barrier island
a long ridge of sand or narrow island that lies parallel to the shore
benthic zone
The bottom region of oceans and bodies of fresh water
benthos
organisms (plants and animals) that live at or near the bottom of a sea
coral reef
a limestone ridge found in tropical climates and composed of coral fragments that are deposited around organic remains
estuary
an area where fresh water from rivers mixes with salt water from the ocean
eutrophication
an increase in the amount of nutrients, such as nitrates, in a marine or aquatic ecosystem
littoral zone
a shallow zone in a freshwater habitat where light reaches the bottom and nurtures plants
mangrove swamp
a tropical or subtropical marine swamp that is characterized by the abundance of low to tall trees, especially mangrove trees
nekton
all organisms that swim actively in open water, independent of currents
plankton
the mass of mostly microscopic organisms that float or drift freely in freshwater and marine environments
salt marsh
a maritime habitat characterized by grasses, sedges, and other plants that have adapted to continual, periodic flooding; salt marshes are found primarily throughout the temperate and subarctic regions
wetlands
landscapes that are covered with water for at least part of the year