A simple solution: Plug Great Lakes at both ends
Written by Detroit Free Press   
Sunday, 17 September 2006 16:13

After more thought, I realize I was mistaken in arguing that we should simply bar ocean-going ships from the Great Lakes to keep exotic species out. What we should do is bar saltwater ships and block the Chicago Sanitary and Ship Canal, plugging the lakes at both ends.

Otherwise, we risk losing a $5 billion annual sport and commercial fishery and who-knows-what in tourism and biological diversity so that a handful of industries can save a few bucks.

Asian silver and bighead carp that escaped from southern fish farms on the Mississippi River more than 25 years ago have displaced native species on large sections of the Mississippi and Illinois rivers. They've been seen in the Chicago Sanitary and Ship Canal less than 50 miles from Lake Michigan and could colonize the entire Great Lakes and hundreds of tributary streams if they get past a temporary electrical barrier.

These exotics can take over with incredible speed. Two years ago biologists set a net in a part the Illinois River to capture Asian carp. When they lifted it 30 minutes later, it was stuffed with hundreds of silver and bighead carp that weighed over a ton. People in that area say Asian carp numbers have since doubled.

The Great Lake Fishery Commission says sport and commercial fishing for salmon, whitefish, lake trout, walleyes, perch and other species is worth about $5 billion a year. If Asian carp reach the Great Lakes, they'll probably wreck those fisheries.

While we've focused our attention on Asian carp, sea lampreys, zebra mussels and other exotics that are very visible, many biologists think the worst threats may come from things we can't see, diseases and toxins that can wreak havoc not over decades but in months or even weeks.

When Lake Huron's salmon fishery collapsed last year, scientists thought zebra and quagga mussels had sucked so much zooplankton and algae from the water that they starved out the other tiny animals at the bottom of the food chain, disrupting the lakes whole web of life.

One of them was diporeia, a little crustacean that was the most important food source for everything from newly hatched bait and game fish to adult whitefish. Diporeia, which once teemed by the thousands in every square foot of mud on the bottom, have disappeared almost entirely from most of Lakes Michigan and Huron. Biologists now think the cause may not be food competition but a virus or a toxin from the mussels.

Biologists also are keeping a wary eye on viral hemorrhagic septicemia, which killed thousands of muskellunge in Lake St. Clair and tens of thousands of bluegills, perch and sheepshead in Lakes Erie and Ontario this spring and summer. Previously known in North America only in the oceans, it hasn't affected walleyes, but biologists worry that may be only a matter of time, because walleyes are closely related to perch. And in other parts of the world VHS has killed trout and salmon.

A study of the St. Lawrence Seaway by Dr. John C. Taylor of Grand Valley State and J.L. Roach, an East Lansing transportation consultant, estimated that banning ocean-going ships from the lakes would cost the economy about $55 million a year, a tiny fraction of what we spend on damage from zebra mussels alone.

The study also shows the 50-year-old Seaway has been an economic pig in a poke, carrying far less tonnage and producing far fewer benefits than promised. Taylor and Roach discovered that although backers claimed that the Seaway saved shippers $1.2 billion a year, all over that savings came from shipping on Great Lakes ore boats and freighters and none from the saltwater ships.

Yet we can now count some 180 exotic species in the lakes, many arriving in the ballast water from ocean-going ships and most costing us money.

We made a similar mistake in 1904 when engineers reversed a river that flowed into Lake Michigan, creating the Sanitary and Ship Canal. It let barges travel between Chicago and the Mississippi and opened the Great Lakes' back door to the risk of introducing exotic species.

In 1904 people didn't understand those environmental risks. By the time the St. Lawrence Seaway was completed in 1959, we were more aware.

Today, we certainly know the right thing to do in most environmental issues. We knew it before Hurricane Katrina -- stop construction in the low-lying areas and move peoplefrom the coast. But the economic and political interests of the few overrode the good of the many, and billions of tax dollars are being spent to repair damage that shouldn't have happened and subsidize rebuilding in areas where it could happen again next week.

The people of the Great Lakes should stand up and say we don't want Katrina-style politics and economics. We like to brag that the Great Lakes hold 20% of all the freshwater in the world. An even more telling figure is that they hold 95% of all the freshwater in the United States!

It's nuts to risk a resource like that for $55 million a year.

 
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