Asian carp jump and fly along a tributary of the Illinois River in Havana, Ill. (2003 file photo by RICHARD LEE / DFP)

BY ERIC SHARP
FREE PRESS OUTDOORS WRITER Anglers in the Great Lakes watershed better fish as much as possible in the next decade. Chances are that yet-another monumental government screwup has let Asian carp into the world’s biggest freshwater reservoir, auguring a potential disaster for many of our sport fisheries. New tests let scientists detect the DNA of fish in a river or lake without actually seeing them. Fish have to pee and poop, too, and epithelial cells sloughed off from their bodies showed that Asian carp were in the Chicago Sanitary and Ship canal last month above an electrical barrier that was supposed to keep them out of the Great Lakes. The carp were 8 miles below Lake Michigan with only one upstream lock between them and the big lake, but the lock opens regularly. So there’s no reason to believe the fish detected above the barrier are the first to reach that spot, especially since they were discovered the first time that area was tested, or that others didn’t pass through months or even years earlier. Truthfully, no one knows what will happen once Asian carp reach the Great Lakes. But looking at the Illinois River, where they’ve become the dominant fish species in a mere 10 years, I’d plan for the worst. We also have the experience of zebra and quagga mussels, invaders from the Baltic that reached the Great Lakes 25 years ago in the ballast of oceangoing ships. They caused a bottom-up collapse of the food chain in Lake Huron by sucking nutrients out of the water, and many biologists believe the same thing could happen in Lake Michigan. Huge amounts of potential energy in Lake Huron that used to go into creating rice-sized plankton that fed pea-sized creatures at the low end of that chain is now locked up on the lake bottom in the form of trillions of mussel shells. …

Asian carp invasion: Prepare for the worst