Asian carp have come a long way from the early ‘70s when they were brought to the U.S. by private fish farmers in Arkansas as a food fish and for water quality control in aquaculture ponds and lagoons.
So long, in fact, that they have become the center of heated debate over the future of several vital waterways and many livelihoods. The latest development to galvanize the public is a U.S. Army Corps of Engineers’ report to Congress released in January outlining eight options to stop the spread of the invasive species.
The most drastic would separate the Great Lakes from the Mississippi River basin, waterways that were joined more than a century ago. It would cost at least $18.4 billion and take 25 years to complete.
The initial carp imports were done “with the complete knowledge” of state and federal officials, said Duane Chapman, leader of Asian carp research, U.S. Geological Survey (USGS) Columbia Environmental Research Center in Missouri. “Back in those days, biosecurity really wasn’t a word.”
Some of the fish got loose in the early ‘90s. People probably just weren’t careful, Chapman said, and “even if you’re careful, things happen. Fish get disturbed by all kinds of things,” such as tornadoes.
Four kinds of carp are here now: grass, bighead, silverhead and Asian. The voracious fish can weigh up to 100 lbs. and leap 10 feet. Silver are the ones usually videoed jumping onto boats.
“Silver carp are beginning to eat bighead out of house and home,” Chapman said. They are “much, much more abundant” in the lower Illinois, Missouri and middle Mississippi rivers. Carp also are moving into the brackish water of Louisiana.
GREAT LAKES CARP?
While the fish have been migrating for decades, the flashpoint for the controversy that’s raged the past few years came in late 2009 when water samples near Lake Michigan tested positive for carp. Michigan politicians and gubernatorial candidates raised the specter of carp invading the Great Lakes, and state attorney general (and candidate) Mike Cox subsequently sued unsuccessfully to close off the waterways.
Lines were drawn pitting states, politicians and businesses against one another. Carp in the Great Lakes would threaten the $7 billion fishing and tourism industries. Severing the waterways would cost the barge, passenger vessel, chemical, agricultural and other industries billions as well, not to mention the cost of the project itself.
In 2011, total traffic in the Chicago Area Waterway System (CAWS) — the heart of the study — was 22 million tons of commodities such as coal, iron, steel and aggregates compared to a high of 28.7 million tons in 1994, Corps statistics show. Shallow-draft traffic, about two thirds of the total, is expected to grow an additional 6 million tons by 2020.
“An absolute solution guaranteeing the complete prevention of [aquatic nuisance species] transfer may not be feasible or even technologically possible,” the Corps said in its Great Lakes and Mississippi River Interbasin Study (GLMRIS), which one expert described as a wakeup call to the sheer complexity of separation.
Meanwhile, the Corps has installed electronic barriers to stop the fish from reaching the lakes.
A recent Corps and U.S. Fish and Wildlife Service study of the carp and barge tows found that “vessel-induced residual flows” could transport fish beyond the barriers. But “there is no evidence that Asian carp are bypassing the barriers … the closest adult Asian carp found in the Illinois River are about 55 miles from Lake Michigan,” and no small carp have been seen closer than 131 miles from the lake.
The USGS announced late last year that four grass carp were found in the Sandusky River — the result of natural reproduction within the Lake Erie basin. There’s also been a lot of discussion about eDNA — environmental DNA.
“It can turn up where live organisms are not,” Chapman said. It can be transported on things like boat hulls or fishing gear, “so that’s problematic … None of that technology is ready for prime time.”
Is there any way to keep carp out of the Great Lakes?
“It doesn’t take an expert to tell you that a barrier that fish can’t swim through is better than one they can swim through, but I don’t have any way to assess if we want to spend that much money,” he said.
Even with total separation, there are other ways fish can get into new bodies of water. “If they got through today, it would take decades for the problem to develop. We’ve got a race against time, and we have some time.
“The other thing that’s truly important is we are developing control methods for Asian carp,” Chapman said. One of the solutions being worked on is a lethal microparticle broken down by the carp’s digestive enzymes.
NO SEPARATION
Terry Hoeckendorff, vice president of operations for Calumet River Fleeting Inc., Chicago, has a different solution for controlling the carp.
“What I wish they would do with this situation is put a $5 bounty on the head of each Asian carp,” he said, “and human nature being what it is, they would have them all fished out in two years. Naturally, we’re all concerned about it.”
Complete separation “would shut this business right down,” said Hoeckendorff.
No doubt, said Spencer Murphy, vice president, risk management, Canal Barge Co., New Orleans. Separation “would have a major, major impact on” CBC subsidiary Illinois Marine Towing, which employs 130.
If any of the separation options becomes reality, “those jobs are definitely in peril,” he said. Closing the connection also would also have a major impact on Canal Barge itself, which operates on a number of waterways but has a “significant chunk” of business in the area under discussion.
Murphy said he hopes Congress and others recognize “that hydrologic separation is a non-starter. It’s too expensive, and it will take too long.” He favors a non-structural solution.
Separation is irrational, said Michael Borgstrom, president of Wendella Sightseeing Co., a Chicago tour boat business. Not enough research has gone into that option.
“Just let’s put up this wall and worry about the consequences later. To sever commercial traffic on our country’s waterways is just crazy,” he said. “Who gets to decide which waterway gets saved?”
The Asian carp debate should concern everyone, he said. Any time there’s an invasive species someone might want to shut a waterway.
“It’s time for the U.S. Fish and Wildlife Service and the EPA to take care of the Asian carp just as they have other invasive species,” Borgstrom said. “It’s not the Corps of Engineers’ job.”
Scientists from the University of Notre Dame, Resources for the Future and the U.S. Forest Service assessing prevention strategies concluded that hydrologic separation would prevent 99 percent of Asian carp access “while electric and acoustic-bubble-strobe barriers would prevent 92” percent.
As for what’s next, the alternatives would require congressional authorization after further detailed studies and completion of legal requirements such as National Environmental Policy Act documentation, said Corps spokesman Sarah Gross.
“There are many complexities to consider with modifying the various existing uses of the Chicago Area Waterway System such as navigation, water conveyance/quality and flood risk management,” she said. “Therefore, implementation of a plan would require significant resource allocations by other federal agencies and state/local stakeholders.”
If Congress chooses separation, Mark Biel, chairman of Unlock Our Jobs, a coalition of maritime, agriculture and other interests, and executive director of the Chemical Industry Council of Illinois, said they would have no choice but to go to court. “But I don’t think that will come to pass,” he said.
