Book excerpt: TRB Special Report 291: Great Lakes Shipping, Trade, and Aquatic Invasive Species reviews existing research and efforts to date to reduce aquatic invasive species introductions into the Great Lakes and identifies ways that these efforts could be strengthened toward an effective solution. Since its opening in 1959, the St. Lawrence Seaway has provided a route into the Great Lakes not only for trade, but also unfortunately for aquatic invasive species (AIS) that have had severe economic and environmental impacts on the region. Prevention measures have been introduced by the governments of Canada and the United States, but reports of newly discovered AIS continue, and only time will tell what impacts these species may have. Pressure to solve the problem has even led to proposals that the Seaway be closed. The committee that developed the report recommends that trade should continue on the St. Lawrence Seaway but with a more effective suite of prevention measures to reduce the introduction of aquatic invasive species that evolves over time in response to lessons learned and new technologies.