Using Citizen Science to Track Sucker Spawning Migrations

When most people think of animal migrations, they tend to think of birds or large mammals, but in the Great Lakes, we have awe-inspiring spring migratory fishes: suckers.

Suckers (family Catostomidae) migrate in large numbers into creeks, streams and rivers to spawn, then return to the Great Lakes. While the suckers are in the tributaries, their eggs and waste products contribute to the health of the ecosystem by providing nutrients to the food web.

Learn more about Shedd's sucker research with our blog, Breathing Life into the Great Lakes: Understanding and Conserving Our Own Backyard.

But how do the suckers know when it is time to migrate? Are they getting cues from the water temperature, or is it when the streams are flowing at a certain rate? How do changes in climate affect the timing of seasonal migrations of suckers? The best way to examine spring migration patterns of suckers is to look at long-term data sets.

Launching a new Shedd study
In March 2017, Shedd research biologist Dr. Karen Murchie launched a collaborative project with the University of Wisconsin-Madison and the Lake Superior National Estuarine Research Reserve to study the timing of sucker migrations in the Great Lakes. The researchers rely on volunteer citizen scientists to collect a large amount of data at multiple locations over an extended period of time. Volunteers are stationed at sites on the western shore of Lake Michigan and the south shore of Lake Superior, providing broad spatial coverage that’s only possible with a citizen-science network.

Two species of suckers, white suckers (shown above) and longnose suckers, were chosen for the study because they migrate in large numbers throughout the Great Lakes basin, they’re big enough for volunteers to see from an observation point, and they’re easily distinguished from other fish species.

Data collected by volunteers will be used to test whether water temperature, stream flow, or lunar cycles cue these fishes to initiate their spawning migrations. The data will also be used to document the rolling wave of migrations along a latitudinal gradient from northern Illinois up through Wisconsin and Upper Michigan every year. Finally, data will be used to understand the local impacts of global climate change by comparing current migration timing to historical records from various governmental agencies, including the Wisconsin Department of Natural Resources, Michigan Department of Natural Resources and U.S. Fish and Wildlife Service. Shifts in the migration of suckers can affect the predators that rely on them as a food source by changing the dynamics of interactions, and even the timing of nutrient inputs into the streams can affect the entire food web.

Building on citizen science
Shedd’s Conservation Research department anticipates expanding this program in subsequent years to include additional locations and more citizen scientists. Aside from the scientific value of the study, public engagement in this sucker migratory study encourages a conservation ethic among citizens and spurs broader conversations about the diverse and unseen impacts of climate change. In addition, those involved in the study become ambassadors for native species such as suckers, spreading the word on their ecological value and impressive behaviors, including annual migrations.


The Great Lakes

About the team

Lear more about Dr. Muchie and the conservation research team!

You can help!

Pitch in to help our native wildlife by taking part in a Great Lakes Action Day. During one of these all-day outdoor excursions, you’ll help restore Illinois lakeshore habitats by cleaning a beach, removing invasive plants, or planting native grasses and wildflowers. You’ll also meet some of your neighbors—fishes and other aquatic animals that call the Great Lakes basin home.

About Dr. Karen Murchie
Dr. Karen Murchie joined the Daniel P. Haerther Center for Conservation and Research at Shedd in 2016. As a research biologist and instructor, Dr. Murchie’s role includes investigations into fish migrations in the Great Lakes and teaching a freshwater ecology course for students within the Associated Colleges of the Chicago Area (ACCA). Dr. Murchie has a diverse background in fisheries research, having worked in freshwater systems from the Arctic to the Amazon, and in marine ecosystems in The Bahamas.