New research from South Dakota State University (SDSU) is shedding light on innovative strategies to prevent the spread of invasive carp across U.S. waterways.
In April 2025, the federal government announced new funding to help the U.S. Army Corps of Engineers strengthen barriers against invasive carp entering the Great Lakes via Lake Michigan. With an estimated project cost of $1.2 billion, the urgency of managing the invasive carp threat has never been clearer.
Understanding the Invasive Carp Problem
Invasive carp, commonly known as Asian carp, were first introduced to the U.S. in the 1970s to clean commercial fish ponds. Unfortunately, flooding events allowed them to escape into the wild. Since then, they have spread throughout major Midwestern waterways, causing severe ecological damage.
Researchers from SDSU’s Department of Natural Resource Management, led by Assistant Professor Alison Coulter and Graduate Research Assistant Hannah Mulligan, are at the forefront of studying this issue. Their work focuses on controlling invasive carp populations, especially in South Dakota and parts of the Missouri River Basin.
New Research on the Live Baitfish Trade
Mulligan and Coulter recently published findings in the journal BioScience, exploring how the live baitfish trade — a $1.56 billion industry in the U.S. — contributes to the spread of aquatic invasive species, including invasive carp.
Their study evaluated prevention efforts such as regulations, education, and inspections, offering actionable recommendations for invasive species management, even when resources are limited.
“Prevention is the most cost-effective way to limit human-mediated introductions and the negative impacts of invasive species,” said Mulligan.
Why Baitfish Management Matters
One major challenge is that it’s hard to distinguish between young invasive carp and other small fish species. As a result, invasive carp juveniles are often unknowingly used as bait.
Mulligan emphasizes that preventing the spread at the source — focusing on live bait disposal and regulating the bait trade — is critical. She recommends installing bait disposal stations at fishing access points to encourage anglers to properly dispose of unused bait, helping prevent accidental introductions.
Key Strategies to Prevent Invasive Carp Spread
- Target Inspections at Wholesalers: Since there are fewer bait wholesalers compared to retailers and anglers, inspections at the wholesale level could be more cost-effective and impactful.
- Implement Harvest Restrictions: Limiting the harvest of baitfish can reduce the chances of invasive species entering new waterways.
- Promote Online Training: Educational programs for anglers and bait retailers can increase awareness and improve compliance with invasive species regulations.
- Enhance Regional Cooperation: States should share resources, research, and best practices across regions to improve management strategies.
- Utilize Existing Unpublished Research: Making management reports, angler surveys, and outreach materials more accessible could strengthen prevention efforts.
The Importance of Cross-Jurisdictional Collaboration
Mulligan highlights that while individual states must tailor their efforts to local needs, regional coordination is essential for broader success. She points to regional management panels as a successful model for sharing resources and information across river basins.
“Prioritizing the live baitfish trade in management and sharing cost-effective approaches will lead to greater impact in reducing the spread of aquatic invasive species,” Mulligan concluded.
Additional Information
📚 Study Reference:
Hannah Mulligan et al., “Aquatic invasive species prevention in the live baitfish trade: the role of regulations, education, and inspections,” published in BioScience (2025). DOI: 10.1093/biosci/biaf027
🧪 Provided by South Dakota State University.