Great Lakes Invaders Invasive species challenge Great Lakes native species

Every year, the St. Lawrence Seaway welcomes hundreds of foreign freighters carrying steel to Great Lakes ports. But these “salties,” as the oceangoing ships are called, often bring a less-welcome cargo. Since the Seaway began operating in 1957, dozens of foreign species have stowed away in the ballast water of salties. Once they establish themselves in the Great Lakes, these hitchhikers wreak havoc on fisheries, boats and ports.

Consider these examples: The sea lamprey preys on lake salmon; the zebra mussel has to be scraped off hulls and out of water intake pipes; and because of the resulting viral hemorrhagic septicemia (VHS) virus, fish that would have filled the nets of trawlers are washing up dead on Lake Huron beaches.

Fed up with this invasion, Michigan decided in 2006 to prohibit salties from dumping ballast in its waters. Nonetheless, a new invader was discovered in the Muskegon River last year: the bloody red mysid, a Eurasian shrimp that feasts on the same plankton as native fish, and swims across state lines.

“For our law to have the effect we want it to have, it has to go beyond Michigan,” says Robert McCann, spokesman for the Michigan Department of Environmental Quality. “The ideal situation would be federal legislation.”

A pending bill in Congress would require salties to flush out their ballast tanks at sea, or treat the water with chemicals that kill any stowaway species. But it wouldn’t take effect until 2015, which is too far away for some Great Lakes advocates.

Great Lakes United, a group based in Buffalo, New York and Ottawa, Ontario, wants a ban on salties until the U.S. and Canada deal with the ballast issue. Salties carry only seven percent of the cargo that travels the Great Lakes each year, says Jennifer Nalbone, the group’s campaign director for invasive species. Nalbone points to a Grand Valley State University study that says it would cost an extra $55 million a year for salties to unload in Quebec, then have their goods carried inland by truck or train. That’s a tenth of the annual economic damage caused by the zebra mussel and its cousin, the quagga mussel.

“We’re not looking to ban salties forever,” says Nalbone, “but just until they install new technology. Every year that we wait for regulations, we get invaded. Unfortunately, we just don’t know what the next invader will be.”