Tuesday, Apr 24, 2018
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Invasive Asian carp raise fear near lakes


Jerry Rasmussen, a biologist with the U.S. Fish and Wildlife Service, displays a 4-foot-long, 85-pound Asian carp in Duluth, Minn. According to Mr. Rasmussen, `We ought to be destroying every [Asian] carp we find.'

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They're as long as first-graders are tall and, at a stocky 85 pounds, probably eat a lot more than kids that age too.

Asian carp are scaring the heck out a lot of people in the Great Lakes region these days, despite the fact that - minus a few random sightings, apparently because of scattered illegal releases - they haven't really entered the lake system yet.

Government officials view them as the new poster child for ecological havoc that can be caused by invasive species. The carp are veritable aquatic bulldozers, capable of plowing through native fish habitat with their mouths wide open and gobbling up microscopic organisms that are a food staple for other fish.

“They act as large aquatic vacuum cleaners,” said Dennis Schornack, U.S. chairman of the International Joint Commission, a government agency that helps the United States and Canada resolve boundary water issues.

Asian carp are seen as a potential overnight nemesis for the region's commercial and sport-fishing industries, which together have a combined value of $4.7 billion. The latter is especially important to the Toledo area's tourism-based economy, because western Lake Erie is the warmest and, therefore, most productive area for Great Lakes fish.

“No question about it. Lake Erie could be impacted as much or more than any of the lakes,” said John Rogner, a U.S. Fish and Wildlife Service field supervisor.

If dramatic declines in habitat and fish populations were not enough to scare off fishermen, consider this: Asian carp are ultra-sensitive to vibrations. They leap into midair as boats approach, sometimes smacking people inside those vessels.

“Get down. They're coming in the boat!” yells a voice in one well-circulated video, as if it were some horror flick. The segment showed how Asian carp become airborne when scared. Two species from Asia are of particular concern, the silver carp and the bighead carp, Mr. Rogner said.

No biological threat to the Great Lakes appears to have received so much attention since zebra mussels started entering the lake system in 1988, via ballast water of oceanic ships.

“My opinion is we ought to be destroying every [Asian] carp we find,” said Jerry Rasmussen, another Fish and Wildlife Service biologist.

Asian carp could be weeks away from becoming the most notorious of some 150 types of unwelcome fish and plants that have made their way into the Great Lakes since the 1830s, often disrupting the lake ecology.

Asian carp were first imported by some Arkansas fish hatcheries 20 years ago to eat pond scum. The Mississippi River floods of 1993 allowed many to escape confinement. The carp have been swimming upstream along the Mighty Miss ever since.

Two carp have been previously captured from Lake Erie and one from Lake Ontario, all viewed as isolated releases.

The focus has been on the pathway between the Mississippi and Lake Michigan. The two major bodies of water are connected by a series of passageways that include the 103-year-old Chicago Sanitary and Ship Canal and the 81-year-old Calumet-Sag Channel, plus the Des Plains River and the Illinois River.

The two canals have helped accommodate movement of some small cargo ships, but there was another driving force: Sewage backing up into the near-shore waters of the Chicago area in the late 1800s. In 1885, the pollution got so bad that Chicago was hit by an epidemic of typhoid, cholera, dysentery, and other waterborne diseases, resulting in 90,000 deaths, 12 percent of the Windy City's population at the time.

For many exotics, Checkpoint Charlie is Montreal and Massena, N.Y. Those two ports are the entry points to the lakes for oceanic ships, the places where Coast Guard officials from the United States and Canada are supposed to inspect ballast water to prevent more intruders.

In the case of Asian carp, Checkpoint Charlie is just south of Chicago - an experimental barrier that the U.S. Army Corps of Engineers built near Lockport, Ill. It's supposed to help repel exotics from that direction with an electrical current.

Congress authorized the multimillion-dollar structure in 1996 with the intent of deterring another type of exotic, the finger-length round goby fish. Those fish out-compete native fish for food. Plus, they can move toxins up the human food chain by eating contaminated zebra mussels and becoming preyed upon by sportfish themselves.

The electrical barrier has been in place for a year, with plans for a second barrier by fall 2004. It was only by coincidence that the initial barrier was in place in time to head off the Asian carp, Mr. Rogner said.

Both barriers are viewed as temporary measures: They are designed to operate for three years and biologists said they won't stop all organisms, especially tiny ones and those that are not sensitive to electricity.

Officials saw evidence of organisms slipping through the electrical barrier as recently as April, Mr. Rasmussen said.

Last month, nearly 70 experts convened at a summit in Chicago to zero in on the best ways of defending the Great Lakes from Asian carp.

Four themes emerged. Each would cost millions of dollars. The most expensive idea - constructing barriers to physically shut down the passageway - could potentially cost billions, officials said.

Another option is the creation of a “dead zone,” a stretch of water that would be depleted of oxygen through chemical treatment. Officials said they also want to research the possibility of a filtration or bypass system, as well as other technological possibilities, such as using sound to help augment electrical barriers.

Officials agree a physical barrier could be the most effective. But they also know it could be the most complicated solution, given the expense, the engineering challenges for sewage overflows, and the potential impact on the shipping industry, Mr. Rogner said. “These are big issues that need to be looked at in detail,” he said.

A decision is expected in six months to a year, after a feasibility study is completed.

Chicago Mayor Richard Daley recognizes the issue as one of major significance for all of the Great Lakes, as well as the nation's third-largest city.

“Our opinion at the city of Chicago is we need to move cargo, we need to move recreational boats - but not invasive species,” said Suzanne Malec, deputy commissioner for the Chicago Department of Environment. “We expect to be at the table on this issue long-term.”

Invasive species that threaten native fish do more than harm tourism. “It puts a lot of our regional culture at risk,” argues Cameron Davis, executive director of the Lake Michigan Federation, a Chicago-based environmental group.

Tom Skinner, administrator of the U.S. Environmental Protection Agency's Midwest regional office and manager of that agency's Great Lakes National Program Office, believes the carp's only redeeming value is its “cartoon quality,” which could shock people into grasping the seriousness of invasive species.

“You can talk to people about zebra mussels until you are blue in the face, but carp jumping into boats could have a galvanizing effect,” he told The Blade last fall at an international symposium in Cleveland.

Government officials are so preoccupied with keeping carp out of Lake Michigan that any thoughts of a ban have been pushed aside. It was legal for the Arkansas fish hatcheries to import them two decades ago, and it remains legal for the fish to be imported today, with proper permits. Mr. Rogner sighed when asked why the possibility of a ban has not become a priority. “It's like closing the barn door after the horse is out,” he said.

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