Trying to stop the introduction of invasive species into the Great Lakes from the ballast water of oceangoing ships has been a long, often unsuccessful effort. As a result, it is estimated that up to 125 invasive species are now in the Great Lakes.
The latest regional control effort was enacted in Minnesota to target ballast water discharges in and near the Duluth-Superior Harbor. The Minnesota Pollution Control Agency Citizens’ Board voted in September 2008 to enact regulations requiring ships to have ballast water discharge permits. Existing vessels must have ballast water treatment systems by Jan. 1, 2016 and any ship built after Jan. 1, 2012 must have the systems.
Other regional governments administering Great Lakes water have ballast water regulations primarily aimed at oceangoing vessels, but the Minnesota rules will apply to all ships including lakers.
Another regional control is the Michigan Ballast Water Statute enacted to require ships to file reports of ballast water discharges and pay a fee. The statute was challenged by a consortium of ship owners, port authorities and others. However, in November 2008, the U.S. Court of Appeals for the Sixth Circuit upheld the state statute.
One proposal to protect the Great Lakes from invasive aquatic species was to close the Saint Lawrence Seaway to oceangoing vessels. Terry Johnson, the Saint Lawrence Seaway Development Corp.’s administrator, said a study by the National Academy of Sciences concluded that the approach was “legally unfeasible, politically unrealistic and economically disastrous for the U.S. and Canada.”
In 2008, the Seaway Development Corp. began requiring oceangoing ships to flush ballast tanks 200 nautical miles from North American shores to ensure that the ballast water contains a high enough concentration of salt to kill freshwater species that might survive if released into the Great Lakes. The rule is now the same as imposed by Canada in 2006. Inspections are done in Montreal, before ships enter the Great Lakes.
According to the Seaway Development Corp., “A study led by the National Oceanic and Atmospheric Administration and the University of Michigan documented that flushing saltwater into ballast tanks that contain residual amounts of water or sediment is highly effective in eradicating most exotic aquatic species potentially introduced into the Great Lakes via ballast water.”
The spread of invasive aquatic species is a concern being addressed by governments worldwide, shipping interests including the International Maritime Organization and equipment suppliers developing ballast water treatment technologies.
For those protecting the waters of the Great Lakes, the cause of the problem outlined in 2007 by the Alliance for the Great Lakes, headquartered in Chicago, has not changed: “The No. 1 pathway for non-native aquatic species to enter the Great Lakes is through ballast discharge from oceangoing vessels originating in foreign ports. Since 1970, fully 77 percent of the invasions are attributable to transoceanic shipping activities.”
Richard O. Aichele