Aquatic Ecosystems

Freshwater Ecosystems Streams Rivers Ponds and lakes

Streams Streams start at the top of mountains. They are clear, fast moving, and cold. Animals that live in streams have hooks or suckers to help them stick to the bottom, and not get pulled away. Some animals have stream line bodies, like trout, so they can swim against the current. It is hard for plants to grow so the animals mostly eat insects and plant that fall into the water from the shore

Rivers When the small streams join together they become warmer, slower, cloudy with soil, and contain less oxygen than the small, higher streams. Plants can grow easily in these rivers, and the animals depend on these plants for food.

Ponds and Lakes The rivers sometimes collect into lakes or ponds. Ponds are shallower that lakes, so more sunlight can get through to the bottom. This means that plants can grow and support the other organisms. In lakes it is harder for the plants to grow, so the lake life depends on algae growing at the surface. Some bacteria and animals, like catfish, live on the bottom and eat waste from other organisms on the surface.

Marine Ecosystems Estuary Intertidal Zone Neritic Zone The Open Ocean

Estuary An estuary is where freshwater rivers and salt water meet. Organisms like crabs, worms, clams, fish, plants, like algae live there. These organisms are special because they can keep their bodies consistent, while the water they live changes in the amount of salt it has.

Intertidal Zone The intertidal zone is between the high tide line, and the low tide line. Organisms that live there are pounded by waves, and are used to changes in temperatures. They cling to rocks, like barnacles, or dig into the the sand, like clams and crabs, to keep from being washed away.

Neritic Zone The Neritic zone is below the low tide line, where the water is still shallow. This water gets a lot of sunlight, so many organisms can thrive there. If the water is warm coral reefs can sometimes grow.

The Open Ocean There are two parts of the open ocean; the surface zone, and the deep zone. The surface zone is the top few hundred feet of water. There is a lot of sunlight in this water so algae can grow. The other organisms in the water depend on the algae. Below the surface zone is the deep zone where it is dark, and the animals look strange. These organisms depend on the waste that floats down from the surface zone.

Photo sources Slide 4: Slide 6: Slide 8: Slide 11: Slide13: Slide 16: Ever slide background: