Water EcosystemsChapter B1

Lesson 4

Types of EcosystemsWater takes up more than 70% of the Earth’s

surface. That means that if you divided the Earth into ten equal parts, seven of those equal parts would be made of water.

The water on earth is categorized into two groups: freshwater ecosystems and saltwater ecosystems.

Saltwater is water that has a lot of salt in it.Freshwater is water that contains very little

salt.

Saltwater Ecosystems

Oceans, seas, and some lakes are examples of saltwater ecosystems.

The amount of salt in each one is not the same.

Plants and animals live in the shallow (not deep) parts because the suns shines more in these areas.

Ocean ZonesOceans are the world’s largest ecosystem. Water is deeper is some places than in

others and the water temperature also changes.

The ocean is divided into three zones. The zones are defined by how much sunlight they get.

The deeper the water, the colder and darker it becomes.

Plants and animals can be found in the areas closer to the surface.

Ocean Zones (continued)

Animals Found in Saltwater Ecosystems

fish

whales

penguins

sharks

crustaceans

sponges

Freshwater EcosystemsThese include rivers, streams, lakes, and

ponds.Rivers and streams have moving water. The

water may be moving fast or slow. Lake are usually larger and deeper than

ponds. Just like in the oceans, plants and animals

live in the shallow (less deep) parts. The sun shines more in the shallow parts.

Animals Found in Freshwater Ecosystems

Puffer fish

Bullfrog

Turtle

Trout

Pelican

Otter

Grebe

Are these saltwater or freshwater ecosystems?

ReviewWhat are two kinds of water ecosystems?Which zone of the ocean gets the least

amount of sunlight?Name some freshwater ecosystems?

Saltwater ecosystems?In both types of ecosystems, where can

the most plants and animals be found? Why?