Great perils of the Great Lakes

On a starry night, the 730-foot Canadian Leader, the last bulk-carrying steamship built on the Great Lakes, slips silently past illuminated buoys near Montreal on a five-day voyage up to Thunder Bay, Ontario, on Lake Superior.

After unloading titanium ore at the St. Lawrence River port of Sorel, the ship is proceeding empty toward the upper lakes. With the recent economic downturn, there is less demand for her typical upbound cargo of iron ore pellets. Capt. George Wheeler, a 40-year veteran of the sea originally from Northern Ireland, has taken on freshwater ballast from the river, to maintain the ship’s stability and maneuverability.

Taken together, the Great Lakes are a vast inland sea representing over one-fifth of all surface fresh water on the planet. More than 40 million Canadians and Americans draw their drinking water from the lakes, which play a vital role in public health, the environment, industry, commerce, and leisure.

But there are causes for concern: invasive species, declining water levels, uncertain quality of drinking water, and pressures to divert water from and into the Great Lakes-St. Lawrence basin. Signed into law by President George W. Bush Oct. 3, the Great Lakes Compact takes effect Dec. 8. The binational agreement, the fruit of regional initiatives, obliges eight American states and two Canadian provinces to work together to protect the lakes system.

“The Great Lakes Compact is an awesome victory,” says Jeff Skelding, national campaign director for Healing Our Waters – Great Lakes Coalition. “No one predicted it could have happened so quickly. We can’t protect the Great Lakes if there’s no water in them…. The cocktail of assaults may be pushing the Great Lakes toward a tipping point, an irreversible change in the food web.”

Part of this assault is the introduction of 182 invasive species such as the zebra mussel, which began disrupting the food web on Lake St. Clair in 1988 and has clogged many water intake pipes since, at an annual cost running in the billions of dollars.

Typically, “salties” (oceangoing ships) reaching the Great Lakes from overseas via the St. Lawrence River have discharged invasive species along with their saltwater ballast once they reached lake ports. Lakers have unwittingly transported these invasive species in their freshwater ballast, from one point on the lakes to the next.

Zebra mussels have made lake water look cleaner than before. But for Mr. Skelding, the clarity of water is a problem. “Sure, zebra mussels filter water,” he says, “but when the water is clearer, sunlight penetrates deeper, and organic material proliferates and absorbs much-needed oxygen in the water that is needed by fish and microorganisms.” The result: “Dead zones.”

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