St. Lawrence River: water and sediment

Scientists at the Government of Canada undertake several projects regarding freshwater quality monitoring in aquatic ecosystems. The St. Lawrence River is one of the Canadian aquatic ecosystems for which water quality information is available in this section.

• Monitoring the water quality of the St. Lawrence River
  Ten freshwater sampling sites on the St. Lawrence River and a few tributaries serve to assess the water quality.
• Sediment quality in Atlantic ocean watershed
  Sediments are generally less contaminated than they were 20 years ago. Yet, concentrations of some susbtances have remained unchanged or are even increasing.
•  What is the status of benthic communities in lake St. Pierre?
  Macroinvertebrates-insects, worms and molluscs that live on the bottom of lakes and rivers- are used as environmental indicator.
• Water quality in the fluvial section: contamination by toxic substances
  Polybrominated diphenyl ethers, metals, pesticides and pharmaceutical products have been analysed at four water sampling sites of the St. Lawrence River.
• Phosphorus at the mouths of lake Saint-Pierre tributaries
  What is the contribution of Yamaska, Saint-François and Nicolet rivers regarding the phosphorus observed in lake Saint-Pierre.
• Drug cocktail in the St. Lawrence River offers no relief to aquatic organisms
  Around 15 pharmaceutical, and personal care products (PPCPs), and other substances were detected int the water of the St. Lawrence River.
• Pesticides are entering the St. Lawrence River through its tributaries
  Atrazine and metolachlor were found most frequently and in the highest concentrations.
• PBDEs, contaminants of emerging concern accumulating in the St. Lawrence food network
  Sample of sediment, suspended matters, aquatic organisms and birds' eggs were analysed to detect the presence of PBDEs in the food Web and to determine the impact of wastewater discharges on the concentrations measured.
  St. Lawrence River: Tracking polybrominated diphenyl ethers (PBDE)
  Polybrominated diphenyl ethers, or PBDEs, accumulate in the environment, including the sediment of the St. Lawrence River.
• Changes in the wetlands of the St. Lawrence River
  Aquatic grass beds accounted for only 10 % of wetlands in Boucherville Islands park in 2010. Their surface area was four times larger in 2002.