Biological and chemical contaminants as drivers of change in the Great Lakes–St. Lawrence river basin

Abstract

Many initiatives since the early 1900s have been implemented to maintain water quality within the Great Lakes–St. Lawrence River basin. Despite these substantial efforts, emerging and re-emerging biological and chemical contaminants continue to pose serious human, animal, and ecosystem health risks. With over 100 biological and chemical contaminants detected in the basin and over 600 persistent and bio-accumulative contaminants listed in international databases, the threat of these contaminants to the basin is immense. This article discusses examples of legacy and emerging contaminants and their interactions with other drivers within the basin. A historical review of these contaminants from the past 50years (1963 to present) has been prepared, as well as a synthesis of their current state. From this information and based on local and global initiatives and reports, three future scenarios for contaminants have been described projecting to the next 50years (present to 2063), which are categorized as Status Quo, Utopian, and Dystopian. These are meant to categorize the possible range of occurrences and help decision makers prepare for various management options and improve resilience to future changes. In addition, we have highlighted some tools that are needed to effectively detect emerging contaminants in the basin. By exploring the plausible future scenarios of contaminants in the basin, we aim to highlight the need for bi-national agreements and initiatives to be developed and extended, both in time and scope, to restore and protect the basin and encourage ecosystem health.