Aquatic Ecosystems

2. increase in the amount of nutrients, such as nitrates, in a marine or aquatic ecosystem
6. tropical or subtropical marine swamp that is characterized by the abundance of low to tall trees, especially mangrove trees
7. area where fresh water from rivers, mixes with salt water from the ocean; the part of a river where the tides meet the river current
10. area of land that is periodically underwater or whose soil contains a great deal of moisture
11. limestone ridge found in tropical climates and composed of coral fragments that are deposited around organic remains
12. organisms that swim actively in open water, independent of currents

1. shallow zone in a freshwater habitat where light reaches the bottom and nurtures plants
3. Organisms that live at the bottom of oceans or bodies of fresh water
4. habitat characterized by grasses, sedges and other plants that have adapted to continual, periodic flooding; salt marshes are found primarily throughout the temperature and subartic regions
5. long ridge of sand or narrow island that lies parallel to the shore
8. bottom region of oceans and bodies of fresh water
9. mass of mostly microscopic organisms that float or drift freely in the water of aquatic 9freshwater and marine) environments