abiotic factors - Physical environmental factors (i.e. water, temperature, soil, light) that influence the composition and growth of an ecosystem.

adaptation - A specific structure or behavior that helps an organism survive and reproduce in a particular environment; the process that enables organisms to become better suited to their environment.

aerobic - Any process that requires oxygen.

agriculture - The science or process of farming or cultivating the soil for the production of plants and animals that will be useful to humans in some way.

alderfly - An aquatic macroinvertebrate of the order Megaloptera. Alderfly larvae have projections or filaments, but no wings. They are somewhat sensitive to pollution. image

algae - Varied aquatic protists, or phytoplankton, that lack vascular tissue, and are usually photosynthetic. image

algal bloom - An explosive population increase in algae that occurs when large amounts of phosphates and/or nitrates enter a body of water in the presence of warm temperatures.

anadromous fish - Fish that migrate up rivers from the sea to breed in fresh water.

anaerobic - Lacking or not needing oxygen.

annelids - Aquatic macroinvertebrates of the phylum Annelida; segmented worms with bilateral symmetry, closed circulatory systems, and complete digestive systems; includes leeches. image

apparent color - The color given to water by dissolved substances and suspended matter (i.e. metallic ions, plankton, algae, industrial pollution, and plant pigments). Apparent color provides useful information about the water's source and content.

aquaculture - The production of fish, shellfish, invertebrates, and plants in marine, brackish, or freshwater.

aquatic - Living or growing in or on the water.

aquatic worms - Aquatic macroinvertebrates without legs, including flatworms (planaria), roundworms (nematodes), and freshwater earthworms (oligochaetes). They can tolerate pollution. image

arrow arum - Peltandra virginica or duck corn. Arrow arum is an emergent vegetation found in freshwater wetlands; its seeds develop in spike-shaped pods.

assessment - An evaluation.

atmosphere - The gaseous mass or envelope surrounding the earth.

autumn-flowering clematis - Clematis terniflora, exotic invasive plant that grows in intermittently flooded lowland forests. image

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bacteria - (singular bacterium) Phytoplankton; single-celled prokaryotic organisms.

bald eagle - Haliaeetus leucocephalus, a North American eagle, having a dark body and a white head and tail. The white head develops once they are mature at age 5.

banded killifish - Fundulus diaphanous, a native fish found in major river drainage areas.

bank erosion - The process in which individual soil particles of a stream bank are carried away as the stream channel moves. The amount of erosion is affected by vegetation, soil composition of the bank, flow of water in the stream, and runoff from the land.

bank slumping - An indication of the degree of bank erosion. A healthy habitat has gentle bank slopes and no evidence that the stream is undercutting the bank. image

bank vegetation - Trees, shrubs, grasses, and other vegetation growing on the stream bank. image

bay - A body of water partly enclosed by land, but having a wide outlet to the sea.

bed load - Sediment consisting of coarse material such as gravel, stones, and boulders that move along the bottom of a stream channel.

beefsteak plant - Perilla frutescens, an exotic invasive plant, originally from Asia, that grows in a clearing (meadow or field). image

beetle - An aquatic macroinvertebrate with larvae that have lateral filaments off their sides, a hook at the end of their body, and no wings. Adults have outer wings and are often black in color. The larvae are somewhat sensitive to pollution.

bend - A change in the direction of a stream channel and the flow of water in the stream.

benthic plants - Aquatic plants that grow attached to or rooted to the bottom of the body of water and withdraw nutrients from the sediment. image

benthos - Organisms that live on or in the bottom sediments of a water body.

biochemical oxygen demand (BOD) - A measure of the quantity of oxygen used by organisms to decompose organic matter, usually measured at the end of a five-day period.

biodiversity - Refers to variety of organisms, their genetic information and the biological communties where they live.

blackfly - An aquatic macroinvertebrate of the order Diptera, a true fly. Dumb-bell-shaped, soft larvae attach themselves to the substrate and prefer soft sediment; it is pollution tolerant. image

broad-leaved plantain - Plantago major; an exotic invasive plant, originally from Europe, that grows in a clearing (meadow or field) image

brine - A strong salt solution such as salt water.

burrow - To live or hide in a hole or tunnel. Animals that burrow dig tunnels or holes in the ground.

bush honeysuckle - Lonicera x spp., an exotic invasive plant, originally from Eurasia, that grows in intermittently flooded lowland forest. image

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