TRAVERSE CITY, Mich. (AP) — The U.S. Supreme Court refused on Tuesday to order the immediate closure of shipping structures near Chicago to contain the ravenous Asian carp, before authorities said DNA from the invaders had been found in Lake Michigan for the first time.

The court rejected Michigan’s request for a preliminary injunction to shut the locks and gates temporarily while officials and interest groups debate a long-term strategy. The one-sentence decision included no explanation and didn’t say whether the justices would consider the case on its merits.

Hours later, federal officials said two DNA samples taken beyond the final barriers between Chicago-area waterways and the lake had tested positive for Asian carp — including one in the lake’s Calumet Harbor. They insisted it was far from certain that carp have actually reached the lake, however, saying no live or dead specimens had been spotted there.

“We feel confident that despite this new information, we still can and will win this fight,” Gen. John Peabody of the U.S. Army Corps of Engineers said in a teleconference.

Authorities consider DNA testing “an early warning device where Asian carp may be present,” Peabody said. Agencies will use netting and electrical stunning to search for live or dead fish while continuing to process hundreds more DNA samples taken last fall, he said.

Peabody said the discovery did not change the Army Corps’ view that the locks and gates on the Chicago Sanitary and Ship Canal and other waterways should remain in operation. Closing them would be “totally inadequate to the task” of blocking the carp, he said. “The locks are leaky, and there are alternate pathways around them.”

No actual carp have been found north of an electronic fish barrier in the canal. One dead carp turned up just south of the barrier — more than 25 miles from the lake — after officials poisoned the canal in December.

But Lindsay Chadderton, an invasive species specialist with The Nature Conservancy and a member of the scientific team analyzing the DNA, said the positive results likely mean at least some live Asian carp are in the lake. “What we can’t tell you is how many,” he said.

Several hundred probably would be needed to confirm that an established, breeding population has taken hold, said Charles Wooley, the U.S. Fish and Wildlife Service’s deputy regional director.

Govs. Jennifer Granholm of Michigan and Jim Doyle of Wisconsin requested a meeting between White House officials and the Great Lakes governors.

“We cannot allow carp into the Great Lakes. It will destroy our Great Lakes fisheries, the economy,” Granholm said. “It is urgent.”

The Obama administration said it would welcome such a meeting and called defeating Asian carp “one of our immediate priorities.” It sided with Illinois against closing the locks, however, telling the court that such action would disrupt the transport of coal and other commodities on waterways linking Lake Michigan with the Mississippi River system.

Asian carp have been migrating up the Mississippi and Illinois rivers toward the Great Lakes for decades. Scientists fear that if they reach the lakes, they could disrupt the food chain and endanger the $7 billion fishery. Asian carp can weigh up to 100 pounds and consume up to 40 percent of their body weight daily in plankton — the foundation of the Great Lakes food web. Many scientists say they could starve out other species.

Michigan, joined by Minnesota, New York, Pennsylvania, Ohio, Wisconsin and the Canadian province of Ontario, asked the Supreme Court to order the locks closed as a stopgap measure while considering a permanent separation between Lake Michigan and the Mississippi basin.

“If effective measures are not taken to stop the advance of Asian carp, and soon, these alien invaders will be in Lake Michigan where it will be, by most accounts, impossible to stop them from spreading to all the Great Lakes and the numerous inland lakes, rivers, and streams that connect to them,” Michigan told the court. “Partial measures are no longer an option.”

Illinois and the Obama administration said the electronic barrier was performing well. Closing the locks would could cause flooding in addition to economic damage, the government said. The Illinois Attorney General’s office said it was pleased with the Supreme Court’s ruling.

But its denial of the injunction doesn’t necessarily mean the court would rule against Michigan and its allies if the full case came before the justices, said Noah Hall, an environmental law professor at Wayne State University.

“It just means you have to wait to get your day in court,” Hall said. “But the danger is that by the time the Supreme Court does hear the case, the carp will already be in Lake Michigan.”

Mike Cox, Michigan’s attorney general, said he would press on. Meanwhile, U.S. Rep. Candice Miller requested a hearing of the House Water Resources Subcommittee to consider legislation ordering the locks to close.

The American Waterways Operators, a trade group representing the tug and barge industry, urged all sides to step out of the courtroom.

“We want to focus on collaboration and not spending money on lawsuits,” said Lynn Muench, the group’s vice president.

Posted 1/20/2010