This report is an executive summary of the major findings and recommendations Of the Upper Great Lakes Connecting Channels Study. These findings and recommendations are based upon data collected in 1985 and 1986. It is volume 1 of a 3 volume set. The study is a landmark in advancing the overall understanding of environmental conditions in the Great Lakes Basin. It is a unique cooperative undertaken by eleven institutions at the federal, state, provincial and municipal levels to access the environmental quality of the Detroit, St. Mary's, St. Clair Rivers, and Lake St. Clair. It seeks to identify the major pollution sources of these waters, and to recommend actions to ensure the remediation and protection of these waters.