Another reason to close Great Lakes
Written by Detroit Free Press   
Thursday, 09 November 2006 15:29

A federal agency has banned transporting 27 species of live fish out of eight Great Lakes states or importing them from two Canadian provinces in an effort to stop the spread of a disease called viral hemorrhagic septicemia.

But the ban makes little sense.

It's illegal for the Illinois Department of Natural Resources to ship live walleyes to Iowa on the other side of the Illinois River. But Illinois fisheries biologists can pour live walleyes into their side of the river while waving at the Iowa fisheries biologists on the opposite shore.

It's illegal under the ban for Michigan to ship live steelhead and salmon to other Great Lakes states. But Michigan can dump salmon and steelhead into its own Great Lakes waters and watch them swim to other states.

The emergency order issued last month by the Animal and Plant Health Industry Service, a division of the U.S. Department of Agriculture, was well intended but poorly thought out.

It probably will do little to stop the spread of a disease that first showed up in the lower Great Lakes last year and has the potential to cause fish kills throughout the system, and perhaps in most of America's fresh waters.

The APHIS order caught state departments of natural resources and the live bait and aquaculture industries by surprise. APHIS should have convened a meeting of all parties with a stake in the issue and worked out an order that would have a better chance of curbing the spread of VHS and avoided pointless disruptions for state agencies and private businesses.

VHS kills fish by causing their internal organs to bleed and has been found in lakes St. Clair, Erie and Ontario and adjacent rivers. Before showing up in the Great Lakes, it had only been seen in saltwater fish, and most experts believe it reached the lakes in the ballast water of an ocean-going ship.

But other possible vectors include live fish from the aquaculture and bait industries, which daily move millions of fish throughout the region. So once it was discovered that the disease infects at least 27 Great Lakes species (although it may not harm them all), APHIS decided to stop the transport of those fish.

Unfortunately, that ignores a more likely source of VHS -- ships that already have brought in dozens of exotic species, including zebra mussels and round gobies, and still move exotic organisms and bacteria around the lakes.

While VHS doesn't affect people, saltwater ships are known to have been the source of cholera from Colombia that infected oyster beds in Alabama. In the past decade, globalization has created trade routes with a host of new places in the world and made the lakes far more vulnerable to exotic species and diseases that could affect both fish and humans.

Gary Whelan, who runs the Michigan's Department of Natural Resources fish production program, believes VHS eventually will reach the three upper lakes. How fast it arrives will be one way to determine the vector that moves it.

"I think it will be in (lakes) Huron and Michigan within three or four years. It probably will reach Lake Superior eventually, but if the vector is fish swimming in with it, that could take decades. Fish don't pass through the St. Marys river and the locks very easily," he said. "But if it shows up three or four years from now in Duluth (at the western end of Lake Superior), then we can be sure that the vector is ships," which carry animals and microorganisms in their ballast water.

Exotic species weren't much of a threat before we opened the Great Lakes to invaders at both ends. The St. Lawrence Seaway allowed ships to come in from the Atlantic, and the Chicago Sanitary and Ship Canal brought in ships and barges from the Mississippi River drainage.

VHS simply adds another reason to an already-long list of reasons why we need to remedy our mistakes and close them again.
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