A researcher at the University of Illinois has found a new way to possibly stop the spread of Asian carp throughout the country’s waterways: carbon dioxide.
Cory Suski experimented with adding carbon dioxide (CO₂) into the water as a supplemental tool to work in tandem with the electric fence, which has been used to divert the carp from entering the canal, with the goal of providing a second line of defense. Suski found that carbon dioxide is quick and effective in repelling fish from an area.
“In one experiment using tanks, we could actually chase the fish with the gas,” Suski said. “Once carbon dioxide reached a threshold, fish would ‘choose’ to leave the area of the tank that had CO₂. The fish initially showed signs of being irritated or agitated after exposure, and eventually they lost equilibrium. If fish cannot leave or are slow to leave the carbon dioxide accumulates to a point where it will act like an anesthetic gas used for patients who are undergoing surgery.”
Suski still has to reproduce the experiment on a larger scale. He still isn’t sure whether using Co2 would be financially feasible and what effect it would have on other fish species and the environment.
If you haven’t been following the whole Asian carp fiasco, the species is an invasive species that has been gradually spreading throughout waterways in the region. Carp are in the Ohio River and the Mississippi, and scientists have been spending lots of time trying to keep them out of the Great Lakes. Once carp get into an ecosystem, they wreck havoc and are nearly impossible to eradicate.
The National Wildlife Foundation has a cool map showing how the species has spread since 1975. Some have suggested that one way to control the spread would be to start harvesting the fish, and some fisheries have begun capitalizing on their abundance. And if for some reason you’ve never seen a video of the giant carp jumping out of the river and putting boaters in peril, check out the video below.