CHICAGO (FOX 32 News) - A destructive invasive species nearly made it to Lake Michigan six years ago. The Asian carp caused widespread fear that they would destroy the great lakes ecosystem.
As FOX 32’s Larry Yellen reports, a new wave of the fish are now threatening to push the lake Chicago overlooks to the tipping point.
It's a quiet morning on the Illinois River, near downstate Havana. And beneath the surface, there’s a potential threat to the future of the Great Lakes.
“When they go up, it's almost like fireworks going off,” said Kevin Irons, an Aquatic Nuisance Species Program Manager.
To prove his point, the DNR's Irons asked a co-worker to power up the electro-fishing gear used to survey fish populations.
These carp have been migrating north from Mississippi fish farms since 1993. If they reach the Great Lakes, the voracious eaters could wipe out existing fish populations, and a multi- billion dollar sport fishing industry could disappear.
It was six years ago when state officials revealed such dire predictions were close to becoming a reality.
“They're now at the gates to the Great Lakes,” said John Rogner of the Illinois Department of Natural Resources in 2009.
There was concern that three electrified barriers near Romeoville had failed to stop the migration. But a massive fish kill beyond those barriers discovered just one Asian carp.
None have been discovered since. But states like Michigan, and some environmental groups, insist that local waterways, including the Chicago River, need to be sealed off from the Mississippi River basin to stop the migration.
“Right now, if you're talking about preventing all invasive species from moving in both directions, and there are at least 13 species lined up moving both ways, the only thing that we know will work is separation, a physical barrier. Everything else is an engineer's fantasy drawn on a napkin,” said Robert Hirschfeld of Prairie Rivers Network.
Chicago area businessmen, from barge owners to tour guides, say a separation like that would be an economic catastrophe.
“The impact would be far reaching, it would actually have international consequences,” said Mike Borgstrom, President of Wendella Boats.
Opponents also say more barriers aren't necessary. Over the last six years, no additional carp have been discovered beyond the electrified barriers.
Most of the fish FOX 32 saw were three to four years old, from a bumper crop back in 2011. But the bad news is there was a record setting spawning in 2014, so a lot more fish are on the way.
“They don't spawn every year, but we know that 14 was one of the best one's ever,” Irons said.
So what's ahead? The Army Corps of Engineers is studying whether near Joliet, the Brandon Road lock and dam, a sort of "pinch point" on the river, can be converted into an additional barrier using either loud noises, carbon dioxide gas, heated water or chemicals.
“Now the lock is set up just to fill with water and empty with water. We need to disperse the chemical or the heated water throughout the lock, so that the species are deterred or flushed out,” said Jeff Heath, Program Manager of Great Lake and Mississippi River Interbasin Study.
And downstate, commercial fishermen are hauling 6 million pounds of carp out of the river every year. The DNR would like to get that up to 50 million pounds, most of it going to China where it's a popular dish..
“They're actually a very delicious fish. They’re healthy for you, high in omega threes, low in fat,” Irons said.
And eating one might help save the Great Lakes.
The study regarding a new barrier at the Brandon Road Lock and Dam is expected to take at least three years, and it would be several years after that before any new barrier is in place.