By Juliet Eilperin
Washington Post Staff Writer
Sunday, January 31, 2010; A07
Which is worse? Closing two locks on a waterway that's used to ship millions of dollars' worth of goods from the Great Lakes to the Mississippi basin? Or allowing a voracious Asian carp to deplete the food supply of native fish sustaining a Midwestern fishing industry that nets $7 billion a year?
And how do you put a price tag on the damage caused by the Burmese python and other constrictor snakes that are strangling the precious ecology of the Everglades?
Invasive species, long the cause of environmental hand-wringing, have been raising more unwelcome questions recently, as the expense of eliminating them is weighed against the mounting liability of leaving them be.
Those questions became more urgent Tuesday when a team of scientists led by the University of Notre Dame disclosed that silver carp dominating stretches of the Mississippi River and its tributaries had infiltrated Lake Michigan. The federal government had spent $22 million on electric barriers in the Chicago Sanitary and Ship Canal to keep carp out, but it clearly wasn't enough. An additional $33 million is going into the effort next year.
A coalition of six Great Lakes states and the Canadian province of Ontario sought a preliminary injunction from the Supreme Court to shut down two major locks immediately on the grounds that an Asian carp invasion would cause "irreparable harm." The court declined to grant the injunction this month, but it will accept briefs next month on the broader question of whether to close them at all.
Army Corps of Engineers officials say it's too early to shut down the locks. They are focused on building a third electrical barrier to provide yet another obstacle to Asian carp infiltrating Lake Michigan. "It's not a silver bullet, but it's a good tool to impede the movement of the silver and bighead carp," said Col. Vincent Quarles, commander of the Army Corps' Chicago District.
But the barriers are not surefire, and experts say it's difficult to say how many Asian carp would have to make it through to establish a viable population.
Southern catfish farmers began importing silver and bighead carp from China in the 1970s to eat up algae in their ponds. Some carp escaped during flooding, and now the fish so thoroughly dominate the Illinois River that communities have annual fishing tournaments targeting them.
U.S. officials have been fighting invasive species for many years, but efforts have intensified in recent years as the impact has become clear. For instance, zebra and quagga mussels that were once restricted to the Great Lakes have moved west, clogging systems at critical dams.
In the D.C. area, state and federal officials have been waging war against the snakehead, a voracious fish that infiltrated the Potomac River and occupies 70 river miles downstream from Great Falls. Scientists first detected the fish in 2004. Now thousands swim there, posing a threat to such native species as the American shad and alewife herring.
Interior Secretary Ken Salazar announced last week that he would ban the importation and interstate trade of the Burmese python and eight other large constrictor snakes that threaten the Everglades. And he recently instructed his staff to review how Interior can better combat exotic plants and animals.
"It sometimes takes dramatic evidence to bring public attention to something that's been a problem for some time," said Tom Strickland, Interior's assistant secretary for fish and wildlife and parks.
Although the impact of these invasions can take years to become clear, researchers estimate that nationwide they cause environmental losses and damages of nearly $120 billion a year. Silver and bighead carp have enormous appetites and consume vast amounts of food that native fish depend on, and Fish and Wildlife Service senior biologist Art Roybal calls pythons "all-terrain eating machines" that have been swallowing imperiled wading birds and the nearly extinct Key Largo wood rat.
Sam Hamilton, director of the Fish and Wildlife Service, called exotic species "probably the single greatest threat in our country to our native wildlife." But despite the growing concern, some say the United States is just beginning to come to terms with a formidable environmental foe.
"It seems to me we are in denial," said Lindsay Chadderton, aquatic invasive species director for the Nature Conservancy's Great Lakes Project and one of the researchers who found the Asian carp's genetic fingerprint in Lake Michigan. "By the time we understand the severity of the problem, it's too late. Prevention is the only cost-effective way of dealing with this."
The dispute has spurred competing economic analyses. Illinois, which uses the canal system to move wastewater as well as to ship a slew of commercial goods, argued in its recent Supreme Court brief that closing locks would "have a devastating effect" on the region's economy and hamper boat rescue operations. And the American Waterways Operators, the trade association for the nation's tugboat, towboat and barge industry, estimates that closing the Mississippi locks to Lake Michigan would cost suppliers tens of millions of dollars and perhaps thousands of jobs.
Michigan Attorney General Mike Cox, who has led the legal battle to close the locks, said those numbers look modest compared with the potential collapse of the Great Lakes' $7 billion annual fishery. In his Supreme Court brief, he noted that the Army Corps stated in a report, "The prevention of an interbasin transfer of bighead and silver carp from the Illinois River to Lake Michigan is paramount in avoiding ecologic and economic disaster."
Nancy Sutley, chair of the White House Council on Environmental Quality, and several senior Obama administration officials will meet with Michigan Gov. Jennifer M. Granholm (D), Wisconsin Gov. Jim Doyle (D) and Illinois Gov. Pat Quinn (D) on Feb. 8 to attempt to broker a resolution to the Asian carp dispute.
"Keeping the numbers low is key," said Phil Moy, a fisheries and invasive species specialist at the University of Wisconsin Sea Grant Institute. He said such steps as electrical barriers buy time, "but it's not the end-all solution. We've got to move towards this ecological or hydrological separation."
For Michiganders focused on the fish encroaching on their turf, the response couldn't come soon enough. "Everywhere I go in Michigan, everyone talks about it," said Cox (R), who is now crisscrossing the state in his bid for governor. "It's on the minds and lips of everyone here, more so than health care, more so than anything else going on, outside of the economy. I thought it was the issue of the week. It's become the issue of the month."
Staff researcher Madonna Lebling contributed to this report.