Glossary

Definition of Terms

Acid/Acidic

Acid is any of a large class of substances the aqueous solutions of which are capable of turning litmus indicators red, of reacting with and dissolving certain metals to form salts, of reacting with bases or alkalis to form salts. Acidic is a tendency to form an acid.

Algae

Algae (pl), a collective term referring to several groups of simple tiny photosynthetic plants, mostly microscopic, lacking roots, stems and leaves. They can be found in a variety of habitats. Many species of algae exist as single cells, others form simple filaments or colonies, and others exist as more complex structures like the larger seaweeds

Algal bloom

Algal blooms are the profuse growth and reproduction of a particular species of alga that responds to certain conditions in a water body (e.g.,temperature, nutrient content, etc.); this is usually a result of increased nutrient content, often from excessive use of fertilizers and detergents

Amphibian

Any of various cold-blooded, smooth-skinned vertebrate organisms of the class Amphibia, such as a frog, that characteristically hatch as aquatic larvae that breathe by means of gills and that metamorphose to an adult form with air-breathing lungs.

Annelid

Any of the group of segmented worms (earthworms, ragworms, leeches)

Annelids are characterized by a long, soft body and cylindrical or somewhat flattened cross-section.

Aquifer

A layer of porous rock or soil that both holds water and allows this water to percolate through. A geologic formation that is capable of providing a usable amount of water to a well or spring

Arable

Land suitable for the economic production of crops, usually involving regular cultivation

Bedrock

The solid rock that underlies all soil, sand, clay, gravel, and loose material on the earth's surface.

Benthic

The bottom layer of a water body

Benthic macroinvertebrates

Bottom-dwellers without backbones that can be seen with the unaided eye, such as some bugs, mollusks, crabs.

Benthos

Plants and animals living on the bottom of a water body

Biological availability

The amount that can be utilized by plants and animals.

Biotic adjustment

Bloom (see Algal bloom)

Describes the discoloration of the waters of ponds, lakes or sometimes slow-flowing rivers by the dense growth of free-floating algae or algae forming a scum on the surface

BOD (Biochemical Oxygen Demand)

The amount of oxygen used by microorganisms to break down organic matter; measures of BOD are used to estimate organic loads in water samples

Buffer zone

Established zone along a stream or river (riparian zone) or a margin of perennial grass or other erosion-resistant vegetation next to a water-body that filters pollutants and reduces erosion before the run-off enters the water.

Buoyant

Capable of floating or keeping things afloat.

Canopy cover

Branches from trees and shrubs that shield the ground and water from the sun

Capillary action

Movement of water from saturated soil toward an area of drier soil; it can refer to movement in any direction, but upward capillary movement is of most significance to the salinity problem

Chlorophyll

The green pigment in plants that enables them to use the energy of the sun for photosynthesis

Clay

A fine-grained, firm natural material, plastic when wet, that consists primarily of hydrated silicates of aluminum.

Coliform bacteria (see Fecal Coliform bacteria)

Collectors

Aquatic invertebrates that process food particles smaller than 1 mm. Tend to be present in all stream types, but make up a greater part of the "bug" populations in the lower river reaches

Community

A directly or indirectly interacting group (assemblage) of organisms occupying a particular habitat

Confluence

Running together, flowing together or intermingling - as where a tributary joins a river

CPOM

Coarse Particulate Organic Matter; food for "bugs" in streams

Debris

The scattered remains of something broken or destroyed.

Decomposition

The breakdown of organic materials by micro-organisms

Detritus

Decomposing plant material. The decomposing plant material releases nutrients which support the growth of estuarine phytoplankton, which are food for sponges, mollusks, snails and some fish. Non-living organic matter, such as fallen leaves or dead algae.

DO

Dissolved Oxygen held within water; this oxygen is available to aquatic organisms and is affected by facors such as temperature, nutrient and pollutant input, and decomposition within the water column.

Distributory

Branch of river or stream that does not return to the main stream after leaving it

Ecotones

Areas that exist as bridges between two different types of habitat or environment.

El Nino

A long-term cyclic global weather event that changes the composition of Pacific Ocean conditions and adjacent continental weather patterns

Ephemeral

Lasting for a brief time; short-lived; transitory.

Epilimnion

The upper layer of water in a lake that is comprised of uniformly warmer water.

Epilithon

A biological film that converts the organic matter into food for larger organisms, such as stonefly larvae or larger crustaceans that feed within the hyporheic zone.

Estimating hours

When estimating hours spent at a site, whether you visit it once a year to evaluate your restoration activities or conduct monitoring measurements, it is important to consider the 'people hours'. A one hour site visit by 5 people would translate to 5 hours of spent at the site. Estimating weekly or monthly hours spent at a site can then be calculated to the length of time the site was actively visited. Some sites are monitored seasonally and others may be monitored throughout the year. If 3 people visited a site 2 hours (=6 hours per day) for 7 days a week (=42 hours per week) over an 8 week time period, then an estimated 336 hours per year were spent at the site.

Estuarine

A general wetland habitat type the is related to the estuary.

Eutrophic

Productive, rich in dissolved nutrients, and sometimes resulting in a seasonal oxygen deficiency.

Evaporation

The change of liquid into a vapor

Evapotranspiration

Plants absorb water and release it as vapor into the atmosphere during the process of photosynthesis.

E.P.T.

The three groups of macroinvertebrates that are indicators that a stream is relatively healthy: Ephemeroptera [eh FEMER opt ura] (Mayflies), Plecoptera [ple COP tera] (Stoneflies) and Trichoptera [tri COP tera] (Caddisflies). Generally, the more EPT taxa, the better the water quality and the less challenging the environment.

Faults

Where tectonic plates meet with each other. When they grind against each other or dislocate laterally or vertically, an earthquake occurs.

Fecal Coliform bacteria

Bacteria found in the intestines of warm-blooded animals, that aid in the digestion process; used as indicators of fecal contamination in water-quality analyses.

Fines

Silt (fines) are easily suspended in the water column. The natural influx of fines into a stream system most often comes from streambank erosion. Fines are deposited in the slow moving water, which typically can be found in the pool structure and long the "inside" edge of a meandering streambank.

FPOM

fine particulate matter. Food for "bugs" in streams.

Flushing

Replacement of "old" water with new, as in a lake or estuary.

Fractures

The act or process of breaking or being broken.

Geologic formation

Describes the building materials (i.e. rocks, etc.) and the types of materials (i.e. basalt, limestone) of the land.

Gradient

A rate of inclination; ascending or descending part of slope.

Grazers

Aquatic invertebrates that remove attached algae from rock or wood surfaces in the current of a stream.

Ground water

Water found in aquifers or underground streams in bedrock fractures and between the individual grains of sand and gravel deposits.

Herbivorous

Only eats plants

Hortonian flow

Water running (flowing) over the land

Hydraulic head

The measure of the energy within the water and is often measured as the water's elevation above sea level.

Hypolimnion

The bottom layer of water in a lake that is comprised of uniformly cooler water.

Impervious surfaces

Surfaces, such as roads and parking lots, that do not absorb water. Lawns are considered impervious surfaces because during heavy rains, water runs off of them.

Infiltrate

To permeate by passing through the pores of another substance such as soil.

Intertidal zone

The area above the mean (average) low tide mark and below the mean high tide mark.

J

K

L

Lacustrine

Living or growing in lakes. A lacustrine wetland is permanently flooded or wet when the tide is in.

Leach

Similar to leak. Water slowly moves downward carrying and moving particles of dirt, minerals and other debris as it goes.

Lotic

Of, pertaining to, or living in moving water.

Meiofauna

Very, very small organisms that eat plant matter. Meiofauna are food for fish fry and amphibians.

Mesotrophic

Metabolism

The complex of physical and chemical processes involved in the maintenance of life.

Metalimnion

The middle layer of water in a lake that marks the transition between the top and bottom layers, where temperature changes rapidly with depth.

Meter

There are many devices that will measure water quality. For the purposes of water quality data collection, a meter can be an instantaneous meter/probe, a continuous meter/probe, or a spectrophotometer which is used for measuring nitrates and phosphates.

mg/L

Milligrams of gas per liter of water (dissolved oxygen is reported in units of mg/l); mg/l is equivalent to parts per million or "ppm."

Monoculture

One type or species of plant covering large areas. Many agriculture fields are monoculture, where only one type of plant is raised. A monoculture does not have the adaptabilty and resilience of a natural system and is not as sustainable.

Neutral

Between acid and alkaline.

Non-point pollution

Pollution coming from many small, unidentifiable sources, usually pollution carried by runoff.

Nymph

One of the young of any insect that undergoes imcomplete metamorphosis.

Obligates

Capable of surviving in only one environment.

Oligotrophic

Lacking in plant nutrients and having an abundance of dissolved oxygen throughout.

Omnivore

Eats plants and other animals

Organic Loading

The excessive input of nutrients into a water system

Osmosis

The diffusion of fluid through a semipermeable membrane until there is an equal concentration of fluid on both sides of the membrane.

Oxygenated water

Water constantly supplied with oxygen. Water falls, for example, mix oxygen with water.

Packing density

The shape of the particles will make a difference in how water will move through them. For example, large round pebbles will leave a lot of open spaces whereas sand packs tightly into an area.

Palustrine

Wetlands, nontidal, dominated by shrubs and trees - small, shallow, permanent or intermittent pond

Parasite

Uses a host animal to gets its nourishment

Particle geometry

The shape of the particle (i.e., round, square, etc.)

Pathogens

Agents that cause disease, especially microorganisms such as a bacterium or fungus.

Permeability

The ease with which water can pass through a material.

Perennial

A plant that lives longer than one year

Photosynthesis

The process by which chlorophyll-containing cells in green plants convert incident light to chemical energy and synthesize organic compounds from inorganic compounds, especially carbohydrates from carbon dioxide and water, with the simultaneous release of oxygen.

Phytoplankton

Minute, floating aquatic plants.

Pigment

A substance, such as chlorophyll or hemoglobin, that produces a characteristic color in plant or animal tissue.

Point source pollution

Pollution caused by an identifiable source like a sewer discharge or the outfall from a factory.

Pollutant

Something that pollutes, especially a waste material that contaminates air, soil, or water.

Porosity

The amount of empty space in a material which determines how much water it will hold: the more pores, the more water.

Predate

Precipitation

Water droplets or ice particles condensed from atmospheric water vapor and sufficiently massive to fall to the earth's sufrace, such as rain or snow.

Predator

Hunts other animals for food. Predators consume other animals. Some benthic macroinvertebrates are predators which capture, grasp, pierce and suck the juice out of their prey. Found in all stream habitat types.

Prolegs

Small appendages that look like legs, located in the thorax of an insect. Black flies and midges, and caddisflies have prolegs.

Pupa

The inactive stage in the metamorphosis of many insects, following the larval stage and preceeding the adult form.

Redd

A depression in gravel dug by salmon to lay their eggs.

Resistance

A force that tends to oppose or retard motion.

Respiration

The metabolic process by which an organism assimilates oxygen and releases carbon dioxide and other products of oxidation.

Riffle

A riffle is characterized by shallow water two inches to one foot deep, moderately swift moving water, and a rocky stream bottom consisting of gravel from 1/4 inch to 10 inches in size.

Riparian area

The vegetated area constituting a buffer zone between the edge of the waterbody and the beginning of land use.

River continuum concept

The pattern of physical change in a watershed and the biotic adjustments are called the "River Continuum Concept".

Riverine

Wetlands. Usually in a channel where the water flows or moves, at least occasionally.

Root wads

Root wads are individual roots of a plant or group of plants that intermingle creating a fine mesh or wad.

Runoff

Rain or irrigation that cannot be absorbed into the ground, so it washes into the nearest water body, carrying soil, minerals, debris and pollution.

Saturated

"can hold no more." Every space between rock and soil particles is filled with water.

Salmonids

belonging to the family Salmonidae, which includes salmon, trout and whitefishes.

Scrapers

Aquatic invertebrates common in the middle reaches of a stream.

Sea water intrusion

A freshwater system that has been subjected to the effects of nearby saltwater source. This may by caused by a geologic event such as an earthquake or by human impacts such as over-explotation of a ground water source

Sediment

Soil, sand and minerals which are washed from land into waters, usually during a rain, and settle on the bottom as new substitute.

Sessile

Do not move; may be attached to an object to keep from moving.

Sheath

A thin layer of cells surrounding an object.

Shredders

Aquatic invertebrates that process leaves and particulates greater than 1 mm, breaking them into smaller pieces for the "collector bugs." Tend to inhabit headwater streams and other areas with lots of canopy cover.

Silt and clay

Types of soil

Solubility

The amount that can be dissolved in water.

Solvent

A liquid capable of dissolving another substance.

Substrate

The material comprising the streambed or beach; the surfaces which plants or animals may attach or live on.

Surficial deposits

Gravel, soil, rock and other loose material that lie on top of the bedrock. In these deposits, the spaces between the large materials are filled with smaller particles. For example, the spaces between pebbles and large stones are filled with sand, and the spaces between the grains of sand are filled with clay. This leaves very few open spaces for ground water storage and makes it difficult for water to move through the pores.

Tarsal

Of, pertaining to, or situated near the tarsus of the foot.

Taxon (pl. taxa)

A particular taxonomic grouping, for example, a particular species, genus, family, order, class, phylum, or kingdom.

Taxonomy

The orderly classification of organisms into appropriate categories (taxa) with application of suitable and correct names:

• kingdom
  • phylum
    • class
      • order
        • family
          • genus (plural: genera)
            • species

Tectonic plates

In being analogous to an orange peel, these plates represents the fragmented layer of the earth's crust. These plates may collide, fold, or slide by one another. They may create subduction zones, mountain ranges, or fault lines.

Toxic

Being harmful, destructive or deadly to organisms

Transpiration

The process by which water taken up by plants from the soil evaporates from tiny pores on the leaf surfaces.

Tributary

Smaller body of water flowing into a larger one.

Trophic

The nutrient status of water body. See eutrophic, mesotrophic, and oligotrophic.

Turbidity

The degree of cloudiness is mainly indicative of the amount of solids suspended in the water and, to a lesser extent, the color of the water; this is usually measured by some type of 'light penetration' test.

Turbulence

The state or quality of being turbulent.

Velocity

The rate of travel.

Water cycle (also hydrologic cycle)

Movement of water from the atmosphere to the earth -precipitation-and back to the atmosphere through run-off, infiltration, percolation, storage, evaporation and precipitation.

Watershed

The area of land that drains a river system, a lake, or a bay; the dividing line between watersheds is physically defined by mountains, crests of hills or a ridge of higher ground.

Wetland

A transitional area where the soil or substrate is at least periodically saturated or covered with water. Only those plants and animals adapted to this unique habitat can survive in wetlands.