Researchers from Central Michigan University and the University of Notre Dame have spent roughly two years analyzing environmental DNA—or eDNA—in water samples from bait fish shops across the Great Lakes region in an effort to understand the role the trade industry plays in the spread of invasive species. Their results suggest that bait dumping and inconsistent regulations could allow some of the most feared invaders to reach the Great Lakes.

 From The New York Times:

… they tested water samples from tanks containing small fish for sale as bait at more than 500 shops across the eight states on the lakes and found that 27 tested positive for invasive species’ DNA. Positive hits for silver carp, one of the Asian varieties threatening to reach the Great Lakes, were recorded in three water samples from shops along the Lake Erie shore in Ohio. 

The team also detected genetic material from round goby, tubenose goby and Eurasian rudd, which are already in the Great Lakes although authorities hope to prevent them from reaching inland lakes and other waters. They also found traces of goldfish, which are classified as an invasive foreign species despite being widely available for purchase at pet stores. 

“While overall only a small percentage of bait shops had evidence of invasive species, it is nevertheless alarming that at least some invaders are being spread by anglers, the very group of people that value the Great Lakes fishery the most,” said Andrew Mahon, one of the paper’s co-authors and a molecular ecologist at Central Michigan’s Institute for Great Lakes Research. The report was being published in the journal Conservation Biology. Read more 

Fortunately, a new suite of tools can help resource managers in the region develop consistent policies that target commercially sold species posing the greatest threat to the Great Lakes. Work on these risk assessments is still underway, but one tool has already led officials in Illinois and Indiana to ban high-risk plants commonly imported for the aquarium and water garden trades.

And you can help too! Next time you go fishing, be sure to throw any unused bait in the trash and drain your bait bucket on land. 

For more simple steps you can take to prevent the spread of invaders, visit our AIS page