Authorities Try Shocking Solution To Halt Menace
By Peter Slevin
Washington Post Staff Writer
Sunday, May 22, 2005
ROMEOVILLE, Ill. -- These fish jump. Oh, how they jump. It's common for an Asian carp to leap four feet out of the water and flop into whatever may rumble into its path, be it watercraft or fisherman. They also make a big splash. A 60-pounder is not unusual.
"Every day we go out on the water, the number of fish we see jumping around the boat is just astounding. It's incomprehensible," said Mark Pegg, a fisheries biologist for the Illinois Natural History Survey. "You just have to see it to realize there are that many fish jumping around you."
Near the Illinois River, Pegg and his colleagues inspected a 43-pound female, which he described as "a small one." She was carrying 2.2 million eggs, and she had plenty of company. "There were hundreds, if not thousands, of large females in this one inlet we were sampling."
The Asian carp is sowing fear in marine biologists and fishermen. Descendants of the fish, imported from China 30 years ago by catfish farmers in the deep South, escaped their pens when floodwaters rose and have been swimming north and procreating ever since, each day consuming as much as 50 percent of their body weight in plankton and other microorganisms.
The danger, experts say, is that the voracious jumping carp will overrun the waterways and other fish will starve to death. Here along the Chicago Sanitary and Ship Canal, a gateway to the Great Lakes, government authorities hope to shock the carp into submission.
Literally.
At a construction cost of $9 million and an annual expense of $500,000, state and federal engineers are electrifying 500 feet of water to prevent the Asian carp from reaching Lake Michigan. Crews are using heavy cranes to lay 84 steel belts at the bottom of the 160-foot-wide canal. Transformers equipped with backup generators will juice the metal and create a pulsing electrical field.
"What we're doing here is plugging the biggest hole. This is something that deters the fish without killing them," said Charles B. Shea, project manager for the U.S. Army Corps of Engineers. "We can't make a 100 percent guarantee, but it certainly seems unlikely any fish could swim through this barrier."
What about a human?
"You'd get a hell of a headache," Shea said.
The new electrified field, scheduled to be in full buzz by October, is modeled on a three-year-old pilot project nearby that stretches across 55 feet of canal. The existing zapper, believed to be the largest such fence in the world, relies on technology used to contain the fish in fish farms.
Researchers study its effectiveness by implanting radio transmitters in more than 100 fish swimming in the neighborhood. Each fish sends a unique signal.
"They test the barrier a couple of times, and they usually go far away and don't come back up here again," Shea said. "We've had only one fish get through."
That fish -- not an Asian carp -- passed through the barrier in the churning wash of a tug pushing a barge, Shea said. It happened in 2002, and the transmitter soon fell to the bottom of the 25-foot-deep canal, where it still emits a signal. Researchers concluded that the fish did not survive the trip.
The closest an Asian carp has been spotted to the fence is about 20 miles, also in 2002, said Shea, who reported that the nearest concentration is believed to be 60 miles from the fence, which is about 25 miles southwest of Chicago and the entrance to Lake Michigan. Monitors conduct monthly surveys, just to be sure.
The Chicago Sanitary and Ship Canal is a valuable choke point because it is the major liquid link between the Mississippi River Basin and Chicago, which sits along Lake Michigan. The trench, built in the 1890s in response to deadly cholera and typhoid epidemics, was engineered to carry sewage away from Chicago and its drinking-water supply. Most famously, it reversed the flow of the Chicago River. Fifty-five years after the canal opened, the American Society of Civil Engineers called it one of the seven wonders of American engineering.
Keeping Asian carp out of the Great Lakes is considered essential at a time when countless invasive species, often traveling in the ballast water of large ships, are changing the ecology of the world's largest surface supply of fresh water. The lakes cover 94,000 square miles, and Michigan alone has 3,288 miles of coastline.
Two of the most troublesome recent arrivals are the round goby and the zebra mussel, a fingernail-size shellfish native to the Caspian Sea region. Wags call the Asian carp a hundred-pound zebra mussel.
"There have been massive changes in the Great Lakes," said David Jude, a University of Michigan professor who sits on the advisory committee that oversees the electrified fence. "We sure as heck don't need a big fish that's coming here, feeding on this zooplankton and competing with other fish in the lakes."
Illinois has invested $2 million in the new fish-shocking project, with at least half a dozen other states making smaller contributions. The federal government committed about $7 million. For now, the $500,000 annual expense for electricity, upkeep and a manager is to come from Illinois coffers, but the state is hoping to make it a federal issue -- and expense.
"We think it's an issue of federal concern. It's interstate and international waters, like from the Great Lakes into the national shipping conduit," said Scott Stuewe, acting chief of the fisheries division at the Illinois Department of Natural Resources. He has no doubts about the importance of the project.
"If you've seen what tarpon look like on the end of a line, like a sport fish on TV, that's kind of what these things look like," Stuewe said. "They've been proliferating up through the Illinois river system. We tend to think they may proliferate in the Great Lakes, but we just don't want to find out."