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A

Alaska steeppass fishway

Type of Denil fishway that is typically constructed of one or more sections of pre-fabricated sheet aluminum. These sections are relatively compact thus allowing them to be transported to remote areas where manual installation can be readily accomplished. Steeppass units are generally installed in association with an entranceway downstream of a barrier, while the upper end of the steeppass is placed in the exitway within the crest of the dam. Steeppass fishways are generally installed at 1:4 grades or flatter on smaller streams where stream flow is relatively small.

Allochthonous material

Organic material found in the stream but produced externally, such as leaves, twigs and other woody debris.

Anadromous fish

Fishes that migrate between fresh- and saltwater, in which reproduction, egg deposition, and often larvae and initial juvenile rearing occur in freshwater; while juvenile and adult stages remain in the ocean, often for multiple years (modified from Armantrout 1998). Certain species return to natal sites to spawn. Adults of some species die soon after spawning (e.g., Pacific salmon), while others may be repeat spawners (e.g., alewife).

Articulated shells

Shells still joined together at the narrow, umbo end, by a hinge ligament.

Attraction flows

Water flow at entrance of a fishway or eelway that attracts fish into and stimulates them to move up the fishway.

Autochthonous

Organic material found and produced within the stream, such as phytoplankton, algae, and wetland plants.

B

Bankfull discharge

Flow of a stream or river at which water levels begin to spill over into the floodplain or land adjacent to the stream or river that receives floodwaters and deposited sediment. Bankfull discharge occurs at a specific flow rate for a given river stretch, and typically reoccurs about every 1.5-2.5 years.

Bankfull height

Water level, or stage, at which a stream, river or lake is at the top of its banks and any further rise would result in water moving into the flood plain.

Base flows

Portion of the stream discharge that is derived from natural storage (e.g., groundwater, large lakes, swamps or wetlands) and that is not a result of direct runoff. Base flows are also considered sustained, normal, dry-weather, ordinary, or groundwater flow (modified from Armantrout 1998).

Bedload

Particles of sand, gravel, or soil carried by the natural flow of a stream on or immediately above its bed (modified from McGraw-Hill 2003).

Benthos

Organisms that live at or near the bottom or substratum of marine environments.

Biocoenose

All of the organisms living together and interacting in a specific habitat type, usually containing producers, consumers, reducers, and transformers

Biodiversity

The diversity of life in an area, including the diversity of genes, species, plant and animal communities, ecosystems, and the interaction of these elements.

Burst swimming speed

Velocity at which a fish swims to pass through higher river flows and in particular areas that may be hydraulic jumps and difficult sites to pass.

Bypass channel

Channels around a dam or other obstruction carrying a minimum and controllable flow that allows fish to pass efficiently. These channels do not generally carry the dominant river flow.

C

Catadromous fish

Fishes that migrate between fresh- and saltwater, in which these fishes reproduce and spend their early life stages in saltwater, migrate to freshwater to rear as sub-adults for several years, and return to saltwater to spawn as adults. The only catadromous fish in the United States is the American eel on the East Coast (modified from Armantrout 1998). Adult eels die after spawning.

Climate dynamics

Processes that determine the behavior of the atmosphere, ocean, land surface and sea ice averaged over timescales of weeks to millions of years.  Climate dynamics may include processes such as climate variability (e.g., El Niño/Southern Oscillation, North Atlantic Oscillation) and global change.

Cultch

Substances (especially oyster shell) which serve as places of attachment for oyster larvae.

D

Dam

A structure obstructing the flow of water that increases the water surface elevation upstream of the barrier. Usually built for water storage, flood control, or power generation, but occasionally also built for recreation (to create a lake or pond for boating, fishing, or aesthetics), fire protection, and/or as a result of transportation corridor crossings (modified from Armantrout 1998). Dams often act as effective barriers to passage by diadromous and resident fishes, as well as benthic macro-invertebrates.

Denil fishway

Typically a sloping (slope usually flatter than 1:4 grade) sluice with concrete walls and bottom that contains a series of frame baffles often constructed of wood or fiberglass to slow velocities through the fishway.

Deposit feeders

Organisms that feed on particulate matter on or in the substrate and process a high ratio of solids to fluids.

Deposition

Settling of material from the water column and accumulation on the streambank or bed. Occurs when the energy of flowing water is unable to support the load of suspended material.

Derelict fishing gear

Nets, lines, crab/shrimp pots, and other recreational or commercial fishing equipment that have been lost, abandoned, or discarded in the marine environment.

Design plans

Document that depicts the existing and proposed project conditions, in plan view, cross section and profile. These plans may be prepared by professional engineers working collaboratively with professionals in other disciplines such as ecologists, modelers, and landscape architects.

Detritus

Decomposing plant or animal material.

Dewatering and water diversion plans

For many river restoration and fish passage projects, temporary diversion of river flows and dewatering is needed in providing dry work conditions. These plans may include coffer dam, inflatable dam or concrete block structures. Dewatering pumps and plastic pipes may be other design components to divert stream flow and remove water from closed work compartment sites.

Diadromous fish

Fishes that migrate between fresh- and saltwater, with the species undertaking migrations to spend a portion of their lives in different ecosystems. Anadromy and catadromy are two types of diadromy (modified from Armantrout 1998).

Discharge rate

Rate of water flow at a specific stream or river stretch and is usually measured as a rate in cubic feet per second (cfs) and is often depicted as a hydrograph of flow rate over time. Peak discharge occurs during storm events when flow reaches a maximum rate. Peak discharge rate becomes steeper and sharper with increasing areas within a watershed lacking vegetation to slow, uptake and transpire water, and increasing impervious surfaces, resulting in rapid storm water runoff.

E

Ecosystem

Conceptual unit comprising organisms interacting with each other and their environment having the major attributes of structure, function, complexity, interaction and interdependency, temporal change, and no inherent definition of spatial dimension.

Environmental assessments

Phase I Environmental Assessments (EAs) are conducted as an initial phase for identifying potential site contamination. Phase II EAs may be required for sites needing soil and other media sampling. Remediation clean-up plans may be required if contamination exceeds state and/or federal clean-up thresholds.

Erosion and sediment controls

Standard control techniques are provided to help minimize potential disturbance and transport of soils overland and into streams. Techniques include silt fence, haybales, erosion control blankets, construction entrance, and silt curtains.

Excavation and grading plans

Plans created to depict existing and proposed topographic grade contours and spot elevations identifying where fill materials will be removed from or regarding will occur within floodplain and riparian habitats.

F

Fascine

Vegetation restoration technique where bundled sets of live woody plant cuttings are laid in parallel and typically installed in shallow trenches in streambank slopes and in riparian areas paralleling the river length.

Feasibility study or restoration plan

Technical assessment to determine potential feasibility of restoration/rehabilitation projects and their design and implementation constraints.  A study will help in assessing the spatial scale and complexity of a potential project (see natural resource mapping, hydrologic and hydraulic modeling, soil and geo-technical borings and sediment coring, environmental assessments, structural analysis, historical and archaeological surveys, and design plans).

Filter feeders

Animals that feed by straining suspended organic particulate matter from water, typically by passing the water over a specialized structure (e.g., gills in bivalves); also known as suspension feeders.

Fishway

Man-made structure to allow passage of diadromous and resident riverine fishes around obstructions, primarily dams. There are a number of fishway types including structural fishways or fish ladders (see bypass channel, hybrid, mechanical, pool-and-weir, Denil, Alaska steeppass, vertical slot), and nature-like fishways (see roughened channel or rock ramp) consisting of natural rock bottoms, cross vanes and other features.

Floodplain

Includes typically flat lands bordering rivers and larger streams where storm flows above the bankfull height overtop banks and spread out, and where flows are reduced and sediments may be deposited. The 100-year floodplain, or lands that have a one percent chance of flooding in any given year, are typically regulated for protection by federal, state and municipal agencies.

Functional characteristics

Processes occurring within and between habitats as a result of their structural characteristics. For example, the natural recruitment rate of native species is a functional characteristic.

G

Geo-fabric

Synthetic materials such as coir fiber logs and mats used to minimize erosion potential on regraded banks.

Gradient

Longitudinal slope of a stream or river between two selected points. Stream gradient is the elevational channel drop over a selected stream reach and is usually identified as a percentage.

H

Habitat

The natural environment of a plant or animal. An animal's habitat includes the total environmental conditions for food, cover, and water within its home range. The National Marine Fisheries Service has identified Essential Fish Habitat (EFH) that is vital to sustaining certain living marine resource species.

Hard / structural stabilization

Shore erosion control practice often used in high-energy environments to minimize wave energy through the use of seawalls, bulkheads, stone revetments, and other hard materials. Ironically, hardened structures often increase the rate of coastal erosion, remove the ability of the shoreline to carry out natural processes, and provide little habitat for estuarine species. Use of hard structures in low- to medium-energy environments should be weighed against other options that provide habitat for aquatic organisms, such as the Living Shoreline stabilization approach.

Hard point

One or more features, that can exist naturally or be constructed with boulders and other natural materials, that prevent substantial erosion of the channel bottom by river flows.

Headcut

In-stream feature where an unstable stream substrate exists due to flows being in disequilibrium with the existing channel gradient. Headcutting usually occurs when an in-stream feature such as a dam is removed from a channel causing an abrupt change in channel gradient. The stream channel reacts to the flows by eroding to a level that re-establishes equilibrium with the flow conditions. Headcutting, often observed as a collapsing vertical wall of sediment will continue to migrate upstream until a point where stream gradient and flows again reach equilibrium.

Headpond

Impounded water above a dam.

Hemolymph

Bluish circulatory fluid found in some invertebrates, especially some molluscs, which contains a copper-based protein for transporting oxygen.

Hermaphrodite

Organism which possesses both male and female reproductive organs.

Historic and archaeological surveys

A survey to determine the presence of any on-site resources, buildings or other structures listed on or eligible for the National Historic Registry; or location within a National Historic District.

Hybrid fishway

Combination of pool-and-weir, vertical slot, or roughened channel fishways.

Hybrid stabilization

A shore erosion control and restoration practice that uses a combination of soft/nonstructural and hard/structural materials to minimize shoreline erosion. Such materials include natural vegetation (e.g., SAV and marsh/dune grasses), sand fill, natural fiber logs, organic matting, other biodegradable materials, and low-profile stone reinforcement structures such as segmented sills, containment groins, and offshore breakwaters seeded with oyster spat. Hybrid stabilization restores and protects shoreline habitat, provides substrate upon which oysters and barnacles can attach, maintains natural sand movement and tidal water exchange, and facilitates the movement of estuarine species into critical wetland habitat. This method of stabilization is typically implemented in rivers, major tributaries, and other medium-energy riverine, estuarine, and coastal environments. Hybrid stabilization should only be utilized along shorelines where soft/nonstructural approaches are not technically feasible due to high wave energy.

Hydrograph

Line graph depicting stream or river discharge, usually in cubic feet per second (cfs) (x axis), over time (y axis).

Hydrologic and hydraulic modeling

Analyses of river flow elevations and velocities, flow and flood frequency analysis, and potential hydraulic barriers (calculated for 1-year, 10-year, 50-year and 100-year flows), often completed by hydraulic engineers. Discharge data are often available from USGS gauge stations. For project sites where gauge data are unavailable, hydraulic engineers will use data from other nearby watershed gauge stations or set data loggers at the project site to obtain this information. The use of existing FEMA Flood Insurance Rate Maps (FIRM) for various watersheds throughout the U.S. and the U.S. Corps of Engineers HEC-RAS model are often used to complete analysis of a project site, analyzing existing conditions and comparison to proposed conceptual design alternatives.

I

Impervious surface

A surface that cannot absorb water and therefore increases the rate and volume of runoff. Roads, rooftops, and parking lots are examples of impervious surfaces.

Invasive species

A species that does not naturally occur in a specific area and whose introduction is likely to cause economic or environmental harm.

Invert

Elevation of the lowest point in a culvert or fishway opening usually measured in feet in relation to a known vertical reference datum. Invert information is important to properly designing fishways and culvert installations so fish and other motile aquatic biota have the capability to freely pass the structure.

Isostatic rebound

The rising elevation of land masses due to the reduced weight of glaciers as they melt and recede.

J

K

L

Landscape plan and planting schedule

Registered landscape architects (RLA) are generally responsible for preparing and stamping planting and seeding plans for restoration sites. These plans depict specific locations and numbers of sapling, shrub and emergent plantings and seeding locations. These plans are accompanied by a planting schedule that identifies specific plant species and number of each, delivery type (container or balled and burlap), plant size, and plant on-center spacing. Specifications addressing seed mixes (native species and application rates), fertilizers, and planting notes also accompany planting plans and schedules.

Large woody debris (LWD)

Logs, stumps ("rootwads"), and brush that can be strategically located to help provide cover habitat, structure for fish to hide, substrate for macroinvertebrates to attach or live on/in, and a feature to alter flows and enhance microhabitat diversity.

Litterfall

Includes leaves, twigs and bark from trees, shrubs and other vegetation that fall to the ground and nearby streams. If this material enters a stream, it can be carried downstream to other ecosystems and can become energy sources for those areas.

Living shoreline stabilization

Shoreline management approach that uses hybrid or soft/nonstructural shore stabilization methods to minimize coastal erosion while protecting, restoring, enhancing, or creating natural shoreline habitat. Living Shoreline stabilization is implemented via the strategic placement of native vegetation, sand fill, and organic materials, with a small amount of reinforcing rock seeded with oysters, if necessary. The Living Shorelines approach can be used in low- to medium-energy environments in creeks, coves, rivers, major tributaries, and coastal, marine, and estuarine environments.

Lotic

Type of flowing body of fresh water, such as a river or stream.

M

Mechanical fishway

Mechanically operated fishways, such as lifts (fish elevators), brails, and locks, that can raise fish over an barrier or into a trap or hauling tank on a truck or barge. These techniques are generally used only on large rivers and large-scale fish runs.

Mountaintop removal

Uncommon in the West, a method of mining coal that first clear-cuts all vegetation, and then uses explosives to remove the overburden and expose the coal at the mountain’s core. The overburden is usually pushed to the side as valley fill, often completely filling and destroying stream drainages.

N

Natural resource mapping

Maps that depict wetlands, floodplains, rare species and specimen tree locations within the project area. Wetlands may be depicted using information from USFWS National Wetland Inventory Maps. Fish, aquatic macroinvertebrate and wildlife surveys may also be required.

Nekton

Organisms which swim freely in the ocean.

NOAA trust resources

Resources associated with coastal, marine, and Great Lakes habitats, including rivers and estuaries. These resources include: commercial and recreational fishery resources; diadromous species; marine mammals; endangered and threatened marine species and their habitats; marshes, mangroves, seagrass beds, coral reefs, and other coastal habitats; and resources associated with National Marine Sanctuaries and National Estuarine Research Reserves.

Non-native species

(also called alien, foreign, non-indigenous, introduced, and exotic species) A species that has been introduced by humans to a location outside its native or natural range.

Nonpoint source pollution

The result of diffuse contaminants being introduced indirectly to waterways. Typically, nonpoint source pollutants are carried by groundwater and runoff to streams.

O

Operational period

Period of time when a fishway needs to be fully functioning during the normal upstream and downstream migration periods of targeted diadromous fish species. The period length depends on the species and location of the river or stream.

P

Placer mining

Any mining that removes loose materials in unconsolidated river sediment. Some placer mining techniques include panning, dredging, blasting with high-pressure water, or sluicing.

Passage efficiency

Measurement for how efficiently a fishway allows fish to pass through the structure, frequently given as a percentage of number of fish that successfully pass the structure compared to number of fish that would naturally pass if the structure were not present. It is generally believed in the fish passage discipline that no fishway is 100 percent efficient.

Passive integrated transponder (PIT)

PIT is associated with radio telemetry. These tags are placed under a fish's skin or in the body cavity of live fish that will be released and monitored. Each fish that has a PIT tag has its own unique code, and therefore, movement of individual fish can be recorded. Measurements may include if and how long it takes a tagged fish to pass between two or more antennas. Continuous dataloggers record information and require frequent downloading of data for analysis. If the telemetry components are set-up and monitored correctly, the information obtained can be used to assess the functioning of the fishway attraction flows, overall passage, and the time for the fish to pass the structure or restored river reach.

Perched culvert

Culvert with an invert, or bottom, lying above the stream bottom elevation. In many cases, a perched culvert can be high above natural stream bottom, making it impossible for fish to jump from the stream into the culvert. Perched culverts are sometimes incorrectly set during construction, or result when excess scour occurs below the culvert and the stream channel is lowered.

Phytoplankton

Minute alga (e.g., diatoms and dinoflagellates) that float in the well-lit surface layer of oceans.

Pool

Deeper, slower stretches of rivers where finer-grained sediments and organic matter accumulate and fish and other biota often seek refuge.

Pool-and-weir fishway

Has distinct pools in which the energy of the flow entering each pool is dissipated, thereby providing resting sites for passing fish. The hydraulic controls between the pools are overflow weirs with or without orifices/notches. These are also constructed as step-pool fishways using natural rock and boulder.

Prolonged swimming speed

Speed that can be endured by fish for some time, often several minutes, but eventually lead to fatigue.

Protandric hermaphrodite

Organisms which develop first as males and change to females (e.g., Eastern oyster) during their lives and may contain both male and female reproductive organs during the transitional period.

Pseudofeces

Particulate matter ingested by suspension or deposit feeders and usually bound up in mucus, but rejected as potential food before entering the gut.

Q

Quadrat

Two-dimensional area with defined location and size used as permanent field monitoring location. For the herbaceous layer and other ground vegetation, 1-square meter or smaller sized plots are often used, while 5+-square meter quadrats are typically used for shrub and tree layers. The number of plots and distance between plots and along transects is dependent on the project site area and variability. Direct counts and inspections of plantings are used to assess the survivorship and condition of plantings over time, but if a large number of plants are installed over a large area, plots are also used for planted vegetation.

R

Rehabilitation

Process of returning a degraded ecosystem to a close approximation of of its remaining natural potential (USEPA, 2000 definition).

Restoration

Process of re-establishing a self-sustaining habitat that closely resembles a natural condition in terms of structure and function. Does not focus on a single species, but rather strives to replicate the original natural system to support numerous species.

Restoration plan or feasibility study

Document that describes appropriate restoration types and opportunities for degraded resources. Includes description of the affected environment, including biological resources and associated habitat types that are lost to degradation.

Riffle

Stretches of streams and rivers characterized by fast-flowing, generally shallow waters with boulder, cobble, and gravel substrates where the bottom is higher than reaches immediately up- or downstream.

Riparian habitat

Stream or river, along with bordering lands, situated within the floodplain, and areas that contribute leaves, wood, and other materials to the stream or river. Riparian habitat is typically recognized for its vegetation, often wetlands, along streambanks and for providing canopy cover overhanging streams and rivers.

Rootwad

Root mass of an uprooted or overturned tree that is sometimes used as structure to stabilize streambanks and provide fish and macroinvertebrate cover habitat.

Roughened ramp

In-stream, nature-like fishways constructed by placing sloping earth and stone in a series of stepped, large rock chevrons typically with a gradient of 2 to 5 percent; also termed rock ramp.

Run

Shallow, slower flowing section of stream or river. Runs are downstream of pool features and usually upstream of riffles or other pools.

S

Sediment load

Material, including fine grains, cobble, and boulders, that a stream or river system transports downstream.

Sediment removal plan

For dam removal projects, riverbeds with heavy sedimentation, and fishway installation, sediment removal plans are required to identify limits of excavation, equipment staging areas, and stockpiling areas. For sites with contaminated sediments, special excavation, stockpile, and disposal measures and specifications may be needed.

Shear stress

Eroding force, per unit area, on the bed and banks. The most stable form the channel can assume is one in which the shear stress at every point on the perimeter of the channel is approximately balanced by the resisting stress of the bed and bank.

Siltation

The settling of fine sediments in water where velocity is reduced (Armantrout 1998).

Sinuosity

Ratio of channel length to valley length, or approximated as the valley slope to channel slope.

Smolt

A juvenile salmonid (salmon or trout species) that has undergone physiological changes to cope with a marine environment; the seaward migration stage of an anadromous salmonid.

Soft / nonstructural stabilization

Shore erosion control and restoration practice that uses natural vegetation (e.g., SAV and marsh/dune grasses), sand fill, natural fiber logs, organic matting, and other biodegradable materials to restore, protect, or enhance the natural shoreline environment. This method of stabilization creates a natural buffer to protect the shoreline from erosion; traps sediment and allows for increased vegetation; preserves or creates habitat for benthic, estuarine, shallow water, and intertidal organisms; and maintains natural habitat features and shoreline dynamics. Soft/nonstructural stabilization is often used in low- to medium-energy creeks and coves or in coastal environments experiencing a low rate of erosion.

Soil and geo-technical borings and sediment coring

Information on sub-surface conditions is often required to evaluate excavation, rubble removal and bedrock blasting costs. Hand auger, geo-probes and other equipment may be required for soil sampling, while a vibracorer or hand corer (e.g., MacCauley peat auger) manned by technicians in boats may be needed to complete sediment sampling. Soil, sediment and rock cores are generally analyzed by state-certified laboratories for contaminants, grain size, and moisture and organic carbon content.

Spill

Water passed over a spillway without going through turbines to produce electricity. Spill can be forced (when there is no storage capability and flows exceed turbine capacity), or planned (for example, when water is spilled to enhance juvenile fish passage).

Spillway

The channel or passageway around or over a dam through which excess water is released or "spilled" past the dam without going through the turbines. A spillway is a safety valve for a dam and, as such, must be capable of discharging major floods without damaging the dam, while maintaining the reservoir level below a predetermined maximum level.

Stone placement plan

Stream boulders, rip rap, gravel and other stone materials are added to plans for restoring river channels, constructing nature-like bypass channels, protecting stream banks, and creating in-stream hard points (e.g., embedded rock weir) to prevent sediment headcutting with dam removals.

Stream order

Classification system used to define stream size. First order streams are the smallest size and found at the headwaters. The Mississippi River is classified as tenth order, and Amazon River is defined as a twelfth order river.

Strip and open pit mining

Methods requiring the removal of all vegetation, topsoil, and rock (collectively called overburden) to reach the mineral ore buried beneath.

Structural analysis

Structural engineers are often required to assess condition of and proposed action to existing dams (e.g., dam break analysis), bridge footings (e.g., scour analysis), and streambank protection.

Structural characteristics

Physical, chemical, and biological characteristics that define a habitat. Such characteristics are important to consider because the functions an ecosystem can perform are often dependent upon its structure. For example, the percent cover of vegetation is a structural characteristic.

Structural design

Structural engineers are often required to design installation of complicated structures, such as fishways, and strategically plan the removal and disposal of dams.

Suspension feeders

Animals that feed by straining suspended organic particulate matter from water, typically by passing the water over a specialized structure (e.g., gills in bivalves); also known as filter feeders.

Sustained swimming speed

Speed maintained by fish indefinitely without fatigue.

T

Tailwater

The water below a barrier.

Target species

Specific species for which an activity is performed. For example, the target species for many east coast fish passage projects is alewife (See Appendix A).

Telemetry

Technique to monitor the movement of animals including fish that have been tagged with a locating device:

. Radio telemetry is used to monitor the movement of animals, including fish, which have been tagged with a locating device that transmits radio waves. Radio telemetry systems that operate in the VHF (very high frequency) band can be used in most freshwater environments. (See example)

. Acoustic telemetry is used to monitor the movement fish that have been tagged with a locating device that transmits sound waves. An alternative method to radio telemetry, this technique is more frequently used to monitor fish in estuaries and marine environments, although it is also used in some freshwaters such as freshwaters with high conductivity environments and/or in waters where depths typically exceed 40-50 feet.

Transect

Process by which vascular plant uptake water and release water through the leaves to the atmosphere.

Transpiration

Free-swimming, ciliated larva of some groups of invertebrates, including some mollusks and annelids.

Trochophore

Free-swimming, ciliated larva of some groups of invertebrates, including some mollusks and annelids.

U

V

Veliger

The characterisitic larval stage in molluscs which possesses a velum, a ciliated organ for swimming and feeding.

Vertical slot fishway

Similar to pool-and-weir fishway, has distinct steps with hydraulic control provided by a narrow vertical slot opening, often to the full depth of the fishway. Its greatest advantage is that it is entirely self-regulating with varying river flows.

Video monitoring

Technique used, typically including above river and underwater filming, to qualitatively assess fish passage at a fishway or river restoration site. Video can be used to assess fish behavioral responses to flow, turbulence, and in-stream structures.

Visual monitoring

Typical fish passage monitoring practice by fishery biologists and trained project volunteers. Visual monitoring of migrating fish often involves specific time(s) of day (e.g., early morning), length of the daily monitoring period (e.g., 15-60 minutes), and consistent procedures for observations and recordings amongst the project monitors throughout the fish run period or fishway operational period. To more effectively conduct site monitoring/fish counts at structural fishways, light-colored boards or plates are placed on the bottom of a fishway exitway to help allow the sighting of passing fish.

W

Watershed

Land area from which water drains toward a common stream or river in a natural basin.

Wetlands

Areas with at least temporary to seasonal surface waters or near surface groundwater, hydric soils, and dominant hydrophytic plants that are adapted to growing in wet soils. Cowardin et al. (1978) provides an in-depth discussion of wetland definition and classification.

Work Zone

Area encompassing a restoration site where laborers, volunteers, equipment, and materials are present and where sound safety practices should be followed at all times by workers and anyone else entering this area. This area also includes flagged or marked areas highlighting wetland and other important natural resources and historic or archaeological features that are not to be disturbed.

X

Y

Z

Zooplankton

Microscopic animals that drift or float in marine and fresh waters.