Invaders worry Northern Michigan

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By TRENTON JOHNSON
Capital News Service
LANSING—Invasive species are continuing to threaten Michigan in the water and on the land, experts warn.
“Invasive species come in and disrupt the ecological balance. They can also disrupt habitat and wildlife,” said Deputy Director Frank Ruswick of the Department of Natural Resources and Environment (DNRE).

(U.S. Fish & Wildlife Service)


Ruswick said the invaders include Asian carp, zebra mussels, phragmites, purple loosestrife, Eurasian watermilfoil, quagga mussels, rusty crawfish, bloody red shrimp, Eurasian ruffe, round gobies and sea lamprey. The Asian carp, zebra mussels and phragmites appear to be the ones of most concern, he said.
Media and political attention is focused on the fear that Asian carp will invade Lake Michigan from the Chicago River.
Invasive species of major concern in the northern Lower Peninsula include Asian carp and zebra mussels.
What are the long-term consequences of invasive species?
Kevin Cronk, monitoring and research director of the Tip of the Mitt Watershed Council in Petoskey, said, “Invasive species cause a reduction in the biological diversity of the ecosystem. In certain cases, invasive species can change the food web in an ecosystem by destroying or replacing native food sources.”
The council is the lead organization for water resources protection in Antrim, Charlevoix, Cheboygan and Emmet counties. It works to maintain the environmental integrity and economic and aesthetic values of lakes, streams, wetlands and groundwater.
Jim Sygo, deputy director of DNRE, said “Asian carp can disrupt the Great Lakes ecosystem by consuming large quantities of phytoplankton and competing with native fish for habitat.”
Phytoplankton serves as the base of the aquatic food web, providing an essential ecological function for all aquatic life, Sygo said.
Cronk said Asian carp has the ability to displace native fish altogether.
With no natural predators and the ability to produce 2.2 million eggs a year, the Asian carp could devastate the Great Lakes multibillion-dollar fishing industry, Sygo said.
Sygo said zebra mussels have spread rapidly to all of the Great Lakes and an increasing number of inland waterways throughout the United States and Canada.
Zebra mussels can also disrupt aquatic ecosystems.
Each zebra mussel can filter a liter of water per day removing almost every microscopic aquatic animal plant, including phytoplankton. They also can filter out toxic contaminants, Sygo said.
Phragmites, a large perennial grass, are a threat as well.
Ruswick said phragmites crowds out native plants, degrading wildlife and increasing fire potential.
© 2010, Capital News Service, Michigan State University School of Journalism. Not to be reproduced without permission.

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