A new study says Asian carp could easily establish in the Great Lakes unless physical barriers are built to keep them out.
Fisheries and Oceans Canada says it would take as few as 10 female and even fewer male Asian carp to create a breeding population.
The invasive fish have already infested the Mississippi River and many of its tributaries.
Andy Buchsbaum is with the National Wildlife Federation's Ann Arbor office.
"The actual construction of a physical barrier in the Chicago canals is the only way of making sure that those carp don't move to the rivers, into the canals and into Lake Michigan," Buchsbaum says.
Buchsbaum says the Canadian report for the first time confirms that the Great Lakes are not too cold for Asian carp to become established and that there's enough food for them to thrive.
The report says the carp would have major ecological impacts on the lakes.