ZANESVILLE, Ohio — As it cuts a squiggly track through the southeast Ohio hill country, the Muskingum River might seem like an unlikely battlefront in the war to keep Asian carp out of the Great Lakes, but the results of a recent study indicate these dreaded invaders could be present near there, and pushing north toward a gateway to the Lake Erie watershed.
Multiple water samples taken from the Muskingum River in the fall of 2013 carried the environmental signature of bighead carp, an invasive species threatening the ecosystem of the Great Lakes. A report released Friday by the Nature Conservancy, in conjunction with the Muskingum Watershed Conservancy District, the Ohio Department of Natural Resources, and researchers from Central Michigan University, indicated 10 of the 222 samples from the river tested positive for bighead carp eDNA.
The eDNA means Asian carp genetic material, which could be from scales, body fluids, blood, waste, or live fish. Biologists use eDNA analysis of water samples as an early detection weapon to determine if Asian carp are present in a system. While eDNA is not as conclusive as the presence of live or dead fish, it does confirm the presence of Asian carp genetic material.
“I don’t want to think about what this might mean,” said a stunned Darrell Gibbons, who has operated the D&D Bait and Tackle shop in Zanesville near the river for the last 18 years. “We catch a lot of catfish, bass, crappie, and walleye from that river, so this can’t be good news.”
Asian carp have been established in the Ohio River for more than a decade, but these most recent eDNA results indicate the fish could be present in the Muskingum as far north as the Ellis Lock 11 and dam, some 80 miles north of where the Muskingum joins the Ohio at Marietta. Samples from above the Ellis Lock did not show the presence of Asian carp eDNA, but they were taken in less than ideal carp habitat, according to John Stark, director of freshwater conservation in Ohio for the Nature Conservancy.
“These results are concerning, since they indicate the fish are moving up pretty far into the system,” Mr. Stark said. “We’ll feel better about relying on the information once it is more conclusive, but it makes sense, since these fish have been in the Ohio River for some time.”
The Muskingum River has a series of old dams and deteriorating locks, but if the eDNA evidence is accurate, those have not provided a significant impediment to the carp moving up the river system.
“This information seems to indicate they have already gotten past the dams,” said John Navarro, program administrator for the ODNR. “They’ve shown no tendency to slow down. They are barreling up these waterways.”
Through a link at Portage Lakes, south of Akron, the carp could conceivably use the Tuscarawas River, which flows into the Muskingum River, to access the Cuyahoga River system, which feeds into Lake Erie at Cleveland.
Water is actively moved between the two basins, Mr. Navarro said. “It is a direct connection, not nearly as big as some others, but one that is real complicated, with a number of jurisdictions involved,” he said.
Closing that link is a priority for many involved in the Asian carp fight, which has been going on for at least two decades and involves a cadre of state and federal agencies.
“The upside now is that we have started pecking away to shut down these secondary connection points, and there’s work being done on the engineering and feasibility aspects of that,” said Jeff Tyson, the Sandusky-based Lake Erie Program Administrator for the ODNR’s Division of Wildlife.
The term Asian carp refers to four invasive species that present various levels of threat to the waterways of the United States and the Great Lakes: bighead, silver, grass, and black carp.
Bighead and silver carp were imported in the 1970s to help control algae in fish farms in Arkansas, and reached the Mississippi River system either by escaping those facilities during floods, or by accidental introduction. These two species have been surging across the watershed ever since and are the most destructive as well as the most feared.
Grass carp consume aquatic vegetation and destroy habitat used by native fish, while black carp eat snails and mussels and are a threat to those species. Bighead and silver carp are filter feeders that devour massive amounts of plankton, depleting the food sources for native fish. They thrive in nutrient rich waters, such as those offered by the Muskingum River or western Lake Erie. They are also prolific breeders.
Bighead and silver carp now dominate large stretches of the Missouri, Mississippi, and Illinois rivers, making up as much as 90 percent of the fish in certain areas. Their primary access route to the Great Lakes would be through the Chicago Sanitary and Ship Canal, a man-made link between the Mississippi Watershed and Lake Michigan. An electrical barrier operated by the U.S. Army Corps of Engineers about 30 miles from Lake Michigan is intended to keep the Asian carp out of the Great Lakes, but biologists and politicians in Ohio and Michigan have clamored for a permanent closing of the canal.
“We are addressing what we can in our backyard, and that provides us with some leverage, something we can hold up and show that we are doing what we can to actively address any potential problem areas in Ohio,” Mr. Tyson said.
Captain Paul Pacholski, president of the Lake Erie Charter Boat Association said the revelation of positive bighead eDNA hits in the Muskingum River serves as a grim reminder of how close the invasive carp are to the lake.
“It absolutely feels like they are trying to outflank us,” he said. “I was hoping against hope that it wouldn’t come to this. We have to act immediately.”
Rich Carter, executive administrator of fish management and research for the ODNR, said the next step on the Muskingum will be to search for live fish.
“Since we know that both bighead and silver carp have been present in the Ohio River for a number of years, it is reasonable to assume some fish have migrated up the Muskingum,” he said. “The eDNA sampling is just part of the proactive approach to determine how far up the Muskingum they could be.”
Adult bighead carp have been located as far upstream in the Ohio River as the Moundsville area in West Virginia’s Marshall County in 1997, and in Monroe County, Ohio, at the Hannibal Lock and Dam, near Wheeling, W.Va. in 2006, according to the U.S. Geological Survey.
In November, 2013, the Pennsylvania Fish and Boat Commission and the West Virginia Division of Natural Resources confirmed that eDNA from silver carp had been found in two water samples collected from the Ohio River. One positive hit came from the Ohio River in Aliquippa, in Beaver County, Pa., approximately 6 miles upstream of the junction with the Beaver River. A second positive eDNA sample came from near Chester in West Virginia.
“The more we learn about these fish, the scarier it gets,” ODNR’s Mr. Navarro said. “They’re not in China — they’re here in the U.S. and we have to keep a very close eye on them. We don’t dare undersell their adaptability.”
Contact Blade outdoors editor Matt Markey at: firstname.lastname@example.org or 419-724-6068.