Isle Royale order aims to protect fish, lake from virus

Freighters no longer can dump untreated ballast water within the park's boundaries.

By Tom Meersman, Star Tribune

Last update: September 17, 2007 - 11:56 PM

Isle Royale National Park officials on Monday announced emergency restrictions affecting commercial freighters to prevent the spread of a fish virus that has killed large numbers of species in every Great Lake other than Lake Superior.

Isle Royale Superintendent Phyllis Green issued an order that prohibits ships from dumping untreated ballast water within park boundaries. They extend 4½ miles around the main island and several neighboring park islands in Lake Superior.

Shipping officials questioned the need for the order and said that the industry is trying to develop practical ways to stop the virus and other invasive species from spreading.

Green said that the emergency order is warranted because the park has the best remaining genetic diversity in the Great Lakes of lake trout and coaster brook trout, which would be at serious risk if the virus spreads.

Exposure at this time of year would a huge problem, she said, because large numbers of trout from around the lake converge to spawn near the island's reefs.

"We want to be the last place this virus shows up, not the first place from which it spreads to other parts of Lake Superior," Green said.

The virus, called viral hemorrhagic septicemia, causes severe bleeding in fish that results in organ failure. It has infected several dozen species, and can be spread by fish moving within the Great Lakes and by large shipping vessels carrying infected fish or their fluids in large ballast tanks.

The ballast water is used for stability and is taken on or discharged as ships load and unload cargo at ports throughout the Great Lakes.

The emergency order prohibits freighters from discharging ballast water within park boundaries unless it has been treated with chlorine or other methods to kill the virus.

Green said that freighters don't stop at Isle Royale, but hundreds of them move annually through park waters on a major shipping route to Thunder Bay, Ontario, about 40 miles away.

Glen Nekvasil, vice president of corporate communications for the Lake Carriers' Association, said that the restrictions would not affect most vessels because they usually wait to discharge ballast water in ports rather than in transit. Nekvasil said that treating ballast water with chlorine is impractical, because some vessels contain 3 million to 5 million gallons of ballast.

Michigan began regulating ballast water this year, he said, and Ohio and Wisconsin are considering similar state laws, in addition to the National Park Service order. "This is exactly the kind of hodgepodge that will be the result if we don't get federal regulations," Nekvasil said.

The association represents 18 companies that ship cargo on 63 U.S.-flagged vessels in the Great Lakes. Canada has a similar association.

Green said that she expects to meet with industry leaders and ship owners during the winter to explore different methods that will be acceptable to treat ballast water.

The order does not affect most recreational craft or the two commercial vessels that shuttle visitors to the park from Michigan and Minnesota, Green said, because they are too small to have ballast water tanks.

Tom Meersman • 612-673-7388

Tom Meersman • meersman@startribune.com

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