Ballast water release from ocean vessels has introduced hundreds of invasive species to coastal ecosystems worldwide, causing major disruptions to fisheries and biodiversity. Attempts to control aquatic invasions have met with mixed success in general. However, a new study suggests that a bi-national regulation targeting ships entering the Great Lakes since the mid-2000s has been remarkably effective in reducing a large proportion of the invasive species in the world's largest freshwater ecosystem. The study by Anthony Ricciardi, (Professor of Biology in the Redpath Museum and Bieler School of Environment, McGill University) and co-author Hugh MacIsaac (Professor and Canada Research Chair in the Great Lakes Institute for Environmental Research, University of Windsor) was recently published in Conservation Letters.