Asian carp invasion nearing 3 rivers
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Que ominous music: The ...carp ... are ... coming. ...
Asian carp -- the alien and invasive species that can overrun and wipe out the native aquatic ecosystem, ruin recreational fishing and even smash into and injure boaters and anglers as they jump high out of the water when spooked by a passing boat -- are working their way up the Ohio River.
Despite the recent cooperative efforts of federal and state agencies, they will sooner or later swim up the Ohio River into Pennsylvania, imperiling native fish populations and riverine ecology in the Ohio, as well as the Allegheny and Monongahela rivers and their tributaries, said Tim Schaeffer, director of the Pennsylvania Fish and Boat Commission policy and planning office.
"We want to minimize their impact and we're working on ways to do that, but it's almost impossible to erect a fence on the Ohio to keep them out," Mr. Schaeffer said. "It's scary what they can do."
Asian bighead, black and silver carp, all voracious plankton consumers, were first brought to the United States in the 1970s by Southern catfish farmers to clean algae from their commercial ponds and also were used in sewage treatment plants.
They soon escaped those closed water systems, aided by massive Mississippi River flooding in the early 1980s that literally opened up the flood gates.
The carp -- which can tip the scales at 60 to 100 pounds -- are now found in 18 states along the Mississippi and its tributaries, are moving rapidly up those river systems, including the Ohio, and are on the verge of entering the Great Lakes.
An electrical barrier in a navigation canal linking the Illinois River to Lake Michigan near Chicago, is all that blocks the carp's northward movement into the lakes.
Because of their size, consumption of plankton needed to sustain native fish species and rapid reproduction, dense populations of the carp can quickly colonize a river or lake and crowd out native species, including commercial and sport fish species. That crowding and competition for food is also what moves them to migrate.
"This is something that's become a big priority for us," said Mr. Schaeffer, citing a June meeting in Pittsburgh of federal agencies and state officials from Kentucky, Ohio, West Virginia and Pennsylvania to identify watersheds at risk and draw up a plan to limit and slow carp migration.
"We certainly don't want to see them in the Great Lakes where the full force and attention of federal and state efforts have been focused so far," Mr. Schaeffer said. "But we also need more attention in the Mississippi watershed and on up the Ohio."
"Our focus is to keep them out of Pennsylvania, and we're grateful the surrounding states are taking this seriously and working together."
Pennsylvania is not alone in trying to halt the invasion of Asian carp. Minnesota, where a number of bighead have already been caught on the northern Mississippi River, is in the same boat. The state's November 2011 Asian Carp Action Plan served as a blueprint for discussions at the June meeting in Pittsburgh.
But the cooperative strategies to slow carp migration in the Ohio River is in its early talking stages, remain unfunded on the federal level and are moving slowly, especially when compared to the carp.
Following the 1980 floodings, bighead and silver carp in Arkansas began moving up the Mississippi River and have been caught as far north as Minnesota. On the Ohio River they are breeding in the Markland Pool in Kentucky, about 450 miles upriver from the Mississippi and 531 river miles from Pittsburgh's Point.
This year adult bighead carp, which can grow to 100 pounds and more than 4 feet long, have been found for the first time in the Greenup Pool, on the northern border of Kentucky and 341 river miles from Pittsburgh.
"The carp were mainly below the Falls of the Ohio when I started working here three years ago. Since then they've moved up three pools to Markland," said Ron Brooks, fisheries director at the Kentucky Department of Fish and Wildlife Resources. "They're catching bighead in that pool now and once they start catching them, you know there are a lot of them.
"These things will take over and will out-compete the native species for food. Pennsylvania realized this and is trying to nip it in the bud."
Mr. Brooks said the June meeting in Pittsburgh was an attempt to get federal agencies to understand the "enormity of the issue" in the Ohio River Basin, and support authorization of a 2007 carp management study that has yet to receive funding.
By contrast, approximately $200 million of federal money has been spent to keep the carp out of the Great Lakes.
"Those are different situations," said Rich Carter, fisheries administrator for the Ohio Department of Natural Resources who has to worry about both. "In the Ohio River we know they are there versus the Great Lakes where we have spent considerable money and effort in the Chicago waterway system to prevent their migration into the lakes."
Mr. Carter said Ohio conducts regular gill netting and DNA sampling in Sandusky and Maumee bays on the western end of Lake Erie to detect Asian carp.
And a number of research studies are also under way to figure out how to control carp populations on the Ohio River and its tributaries.
Among the strategies under consideration are poison micro-pellets that would be eaten by the carp, creation of genetic abnormalities that would be introduced into the carp population to reduce reproduction and use of fish pheromones to attract carp into traps or nets.
Jeff Hawk, a spokesman in the Pittsburgh District of the U.S. Army Corps of Engineers, which owns and operates navigational and flood control dams on the region's rivers, said the agency has conducted no formal study of the Asian carp situation in the rivers, and no money has been appropriated to do so.
"We're being as proactive as we can, exploring our options," he said. "Our researchers are interested in this and are trying to push into new areas. As an agency with a presence on the rivers we know we will be involved and we are looking for ways to work with the states."
Although it would seem logical that the navigation dams that stretch across the Ohio River might create barriers to the carp migration, Tom Maier, a Corps wildlife biologist, said studies show they don't.
"If there's any passage at all, carp have shown that they are strong swimmers and they'll find a way through," he said.
The only strategy in use now involves encouraging aggressive and expanded commercial fishing for the Asian carp. There is a hungry market for the fish in China, where they are raised commercially for food and which has said it would buy 30 million pounds a year, Mr. Brooks said.
But supplying that market doesn't work economically for the American commercial fishing industry, he said, because China will pay just 12 cents a pound and the industry needs to get 20 cents a pound.
Efforts are also under way to expand the domestic market for the fish, which has firm, white flesh and a clean taste, unlike other carp species introduced into the U.S. earlier. To facilitate that expansion, Asian carp is being marketed in some restaurants and markets as "White fin," while others have renamed it "Kentucky tuna."
First Published August 12, 2012 12:00 am