Page 28 - Science Course 3 (Book 1)

Aquatic Ecosystems Mo1-L3a: What are the Types of Freshwater?
Lesson 3

Let’s Begin

In this topic, you will learn the following
lessons: Aquatic Ecosystems
There are four major types of water, or aquatic,
Mo.1–L3a: What are the Types of Freshwater? ecosystems: freshwater, wetland, estuary, and
Mo.1–L3b: What are the Types of Aquatic Ecosystems? ocean.

Each type of aquatic ecosystem contains a unique
variety of organisms.
Mo1-L3a What are the Types of Freshwater? Salinity is the amount of salt dissolved in water.
Water in saltwater ecosystems has high salinity
KEY CONCEPTS: compared to water in freshwater ecosystems.
1. How do ponds and lakes differ?

Vocabulary A-Z

Let us learn some vocabulary

Salinity

a measure of the mass of dissolved salts in a mass
of water.

Salinity Increase

Freshwater Brackrish Saltwater

Freshwater: Streams and Rivers

Freshwater ecosystems include streams, rivers,
ponds, and lakes.

Oxygen levels in streams
are high because air
mixes into the water as it
splashes over rocks.

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