Invasion of the Zebra Mussels
How political gridlock is helping a pesky mollusk gum up the Great Lakes
The increasingly clean water of the Great Lakes would appear to signal a healthy ecosystem. In Lake Erie, water clarity now goes as deep as 30 feet. But under that crystal surface lurks a dark reality: The sparkling water is the result of an explosion of zebra mussels, a Russian mollusk that sucks up nutrients with ruthless efficiency. The result is chaos for the fishing industry and other wildlife, as well as growing maintenance problems for boats and port facilities. One key link in the food chain-the tiny crustacean diporeia-has plummeted 99 percent in some lake areas since the mussels began taking hold in the late 1980s. "Diporeia are being starved," says Jennifer Nalbone of the environmental group Great Lakes United, "because the zebra mussel is consuming their food."
From 1993 to 2003, rapidly multiplying zebra mussels caused $3 billion in damage to the Great Lakes region, crippling the fishing industry while rapidly colonizing everything from turtles to boats. One Michigan town lost water for three days after a mussel colony clogged its water-intake pipe. The mussels are one of about 180 foreign species of all kinds that have invaded the Great Lakes, largely by hitching a ride on overseas shipping vessels. And many have spread through streams and lakes to affect other states. Locals say cries for federal help have yielded little in return. As a result, a patchwork quilt of tough state laws is emerging, frustrating the shipping industry and prompting Washington to take another shot at enacting blanket federal rules.
Ballast. At the heart of the battle is the shipping industry. When cargo vessels are light, they take on water for stabilization. Called ballast water, it's often teeming with stowaways in the form of small organisms, eggs, and plant matter. When the water is released, so are they. The amount of ballast water may vary with the cargo; even laden ships still carry some water swishing in their tanks. The problem hit the Great Lakes with the 1959 opening of the St. Lawrence Seaway, which cleared a path for large cargo ships from the Atlantic. Congress attempted to stem the problem in 1990 with the Nonindigenous Aquatic Nuisance Prevention and Control Act, which forced ships to exchange ballast water hundreds of miles from shore before entering the Great Lakes. Though the law has been expanded to all U.S. waters, critics like Phyllis Windle of the Union of Concerned Scientists say that "it's increasingly behind the times." New technology such as ultraviolet light or deoxygenation can kill many organisms but is still not widely used. And while the law allows ships designated as "No Ballast on Board" to dock freely, these ships still carry low levels of water from which organisms seep out.
Many states have had enough. California, Oregon, and Washington have passed strict regulations for ballast water. But the toughest of all is Michigan, which as of January requires oceangoing vessels at its ports to obtain a permit by proving to officials they will not discharge contaminated water. Wisconsin, which has spent over $5 million in the past four years fighting invasive species, may follow the lead. Wisconsin state Rep. Louis Molepske, who recently introduced legislation, says, "We will not sit back while our waters are destroyed."
The state rules have dismayed the shipping industry, which argues that the array of permits and regulations is costly and time consuming. The shipping industry took another blow in 2005, when a federal judge ruled that ballast water is a pollutant and must be regulated by the EPA under the Clean Water Act. The EPA is appealing, arguing the act is more appropriate for stationary pollution sources. Congress is looking at a permanent fix after several attempts in recent years were stalled by competing bills or key committee chairmen seeking to use the legislation as a trading chip for their own priorities.
In coming weeks, Michigan Sen. Carl Levin will introduce a bill with tough new standards on ballast discharge that he hopes will encourage vessels to install technology that kills a large percentage of biomatter. But even Levin's office worries about the proposal's fate. Because the legislation wouldn't supersede state laws, the shipping industry is likely to fight. That could mean more gridlock. "The integrity of the Great Lakes," laments Nalbone, "is being erased by our inability to act." The last best hope may be to find some integrity in Washington.
This story appears in the March 5, 2007 print edition of U.S. News & World Report.
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