15 terms


Aquatic Ecosystems
Continental Shelf
A relatively shallow seabed surrounding a continent.
Tiny soft-bodied animals that make up an underwater structure with its skeletons.
Dark Zone
Ocean zone where it is very deep and no light reaches.
Intertidal Zone
The ocean shore between the lowest low tide and the highest tide.
The amount of salt dissolved in water.
Sunlit Zone
Ocean zone where photosynthesis can take place.
Twilight Zone
Ocean zone where very little sunlight reaches.
Freshwater, Wetland, Estuary, Ocean
The four major types of aquatic ecosystems.
Rivers and Streams
Form from underground sources of water, such as springs or from runoff from melting snow. Water is often clear. Soil particles are quickly washed downstream. Oxygen levels here are high because air mixes into the water as it splashes over rocks. Soil introduces nutrients such as nitrogen. When slow-moving, has higher levels of nutrients and lower levels of dissolved oxygen.
Ponds and Lakes
Not flowing downhill and in low areas of land. One is shallow and warm the other is larger and deep. Sunlight reaches the bottom of most of one and penetrates into the top few layers of the other.
Have a thin layer of water covering soil that is wet most of the time. Contains freshwater, salt water, or both. Most fertile ecosystem. Form at the edges of lakes and ponds in low areas on land. Saltwater ones are form along ocean coasts. They trap sediments and purify water. Plants and microscopic organisms filter out pollution and waste materials.
Along coastlines where streams or rivers flow into a body of salt water. Salinity depends on rainfall, the amount of freshwater flowing from land, and the amount of salt water pushed in by tides. Help protect coastal land from flooding and erosion. Purify water and filter out pollution. Nutrient levels and biodiversity are high.
Open Ocean
High salinity, from steep edges of continental shelves to the deepest part of the ocean. Amount of light depends on depth. Decaying matter and nutrients float down from the sunlit zone, through the twilight and dark zones, to the sea floor.
Costal Ocean
Includes several types of ecosystems such as the Continental Shelf and Intertidal Zone. Sunlight reaches the bottom of shallow parts. Nutrients washed in from rivers and streams contribute to high biodiversity.
Coral Reefs
Underwater structure made from the outside skeletons of tiny, soft-bodied animals. Most form in shallow tropical oceans. Protect coastlines from storm damage and erosion.