...

How Many Sport Fish Can Lake Michigan Support?
An environmental food web is an intricate, organic and delicate thing. That's why researchers have paid such close attention to the food webs in Lake Michigan. Read more...

Who Are the Critters in Your Neighborhood
Finding out who eats who in Lake Michigan -- and how two tiny water fleas could restructure the food web. Read more...

Growing Fish in Greenhouses
Milwaukee's Growing Power, a community-based urban food center, is using plants as natural water filters for raising yellow perch. Fred Binkowski of Wisconsin Sea Grant Institute provides technical advice on the experimental effort. Read more...

Jumping Carp
This video, courtesy of the Illinois Natural History Survey, shows Asian carp on the Illinois River near Havana, Ill. The fish jump in response to the noise of the motor or the charge from the electrofishing boat. Read more...

Effects of Climate Change on the Fish and Fisheries of the Great Lakes Basin
Brian Shuter, research scientist, Ontario Ministry of Natural Resources and Adjunct Professor of Zoology, University of Toronto presents at a meeting of the Wisconsin Fisheries Forum. Read more...


Virulence Factors and Control of the Fish Pathogen Flavobacterium Columnare

Mark McBride. UW-Milwaukee, (414) 229-5844,
David Hunnicutt, St. Norbert College, (920) 403-3200,
Osvaldo Sepulveda-Villet, UW-Milwaukee, (414) 382-1740,

Flavobacterium columnare causes columnaris disease in wild and farmed freshwater fishes, resulting in significant losses in aquaculture. Although the disease has been recognized for nearly 100 years, the mechanisms of pathogenesis of the bacterium are unknown and protective measures are inadequate. We used genetic techniques to construct deletion mutants of F. columnare. Mutants lacking the type IX protein secretion system (T9SS) gene gldN were avirulent in zebrafish. They failed to secrete toxins that were secreted by the wild type strains. Preliminary results suggest that the gldN mutants are also avirulent in yellow perch. This project will examine the effect of deletion of gldN on virulence in yellow perch in greater detail. Virulence factors secreted by the T9SS will be identified, and the genes encoding these will be deleted to determine the effect on virulence. Avirulent mutants will be tested as effective vaccine strains to protect against wild type F. columnare. R/SFA-11

Molecular Genetic Analysis of Zooplankton Community Structure in Lake Michigan

Russell Cuhel, UW-Milwaukee, (414) 382-1711,
Rebecca Klaper, UW-Milwaukee, (414) 382-1713,
Carmen Aguilar, UW-Milwaukee, (414) 382-1755,

More than a decade of fisheries collapse in Lake Michigan has eradicated significant commercial and sport fishing businesses and upset the traditional food web. Although the near extirpation of planktivorous forage fish in the mid-2000s coincides a massive reduction in phytoplankton (largely brought about by Dreissenid mussels), the link between phytoplankton and juvenile and/or forage fish is not well developed. This proposal offers to construct a genetic sequence library of commonly occurring freshwater zooplankton of Lake Michigan; to establish the validity of preservation techniques for the genetic material; to attempt molecular analysis of species composition, richness, and diversity using sequence analysis side-by-side with microscopic enumeration; and to assess the likelihood that alcohol-preserved collections coinciding with hydrographic and biogeochemical time series can be queried to examine known forcing functions of zooplankton abundance and community structure. R/SFA-12

Diagnosis and Management of Viral Hemorrhagic Septicemia Virus in Wisconsin

Tony Goldberg, UW-Madison, (608) 890-261,

Viral hemorrhagic septicemia virus (VHSV) is an invasive pathogen that continues to threaten Wisconsin’s fisheries. With previous Sea Grant support, our team developed an accurate non-lethal test for VHSV. Our current goal is to validate our test for four important fish species in Wisconsin: bluegill, yellow perch, northern pike and brown trout.   We will set test thresholds using samples from known positive and known negative fish. We will then measure the development of the immune response to understand how long fish retain antibodies. Finally, we test fish across Wisconsin, to map the distribution of VHSV in our state. The result will be new information about whether fish have been exposed to VHSV, the current immune status of populations, and where in Wisconsin VHSV has spread.  This information will be used to manage VHSV and reduce its impact on our economy and recreational fisheries. R/SFA-13

Optimizing Walleye Stocking Density and Nutrient Recycling in Traditional and Integrated Aquaculture Systems

Chris Hartleb, UW-Stevens Point, (715) 346-3228,
Greg Fischer, UW-Stevens Point, (715) 779-3461,
Emma Wiermaa, UW-Stevens Point, (715) 779-3262,

Water shortages and stricter environmental regulations are shifting aquaculture production to integrated aquaculture systems. Only one fish type has been extensively researched and had its production methods optimized in these systems—tilapia. The aquaculture and aquaponic industries need more fish options, and walleye is a species with substantial aquaculture potential because of its high market value and limited supply from traditional commercial sources. Our project will conduct key commercial production evaluations using traditional and integrated aquaculture systems raising walleye and hybrid walleye from fry to market size based on three stocking densities. Nutrient dynamics, nutrient removal, and plant and fish growth will be evaluated to determine optimal stocking density and production methods in both systems. Biological and economic models will be developed for producers so they can evaluate the introduction of a new fish type into their traditional and integrated aquaculture production systems. R/SFA-14

Seasonal Depth Distribution of Round Goby in Lake Michigan, Emphasizing Cold Seasons

John Janssen, UW-Milwaukee, (414) 382-1733,

Round gobies are significant in the diet of certain coldwater predators, even though they are a warmwater species (based on summer habitat and spawning). This project is evaluating these evolving predator-prey interactions by finding areas in which round gobies are most accessible to coldwater predators. An understanding of the cold season predator-prey interaction will facilitate management by allowing managers to better assess the best balance of predators, particularly the largely stocked salmons and trouts. The current shallowest USGS trawls are both off the preferred substrate and preferred summer depths for round gobies. In this novel and still evolving coastal ecosystem, management of round gobies is a balance between control of a nuisance species and management of the forage base. R/HCE-32


Understanding the Changing Lake Michigan Food Web
The Lake Michigan food web is in a constant state of flux due to invasive species, pollution and changing climate. Providing the most current information on the science of Great Lakes food webs and ecosystems is necessary for creating informed policy makers and citizens. This project, in partnership with the Wisconsin Maritime Museum, has developed an outreach and education program aimed at angler and conservation groups and students. It outlines food web ecology, the structure of Lake Michigan’s food web and how it has been changed by invasive species.

Commercial Trawling for Whitefish
This study is investigating the capture rate of non-target species resulting from lake whitefish trawling. The research will be used to determine if trawling could be conducted without impacting other fisheries such as salmon and lake trout. Fishing will be conducted over all seasons and at a range of depths in order to identify temporal and spatial patterns in lake whitefish distribution that minimize bycatch. The study could inform winter commercial whitefish harvest. That is a time when prices are high but trap nets cannot be set. Potential conflict with recreational fishers would be reduced because fewer trap nets are in the water.

Salmon Ambassadors Wisconsin
This project is engaging Wisconsin anglers in the management of Lake Michigan Chinook salmon. Anglers are being
recruited from Wisconsin ports to collect information about the fish they catch. Fish size and fin clip (an indicator of stocked versus wild) data will be collected by anglers to increase the knowledge of seasonal change in the abundance of wild salmon in Wisconsin waters. This program is also allowing for increased and more targeted collection of Chinook salmon heads for retrieval of coded wire tags, which offer information on the movement of stocked and wild salmon.

Great Lakes Commercial Trap Nets Location
In order to diminish life-threatening entanglement events involving sport anglers’ equipment and commercial fishing nets, Sea Grant works with the Lake Michigan commercial whitefish fleet to make the GPS coordinates of commercial trap nets available to anglers on its website and through printed maps placed in high-use launching locations.

Eat Wisconsin Fish
Many people are interested in purchasing more of their food from local sources, but when it comes to local fish,
consumers often have questions about nutrition benefits and risk, as well as environmental sustainability. Sea Grant is continuing its Eat Wisconsin Fish campaign to educate consumers about wild Great Lakes fish and Wisconsin farm-raised fish, and the environmental impacts associated with commercial fishing and aquaculture. The project is also connecting producers and fishermen with retailers and restauranteurs.

Enriching the Lifestyle for Carnivores at the Milwaukee County Zoo
The goal of this project is to provide the necessary stimulation to trigger predatory behavior by introducing live prey organisms such as fin fish. As a result, the animals exhibit behavior patterns that are more natural such as hunting, stalking, aggression and capture. Different food presentation scenarios are being explored to determine the best
approach to challenge animals’ natural instincts and intelligence. This project represents a unique opportunity to utilize the “Aquaculture Tool Box” and most advanced biosecurity practices to produce fin fish to support this special application.

Ghost Nets
Members of the Apostle Islands Sport Fisherman’s Association initiated the project, and it is being conducted in partnership with the Great Lakes Indian Fish and Wildlife Commission. The groups are developing outreach and education materials for the prevention of marine debris. The project educates not only anglers but also commercial and tribal fishers to reduce the creation of new ghost nets and presents best-management practices to commercial and tribal fishers through educational workshops. Lake Superior’s tribal fishers, an underserved group, benefit. This project also educates the group most likely to encounter commercial and ghost nets—recreational anglers, who have a stake in the quality of the fishery. Funding source: NOAA Marine Debris Grant

Asian Carp Research
This is a literature review of current research on the control of the spread of Asian carp throughout the Great Lakes and Mississippi River basin. The material will then be shared with interested members of the public, resource managers and policymakers. It will identify research gaps that can guide future investigations and management activities. Funding source: Asian Carp Regional Coordinating Committee through Ohio Sea Grant

Related Publications

Fishes of Wisconsin by George Becker
This classic book is available in its entirety in a digital format through the University of Wisconsin library system. Read more...

More Related Publications
For more publications about fish and the Great Lakes fisheries, see our publications store. Read more...

Related Websites

Video on Lake Sturgeon
Learn more about Wisconsin's Lake Sturgeon population through Sea Grant-produced video, which is located on the organization's You Tube channel. Read more...

Wisconsin's Water Library

Wisconsin's Water Library has reading lists on many different topics.  Take a look at the fish and fishing reading list, the Great Lakes fish reading list and books for kids on fish and fishing.