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Other glossaries of fisheries terms are available from North Carolina Division of Marine Fisheries and from the United Nations Fisheries and Agriculture Organization.
(The FAO glossary does not work with all web browsers.)

Anabranch -- A diverging branch of a river which re-enters the main stream.

Analytical watershed -- For planning purposes, a drainage basin subdivision used for analyzing cumulative impacts on resources.

Aquatic ecosystem -- Any body of water, such as a stream, lake or estuary, and all organisms and nonliving components within it, functioning as a natural system.

Aquatic habitat -- Habitat that occurs in free water.

Backbar channel -- A channel formed behind a bar connected to the main channel but usually at a higher bed elevation than the main channel. Backbar channels may or may not contain flowing or standing water.

Backwater -- (1) A small, generally shallow body of water attached to the main channel, with little or no current of its own.

Backwater pool -- A pool that formed from an eddy along a channel margin as a result of an upstream obstruction like a large tree, rootwad, or boulder.

Bank stability -- The properties of a stream bank that counteract erosion, for example, soil type, and vegetation cover.

Bar (stream or river bar) -- An accumulation of alluvium(gravel or sand) caused by a decrease in water velocity.

Blowdown -- Trees felled by high winds.

Bog -- Freshwater wetlands that are poorly drained and characterized by a buildup of peat.

Boulder -- A large substrate particle that is larger that cobble, >256 mm in diameter.

Braided stream -- A complex tangle of converging and diverging stream channels (Anabranches) separated by sand bars or islands. Characteristic of flood plains where the amount of debris is large in relation to the discharge.

Braiding (of River Channels) -- Successive division and rejoining of riverflow with accompanying islands.

Buffer strip -- A barrier of permanent vegetation, either forest or other vegetation, between waterways and land uses such as agriculture or urban development, designed to intercept and filter out pollution before it reaches the surface water resource.

Canopy -- A layer of foliage in a forest stand. This most often refers to the uppermost layer of foliage, but it can be used to describe lower layers in a multistoried stand. Leavs, branches and vegetation that are above ground and/or water that provide shade and cover for fish and wildlife.

Channel -- An area that contains continuously or periodically flowing water that is confined by banks and a stream bed.

Channelization -- The process of changing and straightening the natural path of a waterway.

Coarse woody debris (CWD) -- Portion of a tree that has falled or been cut and left in the woods. Usually refers to pieces at least 20 inches in diameter.

Cobble -- Substrate particles that are smaller than boulders and are generally 64-256 mm in diameter. Can be further classified as small and large cobble. Commonly used by salmon in the construction of a redd.

Conifer -- A tree belonging to the order Gymnospermae, comprising a wide range of trees that are mostly evergreens. Conifers bear cones (hence, coniferous) and needle-shaped or scalelike leaves.

Conservation -- The process or means of achieving recovery of viable populations.

Conservation area -- Designated land where conservation strategies are applied for the purpose of attaining a viable plant or animal population.

Conservation recommendations -- Suggestions by the Fish and Wildlife Service or National Marine Fisheries Service in biological opinions regarding discretionary measures to minimize or avoid adverse effects on a proposed action of federally listed threatened or endangered species or designated critical habitat.

Conservation strategy -- A management plan for a species, group of species, or ecosystem that prescribes standards and guidelines that if implemented provide a high likelihood that the species, groups of species, or ecosystem, with its full complement of species and processes, will continue to exist well-distributed throughout a planning area, i.e., a viable population.

Contiguous habitat -- Habitat suitable to support the life needs of species that is distributed continuously or nearly continuously across the landscape.

Core area -- The area of habitat essential in the breeding, nesting and rearing of young, up to the point of dispersal of the young.

Creel census survey -- The collection of data concerning the number of fish caught by sport fishers on a particular stream or in a particular area.

Critical habitat -- Under the Endangered Species Act, critical habitat is defined as (1) the specific areas within the geographic area occupied by a federally listed species on which are found physical and biological features essential to the conservation of the species, and that may require special management considerations or protections; and (2) specific areas outside the geographic area occupied by a listed species, when it is determined that such areas are essential for the conservation of the species.

Crown -- The upper part of a tree or other woody plant that carries the main system of branches and the foliage.

Crown cover -- The degree to which the crowns of trees are nearing general contact with one another.

Crucial habitat -- Habitat that is basic to maintaining viable populations of fish and wildlife during certain seasons of the year or specific reproduction periods.

Culvert -- A buried pipe that allows streams, rivers, or runoff to pass under a road.

Deciduous -- Trees and plants that shed their leaves at the end of the growing season.

Diversion channel -- (1) An artificial channel constructed around a town or other point of high potential flood damages to divert floodwater from the main channel to minimize flood damages. (2) A channel carrying water from a diversion dam.

Down log -- Portion of a tree that has fallen or been cut and left in the woods.

Drainage -- An area (basin) mostly bounded by ridges or other similar topographic features, encompassing part, most, or all of a watershed and enclosing some 5,000 acres.

Drainage area -- See watershed.

Ecosystem management -- A strategy or plan to manage ecosystems to provide for all associated organisms, as opposed to a strategy or plan for managing individual species.

Enhancement -- Emphasis on improving the value of particular aspects of water and related land resources.

Environmental analysis -- An analysis of alternative actions and their predictable short-term and long-term environmental effects, incorporating physical, biological, economic, and social considerations.

Environmental assessment (EA) -- A systematic analysis of site-specific activities used to determine whether such activities have a significant effect on the quality of the human environment and whether a formal environmental impact statement is required; and to aid an agency's compliance with the National Environmental Policy Act when no environmental impact statement is necessary.

Environmental impact -- The positive or negative effect of any action upon a give area or resource.

Environmental impact statement -- A formal document to be filed with the Environmental Protection Agency that considers significant environmental impacts expected from implementation of a major federal action.

Estuary -- A coastal body of water that is semi-enclosed, openly connected with the ocean, and mixes with freshwater drainage from land.

Final environmental impact statement (FEIS) -- The final report of environmental effects of proposed action on an area of land. This is required for major federal actions under Section 102 of the National Environmental Policy Act. It is a revision of the draft environmental impact statement to include public and agency responses to the draft.

Floodplain (100-year) -- The area adjacent to a stream that is on average inundated once a century.

Forest canopy -- The cover of branches and foliage formed collectively by the crowns of adjacent trees and other woody growth.

Forest landscape -- Land presently forested or formerly forested and not currently developed for nonforest use.

Freshwater marsh -- Open wetlands that occur along rivers and lakes.

Freshwater swamp -- Forested or shrubby wetlands.

Gabion -- A wire basket or cage that is filled with gravel and generally used to stabilize stream banks and improve degraded aquatic habitat.

Gaging station -- A particular site in a stream, lake, reservoir, etc., where hydrologic data are obtained.

Geographic information system (GIS) -- A computer system capable of storing and manipulating spatial (i.e., mapped) data.

Glide -- A section of stream that has little or no turbulence.

Gradient -- Vertical drop per unit of horizontal distance.

Grass/Forb -- An early forest successional stage where grasses and forbs are the dominant vegetation.

Gravel -- See cobble.

Habitat -- The local environment in which a organism normally lives and grows.

Habitat conservation plan (HCP) -- An agreement between the Secretary of the Interior and either a private entity or a state that specifies conservation measures that will be implemented in exchange for a permit that would allow taking of a threatened or endangered species.

Habitat diversity -- The number of different types of habitat within a given area.

Habitat fragmentation -- The breaking up of habitat into discrete islands through modification or conversion of habitat by management activities.

Hatch box -- A device used to incubate relatively small numbers of fish eggs. The hatch box is usually located adjacent to a stream, which supplies the box with water.

Instream cover -- The layers of vegetation, like trees, shrubs, and overhanging vegetation, that are in the stream or immediately adjacent to the wetted channel.

Key watershed -- As defined by National Forest and Bureau of Land Management District fish biologists, a watershed containing (1) habitat for potentially threatened species or stocks of anadromous salmonids or other potentially threatened fish, or (2) greater than 6 square miles with high-quality water and fish habitat.

Landscape -- A heterogenous land area with interacting ecosystems that are repeated in similar form throughout.

Landscape diversity -- The size, shape, and connectivity of different ecosystems across a large area.

Landscape features -- The land and water form vegetation, and structures that compose the characteristic landscape.

Large woody debris -- Pieces of wood larger than 10 feet long and 6 inches in diameter, in a stream channel.

Leave strips -- Generally narrow bands of forest trees that are left along streams and rivers to buffer aquatic habitats from upslope forest management activities.

Limiting factor -- "A requirement such a food, cover or spawning gravel that is in shortest supply with respect to all resources necessary to sustain life and thus ""limits"" the size or retards production of a fish population."

Oxbow -- An abandoned meander in a river or stream, caused by neck cutoff. Used to describe the U-shaped bend in the river or the land within such a bend of a river.

Peat -- Partially decomposed plants and other organic material that build up in poorly drained wetland habitats.

Perennial streams -- Streams which flow continuously.

Pond -- A body of water smaller than a lake, often artificially formed.

Pool -- A reach of stream that is characterized by deep low velocity water and a smooth surface.

Pool/riffle ratio -- The ratio of surface area or length of pools to the surface area or length of riffles in a given stream reach; frequently expressed as the relative percentage of each category. Used to describe fish habitat rearing quality.

Rearing habitat -- Areas in rivers or streams where juvenile salmon and trout find food and shelter to live and grow.

Rearing pond -- An artificial impoundment in which juvenile salmon and steelhead are raised prior to release into the natural habitat.

Reforestation -- The natural or artificial restocking of an area with forest trees.

Restoration -- The renewing or repairing of a natural system so that its functions and qualities are comparable to its original, unaltered state.

Riffle -- A reach of stream that is characterized by shallow, fast moving water broken by the presence of rocks and boulders.

Riparian area -- An area of land and vegetation adjacent to a stream that has a direct effect on the stream. This includes woodlands, vegetation, and floodplains.

Riparian habitat -- The aquatic and terrestrial habitat adjacent to streams, lakes, estuaries, or other waterways.

Riparian vegetation -- The plants that grow rooted in the water table of a nearby wetland area such as a river, stream, reservoir, pond, spring, marsh, bog, meadow, etc.

Riverine habitat -- The aquatic habitat within streams and rivers.

Rootwad -- The mass of roots associated with a tree adjacent or in a stream that provides refuge and nutrients for fish and other aquatic life.

Salt marsh -- Saltwater wetlands that occur along many coasts.

Slough -- A shallow backwater inlet that is commonly exposed at low tide.

Snag -- Any standing dead, partially dead, or defective (cull) tree at least 10 inches in diameter at breast height and at least 6 feet tall.

Spawning channel -- An artificial gravel-bed area in which flow, depth and velocity are controlled at ideal levels for spawning by a particular species of salmon or steelhead.

Stream Channel -- The bed where a natural stream of water runs or may run; the long narrow depression shaped by the concentrated flow of a stream and covered continuously or periodically by water.

Stream gradient -- A general slope or rate of change in vertical elevation per unit of horizontal distance of the water surface of a flowing stream.

Streambank erosion -- The wearing away of streambanks by flowing water.

Streambank stabilization -- Natural geological tendency for a stream to mold its banks to conform with the channel of least resistance to flow. Also the lining of streambanks with riprap, matting, etc., to control erosion.

Superfund list -- A list of the hazardous waste disposal sites most in need of cleanup. The list is updated annually by the U.S. Environmental Protection Agency (EPA) based primarily on how a site scores using the Hazard Ranking System. Also referred to as the National Priorities List (NPL).

Tidal flats -- Saltwater wetlands that are characterized by mud or sand and daily tidal fluctuations.

Water quality -- A term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose.

Watershed -- An area of land thats total surface drainage flows to a single point in a stream.

Watershed management -- The analysis, protection, development, operation or maintenance of the land, vegetation and water resources of a drainage basin for the conservation of all its resources for the benefit of its residents.

Watershed project -- A comprehensive program of structural and nonstructural measures to preserve or restore a water shed to good hydrologic condition. These measures may include detention reservoirs, dikes, channels, contour trenches, terraces, furrows, gully plugs, revegetation, and possibly other practices to reduce flood peaks and sediment production.

Watershed restoration -- Improving current conditions of watersheds to restore degraded fish habitat and provide long-term protection to aquatic and riparian resources.

Wildfall -- Trees or parts of trees felled by high winds.

Wildlife tree -- A live tree retained to become future snag habitat.

Windthrow -- A tree or trees uprooted or felled by the wind.

Woody debris -- Referring to wood in streams.