Asian carp search turns up nothing

[Spiel]

Asian carp search turns up nothing

Feds to keep trying; critics see it as waste

 

 

March 15, 2010

Dan Egan / Journal Sentinel

 

 

Fishery crews have spent the past month chasing Asian carp with nets and fish-shocking tools on the Chicago canal system near Lake Michigan.

 

They've landed zero Asian carp.

 

Asian carp experts predicted this was a likely result when the fishing expedition started in mid-February.

 

"These are incredibly hard fish to catch when there are not many of them," said Duane Chapman, a biologist with the U.S. Geological Survey.

 

But federal officials remain undeterred.

 

They say the fishing will continue, despite criticism from some who see it as a distraction from the larger issue of forcing big changes on the Chicago canal system that has destroyed the natural separation between Lake Michigan and Mississippi River basin - a canal system that biologists say has become a "revolving door" for unwanted species such as zebra mussels, round gobies and now Asian carp to invade fresh waters with an ease nature never intended.

 

"It is a waste of time and money," Tom Marks, New York director of the Great Lakes Sport Fishing Council, said of the ongoing fish sampling operation.

 

Federal officials see it as a critical piece of their $78.5 million plan to keep the fish from colonizing Lake Michigan. The Obama administration released the plan after revelations that "environmental" DNA testing in and around Lake Michigan showed at least a handful of the ecosystem-ravaging fish had breached an electric fish barrier on the Chicago Sanitary and Ship Canal.

 

The new plan sets aside about $4.6 million to remove Asian carp from the canals, to increase DNA testing and to conduct sampling operations like the one under way that relies on nets and shocking tools to get a better idea of the numbers, ages and locations of any fugitive fish.

 

The operation is being conducted by several government agencies, and last week, no one could say how much it is costing taxpayers, but its weekly tab easily runs into the tens of thousands of dollars.

 

Marks fears the longer crews fish without finding anything, the more it will take pressure off federal agencies to take more significant action to try to protect the Great Lakes. A coalition of Great Lakes states is asking the U.S. Supreme Court to force the agencies to do more to protect the lakes, and congressional pressure has been mounting as well.

 

"I think they believe that a 'good show' with no results (of Asian carp) will prove what they have been saying; there are no carp above the barrier," Marks said. "Very few people . . . understand the (fishing) gear being used and its limitations in the environment it is being used."

 

University of Notre Dame environmental DNA expert David Lodge explained in a recent U.S. Supreme Court filing the limitations of using nets and electricity to find evidence of the "leading edge" of the Asian carp invasion in a waterway the size of the canal system. It stretches over dozens of miles and is in places nearly three-stories deep and wider than a football field. It also is a waterway bursting with other fish species.

 

Lodge wrote it would take an "extraordinary effort" using traditional fish survey tools such as nets and electro shocking to harvest only about 10% of a total fish population in a small lake.

 

Head out onto a bigger system like the canal, he said, and crews can expect to land perhaps 1% of its total fish population.

 

Now, if only 1% of that entire fish population can be expected to be harvested, and only a handful of Asian carp are within that overall population, odds are it's going to be darn hard to land an Asian carp.

 

Feds want a fish

 

While DNA testing during the last half year has yielded evidence of the fish in several areas above the barrier, including Lake Michigan itself, no fish have been found in those areas.

 

The lack of fish is a big deal to the barge operators and tour boat owners who fear federal agencies are about to bow to political and public pressure and order intermittent closures of two navigational locks on the canal to try to choke the number of fish making their way into the lake.

 

Biologists say a handful of fish swimming into the lake doesn't mean the fish will establish a successful colony. First the fish have to find each other, then they have to find a suitable place to spawn, then their offspring have to find enough to eat, live long enough to reach sexual maturity and start the whole process over again.

 

For this reason, most experts say it will take a large number of fish over a sustained period of time to successfully establish a breeding population in Lake Michigan.

 

That's why conservationists and politicians outside Chicago want to take dramatic steps on the canal now, even if it causes economic havoc for waterway-dependent industries still waiting to see an actual fish turn up in the waters above the barrier, which is about 25 miles downstream from Lake Michigan.

 

Despite a lawsuit brought about by a coalition of Great Lakes states and congressional pressure, federal officials have resisted demands to close the locks, contending the leaky structures are less than ideal barriers and that closing them could unleash floods and economic havoc on the Chicago region.

 

They also have sided with those dubious about the DNA results.

 

"We'd like physical evidence, i.e. fish coming up in the gill nets or with electro fishing sampling before we are willing to acknowledge that there are fish there," said Charlie Wooley of U.S. Fish and Wildlife Service.

 

"We're using the (environmental) DNA as an indicator that there might be carp present," he adds. "And then we're going to physically sample to try to validate: Yes or no, are they there?"

 

Yet the fact that they found zero fish tells very little, U.S. Geological Survey biologist Chapman said.

 

"You're never going to prove a negative," he said. "No matter how much you fish, you're never going to prove there is not a fish there."

 

Chapman says the netting operation does have value. While the weather is cold, there might be an opportunity to catch fish attracted to the warm-water discharges from the industries lining the canals, and finding some fish could give researchers a better idea of the size and location of the problem.

 

Still, he says, if there are 100 fish in the canal system, crews could fish and electroshock for months and still never come up with a carcass.

 

The $3 million carp

 

Marks, of the Great Lakes Sport Fishing Council, said it is ironic that the government is using fish nets and electro shocking to try to confirm what the DNA is telling them because it was the failure to find the fish with nets and shocking that drove the government to use the DNA technology in the first place.

 

After years of netting turned up no evidence of fish in the waters below the electric barrier at a time when common sense suggested the north-migrating fish should be there, last summer the Army Corps hired Notre Dame to do the DNA sampling, and those tests determined the fish were in the waters just below the barrier.

 

That DNA evidence was a big reason the government spent about $3 million to poison the canal in December so the barrier could be briefly turned off for maintenance.

 

Fishery crews spent the days after the poisoning picking up the floating carcasses of loads of non-Asian carp fish carcasses. Only one turned out to be an Asian carp.

 

Government crews jokingly dubbed it the $3 million fish, but it did bolster the argument for the accuracy of the DNA testing.

 

Henry Henderson of the Natural Resources Defense Council says that's an argument that should be over.

 

"We have to be painfully aware of fact there is not bottomless pit of money to throw at this problem," he said.