A scientist collects samples of ballast sediment. (Photo courtesy of NOAA)
A new study finds that ocean-going ships that enter the Great Lakes often carry biological pollution in their ballasts, even when they declare their ballasts are empty. The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
A new study finds that ocean-going ships that enter the Great Lakes often carry biological pollution in their ballasts, even when they declare their ballasts are empty. The Great Lakes Radio Consortium’s Lester Graham reports:
The study by the University of Michigan and the National Oceanic and Atmospheric Administration looked at ships coming into the Great Lakes from the ocean. Nearly 80-percent of them declared “no ballast on board” and avoided inspections by the Coast Guard.
But several of those ships were tested by the researchers. They found that although the ballast water was pumped out, there were thousands of organisms left behind in the sediment in the bottom of the ships’ ballast. Then, when the ships unloaded at their first stop, they took on Great Lakes ballast water which stirred up the sediment.
And that made it possible for the biological contaminants to be pumped out at the next Great Lakes port.
The authors of the study warn that more restrictions must be placed on how the ships handle ballast water, or the Great Lakes will continue to be invaded by more invasive species such as the zebra mussel, round goby, and 180 other foreign aquatic species that have harmed the Lakes’ ecosystems.
For the GLRC, this is Lester Graham.