Posts Tagged ‘Mike Cox’

Zebra Mussels vs the Great Lakes

July 15, 2010 3 comments

In 1988 a small unique looking mussel was discovered in Lake St. Claire by Detroit. This seemingly innocuous discovery would slowly rewrite the ecological face of the Great Lakes over the next twenty years as it gradually took over in a Darwinian struggle.

Spread of zebra mussels

Zebra mussels come from Eastern Europe, originally in the Caspian and Black Seas. Scientists speculate that mussel larvae latched onto transatlantic ships and were carried over in the ballast water. Female mussels lay between 30,000 and 10,000 eggs a year, making them virtually impossible to eradicate once introduced to an ecosystem.

From 1988 on the mussels have slowly invaded every one of the Great Lakes, and from there spread to the Illinois, the Mississippi, and the St. Lawrence rivers. Zebra mussels latch on to everything from industrial piping, to boats and docks, and even to other wildlife. The Center of Invasive Species Research estimates that the US spends roughly $500 million a year to control the zebra mussel population in the Great Lakes area. The state of Michigan has attempted to poison the mussels through chemicals, introduce natural predators of the zebra mussel, and dry them out through water draw downs in reservoirs and aqueducts. Unfortunately, they are still spreading and slowly pushing out competing species. According to Sea Grant Michigan, zebra mussels have appeared in 255 inland lakes and 17 rivers in Michigan.

Lake Lansing

Zebra mussels aren’t the only invasive species to threaten the Great Lakes. Asian carp are a large species of fish that can grow up to 100 pounds. The carp were brought to the US to keep algae populations down on fish farms in the south. They have quickly traveled up the Mississippi, and despite efforts to keep them out of the Great Lakes, the species has been found in Lake Michigan.

Michigan’s fishing industry brings in around $7 billion a year according to Senator Debbie Stabenow. Asian carp pose a potentially devastating threat to that industry. Michigan Attorney General Mike Cox has unsuccessfully sued the Supreme Court twice to close the locks on the Chicago waterways, and is considering a third effort.

Both the carp and the zebra mussels are not entirely without benefits. Asian carp are known to be a delicacy, if difficult to cook, and zebra mussels tend to leave infested waters far clearer than before they arrived. The mussels absorb most of the nutrients in the water, allowing sunlight to reach the bottom and new species of plants to thrive. Stabenow and Cox say it is not worth the cost.

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