Aller directement au contenu.

Highlights - 2014

A Fragile Balance

Overall, most indicators remained moderate. Based on their respective indicators, the upper estuary, the lower estuary and the Gulf of St. Lawrence sections seemed to show signs of greater degradation than the fluvial section and fluvial estuary. However, the scale of observation of the indicators is very important and the findings can differ from one sector of the St. Lawrence to another.

  • In the 2003, 2008 and 2014 overview, 67% of the common indicators  remained in the moderate and moderate-good categories.
  • From 2008 to 2014, 43% of the common indicators remained stable, while the rest was split equally between deterioration and improvement.

Long description

This figure represents the distribution of the state of each indicator on a scale from poor to good. Each indicator is identified by a symbol and the colored circle around it is the same color as the status it represents. The classes of states are as follows: poor (red), moderate-poor (orange), moderate (yellow), moderate-good (yellowish-green), and good (green). The upper part represents indicators for the marine environment, i.e. the upper estuary, the lower estuary and the Gulf, and the lower part represents the fluvial section and estuary.

Figure 3
Figure 3. Distribution of indicators assessed in 2014 based on the findings of their current state

Monitoring Activities



Débit et niveau d’eau
Flow and water level

The average annual flows of 2008, 2009 and 2011 were very close to the historic 50th percentile (1933-2012); however, 2010 and 2012 were two years of low flows. From 2008 to 2012, the  findings reveal an average to low flow.
Contamination de l’eau par les toxiques
Toxic water contamination
In terms of toxic water contamination, the substances of most concern are PBDEs, and pharmaceuticals and personal care products.
Paramètres physicochimiques et bactériologiques
Bacteriological and physicochemical quality
According to the index of bacteriological and physicochemical quality (IQBP), water quality was in the moderate-good category in 2008-2010. However, the percentage of stations where IQBP was good or satisfactory decreased from 75% in 2003-2005 to 67% in 2008-2010.

Processus océanographiques
Oceanographic processes

Among the oceanographic processes, several physical changes (milder, almost ice-free winters, early springs, and the warming of summer surface waters) have been observed in the Gulf over the past decade.

Salubrité des eaux coquillières
Shellfish waters

The shellfish waters of the Magdalen Islands and the Lower North Shore are of excellent quality. However, shellfish waters in the Gaspé Peninsula and Lower St. Lawrence are more strongly affected by anthropogenic bacterial contamination.


Contamination des sédiments par les toxiques
Toxic contamination in sediments
Regarding toxic contamination in sediments, the fluvial section between Montreal and Sorel has the most highly contaminated sediment sites and the highest number of substances exceeding the criteria.

Biological Resources

Communautés benthiques
Benthic communities
The fluvial section and Sorel islands have a diminished richness of benthic macroinvertebrates and a higher proportion of species tolerant to pollution.
Communauté phytoplanctonique et zooplanctoniqueCommunauté phytoplanctonique et zooplanctonique
Phytoplankton and zooplankton communities
Changes in oceanographic processes have led to changes in the phytoplankton and zooplankton communities; these changes include early spring phytoplankton blooms and changes in the zooplankton community that favor Atlantic species to the detriment of Arctic species.

Algues toxiques
Toxic algal

The increased warming of surface waters in summer increases the risk of toxic algal bloom.

Bar rayé
Striped Bass

Striped Bass is showing encouraging signs of recovery. Its distribution, rate of growth and abundance are improving. The natural reproduction of Striped Bass demonstrates that the species is in a favorable environment; this progress marks an important milestone for the species' recovery in the St. Lawrence River.
Contamination des poissons par les toxiques
Contamination of fish by toxic substances
As for fish contamination in the fluvial lakes, only mercury in Walleyes and Northern Pikes in Lake Saint-Louis, and PBDEs and PCBs in White Suckers in Lake Saint-Pierre are still a concern.
Communautés de poissons
Fish Communities
The health status of fish communities has remained stable overall since 1995. However, in Lake Saint-Pierre, Yellow Perch have suffered a major decline, mainly due to the degradation of its habitat.


The St. Lawrence beluga population is still threatened, but the situation has worsened due to a decline in abundance, high mortality of newborns in 2008, 2010 and 2012, and a decrease in the proportion of immature belugas and newborns.

Fou de Bassan
Northern Gannets

Northern Gannets are showing signs of difficulty with a loss of abundance and a significant decline in reproductive success. However, the concentrations of toxic contaminants in eggs are all below the criteria.
Contamination du Grand Héron par les toxiques
Contamination of the Great Blue Heron by toxic substances
Among the contaminants measured in Great Blue Heron eggs, only PBDEs slightly exceeded the criteria at three of the four colonies analyzed.

Oiseaux marins

Among the seabirds, the populations of Herring Gulls, Common Murres and Razorbills are in good shape, while the Atlantic Puffin population has been declining since 1993, and Caspian Terns are still very scarce.

Milieux humides

The loss of wetlands due to direct human intervention declined sharply. However, the Boucherville Islands sector is still undergoing relative drying and the wetlands of Lake Saint-Pierre sector are bordered by a low proportion of natural environments.

Espèces envahissantes
Invasive species

Boucherville and Lake Saint-Pierre are the sectors most heavily affected by invasive plants. The most problematic species is the Common Reed.

Go to 2014 Overview


Overview 2014

  • Standardized visual signature
  • Harmonized status classes
  • More systematic use of criteria or reference thresholds
  • Mapping information at local, sector and overall levels per indicator
  • Integration of monitoring results in an overall finding

Overview 2014

[Translate to English:] Couverture du Portrait Global 2014


Logo du Gouvernement du Canada

Government of Canada

  • Environment Canada
  • Fisheries and Oceans Canada
  • Parks Canada

Logo du Gouvernement du Québec

Government of Quebec

  • Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques
  • Ministère des Forêts, de la Faune et des Parcs

Non-Governmental Organizations

  • Stratégies Saint-Laurent