Ohio, Ky. teaming up to find Asian carp on the Ohio
“It’s really an effort that Kentucky has made to learn a little bit more about the distribution of Asian carp on the Ohio River,” said Scott Hale, inland fisheries program administrator for the Ohio DNR Division of Wildlife.
Kentucky has a particular interest because Asian carp are thick in numbers on the Ohio River and its tributaries near Louisville, Hale said.
“What (Ohio) is interested in is the distribution of these fish in the middle Ohio River,” he said. “Markland, Meldahl, and Greenup pools.”
The state of Kentucky receives a grant from a foundation in Pennsylvania to contract with teams of four different commercial fishing outfits to survey for Asian carp. Since the work began in April, West Virginia and Ohio have put observers on those boats, said Hale.
“They generally go out every other week,” he said. “They fish gill nets, basically.
“They aren’t seeing a lot of fish, but the ones that they see are large,” Hale said. “… There have been some silvers and bigheads caught. The early results … were that they had fished 2,015 feet of net starting in April until mid-June, and they had caught 10 bighead carp and two silver carp in the Meldahl pool, one silver carp in the Licking River of the Markland pool, and there was another bighead caught right below the R.C. Byrd dam in the Greenup pool.”
So, the numbers of fish are not there on Ohio’s portion of the river, but they are present.
“They’re not catching a lot of fish but the ones they do catch are large,” Hale said. “That’s significant for a couple of reasons. First, they’re using large mesh gill nets, but at the same time seeing only large fish that are in good condition. It tells us that there aren’t tons of them out there and the ones that are there are in good shape. If we had caught a lot of fish and they were skinny, then we’d really be worried because density would be extremely high.”
The sampling effort currently under way is expected to run through October. Hale said much more monitoring of the Ohio River, though, is planned.
“We’re sort of at the beginning of this effort,” he said. “If you look at it in a positive way, we’re getting information on these fish that we haven’t had and would be difficult to obtain ourselves. We couldn’t send crews out every other week and fish this much gear. We just don’t have the capacity to do that.”
Kentucky has placed acoustic tag transmitters in three of the fish caught so far to track their whereabouts. The plan for this fall is to work with the U.S. Fish and Wildlife Service to put transmitters into up to 120 carp, Hale said.
“We have a pretty deliberate plan of what we’re going to do in a tactical plan,” Hale said. “What that does is that it identifies very clear goals and some very practical objectives that we can address and do so in a meaningful way. The things we want to do are all about prevention: We want to prevent them from moving into Lake Erie, prevent them from moving into inland waters other than the Ohio River.”
Prevention is the key word, says Hale.
“Once they get into an area, if the habitat is there and the environmental conditions are there to let them spawn, that’s what they’re going to do,” he said.
So, what about Asian carp in Lake Erie? Where do we stand?
Last summer, federal and state wildlife officials working in conjunction with academic researchers said that six water samples taken from both the Sandusky and north Maumee bays tested positive for the presence of Asian carp environmental DNA in both Michigan and Ohio waters of Lake Erie.
These positive samples were among 417 taken from Lake Erie in August 2011, and more than 2,000 samples taken from the Great Lakes Basin since 2010.
The Lake Erie batch was analyzed and test results were confirmed by eDNA researchers. The six positive samples represent less than 1.5 percent of the Lake Erie samples.
However, four samples from Sandusky Bay tested positive for bighead carp eDNA, while two samples from north Maumee Bay, in Michigan waters, were positive for silver carp eDNA.
While the eDNA findings indicate the presence of genetic material left behind by the species – such as scales, excrement, or mucous – this does not ensure that Asian carp are now established in Lake Erie, the researchers said.
Quite the contrary, said Rich Carter, executive administrator for fisheries for the Ohio DNR Division of Wildlife.
“After last year with the eDNA hits, we took a step back and looked at what we we’re doing from the standpoint of the Lake Erie Committee (of the Great Lakes Fishery Commission),” he said. “ … We did a significant amount of sampling last year to try and figure out if we could find live fish. Of course, we didn’t find any live fish.
“What we know today is that if there is live fish present, they’re present in very low numbers,” Carter said. “In all the sampling that we’re doing, we can’t find any.”
Ohio has joined with New York, Pennsylvania, Michigan, and Ontario in routine assesments on the lake.
“We also have all the historical sampling that we’ve done in the past and we’ve not seen live fish,” Carter said. “Plus, we have commercial nets that are in the water both on the U.S. and Canadian sides of the lake and we’ve not seen live fish there.”
The U.S. Fish and Wildlife Service conducted sampling in both the Sandusky and Maumee Rivers in mid-June, Carter said, but those results weren’t available for this story.
“We are also looking at other potential sources for eDNA, including the baitfish industry,” he said. “A lot of our baitfish come up from Arkansas. So, we’ll be doing some routine monitoring of our baitfish industry as the summer progresses.”
Is there more concern with Asian carp on the Ohio River or on Lake Erie?
“The two systems are different,” Carter said. “We know that there are fish in the Ohio River. Now, it is a question of what their role is going to be in the Ohio River and consider what actions can be taken to minimize their impact.
“In Lake Erie, or in the Great Lakes, what we’re trying to do is prevent the migration of bighead and silver carp across the barriers, including the Chicago area waterway systems,” he said.