Aquatics Glossary

AQUATICS ECOLOGY GLOSSARY

Acid rain: rain containing pollutants that give it a pH of less than 7.0.

Algae: photosynthetic organisms with a one-celled or simple multicellular body plan.

Aqueous: containing or composed largely of water.

Aquifer: a land, gravel or rock formation capable of storing or conveying water below the surface of the land.

Bacteria: unicellular microorganisms of the class Schizomycetes existing as free living organisms or parasites.

Benthos: bottom dwelling or substrate-oriented organisms.

Best Management Practices: a practice or combination of practices that provide an effective, practical means of preventing or reducing pollution from non-point sources.

Bioaccumulate: the practice of concentrating a particular substance over time.

Biomonitoring: the use of organisms to assess or monitor environmental conditions.

Biochemical Oxygen Demand (BOD): a measure of the quantity of oxygen used by microorganisms in the aerobic oxidation of organic matter.

Brook: a small stream

Buffer: a vegetated area of grass, shrubs or trees designed to capture and filter runoff from adjoining land uses.

Channelization: the practice of straightening a water course or stream to remove meanders and make the water flow faster. Sometimes concrete is used to line the sides and bottom.

Cobble stone: 2-10 inch size stones where stream life can be found.

Coliform Bacteria: a group of bacteria found in cold and warm blooded animal intestines commonly used as indicators of pathogens.

Cultural Eutrophication: process whereby human activity increases the amount of nutrients entering surface waters.

Culvert: a closed passageway (such as a pipe) under roadways and embankments which drains surface water.

Decomposition: the separating or decaying of organic or chemical matter.

Dendritic: a pattern of stream drainage that resembles the pattern of a tree.

Density of water: Is greatest at 4°(39.2°F).

Dilute and disperse: the practice of discharging a substance into a large body of water that will carry the substance away from its source and reduce its concentration.

Discharge: the flow of surface water in a stream or canal or the outflow of groundwater from a flowing artesian well, ditch or spring.

Discharge pipe: a pipe used to carry wastewater from a factory or other facility into a receiving stream or lake.

Dissolved oxygen: oxygen dissolved in water which is readily available to plants and animals.

Drainage basin: a large watershed usually referring to the combination of several watersheds.

Ecology: the science of the relationships between organisms and their environments.

Ecosystem: an ecological community together with its physical environment, usually considered as a unit.

Ephemeral Stream: a stream that flows only during wet periods or rainstorms.

Epilimnion: topmost layer of water in a lake.

Estuary: an arm of the sea that extends inland to meet the mouth of a river, usually characterized by tidal changes and rich diversity of aquatic life.

Eutrophication: a process in which organic matter accumulates in a body of water until eventually it fills in and becomes dry land.

Fecal coliform: that part of the coliform group of bacteria originating in the intestinal tract of warm blooded animals.

Floodplain: a low area of land, surrounding streams or rivers, which holds the overflow of water during a flood.

Freshwater: water that is not saline or brackish.

Groundwater: water beneath the earth's surface between saturated soil and rock.

Habitat: the area or environment in which an organism lives.

Hardness: a characteristic of water caused by the presence of various salts, calcium, magnesium and iron.

Headwaters: the uppermost reaches of a river or stream.

Hydric soils: soils found in saturated, anaerobic environments usually characterized by gray or mottled appearance, found in wetlands.

Hydrologic cycle: the series of pathways the earth's water may take on its journey from the sea to the atmosphere to the land and ultimately back to the sea.

Hydrologic unit: all land and water within a drainage area.

Hypolimnion: lower layer of water in a lake.

Infiltration: the downward entry of water into the soil.

Instar: the individual insect between two molting events or an organism between egg hatching and the first larval molt.

Intermittent stream: a stream which has an interrupted flow or does not flow continuously.

Larvae: the plural of larva, the first major mobile life stage of an insect or first development following egg hatching.

Lentic: standing water as in a lake.

Limiting factor: something that determines the presence, survival and success of an organism.

Limnology: the study of inland water: ponds, lakes and streams.

Littoral: region of shallow water where light reaches the bottom.

Lotic: running water as in a river.

Macroinvertebrates: an animal without a backbone visible to the naked eye or larger than 0.5 millimeters.

Meander: the circuitous winding or sinuosity of a stream, used to refer to a bend in the river.

Monitoring: to watch and care for a stream on a regular basis.

Nitrate: an important nutrient for building protein in plants and animals.

Nonpoint source pollution (NPS): pollution that originates from many diffuse sources and usually is not regulated, such as runoff from streets that carries with it oil, feces and sediment.

Oligotrophic: a body of fresh water that contains few nutrients and few organisms.

Part per million (ppm): the quantity of one substance contained in one million units of another substance. Equivalent to milligram per liter (mg/l).

Perennial stream: a stream which flows continually.

pH: a symbol used to indicate how acidic or basic a solution is.

Phosphorus: an important nutrient for life, especially plants and algae.

Plankton: collective word for microscopic organisms that drift around in the upper level of a body of water.

Point source pollution: Pollution that is discharged through a pipe or other conduit and is usually a regulated discharge.

Pollutant: any substance or mixture of substances that defile or contaminate the soil, water or atmosphere.

Pond: a quiet body of water so shallow that rooted plants usually grow completely across it.

Profoundal: region of water below photosynthetic light penetration.

Receiving waters: all distinct bodies of water that receive runoff such as streams, rivers, ponds, lakes and estuaries.

Riffle: a hallow section of a stream where water bubbles over rocks, often found at the bend in a river.

Riparian: relating to the banks of a stream or river.

River: a body of running water of considerable volume usually moving over the earth's surface in a channel or bed.

Run: the straight section in a river between riffles, also refers to fish migration.

Runoff: water, including rain and snow, which is not absorbed into the ground: instead it flows across the land and eventually runs into streams and rivers. Runoff can pick up pollutants from from the air and land, carrying them into the stream.

Salt water: water that is saline.

Secchi disk: a simple device for measuring turbidity.

Sediment: soil, sand, and materials washed from land into waterways.

Settling ponds: ponds constructed or used to hold storm water and other runoff where heavy materials can settle and the water can become clear before being discharged.

Stream: a body of running water moving over the earth's surface in a channel or bed.

Stream order: system used to number streams and their tributaries with first order as the headwater stream. When joined by another first order stream the union of two streams becomes a second order stream and so on.

Streambank: the side of a stream.

Subwatershed: a small watershed that is part of a larger watershed such as the watershed of a tributary stream.

Surface water: Water that flows over or is found on the earth's surface.

Thermocline (metalimnion): intermediate (middle) layer of water in a lake.

Total solids: a term used to describe all the matter suspended or dissolved in water.

Tributary: a stream or river that flows into another larger stream or river.

Turbidity: a measure of water cloudiness caused by suspended solids.

Waterfowl: birds that depend on water for habitat i.e. ducks.

Watershed: an area of land that drains into a particular river or body of water usually divided by topography.

Watertable: the upper level of groundwater.

Waterway: a natural or man-made place for water to run through (such as rive, stream, creek, or channel)

Wetland: an area of land that is saturated at least part of the year by water, usually found in depressions, low-lying areas or along floodplains or coastal areas.

Aquatics Ecology Glossary