Stand of European common reeds in the fall

The European common reed was introduced to Quebec around 1916. Enormous stands of this invasive plant rapidly took over vast territories, threatening the survival of native plants and reducing wildlife numbers and biodiversity in these wetland habitats.

Philippe Manning
2012-11-20
© 2013, Biophare. All Rights Reserved.


There are nearly 80 species of fish in Lake Saint-Pierre. The main species targeted for sport fishing are Walleye, Largemouth Bass, Northern Pike and Yellow Perch. However, a five-year moratorium on Yellow Perch has been in place since 2012 in Lake Saint-Pierre. This strict measure was necessary to protect this species from extirpation. It is hoped that Yellow Perch stocks will recover over the five-year period, but efforts will have to be made to improve water quality, which has declined significantly in recent years. Low water levels, climate change, agricultural practices that rely on heavy fertilizer use, sedimentation from the erosion of deforested shorelines, outdated water purification plants, and the introduction of invasive exotic species that compete with Yellow Perch for resources have all contributed to the steep decline in Yellow Perch stocks observed in Lake Saint-Pierre.

Once abundant in the Lake Saint-Pierre region, Yellow Perch stocks have declined dramatically due to a variety of factors, from habitat degradation to the introduction of the Round Goby, an invasive exotic species that competes with juvenile Yellow Perch for food. The Round Goby, which is Read More
There are nearly 80 species of fish in Lake Saint-Pierre. The main species targeted for sport fishing are Walleye, Largemouth Bass, Northern Pike and Yellow Perch. However, a five-year moratorium on Yellow Perch has been in place since 2012 in Lake Saint-Pierre. This strict measure was necessary to protect this species from extirpation. It is hoped that Yellow Perch stocks will recover over the five-year period, but efforts will have to be made to improve water quality, which has declined significantly in recent years. Low water levels, climate change, agricultural practices that rely on heavy fertilizer use, sedimentation from the erosion of deforested shorelines, outdated water purification plants, and the introduction of invasive exotic species that compete with Yellow Perch for resources have all contributed to the steep decline in Yellow Perch stocks observed in Lake Saint-Pierre.

Once abundant in the Lake Saint-Pierre region, Yellow Perch stocks have declined dramatically due to a variety of factors, from habitat degradation to the introduction of the Round Goby, an invasive exotic species that competes with juvenile Yellow Perch for food. The Round Goby, which is native to the Black Sea, was transported to Lake Saint-Pierre in ocean vessel ballast water. In 2012, a five-year moratorium was placed on Yellow Perch fishing in the archipelago, the lake and its main tributaries to protect the remaining stocks. Major changes will need to be implemented in various agricultural and industrial activities to improve water quality and restore Yellow Perch stocks to their former abundance in Lake Saint-Pierre.

© 2013, Biophare. All Rights Reserved.

White and yellow buoy indicating the speed limit in the Chenal de Île du Moine.

In the narrower channels, buoys are placed as a clear indication for boaters to slow down. This helps prevent shoreline erosion by reducing the effects of boat wakes.

Francine Ouellet
2012-08-04
© 2013, Biophare. All Rights Reserved.


A woman and a man ride a personal watercraft along a channel.

To protect the shorelines of the islands, boats need to slow down and avoid making large waves. Waves erode the soil along the shore, which is then swept downstream by the current. Islands gradually shrink as their upstream shoreline wears away. Erosion can be caused by currents and moving ice, but is intensified by navigation, deforestation and other human activities. Trees, shrubs, and aquatic plants help retain soil and reduce the impact of waves on the shoreline.

Mario Cloutier
2012-08-04
© 2013, Biophare. All Rights Reserved.


 Eroded shoreline of a channel

In the narrower channels, signs of shoreline erosion are omnipresent. This clearly demonstrates why boats need to slow down.

Mario Cloutier
2012-08-04
© 2013, Biophare. All Rights Reserved.


Two pleasure boats leaving large waves.

During weekends in July and August, the St. Lawrence and the channels of the Lake Saint-Pierre archipelago swarm with boats of all kinds. Such large numbers of boats further weaken the shorelines.

Mario Cloutier
2012-08-04
© 2013, Biophare. All Rights Reserved.


An imposing commercial vessel crosses paths with a pleasure boat on the St. Lawrence.

The shorelines of the islands along the St. Lawrence Seaway are the most affected by erosion. To remedy this, the shipping industry implemented a voluntary speed reduction in sensitive sections of the river in the year 2000.

Mario Cloutier
2012-08-04
© 2013, Biophare. All Rights Reserved.


Notice indicating a risk of explosions near Chenal Landroche.

Until 2000, the Department of National Defence used Lake Saint-Pierre as a firing range. Numerous shells still lie in the sediments south of the St. Lawrence Seaway, making this section of the lake unsafe for navigation. Specialists are working to remove the shells in order to prevent serious accidents that could result from an explosion.

Philippe Manning
2012-08-27
© 2013, Biophare. All Rights Reserved.


Soybean field near the Yamaska

Many rivers, such as the Yamaska, suffer heavy agricultural pollution. Large quantities of sediments loaded with pesticides and fertilizers from the vast fields of corn and soy cultivated in this region run off into the tributaries of Lake Saint-Pierre. Agricultural practices will have to change significantly in the near future to improve water quality in these rivers and prevent Lake Saint-Pierre from filling with sediments and disappearing.

Philippe Manning
2012-09-14
© 2013, Biophare. All Rights Reserved.


Learning Objectives

Educational objectives

  1. Assess the impact of human activities on the environment.
  2. Be able to suggest practices to ensure sustainable development.

Curricular connections

Connections will be established between the virtual exhibit The Human Side of Lake Saint-Pierre and the contents of educational programs: rational resource use for an equitable distribution of wealth; awareness of interdependence between the environment and human activity; citizenship and community life; knowledge related to the organization of a society in its territory.

Learning outcomes

Each team will be able to identify at least two consequences of a type of human activity on the environment.
A class discussion will allow students to draw up an overview of all activities practised in the region.
As a group, the class will propose environmentally respectful ways to practise these activities.

Measures taken to create a lesson plan based on the collection of learning objects

In teams, students will note the information they learn while consulting the sections on various types of human activities practised in the region.

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