Researchers Testing New System to Kill Invasive Species in Ballast Water

Published Aug 24, 2011 2:40 PM by The Maritime Executive

Federal U.S. scientists are making headway with the ballast water invasive species problem prevalent in the Great Lakes by taking new approaches into water treatment of ballast water tanks on ships. 

Currently, scientists have just wrapped up a three-year research endeavor on a new method using sodium hydroxide against zebra mussels and other species that are transported in ballast water tanks.  Before the water is released, it is then treated with carbon dioxide to clean the tank water. 

The superintendent of Isle Royale National Park, Phyllis Green, has been the figure head this research program and describes the method as using the ballast tanks as holding tanks for treating them with an active biocide (sodium hydroxide) designed to kill organisms inside the tank, as well as treating with biocide (carbon dioxide) after its killed the organisms to neutralize the water before releasing it.  She explained that the idea is to kill as much as we can with still being able to release safe water back into the environment.

PHOTO CAPTION: Ballast water is discharged from a ship in a file photo. Scientists have wrapped up three years of research on a new method of cleaning ballast water, which can carry invasive aquatic species. (Photo courtesy of the U.S. Geological Survey)

The Duluth News Tribune reports that further testing is being conducted in Lake Superior using this method, and has yielded a very promising outlook, killing 99% of invasive species.  These resules are still preliminary as it is the first major-scale test to take place on the Lakes.  Results of the functionality on an actual ship utilizing all ballast tanks should be released in the next month.

According to Minnesota Public Radio, invasive species inflict an estimated $5.9 billion damage in the Great Lakes region annually, and it is believed that 60% of these invasive species are pumped into the water through ballast tanks.