Create an account
single and continuous body of water, divided by geographers into the Atlantic, Pacific, Arctic, and Indian Oceans (separated by continents)
aquatic life zone
Marine & freshwater portions of the biosphere. Examples include freshwater life zones (such as lakes and streams) and ocean or marine life zones (such as estuaries, coastlines, coral reefs, and the open ocean).
This term is used to describe a mix of freshwater and saltwater. Examples include estuaries.
Small plant organisms (phytoplankton) and animal organisms (zooplankton) that float in aquatic ecosystems
"drifting plants" includes many types of algae. They are primary producers that support most aquatic food webs. Can be found near shorelines.
"drifting animals" Primary consumers (herbivores) that feed on phytoplankton or secondary consumers that feed on others (of their own kind). They range from single-celled protozoa to large invertebrates such as jellyfish.
Consists of huge populations of much smaller plankton that are photosynthetic bacteria. They may be responsible for 70% of the primary productivity near the ocean surface.
strongly swimming consumers such as fish, turtles, and whales that can swim against the current.
consists of bottom dwellers such as oysters, which anchor themselves to one spot; clams & worms, which burrow into the sand or mud; and lobsters and crabs, which walk about on the sea floor.
mostly bacteria. Break down organic compounds in the dead bodies & wastes of aquatic organisms into nutrients that can be used by aquatic primary producers.
In deep aquatic systems, photosynthesis is largely confined to this upper layer through which sunlight can penetrate. The depth of this zone can be reduced when the water is clouded by excessive algal growth resulting from nutrient overloads.
The warm, nutrient-rich, shallow water that extends from the high-tide mark on land to the gently sloping, shallow edge of the continental shelf. It makes up less than 10% of the world's ocean area but contains 90% of all marine species & is the site of most large commercial marine fisheries. Include estuaries, coastal wetlands, mangrove forests, and coral reefs. Has a high NPP per unit of area due to ample supplies of sunlight & plant nutrients from wind and ocean currents' distribution from the land.
where rivers meet the sea. They are partially enclosed bodies of water where seawater mixes with freshwater as well as nutrients & pollutants from streams, rivers, & runoff from the land.
coastal land areas covered with water all or part of the year. Include river mouths, inlets, bays, sounds, and salt marshes in temperate zones, and mangrove forests in forest zones.
Consist of 60+ species of plants that grow underwater in shallow marine & estuarine areas along most continental coastlines. These highly productive & physically complex systems support a variety of marine species. They also help stabilize shorelines & reduce wave impacts.
tropical equivalent of salt marshes, found along 70% of gently sloping & silty coastlines in tropical & subtropical regions, esp. SE Asia
area of shoreline between low & high tides. Organisms living in this zone must be able to avoid being swept away or crushed by waves, & must deal with being immersed during high tides & left high & dry (& much hotter) at low tides, as well as changing levels of salinity when heavy rains dilute saltwater.
dimly lit middle zone, which, because it gets little sunlight, does not contain photosynthesizing producers.
showers of dead & decaying organisms drifting down from upper lighted levels of the ocean. Reason why abyssal zone teems with life.
Organisms which pass water through/over their bodies & extract nutrients from it, e.g. oysters, clams, sponges
large natural bodies of standing freshwater formed when precipitation, runoff, or groundwater seepage fills depressions in the earth's surface. Causes of depressions include glaciations, crustal displacement, & volcanic activity. Are supplied with water from rainfall, melting snow, & streams that drain their surrounding watershed.
top layer near the lakeshore and consists of the shallow sunlit waters to the depth at which rooted plants stop growing. Species living here include turtles, frogs, crayfish, & many fishes such as bass, perch, & carp.
the open, sunlit surface layer away from the lakeshore that extends to the depth penetrated by sunlight. Produces the food & oxygen that support most of the lake's consumers.
lake bottom inhabited mostly by decomposers, detritus feeders, & some fishes. Nourished mainly by dead matter that falls from the littoral & limnetic zones & by sediment washing into the lake
lakes that have a small supply of plant nutrients; poorly nourished. Often deep and has steep banks
lakes with a large supply of nutrients needed by producers; well nourished. Often shallow with murky brown/green water with high turbidity.
The acceleration of eutrophication of lakes caused by human inputs of nutrients from the atmosphere & from nearly urban & agricultural areas
aka drainage basin, the land area that delivers runoff, sediment, & dissolved substances to a stream.
headwaters/mountain highland streams are usually shallow, cold, clear, and swiftly flowing in this zone.
in this zone, headwater streams merge to form wider, deeper, & warmer streams that flow down gentler slopes with fewer obstacles. They can be more turbid, slower flowing, & have less DO.
In these zones, streams join into wider & deeper rivers that flow across broad, flat valleys. Are usually higher in temperature and have less DO
In the summer, this wet ecosystem can be considered to be an example of inland wetlands.
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together