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Migratory Freshwater Fish Research at Shedd Aquarium Expands with Investment from U.S. Fish and Wildlife Service

New technology informs researchers where these important species go after spawning

October 11, 2022

A Shedd researcher stands in a stream, writing down observations.

CHICAGO — A new collaboration with the U.S. Fish and Wildlife Service (Service) is expanding the capacity of Shedd Aquarium to study the movements of migratory suckers in the Great Lakes basin. Access to acoustic telemetry technology is already providing data on where these important fish go outside of their annual spawning season. Continued research will add rich information to the scientific understanding of these species – which are the most abundant group of migratory fishes in the Great Lakes – and may inform future conservation management strategies.

Shedd’s work over the past five years has been to understand and document site fidelity for suckers – whether they return to the same streams and tributaries each year for spawning– and determine if climate change is impacting their migration in any way. In this time, freshwater biologist Dr. Karen Murchie, with support from local landowners and volunteers, has confirmed that adult fish return to the same waterways year after year for this significant annual event, which floods the system with nutrients and broadly benefits surrounding wildlife. The aquarium’s partnership with the Service out of the Green Bay Fish and Wildlife Conservation Office will now help researchers understand where suckers live outside of their breeding season and what ecological role they play in those locations throughout the rest of the year.

“While this represents the next step in our research effort on migratory fishes, it is also an inspiring demonstration of collaboration in the Great Lakes on behalf of wildlife,” said Dr. Karen Murchie, director of freshwater research at Shedd Aquarium. “Despite their important role, suckers are not widely studied or celebrated, but this investment from the Service signifies the value of all native fish species in the Great Lakes.”

Monitoring the movement of suckers is done through a network of acoustic receivers that are deployed across the Great Lakes. The Great Lakes Acoustic Telemetry Observation System (GLATOS), established by the Great Lakes Fishery Commission (GLFC), allows researchers from both the United States and Canada to operate telemetry research on behalf of countless fish species.

The investment from the U.S. Fish and Wildlife Service in Shedd’s sucker research is three-fold:

  • First, the Service funded the purchase of 50 acoustic transmitters, which researchers can safely implant into migrating suckers while in the field. Like a microchip in a pet, these transmitters are unique to the individual fish. Whenever a fish swims close to one of the acoustic receivers, that information is recorded and later stored in a database.
  • Second, they loaned Shedd five additional acoustic receivers to detect these transmitters. These, combined with five owned by Shedd, were deployed in Sturgeon Bay to expand the current receiver array into an area that researchers believe is a hotspot for suckers outside of spawning season.
  • And lastly, biologists from the Green Bay Fish and Wildlife Conservation Office provided expertise and assisted Dr. Karen Murchie with the fish tagging.

“Working together with Shedd Aquarium and other partners, we’re gaining valuable knowledge about the movements of migratory suckers that will help us improve our management recommendations,” said Susan Wells, Project Leader at the Green Bay Fish and Wildlife Conservation Office. “This effort demonstrates the strength of partnerships in furthering our shared conservation goals.”

The U.S. Fish and Wildlife Service’s commitment to making an acoustic telemetry project on suckers a reality laid the foundation for further support from other organizations. Wisconsin Sea Grant provided 10 additional acoustic transmitters, bringing the number of suckers that could be tagged to 60 fish. In April, 30 male and 30 female white suckers were implanted with the tags.

Prior to tagging the fish, collaborators from University of Wisconsin Stevens Point facilitated the deployment of the additional acoustic receivers for the sucker program. A real-time receiver was also contributed to the project by GLATOS through support from the GLFC.

To date, over 18,000 detections of the tagged suckers have been picked up between the GLATOS acoustic receiver array and the real-time receiver. Shedd will collaborate with researchers from Michigan State University and Cornell University in addition to the organizations listed above to analyze and interpret the data as it is received.

Empowered by these partnerships and new technology, Shedd Aquarium looks forward to sharing more data and details of the journey that suckers take after their annual spawning season while engaging the public around these unsung heroes swimming in the Great Lakes.

VISUALS: High resolution photos of the sucker research: