11 Oct

Officials spin findings on Asian carp


Science is supposed to be unbiased. Yet recent developments on the Asian carp front demonstrate how politicians and industries can try to skew scientific findings to serve their interests.


A look at Asian carp (03:14)

BATH, Ill. — Comercial fishermen took millions of pounds of Asian carp from the Illinois River last year. Yet this year there are more than ever, and some people fear thev may have passed an electronic barier and reached the Great Lakes

First, the Illinois Department of Natural Resources suggested that an Asian carp found above an electric barrier that’s supposed to keep them out of the Great Lakes was put there by people. That bolstered local politicians and businesses that oppose closing the Chicago Sanitary and Ship Canal, the vector by which Asian carp threaten Lake Michigan.

John Rogner, assistant director of the Illinois DNR, said in a news release that studies of the carp’s otoliths (ear bones) suggested the fish “may have been put there by humans” through a religious ritual or “bait bucket transfer.”

That conclusion was rejected by David Lodge, a University of Notre Dame scientist who pioneered a way to detect Asian carp DNA in water.

“No otolith analysis can ever provide information about how a fish got from one environment to another,” Lodge told reporters. After his conclusion was echoed by several other researchers, the Illinois DNR was forced to say that it had overstressed a remote possibility.

Then another biologist said he didn’t think Asian carp could spread in the Great Lakes because there’s not enough plankton to eat or places to spawn.

That argument also was rebuffed by other scientists, including the guy who first warned the federal government about Asian carp more than 20 years ago.

Jerry Rasmussen, a retired U.S. Fish and Wildlife Service fisheries biologist, said he thinks Asian carp will find plenty of food in the Great Lakes shallows. He also suspects they might be able to spawn along shorelines, even though present scientific data says they need rivers with long stretches of flowing water.

“There are plenty of rivers (along the Great Lakes) they could spawn in,” he said. “But I think the wave action in the shallows might be all the Asian carp need for their eggs to hatch if they have a clean bottom.”

Rasmussen pointed out that some scientists who took Asian carp eggs back to their lab were amazed a few days later to see baby carp swimming in the plastic collecting sacks.

“If they can hatch in a Ziploc bag, I wouldn’t be surprised if they could do it in a bay,” he said.

As for the lack-of-plankton theory, Rasmussen said, “How about that 50-pound bighead found in Lake Erie a few years ago? It was probably put there by people for cultural reasons, but it did fine. And it wasn’t that big when it was put in.” (He referred to a practice in Asian communities of buying two live fish, one to kill for dinner and one to release to gain good karma.)

The Great Lakes don’t have as much plankton as they once did (because of two other destructive invaders, zebra and quagga mussels), but another expert said that won’t matter.

Je He, a researcher at the Michigan DNRE’s Lake Huron laboratory in Alpena, earned his master’s degree studying Asian carp in China, where they’re raised as food. He was asked whether filter feeders such as silver and bighead carp could eat the green cladophora algae that now covers thousands of square miles of the Great Lakes bottoms.

Je He said he thinks both species can live on cladophora, and silver carp, with their incredibly fine gill rakers, could filter and intensify toxic blue-green algae, which is taking over places where mussels have eliminated green algae.

That’s backed up by the aquarists at the Shedd Aquarium in Chicago. In the Shedd’s big, crystal-clear tank, it’s easy to see Asian carp feed by filtering the water. But the aquarists also have seen them eat detritus off the bottom.

So why would the Illinois DNR, which supposedly protects that state’s natural resources, oppose closing a canal that could be the biggest threat yet to the greatest of those resources, the Great Lakes?

It could be because businesses and politicians know that closing the canal would increase some transportation costs and make Chicago spend money to renovate its water-treatment infrastructure. But those costs are a fraction of the billions that the Great Lakes states could lose from sport fishing if the carp establish themselves.

So far the Chicago interests seem to have been protected by President Barack Obama, who hails from that city and whose Environmental Protection Agency opposes closing the canal.

Now a team of Canadian and U.S. scientists will spend 18 months studying the likelihood that Asian carp will establish themselves in the Great Lakes. But even if they couldn’t make it in our waters (a scenario that seems very remote), the big question is how to keep out the next threat.

And Step 1 is closing that Chicago canal.

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