Business Owners, Anglers

Work to Stop the Spread of Invasive Species

Research revealed that aquatic invasive species are potentially being sold to anglers as live bait. The researchers are working with agencies, bait shop owners, and anglers to develop a monitoring and public education campaign to prevent the spread of invasive species through the bait trade.


One possible pathway for invasive species like Asian carp to enter the Great Lakes is the commercial bait trade. Anglers purchase live bait fish to catch larger predator fish. At the end of the day, it’s not uncommon for anglers to release unused bait fish into the water. If any of those fish are non-native, it can lead to the establishment or spread of invasive fish—which can wreak havoc on native fish and their habitat. Thanks to a grant from the Great Lakes Restoration Initiative, researchers from the University of Notre Dame and Central Michigan University have collaborated to quantify the prevalence of invasives in the bait trade. The researchers collected samples of tank water from 525 bait shops across the Great Lakes states of Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio, Pennsylvania, and New York. They then genetically screened these samples for the presence of six invasive fish species by searching for their unique DNA sequences among the environmental DNA, or eDNA. eDNA screenings are much more efficient than traditional visual screenings, and make searching for individual juvenile invasives among thousands of minnows feasible. Results indicate that while the issue does not yet appear to be widespread, some invasive fish species are being brought into Great Lakes bait shops.

Resource Challenges Addressed

  • Invasive species
  • Lack of system to track trade


Samples of bait were collected from live bait shops, like the one pictured here, across all eight Great Lake states. Photo courtesy of Lucas Nathan.

Results and Accomplishments

Out of the 525 bait shops sampled, goldfish were detected in 13, round gobies in 8, tubenose gobies in 3, silver carp in 3, and rudd in 1. Bighead carp was not detected in any of the bait shops sampled. These results indicate that while the issue does not yet appear to be widespread, some invasive fish species are being brought into Great Lakes bait shops. Federal and state agencies are developing monitoring programs to prevent the establishment of invasive species populations. Researchers identified a high potential to increase anglers’ awareness of invasive species and prevent practices such as dumping the remainder of bait buckets into the water at the end of the day. Anglers support healthy populations of native fish, and they can play an important role in preserving the integrity of natural ecosystems.