Illinois researchers battle invasive carp species

Once an invasive species like Asian carp shows up, research shows they are almost impossible to eliminate.

For 12 years, scientists at the University of Illinois College of ACES researched ways to stop the spread of invasive carp through physiological barriers.

Originally brought to the southeast U.S. in 1970 to clean aquaculture and wastewater treatment facilities, the species has now invaded 45 states. The rapid growth threatens native fish populations and economic resources.

“What we have been looking at is what prevents them from moving and how we can use that to contain them,” said Cory Suski, a Department of Natural Resources and Environmental Sciences professor. “Rather than trying to have them arrive somewhere and then trying to remove them afterward, it’s a better strategy to just try and stop them in the first place.”

Facing boat and barge traffic in the Illinois River, Suski said his team knew stopping the carp wouldn’t be as simple as blocking off the Illinois River. This created the key question, “How do you stop the fish from swimming when they can’t stop the river?”

In the lab, Suski and his team tested different non-physical barriers that would stop the fish, but not the boats. He said that in the tests, carbon dioxide effectively obstructed the carp.

“All fish don’t like carbon dioxide, they just swim away from it,” Suski told FarmWeek. “What we’ve shown at a bunch of different scales from the lab and a pond, is that if you make an area of high carbon dioxide, you can just exclude fish from going into that area.”

But the tradeoff for this method and other non-physical barriers is you deter all fish, not just carp. To protect other species that rely on migration, Suski said the carbon dioxide needs to be targeted to a smaller area like a shipping lock or dam.

“What we have been looking at is what prevents them from moving and how we can use that to contain them. Rather than trying to have them arrive somewhere and then trying to remove them afterward, it’s a better strategy to just try and stop them in the first place.”

—  Cory Suski, a University of Illinois Department of Natural Resources and Environmental Sciences professor

As the project continues, Suski said the team will combine carbon dioxide with other non-physical barriers, sound and bubbles, to increase and improve the ability to stop fish passage.

The team plans to extend the research beyond trials in labs and ponds, expanding into rivers to test findings at a larger scale.

Suski said that the upcoming research will have projects focused on each stage of carps’ life – eggs, baby carp and adults. However, the primary emphasis will be on studying juvenile and adult carp.

He said that while capturing eggs could put a huge dent in the population, only one project will focus on eggs because it is difficult to gather them.

“One female carp can have hundreds of thousands of eggs,” Suski said. “The eggs are about the size of a small bead so getting those eggs is like trying to scoop thousands of beads out of the Spoon River.”

• This story was distributed through a cooperative project between Illinois Farm Bureau and the Illinois Press Association. For more food and farming news, visit FarmWeekNow.com.