We have conducted 4 experiments to determine the efficacy of ballast water exchange (midocean) for vessels arriving from perceived areas-of-risk (e.g. Baltic Sea).  Matched tanks on ships are filled with freshwater at a North American port. One tank is subsequently flushed on the open ocean while the second tank is not flushed.  At the destination port, samples of the biological composition are taken to compare to each otehr and to samples collected at the outset of the trip.  In addition, we placed hatch-out chambers in these tanks with ballast sediment of known biological composition.  When the experiment is ended, we collect samples of invertebrates from each of the chambers, allowing us to determine if any hatch of resting eggs occurred in during the trip and whether ballast water flushing killed animals in the chambers in the exchanged ballast tank.   While we would have preferred to run the experiments from Europe to North America, we ran them in the opposite direction owing to ease of access to vessels.  We expect that results from these studies would be equally applicable to vessels traveling from Europe to North America. Derek Gray is conducting his MSc on this project.

This study is funded by the Great Lakes Protection Fund.