Lac Saint-Pierre Biosphere Reserve



       Region/Province/ or State


       Web Address

       Date Founded

   Size (hectares)


       Distinguishing Features

most important archipelago of the Saint Lawrence River with more than 100 islands

       Main Industries (in terms of employment)

fishery, hunting, agriculture, commerce


Regional Consultation 1994

The recognition project for the Lac Saint-Pierre region as a biosphere reserve was initiated in the early 1990s by the Tourist Office “The Valleys of the Lac Saint-Pierre Archipelago”. The Bas-Richelieu initiative and conservation society took over from 1994. From the outset, the project was the subject of extensive regional consultation and was endorsed by many political and economic stakeholders. of the greater Lac St. Pierre area.

EcoSummit 1996

The Lac-Saint-Pierre Biosphere Reserve project was prioritized by the three administrative regions of Lac Saint-Pierre and presented as part of the ÉcoSommet1996, initiated by the Government of Quebec. As a result of this initiative, the project was selected as one of the most promising files for the future in Quebec.

Recognition of UNESCO 2000

On November 9, 2000, UNESCO recognized Lac Saint-Pierre, Quebec, as a biosphere reserve. Six years of hard work and an unswerving faith in sustainable development principles have made a vast region a part of a promising project in Quebec. This title was obtained thanks to the tenacity of the three co-founders of the Biosphere Reserve: Normand Gariépy, Hélène Gignac and Louis Gagné.

Source: Cooperation Plan. Solidarity Cooperative of the Lac-Saint-Pierre Biosphere Reserve, 2002, p. 4


Location and general situation

Lac Saint-Pierre refers to a widening of the St. Lawrence River between Sorel and Trois-Rivières. The region is located in the heart of Québec, a short distance from the main urban centers of the province. For example, it is located 65 km east of Montreal. The territory remains 90% natural and forms the last freshwater basin of the St. Lawrence.

The most important archipelago of the St. Lawrence

Lac Saint-Pierre is nearly 30 km long and 13 km wide and covers an area of ​​about 500 km2. In the upstream part of the lake is the archipelago of Sorel, a system composed of a hundred islands and channels. The average depth of the lake is only 3 meters, with the exception of the 11.3-meter-long navigation channel at its center.

Wetlands of International Importance

Lac Saint-Pierre was designated as a RAMSAR site in 1998 for the exceptional quality of its wetlands, protected habitats and wildlife developments dedicated to the conservation of the territory’s biodiversity.

This group of marshes, swamps, emergent and submerged seagrasses represents 20% of all marshes and 50% of all wetlands in the St. Lawrence River. Marshes covering more than 8,000 ha and aquatic grass beds extending over more than 6,200 ha have significant wildlife value.

An exceptional biological diversity

Lac Saint-Pierre presents a fascinating diversity of plants and animals. However, several species such as perch, are in difficulty and show a marked decline.

Amphibians and reptiles include the snapping turtle and painted turtle, bullfrog, green frog and leopard frog. Finally, of smaller size, but essential to the good functioning of the ecosystems, molluscs, crustaceans, insects and their larvae, plankton as well as bacteria live on all the stages of the lake.

The most important flood plain of the St. Lawrence

It has the largest freshwater floodplain in Quebec. In spring, the waters submerge more than 7,000 ha of natural grasslands, shrubs, riparian forests and 4,000 ha of cropland.

In addition, 79 species of fish, 70% of Quebec’s freshwater species, frequent Lake Saint-Pierre. The brown bullhead, northern pike, sunfish, walleye are some examples. More than half of the lake’s species benefit from different types of wetlands to breed and feed in the spring. For example, northern pike and yellow perch spawn in the floodplain during spring floods, and young fish return to the lake when the water recedes.

The largest waterfowl stunt in Eastern Canada

Lac Saint-Pierre has a unique ecosystem that is essential for birds following the North Atlantic Flyway.

Submerged waters are used by more than 800,000 birds during spring migration. It is the largest migratory stopover in eastern Canada for waterfowl. While some species, such as geese and snow goose, are only a short halt, 168 bird species stay longer to breed. The lake is home to 288 bird species, representing 72% of Québec’s species.

The most important heronry in North America

Lac Saint-Pierre is home to the largest heronry in North America with 1,300 breeding pairs. The importance of Lac Saint-Pierre for bird fauna is well recognized: four areas of the lake and its shoreline are considered areas of interest for the conservation of birds (IBA).

Several sensitive wildlife and plant species

In the littoral zone, 67 species threatened, vulnerable or likely to be designated as threatened or vulnerable have been observed. It contains 50% of invertebrate species, 27% of wildlife species and 11% of sensitive plant species. Among the most common are the Short-billed Troglodyte, the Sand Darter and the Grass Ledge, as well as the dragon arisema. Several sites of good quality or rarity for the copper redhorse and lizard lizard for example, are also listed. They are of great importance for the conservation of these sensitive species.

Human activities and conservation actions

What’s more, this exceptional environment meets every day a host of human activities: agriculture, hunting, fishing, wildlife development, vacationing, boating, merchant shipping, trade and light industry. Over the past decade, the Lac Saint-Pierre region has been the location in Quebec that has benefited the most from wildlife habitat conservation efforts. So, it’s over $ 15,000,000 invested in conservation, mainly through the acquisition and development of private lands by various governments and conservation organizations.

The federal and provincial governments have made considerable efforts to monitor and rehabilitate the St. Lawrence River. Recent studies on water quality show a progressing improvement over the last 15 years. One of the main challenges of the Lac St. Pierre Biosphere Reserve is to encourage the recovery of some fish species. A collapse in yellow perch stocks has recently led to a moratorium on commercial and sport fishing.

Source: Biosphere Reserve Proposal Form. UNESCO Program on Man and the Biosphere, January 2000, pp. 6-7.

Source: Ministry of Sustainable Development, Environment, Wildlife and Parks (2013). Lac Saint-Pierre. A jewel to restore. Government of Quebec, pp. 2 and 6