Page 41 - Science Course 3 (Book 1)
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Mo1-L4b: How Do Aquatic Ecosystems Change?
Key Concept
How Do Aquatic Ecosystems Change?
What happens to a pond, a lake, or a wetland over
time?
How Freshwater Ecosystems Change
Eutrophication is the process of a body of water becoming nutrient-rich.
Organic
precipitation
Solar Nutrient Intake
Energy
Algal Bloom
Nutrient Toxic substance
release formation
N, P, C (H S ,NH ,CH )
2 2 3 4
Organic decomposition
Microorganism
Eutrophication is a natural process, but humans High nutrient levels support large populations
contribute to it by introducing fertilizer, waste, and of algae and other microscopic organisms that
other nutrient-rich pollution to a body of water. end up using most of the dissolved oxygen in the
water, leaving less available for fish and other
organisms.
algae bloom
Normal Lake Lake during eutrophication
SUMMARY
How Do Aquatic Ecosystems Change?
The final stage of aquatic succession is a
land ecosystem.
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