TRAVERSE CITY, Mich. (AP) -- The Obama administration will spend $51.5 million this year to shield the Great Lakes from greedy Asian carp, including first-time water sampling to determine whether the destructive fish have established a foothold in the lakes, officials said Thursday.
Officials released an updated strategy that also includes stepped-up trapping and netting in rivers that could provide access to the lakes, as well as initial field tests of scents that could lure carp to where they could be captured. An acoustic water gun that could scare carp from crucial locations will be tested near a Chicago shipping lock some want closed because it could serve as a doorway to Lake Michigan.
"This strategy builds on the unprecedented and effective plan we are implementing to keep Asian carp out of the Great Lakes while we determine the best long-term solution," said John Goss, Asian carp program director for the White House Council on Environmental Quality.
With this year's money, the federal government will have spent $156.5 million over three years in the fight against bighead and silver carp, imported from Asia decades ago. They have migrated up the Mississippi River and its tributaries including the Illinois River, where they've advanced to within 55 miles of Lake Michigan.
The carp eat massive amounts of plankton - tiny plants and animals at the base of the aquatic food web. Scientists differ about how widely they would spread in the Great Lakes, but under worst-case scenarios they could severely damage the $7 billion fishing industry.
Independent studies have called for sealing the lakes from the Mississippi watershed by placing barriers in Chicago waterways linking the two drainage basins. Environmentalists favor that, but Chicago business interests say it would damage the region's economy and cause flooding.
The Obama administration has not endorsed separating the systems, although it's among options in a U.S. Army Corps of Engineers study scheduled for completion in 2015. Goss said the idea deserves consideration but he was concerned about estimates the job would take nearly two decades.
"That's why the technologies we're working on for Asian carp control and detection are very important," he said.
Among them is an electric barrier network in a shipping canal southwest of Chicago. The administration's plan calls for expanded underwater surveillance this year to make sure it's keeping the carp at bay.
Dozens of water samples taken beyond the barrier in recent years have contained Asian carp DNA, although just one actual carp has been found there. Expanded sampling this year will look for signs of the invaders at about 10 locations including southern Lake Michigan, western Lake Erie, the Detroit River, Lake Huron's Saginaw Bay and Lake Michigan's Green Bay.
Their shallow, relatively warm waters are among the most hospitable places for the carp in the Great Lakes, although none have been found there since three turned up in Lake Erie more than a decade ago, said Charlie Wooley of the U.S. Fish and Wildlife Service.
Commercial fishermen have been hired to reduce carp numbers in the Illinois River below the barrier. They'll be provided with new types of nets and other equipment this year to boost the harvest, Goss said.
"As the population is reduced in that area, they're becoming more difficult to catch with traditional netting," he said.
The underwater gun, which emits piercingly loud, high-energy pulses, will be tested near the O'Brien Lock in Chicago, which Michigan and other states have asked federal courts to close so carp couldn't use it to reach Lake Michigan.
Scientists with the U.S. Geological Survey are developing pheromones - chemical extracts that could steer carp to nets or traps. A lure made from females' urine will undergo field testing this year, said Leon Carl, the agency's Midwest regional executive. Progress also is expected on producing food pellets that would poison Asian carp without harming other fish.
The administration plans to intensify a crackdown on smuggling live Asian carp across state lines and the U.S.-Canadian border. Thousands of pounds have been seized at the Ambassador Bridge between Detroit and Windsor, Ontario, in recent years.
About $19.5 million for the carp battle will come from the Great Lakes Restoration Initiative, a federal plan to fix the region's biggest environmental problems. President Barack Obama has requested $300 million for the restoration initiative in 2013 on top of $1 billion appropriated since 2008.
Aside from protecting the lakes, the goal is beating back the carp in the Mississippi and other rivers, Wooley said.
"They're part of the heartland of the United States," he said. "We'd like to reclaim it."