Have mussels beat Asian carp to the punch?

  • Article by: By JOHN FLESHER A ssociated Press
  • Updated: September 29, 2010 - 9:12 PM

Amid fears of Asian carp devastating Lake Michigan, some scientists say a tiny mussel has beat them to a prosperous habitat.

hide

Invasive quagga mussels cover this formerly sunken boat in Lake Mead National Recreation Area, Nev. Scientists are reporting that the tiny quagga mussel has gobbled up much of the plankton that the Asoam carp would need to survive in Lake Michigan.

Photo: Felicia Fo, Associated Press

CameraStar Tribune photo galleries

Cameraview larger

TRAVERSE CITY, Mich. - If huge, hungry Asian carp reach Lake Michigan, their long-dreaded invasion may turn out to be less ferocious than once expected because a tiny competitor is gobbling up their primary food source, some Great Lakes researchers say.

The quagga mussel, a thumbnail-sized foreign mollusk first spotted in the lakes two decades ago, has devoured so much plankton in southern Lake Michigan that the entire food web is being altered, federal and university scientists reported in a series of newly published articles.

Mussels have "beaten the Asian carp to the buffet table," said Gary Fahnenstiel, senior ecologist with NOAA's Great Lakes Environmental Research Laboratory. "While the public has been worried about Asian carp and the Chicago canal, another invader has fundamentally changed the lake and made it inhospitable to the Asian carp."

Some biologists and government officials say if the carp get a foothold in Lake Michigan, they could spread to most of the Great Lakes and vacuum up enough plankton to threaten collapse of the $7 billion fishery. But Fahnenstiel and other researchers said the quagga mussel is a greater danger.

Some types of microscopic plants have declined more than 80 percent with the mussel's arrival, they said, which probably explains a similar drop-off of a freshwater shrimp species that is a dietary staple for small fish pursued by prized sport varieties such as salmon and trout.

Other scientists and policymakers insisted the carp could survive and even thrive in a plankton-depleted environment.

"They can eat other things besides plankton," said Duane Chapman, a U.S. Geological Survey fisheries biologist. "They are very flexible fish."

Bighead and silver carp -- Asian varieties threatening to enter Lake Michigan through Chicago-area rivers and canals -- are filter feeders that consume up to 40 percent of their body weight daily. The biggest can grow to 4 feet in length and weigh 100 pounds.

But Fahnenstiel said that if carp evade electronic barriers and reach the lake, they'll probably find so little nourishment they'll either go back or starve.

Chapman is based at the Columbia Environmental Research Center in Missouri, where researchers are measuring Asian carp's appetite for substances that will remain abundant in the Great Lakes even where plankton runs short. One example: bits of food the mussels spit out rather than digest.

Another is cladophora, a green algae that annoys beachgoers by washing ashore in stinky, rotting clumps. The cause of its resurgence in recent years is unknown, but some believe it's linked to the mussels, which improve clarity as they filter water, allowing sunlight to penetrate deeper.

"Chances are pretty good that Asian carp would do just fine eating that stuff, but we're going to test it to make sure," Chapman said.

Quagga and zebra mussels, believed to have hitched a ride from Europe to the Great Lakes in ballast tanks of freighter ships in the 1980s, have wreaked ecological havoc and done hundreds of millions of dollars in damage to all the lakes except Superior, where only isolated colonies have been found.

Fahnenstiel and Michigan Tech University biologist Charles Kerfoot were among co-authors of a series in the Journal of Great Lakes Research that described the quagga mussel's takeover of southern Lake Michigan this decade.

Quaggas -- which unlike zebra mussels thrive in cold, deep waters -- are a likely culprit in the disappearance of phytoplankton blooms that feed opossum shrimp, the scientists said.

Those tiny invertebrates, crucial food for prey fish, have plummeted by more than 70 percent, said Steve Pothoven, a biologist with the National Oceanic and Atmospheric Administration field station in Muskegon.

Scientists say whitefish and salmon, two of Lake Michigan's most popular species, have gotten smaller in recent years, a probable sign of malnutrition from a deteriorating food web.

"We are really getting a genuine collapse in the third-largest freshwater lake in the world," Kerfoot said.

The quagga population should outgrow its food supply and level off sometime. How soon that happens will determine how severely fish populations suffer, Tom Nalepa, another NOAA researcher.

If Asian carp arrive in large numbers and successfully reproduce, the situation would get even more dire.

Even as scientists debate how likely that is, five Great Lakes states are suing in federal court, demanding the closing of Chicago shipping locks and separation of the lakes from the Mississippi River basin to block the path of Asian carp and other invaders. Chicago business interests say doing so would cripple the local economy.

Marc Gaden, spokesman for the Great Lakes Fishery Commission, says he hopes he never has to find out how well the carp would fare in Lake Michigan.

"What's important is to focus on the prevention," Gaden said. "Once you let the invaders in and they spread, it's permanent."

  • get related content delivered to your inbox

  • manage my email subscriptions

Click here to send us your hunting or fishing photos – and to see what others are showing off from around the region.

ADVERTISEMENT

NY Mets 8 FINAL
Atlanta 2
Philadelphia 3 FINAL
NY Yankees 1
Detroit 5 FINAL
Baltimore 4
Toronto 4 FINAL
Pittsburgh 1
Cincinnati 2 FINAL
Cleveland 4
San Diego 3 FINAL
Seattle 4
Chicago WSox 6 FINAL
Los Angeles 4
Kansas City 13 FINAL
Texas 2
Oakland 9 FINAL
San Francisco 2
Wisc-Milwaukee 0 FINAL
Milwaukee 8
Arizona 6 FINAL
Colorado 3
Univ of Minnesota 1 FINAL
Minnesota 3
New York 82 FINAL
Indiana 105
Phoenix 105 FINAL
Orlando 100
Cleveland 120 FINAL
Toronto 112
Utah 84 FINAL
Boston 85
Charlotte 115 FINAL
Brooklyn 91
Denver 100 FINAL
Minnesota 85
Detroit 85 FINAL
New Orleans 88
LA Lakers 94 FINAL
Miami 100
Philadelphia 118 FINAL
Oklahoma City 123
Memphis 102 FINAL
Houston 100
Sacramento 85 FINAL
San Antonio 112
Milwaukee 93 FINAL
Golden State 102
Portland 98 FINAL
LA Clippers 93
Ottawa 3 FINAL
Winnipeg 1
NY Rangers 1 FINAL(OT)
Detroit 2
Pittsburgh 1 FINAL
Colorado 3
Montreal 1 FINAL
Anaheim 3
Longwood 65 FINAL
Presbyterian 61
Campbell 64 FINAL
Gardner-Webb 72
Liberty 70 FINAL
UNC-Asheville 80
Ohio State 77 FINAL
Penn State 67
Maine 66 FINAL
Albany 83
Duquesne 81 FINAL
Fordham 66
George Washington 67 FINAL
George Mason 51
Tennessee 78 FINAL
LSU 63
Notre Dame 71 FINAL
Louisville 59
SE Missouri St 74 FINAL
Morehead State 79
St Francis-PA 73 FINAL
Mount St Marys 58
Hartford 63 FINAL
New Hampshire 67
Wagner 68 FINAL
Robert Morris 91
Long Island 70 FINAL
St Francis-NY 79
La Salle 50 FINAL
Saint Josephs 55
Providence 79 FINAL
Seton Hall 66
UCF 45 FINAL
South Florida 74
Binghamton 57 FINAL
Stony Brook 62
UMBC 39 FINAL
Vermont 66
Sacred Heart 85 FINAL
Bryant 91
Richmond 56 FINAL
Massachusetts 53
Wake Forest 51 FINAL
Duke 94
Purdue 66 FINAL
Michigan State 72
Miami-Florida 67 FINAL
Pittsburgh 63
St Bonaventure 64 FINAL
Saint Louis 48
New Mexico St 69 FINAL
TX-Pan American 48
Houston 68 FINAL
Tulane 63
Howard 62 FINAL
NJIT 71
TCU 70 FINAL
Oklahoma State 82
Cincinnati 56 FINAL
Tulsa 47
USC 74 FINAL
UCLA 85
Miss State 56 FINAL
Vanderbilt 66
Utah State 53 FINAL
Wyoming 76
St Johns 67 FINAL
Marquette 51
SIU Edwardsville 66 FINAL
Eastern Ill 78
Air Force 66 FINAL
Fresno State 68
Nebraska 57 FINAL
Illinois 69
Colorado State 78 FINAL
Nevada 62
Boise State 68 FINAL
San Jose St 51
San Diego St 60 FINAL
UNLV 58
Oregon 65 FINAL
Oregon State 62
UC Santa Barbara 98 FINAL
Hawaii 90
Toledo 64 FINAL
Northern Ill 68
Wake Forest 69 FINAL
Boston College 53
Eastern Illinois 35 FINAL
UT Martin 68
Austin Peay 69 FINAL
SIU-Edwardsville 72
Virginia Tech 57 FINAL
NC State 56
Massachusetts 55 FINAL
St Bonaventure 49
Auburn 71 FINAL
Florida 49
Penn State 63 FINAL
Indiana 68
Clemson 53 FINAL
Georgia Tech 80
Davidson 63 FINAL
La Salle 74
Loyola-Maryland 46 FINAL
Lafayette 58
Boston U 48 FINAL
Colgate 58
Coll of Charleston 58 FINAL
James Madison 107
Delaware 76 FINAL
Elon 77
Drexel 58 FINAL
Northeastern 42
Hofstra 75 FINAL
UNC-Wilmington 76
Towson 56 FINAL
William & Mary 68
Miami-Ohio 55 FINAL
Akron 67
Ball State 85 FINAL
Central Michigan 69
Buffalo 55 FINAL
Bowling Green 47
Western Mich 65 FINAL
Eastern Michigan 74
Ohio U 69 FINAL
Kent State 56
Youngstown St 62 FINAL
Cleveland State 73
Illinois-Chicago 54 FINAL
Wright State 74
Alabama 56 FINAL
Vanderbilt 66
Detroit 60 FINAL
Milwaukee 56
Purdue 58 FINAL
Wisconsin 56
Connect with twitterConnect with facebookConnect with Google+Connect with PinterestConnect with PinterestConnect with RssfeedConnect with email newsletters

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT

question of the day

Poll: Should the lake where the albino muskie was caught remain a mystery?

Weekly Question

ADVERTISEMENT

 
Close