The Canadian Environmental Sustainability Indicators (CESI) program provides data and information to track Canada's performance on key environmental sustainability issues. The Nutrients in the St. Lawrence River indicator reports on the status of total phosphorus and total nitrogen concentrations along the St. Lawrence River. It rates total nitrogen and total phosphorus status based on whether total phosphorus and total nitrogen concentrations exceed Quebec's total phosphorus water quality guideline for the protection of aquatic life and a total nitrogen water quality guideline for the protection of aquatic life specific to the St. Lawrence River. Exceeding a water quality guideline suggests a greater risk to the health of the St. Lawrence River ecosystem posed by phosphorus and/or nitrogen.Information is provided to Canadians in a number of formats including: static and interactive maps, charts and graphs, HTML and CSV data tables and downloadable reports. See supplementary documentation for data sources and details on how those data were collected and how the indicator was calculated.