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scientific study of interactions among organisms and between organisms and their environment
a condition in a lake or other body of water that is characterized by lush phytoplanktonic growth followed by high amounts of decay in the bottom resulting in depletion of oxygen in the water column.
a region including the bottom of the sea and the littoral zones
Portion of the marine biome that is shallow enough for sunlight to penetrate.
a moderately nutrient rich lake with moderately productive phytoplankton, between an oligotrophic lake and eutrophic lake
temperature, forms of energy, water, inorganic nutrients, and other chemicals
deeper water that never receives sunlight
Ecosystems of several types in which vegetation is surrounded by standing water during part or most of the year
In water, a distinctive temperature transition zone that separates an upper layer that is mixed by wind (the epilimnion) and a colder, deep layer that is not mixed (the hypolimnion)
the area where a freshwater stream or river merges with the ocean
Perennially frozen layer of the soil that forms when the water there freezes. It is found in arctic tundra.
All the organisms that are part of the environment
group of individuals of the same species that live in the same area
bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms
The narrow ocean margin between the high tide mark and the low tide mark.
a group of interdependent organisms inhabiting the same region and interacting with each other
area of ocean that extends from the low-tide line out to the edge of the continental shelf
collection of all the organisms that live in a particular place, together with their nonliving environment
particles of organic material that provide food for organisms at the base of an estuary's food web
vast open ocean from the edge of the continental shelf outward
all the parts of the planet that are inhabited by living things; sum of all Earth's ecosystems
a shallow zone in a freshwater habitat where light reaches the bottom and nurtures plants
a condition of a lake or other body of water characterized by low nutrients, low productivity, and high oxygen levels in the water column.
a natural community of plants and animals, its composition being largely controlled by climatic conditions.
The area of the ocean past the continental shelf, with areas of open water often reaching to very great depths.
the area in a freshwater habitat that is away from the shore but still close to the surface
the deepest area of a large lake characterized by colder waters and lower oxygen levels