More foreign species expected to invade the Great Lakes
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- jefftego
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more from News:
http://blog.cleveland.com/metro/2009/01/more_foreign_species_expected...
The Great Lakes -- especially a warm and shallow Lake Erie -- are in great danger from being invaded by another wave of foreign freshwater aquatic species.That's the gloomy conclusion of a team of U.S. EPA scientists who used satellite data and computer modeling to predict how dozens of new invasive species might spread across the Great Lakes -- causing significant environmental and economic damage in spite of policies designed to keep them out.
The EPA's National Center for Environmental Assessment identified 30 species with a medium or high likelihood of reaching lakes and 28 others already here with a potential to spread and cause harm.
That's bad news -- both economically and environmentally.
Experts have estimated the annual U.S. cost of dealing with invasive species at between $97 billion and $137 billion, the report said. They estimate the impact of nearly 200 species now in the Great Lakes basin at $5.7 billion per year.
Those costs are figured by direct and indirect impacts, including shellfish covering water intake pipes (zebra mussels), kill sport fish or commercial fish (sea lamprey) or by outcompeting sport fish for food (zebra mussels, quagga mussels and round gobies).
EPA models say Lake Erie and shallower portions of the other four lakes are the most vulnerable to more future invasions from fish like the tench and the monkey goby -- species which will have an unknown, but possibly harmful, impact on the lake.
Most invasives are believed to reach the Great Lakes in ballast water discharged by oceangoing ships.
