According to an environmental group invasive species appear to be killing off crucial segments of the Great Lakes food web, from large predator fish to tiny shrimp. It as become a menace to the lakes’ $7 billion commercial and sport fishing industry and the regional economy as a whole. A report issued by the National Wildlife Federation says the foundation of the Great Lakes food web is disappearing before our eyes.
Mike Murray, an environmental chemist and one of the authors, told that as invasive species like zebra mussels overwhelm the Great Lakes, large stretches of the lakes have become underwater deserts. According to scientists 162 aquatic foreigners have made their way into the lake system and continue arriving at a rate of one new species every eight months. Scientists informed that most species hitch a ride in the ballast tanks of ships from abroad.
U.S. Rep. Vernon Ehlers, R-Mich., said that the authority can remove toxins from the waterways and recover the land because most chemical pollutants can be filtered or they degrade over time. He further adds that once a new species takes hold and propagates in the ecosystem, it is with us forever.
Many signs of the invasion are visible such as dock pilings often are caked with zebra mussels, and rotting bodies of alewives litter beaches. According to report zebra mussels are the prime suspect. As huge colonies of the striped mollusk blanket the lake bottoms, they disrupt reproduction of diporeia and similar organisms. It urged the Congress to enact legislation that would regulate activities believed to create pathways for exotic invaders, such as ballast dumping.
