Water quality issue: nutrients

As a result of run-off and leaching from agricultural fields and municipal wastewaters, nutrients (phosphorus and nitrogen) are finding their way into aquatic ecosystems. High levels can cause eutrophication - impairment due to the over-production of algae. Scientists from Environment and Climate Change Canada’s Water Quality Monitoring and Surveillance programme assess the levels and trends over time of nutrients in selected ecosystems.

Web articles

Phosphorus at the mouths of lake Saint-Pierre Tributaries (2014)

Between 2005 and 2014, the average concentrations of phosphorus measured at the mouths of the Saint-François and Nicolet rivers oscillated around values corresponding to a eutrophic environment. However, it was at the mouth of the Yamaska River that the highest concentrations were observed and where conditions were hypereutrophic.

Canada-U.S. Great Lakes Water Quality Agreement : Nutrients

Canada and the United States recognize the urgent need to manage phosphorus concentrations and loadings that are contributing to algae problems.

Phosphorus in Canada’s Aquatic Ecosystems (2011)

Scientists have been tracking and researching nutrients in freshwaters across Canada since the 1960’s. The following article provides highlights of a national level assessment of nutrients in Canadian watersheds based on data from Environment Canada water quality monitoring stations operated in conjunction with federal, provincial and territorial partners.

Phosphorus and Excess Algal Growth (2011)

During the 1960s, water quality issues in the Great Lakes became a public concern. In particular, Lake Erie was perceived to be ‘dying’ because of extensive algal growth that occurred throughout the lake as a result of excessive inputs of phosphorus.

Technical summaries, reports and scientific papers

Nutrients in Lake Winnipeg (2016)

Canadian Environmental Sustainability Indicators

Nutrients in the St. Lawrence Rive (2016)

Canadian Environmental Sustainability Indicators

Phosphorus and deepwater oxygen relationships in Lake Simcoe (2011)

This study revisited the relationships linking phosphorus loading to oxygen concentrations since the invasion of zebra mussels in the 1990s.

Water Quality Status and Trends of Nutrients in Major Drainage Areas of Canada (2011)

This report is a first-ever national level assessment of nutrients in Canadian watersheds. It is based on data from Environment and Climate Change Canada water quality monitoring sites operated in conjunction with federal, provincial and territorial partners. Status (2004-06) and trends (1990-2006) were assessed for four nutrient species.

Nutrients and Their Impact on the Canadian Environment (2001)

National Water River Institut led a comprehensive review of the effects of nutrients from human activities on the Canadian environment. Undertaken to meet the Government of Canada's commitment to the Parliamentary Standing Committee on Environment and Sustainable Development, the review documents the nature of nutrients and their impacts on Canadians health.