Page 40 - Science Course 3 (Book 1)

Mo1-L4b: How Do Aquatic Ecosystems Change?

Mo1-L4b How Do Aquatic Ecosystems Let’s Begin
Change?
KEY CONCEPTS: How Freshwater Ecosystems Change
1. What happens to a pond, a lake or a wetland over
time?

Vocabulary A-Z

Let us learn some vocabulary

Eutrophication Freshwater ecosystems change over time in a
the process of a body of water becoming nutrient natural, predictable process called aquatic
rich. succession.

In aquatic succession the buildup of decomposed
remains accumulate over time as soil.
Explosive algal bloom due to excess nutrients coming
from nitrogen (N) and phosphorus(P) rich pollutants;
oxygen(0 ) consumption by algae, reduced sunlight,
2
breakdown of natural chemical cycles.

Eventually the water disappears and the area
becomes land.

Eutrophication
“Dead Zone”

1. Aquatic succession begins with a body of
water such as a pond.

Duck swimming in a Eutrophication pond Over time, sediments and decaying organism
2-3 build up and create soil. This soil fills the
bottom of the pond or lake.

Eventually the pond or lake fills completely
4.
with soil and a land ecosystem develops.

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