Virtual Museum of Canada




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Sun reflection on water

Aquatic plants absorb energy from sunlight through photosynthesis.

Aquatic plants in a channel

To grow, they also need nutrients (phosphorus and nitrogen), which they absorb from the water.

Cow in a field

The availability of phosphorous and nitrogen is the main factor limiting plant growth.

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Farmhouses in the background in the archipelago

The tributaries of Lake Saint-Pierre are particularly rich in phosphorus and nitrogen because they pass through agricultural areas. This abundance of nutrients promotes plant growth and results in invasive growth of aquatic plants.

Aerial photo of Île du Moine

Aerial photograph showing île du Moine

The tributaries are enriched by the fertilizers spread on farmland.

White flowers and leaves of Arrowheads


Fertilizers leach into aquatic environments.

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Great Blue Heron fishing in a marsh.

Great Blue Heron in a marsh

This raising nutrient loads greatly increase aquatic plant growth in Lake Saint-Pierre.

Underwater view of a Pond-lily leaf

Pond-lily leaf

As part of the process of photosynthesis, plants release oxygen into the water. This element is essential for aquatic organisms.

Muskrat swimming among common duckweeds.

Muskrat among common duckweeds

Plants also transform the sun’s energy into organic matter.

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Common Snipe walking on aquatic plants.

Common Snipe

This matter is then used by other organisms higher up the food chain.

Young Black-crowned Night Heron with a fish in the beak.

Young Black-crowned Night Heron

Young Black-crowned Night Heron eats fish.

Virginia Rail dipping its beak into the water.

Virginia Rail

The Virginia Rail eats small invertebrates.

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