Starting with the effectiveness of ballast water exchange, the current guidelines applying to ships that we call NOBOB ships, those reporting no ballast on board, that regulation went into effect in 2006.
Those are the ones that were not subject to any previous regulation that was put into effect in the early 1990s. That was corrected by the amendment to the regulation in 2006, which became harmonized by both countries in the St. Lawrence Seaway Authority in 2008.
There have been a series of studies by DFO and members of my research network, CAISN, that have tested the effectiveness of that procedure and have found it very promising. That coupled with data that suggest there haven't been any reported invasions attributable to ballast water since that time give us reason to be optimistic.