Wildlife officials and researchers have been testing the waters of an eastern Ohio river for the invasive Asian carp, even though there are no signs of it yet.
The tests will not only help determine whether the voracious fish has moved into the Muskingum River but also help plan how to cut off paths that the carp could use to get into Lake Erie, state officials said.
Scientists fear that if the carp enter the Great Lakes they could wreck its multibillion-dollar fishing industry.
The Ohio Department of Natural Resources said in August that DNA from Asian carp was found in one water sample among hundreds from northern Ohio rivers feeding into Lake Erie. No live Asian carp were found.
The Muskingum River is the farthest east that Ohio officials have searched for carp.
Researchers told The Columbus Dispatch that it will take months to figure out whether Asian carp might be in the river. They already have been found in the Ohio River near Portsmouth. That's about 100 miles from where the Ohio and Muskingum rivers meet.
Bighead and silver carp were imported from Asia to the southern U.S. in 1970s to control algae in fish ponds and sewage lagoons. They escaped and have infested most of the Mississippi River and many of its tributaries, which could provide linkages to Lake Michigan and Lake Erie.
Scientists say if the carp become established in the lakes and spread widely, they could out-compete other fish for plankton — the base of aquatic food chains.
Rich Carter, the Ohio Department of Natural Resource's fish-management and research administrator, said the carp could use two different paths in the Muskingum River system to reach Lake Erie. They could go through the Erie Canal and then to the Cuyahoga River or they could cross over to Black River during a flood and then make it to the lake, he said.
Researchers took 210 samples from the Muskingum's headwaters to the Ohio River.