Aquatic Ecosystems Chapter 19 Lesson 3

Types of Ecosystems Water 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 & Lakes Ponds are shallow and warm and sunlight can usually reach the bottom Lakes 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

Wetlands Aquatic ecosystems that have a thin layer of water covering soil that is wet most of the time. Contain freshwater, saltwater, or both Wetland 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

Estuaries Regions 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 Zones Oceans 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 Zone Twilight Zone Dark 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 Ecosystems Open 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 Ecosystems Ocean: 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 Ecosystems Coral Reef is an underwater structure made from outside skeletons of tiny, soft- bodied animals called coral. Most are in shallow tropical oceans They protect coastlines from storm damage Provide food and shelter for many animals Pollution, 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.