From: National Wildlife Federation
Published October 21, 2004 04:54 PM

Invasive Species Wreaking Havoc on Great Lakes Food Web, According to National Wildlife Federation Report

Scientists, Lawmakers, Industry Leaders Can Overcome Challenge of Invasive Species, Says Congressman Ehlers


GRAND RAPIDS, MI - The Great Lakes remain in a fight for their survival due to the devastating effects of invasive species, according to a new report by the National Wildlife Federation (NWF).


"This report is a wake-up call," said Andy Buchsbaum, director of NWF's Great Lakes office. "We are witnessing profound and rapid changes in the Great Lakes food web that are unprecedented in the recorded history of the Great Lakes. Our Great Lakes are in trouble, and we need to act to save them."


In releasing the report, NWF was joined by Congressman Vernon Ehlers (R-Grand Rapids), who chairs the Environment, Standards and Technology Subcommittee of the House Science Committee.


"This report provides fresh evidence that we need to take action to protect the Great Lakes," Ehlers said. "One important step we should take is for Congress to pass the National Aquatic Invasive Species Act and its companion National Aquatic Invasive Species Research Act, which I authored, to provide necessary federal resources to address this crisis."


Ecosystem Shock: The Devastating Impacts of Invasive Species on the Great Lakes Food Web chronicles how non-native species are wreaking havoc on the ecosystem, threatening predatory fish at the top of the food web, as well as organisms at its base - including Diporeia, a small but high-energy food source that has nearly disappeared in many parts of the Great Lakes.


"The foundation of the Great Lakes food web is disappearing before our eyes," said Mike Murray, NWF scientist. "As invasive species like zebra mussels overwhelm the Great Lakes, large stretches of the lakes have become underwater deserts. Populations of a basic food source, Diporeia, have collapsed in many parts of Lake Michigan and Lake Ontario, declining from 10,000 organisms per square meter in some places to virtually zero in the space of a decade. The Great Lakes fishery cannot withstand such dramatic and sudden changes to its food source."


Aquatic invasive species are harmful, non-native, plants, animals and microorganisms that are introduced into an environment in which they did not evolve. Invasive species often have no natural enemies to limit their reproduction and spread, allowing them to out-compete native species for food and habitat. Nationally, aquatic and terrestrial invasive species cost $137 billion a year in economic losses and control costs.


One new non-native species finds its way into the Great Lakes every eight months, according to Ecosystem Shock, and the frequency of introductions is increasing. To date, 162 aquatic invasive species have entered the Great Lakes.


Invasive species have already impacted the region's world-class fishery. Ecosystem Shock describes how changes to the Great Lakes food web have led to smaller and lighter body sizes for some species of fish, such as lake whitefish, and population declines in other species, such as lake trout and yellow perch. Left unchanged, such trends could devastate the region's commercial and recreational fishery, which generates nearly $7 billion per year and employs 75,000 people.


The report comes at a time when the Great Lakes are in the midst of a decades-long recovery from the devastating effects of over-fishing and toxic pollution. Ecosystem Shock reveals that the Great Lakes remain in a fight for their survival.


"On the surface, the Great Lakes appear to be healthier than they have ever been in years," said Steve Pothoven, a researcher with the Cooperative Institute for Limnology and Ecosystem Research.


"Appearance, however, is not reality. While the lakes are clearer in many places, they are not cleaner. We need to remain vigilant and committed to studying, monitoring and restoring the Great Lakes."


The report highlights some of the most infamous of the 162 aquatic invasive species to enter the Great Lakes, including:


* The predatory sea lamprey, an eel-like fish which attaches to fish and drains them of blood and bodily fluids. An adult lamprey can kill up to 40 pounds of fish in 12-20 months.


* The round goby: an aggressive fish that decimates the nests of smallmouth bass, consuming its eggs. To offset the population decline of bass, the Ohio Department of Natural Resources restricted anglers from catching these fish in Lake Erie in May and June.


* Zebra and quagga mussels: opportunistic filter-feeding mollusks that reproduce rapidly and consume incredible amounts of microscopic plants and animals from the water - depriving native species of food. Researchers also blame these mussels in the reappearance of toxic algae blooms that foul drinking water supplies.


The number one pathway for aquatic invasive species to enter the Great Lakes is through the ballast water of ocean-going vessels, according to the report. Other vectors include live fish food sales, aquarium trade, bait buckets and aquaculture.


"Invasive species pose a national problem that requires a national solution," said Buchsbaum. "Our options for recovery once an invasive species has entered the Great Lakes are limited-which is why we need to inoculate the lakes from further introductions. When it comes to shutting the door on invasive species, an ounce of prevention is worth a pound of cure."


To address the problem of invasive species, the report calls for legislative, research and public education initiatives. These include:


* Passing the National Aquatic Invasive Species Act, comprehensive legislation that would regulate the most common pathways of entry for invasive species.


* Increasing funding for research, monitoring and response efforts.


* Initiating public awareness campaigns for the public and federal decision-makers.


"Working together, legislators, scientists and industry leaders can overcome the challenge of invasive species," said Ehlers. "We realize the importance of the Great Lakes and other U.S. inland and coastal waterways, and we will do everything we can to preserve them now and for future generations."


Ecosystem Shock is available on the Internet at: www.nwf.org/news Protecting wildlife through education and action since 1936, the National Wildlife Federation is America's conservation organization creating solutions that balance the needs of people and wildlife now and for future generations.


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