Aquatic EcosystemsChapter 19

Lesson 3

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.Salinity is the amount of salt dissolved in water.

Freshwater is water that contains very little salt.

Freshwater Ecosystems rivers & streams, Rivers and streams have moving water. The

water may be moving fast or slow. Streams are often clear and form

underground.Rivers form when streams run together.

Biodiversity-Water-loving plants-Species adapt to fast/slow moving water

Human Impact-People take out the water-Hydroelectric dams stop water-Runoff a source of pollution

Freshwater Ecosystem

Ponds & LakesPonds are shallow and warm and

sunlight can usually reach the bottomLakes are larger and colder where

sunlight barely reaches the bottom

Human Impact-Humans fill-in ponds/lakes-Run-off washes pollutants into water

Biodiversity-Plants surrounds ponds/lakes-Fewer organisms live in deeper, colder water of lakes

WetlandsAquatic ecosystems that have a thin layer

of water covering soil that is wet most of the time.

Contain freshwater, saltwater, or bothWetland trap sediments and purify water.

Biodiversity-Few trees live in saltwater wetlands-Insects are abundant-More than 1/3 of NAm birds species use wetlands-alligators, turtles, frogs, snakes

Human Impact-Once drain off and built on-Now, major preservation and focus on restoring wetlands

EstuariesRegions along coastlines where streams

or rivers flow into a body of saltwater.Salinity depends on rainfall, freshwater

flowing from land and tides.Protect coastal land Filter out pollution

Biodiversity-Many ocean animals lay their eggs in estuaries-Many species of birds depend on estuaries for breeding, nesting, and feeding

Human Impact-Filled in for land and destroys natural habitats.-Exposed coastlines are prone to coastal flooding and storm damage

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.Sunlight ZoneTwilight ZoneDark Zone

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

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

Saltwater EcosystemsOpen Oceans: from continental shelf to

deep ocean.Photosynthesis can take place only where

the sunshine reaches. Little in Twilight Zone and none in the Dark Zone/sea floor

Decaying matter and nutrients float down Biodiversity-Microscopic algae and other producers are the base of most ocean food chains.-Most animals live in light or twilight zones-Dark zones have lava eruptions

Human Impact-Overfishing-Trash discarded on cruise ships and from the land greatly impact ocean life

Saltwater EcosystemsOcean: Coastal Oceans/Intertidal Zones is the

ocean shore between the lowest low tide and the highest high tide.

Sunlight reaches the bottom of shallow coastal ecosystems

Nutrients washed in from rivers and streams contribute to high biodiversity.

Intertidal species have adaptations for the extreme living conditions of low tide and heavy waves of high tide.

Oil spills can destroy all living organisms.

Saltwater EcosystemsCoral Reef is an underwater structure

made from outside skeletons of tiny, soft-bodied animals called coral.

Most are in shallow tropical oceansThey protect coastlines from storm damageProvide food and shelter for many animalsPollution, overfishing, and harvesting

threaten coral reefs.

Animals Found in Saltwater Ecosystems

fish

whales

penguins

sharks

crustaceans

sponges

Animals Found in Freshwater Ecosystems

Puffer fish

Bullfrog

Turtle

Trout

Pelican

Otter

Grebe

The largest source of freshwater on earth is ice sheets, glaciers, and icebergs.

The Great Lakes are the largest fresh water on the planet.