glossary
Some Common Water Remediation Terms
Abiotic: Non-biological. Example – temperature, salinity and pH are abiotic factors that influence the characteristics and health of an aquatic or marine ecosystem. Photosynthesis, respiration and predator-prey interactions are examples of biotic factors.
Acid: A solution that is a proton (H+) donor and has a pH less than 7 on a scale of 0-14. The lower the pH the greater the acidity of the solution.
Acid rain: Precipitation having a pH lower than the natural range of ~5.2 - 5.6. Acid rain is caused by sulfur and nitrogen acids from anthropogenic (human source) emissions.
Acidification: The process by which acids are added to a water body, causing a decrease in its buffering capacity and ultimately a decrease in pH and increase in acidity (pH < 7).
Algae: Simple, single-celled, colonial, or multi-celled, aquatic plants. Aquatic algae are (mostly) microscopic plants that contain chlorophyll and grow by photosynthesis, and lack roots and stems (non-vascular), and leaves. Algae absorb nutrients from the water or sediments, add oxygen to the water, and are usually the major source of organic matter at the base of the food web in lakes. Freely suspended forms are called phytoplankton. Algae attached to rocks, stems, twigs, and bottom sediments are called periphyton. When too many nutrients are in a system an algal bloom can occur.
Algal Biomass: The amount of algae in a waterbody at a given time. Algal biomass in a water body can be estimated in three ways: (1) by quantifying chlorophyll a (CHL a), (2) by measuring carbon biomass as ash-free dry mass (AFDM), or (3) by measuring the particulate organic carbon (POC) in a sample.
Algae bloom: A rapid increase in the population of algae in an aquatic system. Algal blooms may occur in freshwater, estuarine and marine environments. Algae can be considered to be blooming at concentrations of hundreds to thousands of cells per milliliter. Severe algal bloom concentrations may reach millions of cells per milliliter. Algal blooms are often green, but they can also be yellow-brown or red (red tide), depending on the species of algae. Bright green blooms are often a result of blue-green algae, which are actually bacteria (cyanobacteria).
Alkalinity: Acid neutralizing or buffering capacity of water; a measure of the ability of water to resist changes in pH caused by the addition of acids or bases. In natural waters, alkalinity is due primarily to the presence of bicarbonates, carbonates and to a much lesser extent occasionally borates, silicates and phosphates. It is expressed in units of milligrams per liter (mg/l) of CaCO3 (calcium carbonate) or as microequivalents per liter (ueq/l) where 20 ueq/l = 1 mg/l of CaCO3.
Anaerobic: Technically this means "without air". In limnology (the study of freshwater ecosystems) it is used synonymously with "anoxic."
Anoxia: Condition of being without dissolved oxygen (O2).
Anoxic: Completely lacking in oxygen.
Anthropogenic: Human caused.
Aquatic respiration: Refers to the use of oxygen in an aquatic system including the decomposition of organic matter and the use of oxygen by fish, algae, zooplankton, aquatic macrophytes, and microorganisms for metabolism.
Aufwuchs: The community of algae and other microorganisms that attach to surfaces such as rocks, twigs, and aquatic plants; essentially the same as "periphyton" that means "attached algae."
Bacteria: A large group of unicellular organisms that are common in every habitat on earth. Typically a few micrometers in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals. Bacteria are important in nutrient cycling. A few bacteria are pathogenic and cause infectious diseases.
Base: A substance which accepts protons (H+) and has a pH greater than 7 on a scale of 0-14; also referred to as an alkaline substance.
Basin: Geographic land area draining into a lake or river; also referred to as drainage basin or watershed.
Best Available Technology: The most effective, economically-achievable, and state-of-the-art technology currently in use.
Benthic: Refers to being on the bottom of a lake or water body.
Benthic zone: Water body bottom sediment.
Best Management Practices: Methods that have been determined to be the most effective, practical means of preventing or reducing nutrient and pollution loads from non-point sources.
Bicarbonate: The anion HCO3-.
Bioaccumulation: The increase in concentration of a chemical in organisms that reside in environments contaminated with low concentrations of various organic compounds. Certain chemicals, such as PCB’s, mercury, and some pesticides, can be concentrated from very low levels in the water to toxic levels in animals through this process.
Bioavailable: Able to be assimilated (absorbed) by organisms.
Biochemical (Biological) Oxygen Demand (BOD): A measure of the amount of oxygen removed (respired) from aquatic environments by aerobic microorganisms either in the water column or in the sediments.
Biomass: The weight of a living organism or assemblage of organisms.
Biotechnology: Biological technology is technology based on biology, especially when used in agriculture food science and medicine.
Biotic: Referring to a live organism; see also abiotic.
Buffer: A substance which tends to keep pH levels fairly constant when acids or bases are added.
Buffering Capacity: Ability of a solution to resist changes in ph when acids or bases are added; the buffering capacity of natural freshwater systems is mostly due to dissolved carbonate rocks in the basin. Marine waters have a stronger buffering capacity because of the existence of bicarbonate (HCO3-) and carbonate (CO32-). The co-existence of these species in seawater creates a chemical buffer system, regulating both the pH and the dissolved CO2 of the oceans.
Carbon Cycle: The circulation of carbon atoms through the earth's whole ecosystem.
Carbon Dioxide: A gas which is colorless and odorless; when dissolved in water it becomes carbonic acid; CO2 is assimilated by plants for photosynthesis in the "dark" cycles of photosynthesis.
Carbonate Buffering System: The most important buffer system in natural surface waters and wastewater treatment, consisting of a carbon dioxide, water, carbonic acid, Bicarbonate, and Carbonate ion equilibrium that resists changes in the water's pH.
Carnivores: Organisms that eat other organisms.
Cations: Positively charged ions.
Chemical Equilibrium: Concentrations of reactants and products at which a reaction is in balance; there is no net exchange because the rate of the forward reaction is taking place at the same rate of the reverse reaction.
Chlorophyll: Green pigment in plants that transforms light energy into chemical energy in photosynthesis.
Clarity: Transparency; routinely estimated by the depth at which you can no longer see a secchi disk. The Secchi disk is a 20 cm (8 inch) diameter weighted metal plate with alternating quadrants painted black and white that is used to estimate water clarity (light penetration). The disc is lowered into water until it disappears from view. It is then raised until just visible. An average of the two depths, taken from the shaded side of the boat, is recorded as the Secchi depth.
Clean Water Act: The Clean Water Act (CWA) is the cornerstone of surface water quality protection in the United States. The CWA established the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters. The basis of the CWA was enacted in 1948 and was called the Federal Water Pollution Control Act, but the Act was significantly reorganized and expanded in 1972. "Clean Water Act" became the Act's common name with amendments occurring in 1977. Under the CWA, EPA has implemented pollution control programs such as setting wastewater standards for industry. We have also set water quality standards for all contaminants in surface waters.
Consumers: Organisms that must eat other organisms for their energy metabolism; organisms that cannot produce new organic matter by photosynthesis or chemosynthesis (producers).
Convection Currents: Air or water movement caused by changes in density or thermal (temperature) gradients.
Covalent: Refers to the chemical bond formed by the sharing of one or more electron pairs between two atoms.
Cyanobacteria: also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. The name "cyanobacteria" comes from the color of the bacteria (Greek: κυανός (kyanós) = blue). Cyanobacteria are found throughout the world in terrestrial, freshwater and marine habitats. However, it is the freshwater habitat that typically experiences a cyanobacteria "bloom". Some of these blooms may be toxic.
Dead zone: An area of low oxygen (hypoxic – less than 2 ppm dissolved oxygen) in estuaries, lakes, and coastal waters. In many cases hypoxic waters do not have enough oxygen to support fish and other aquatic animals. Hypoxia can be caused by the presence of excess nutrients in water. Excess nutrients can cause intensive growth of algae that reduces sunlight penetrating the water, decreases the amount of oxygen dissolved in the water, and causes a loss of habitat for aquatic animals and plants. The decrease in dissolved oxygen is caused by the degradation of dead plant material (algae), which consumes available oxygen. The overall effect is called eutrophication.
Decomposition: The breakdown of organic matter by bacteria and fungi.
Denitrification: Metabolic process of anaerobic bacteria in which nitrate is used instead of oxygen during the oxidation of organic carbon compounds to yield energy (respiration). The process oxidizes organic carbon and (chemically) reduces nitrate to the gaseous end products N2 (nitrogen gas) or N2O (nitrous oxide). This is the major process used in wastewater treatment plants.
Density: The mass of a substance or organism per unit volume (kg/cubic meter; grams/liter).
Density Stratification: Creation of layers in a water body due to density differences; controlled by temperature, dissolved solids concentration and particle concentration.
Detritus: Dead or decaying organic matter; technically called organic detritus to distinguish it from the mineral detritus classified by geologists.
Diatom: Group of algae characterized by glass (silica) cell wall, beautifully ornamented; often the brown stuff attached to rock surfaces.
Dissolved Oxygen (DO or O2): The concentration of free (not chemically combined) molecular oxygen (a gas) dissolved in water, usually expressed in milligrams per liter, parts per million, or percent of saturation. Levels above 5 milligrams per liter (mg O2/L) are considered optimal. Levels below 1 mg O2/L are often referred to as hypoxic and when O2 is totally absent anoxic (often called anaerobic which technically means without air).
Drainage lakes: Lakes having a defined surface inlet and outlet.
Energy/Ecological pyramid: Energy/biomass flow concept where the amount of biomass or energy at each level of the food "chain" decreases as you move from primary producers through the different levels of consumers.
Ecoregion: An environmental area characterized by specific land uses, soil types, surface form, and potential natural vegetation.
Ecosystem: All of the interacting organisms in a defined space in association with their interrelated physical and chemical environment.
Epilimnion: The upper, wind-mixed layer of a thermally stratified lake. This water is turbulently mixed throughout at least some portion of the day and because of its exposure, can freely exchange dissolved gases (such as O2 and CO2) with the atmosphere.
Euphotic zone: Layer of water where sunlight is sufficient for photosynthesis to occur.
Eutrophic Lake: A very biologically productive type of lake due to relatively high rates of nutrient input.
Eutrophication: The process by which surface waters are enriched by nutrients (usually phosphorus and nitrogen) which leads to excessive plant growth (i.e. algae in the open water, periphyton (attached algae) along the shoreline, and macrophytes (the higher plants we often call weeds) in the nearshore zone). The extent to which this process has occurred is reflected in a lake's trophic classification: oligotrophic (nutrient poor), mesotrophic (moderately productive), and eutrophic (very productive and fertile).
Evaporation: The process of converting liquid to vapor.
Evapotranspiration: Term used to describe the sum of evaporation and plant transpiration from the Earth's land surface to atmosphere.
Export rates: Amount of a particular nutrient or contaminant annually transported from its source to a lake or stream; usually related to land uses and expressed per unit area per year.
Fecal coliform: The presence of fecal coliform bacteria in aquatic environments indicates that the water has been contaminated with the fecal material of man or other animals. In general, increased levels of fecal coliforms provide a warning of failure in water treatment, a break in the integrity of the distribution system, or possible contamination with pathogens. When levels are high there may be an elevated risk of waterborne gastroenteritis.
Flow Rate: The rate at which water moves by a given point; in rivers it is usually measured in cubic meters per second (m3/sec) or cubic feet per second (cfs).
Flushing Rate: The retention time (turnover rate or flushing rate), the average length of time water resides in a lake, ranging from several days in small impoundments to many years in large seepage lakes. Retention time is important in determining the impact of nutrient inputs. Long retention times result in recycling and greater nutrient retention in most lakes.
Food Chain: The transfer of food energy from plants through herbivores to carnivores. An example: insect-fish-bear or the sequence of algae being eaten by zooplankton (grazers; herbivores) which in turn are eaten by small fish (planktivores; predators) which are then eaten by larger fish (piscivores; fish eating predators) and eventually by people or other predators (fish-eating birds, mammals, and reptiles).
Food Web: Food chains hooked together into a complex interconnected web.
Gas Solubility: The ability of a gas to dissolve into another substance.
Grazers: Herbivores; zooplankton in the open water zone.
Herbivores: Plant eaters.
Heterogeneous: Not uniform; patchy.
Holomictic: Typically mixes completely throughout the water column at least once a year.
Hydrology: The study of water's properties, distribution and circulation on Earth.
Hydrostatic Pressure: Pressure exerted in a column of water.
Hypolimnetic Oxygen Depletion: A condition where the dissolved oxygen in the bottom layer (hypolimnion) of a water body is gradually consumed through respiration and decomposition faster than it can be replaced over the course of the summer. A similar phenomenon may occur in the winter under ice cover. The rate at which O2 is depeleted is a measure of the productivity of the system.
Hypolimnion: The bottom, and most dense layer of a stratified lake. It is typically the coldest layer in the summer and warmest in the winter. It is isolated from wind mixing and typically too dark for much plant photosynthesis to occur.
Impervious surfaces: Land surfaces such as roads, parking lots, buildings, etc that prevent rainwater from soaking into the soil.
Inflow: Water flowing into a lake.
Inorganic: Substances of mineral, not carbon origin.
Inorganic Contaminants: Inorganic contaminants are compounds that typically do not contain the element Carbon in their structure. Inorganic contaminants can become dissolved in water from natural sources or as the result of human activity. Inorganic contaminants are regulated in public water supplies due to their ability to cause acute poisoning, cancer, and other health effects.
Lake Profile: A graph of a lake variable per depth; where the depth is on the z-axis and the variable is on the x-axis. Depth is the independent variable and the x-axis is the dependent variable.
Land use: The primary or primary and secondary uses of land, such as cropland, woodland, pastureland, forest, water (lakes, wetlands, streams), etc. The description of a particular land use should convey the dominant character of a geographic area and establish the dominant types of human activities which are prevalent in each region.
Landscape: All the natural geographical features, such as fields, hills, forests, and water that distinguish one part of the earth's surface from another part. These characteristics are a result not only of natural forces but of human use of the land as well.
Limnetic zone: Open water zone.
Limnology: The study of inland waters.
Littoral: Nearshore out from shore to the depth of the euphotic zone where it is too dark on the bottom for macrophytes to grow.
Loading Rates: The rate at which materials (typically suspended sediment, nutrients [N and P], or contaminants) are transported into a water body.
Macrophytes: Higher aquatic plants; in the sense of "higher" evolutionarily than algae and having roots and differentiated tissues; may be emergent (cattails, bulrushes, reeds, wild rice), submergent (water milfoil, bladderwort) or floating (duckweed, lily pads).
Meromictic: Describing a lake that doesn’t mix completely.
Mesotrophic: Moderately productive; relating to the moderate fertility of a lake in terms of its algal biomass.
Mean Depth: The average depth of a water body; determined by dividing lake volume by the surface area (also called z mean).
Metabolism: The chemical and physical processes continually going on in living organisms and cells, by which the energy is provided for cellular processes and activities, and new material is assimilated to repair waste.
Metalimnion: The middle or transitional zone between the well mixed epilimnion and the colder hypolimnion layers in a stratified lake. This layer contains the thermocline, but is loosely defined depending on the shape of the temperature profile.
Micronutrient: Trace nutrients required by microrganisms or zooplankton such as molybdenum and cobalt; nitrogen and phosphorus are considered to be macronutrients.
Microcystins: Microcystin-LR is one of over 80 known toxic variants produced by cyanobactyeria. Microcystins usually occur within the cells, and substantial amounts are released to the surrounding water only in situations of cell rupture. Microcystin containing 'blooms' are a problem worldwide, including China, Australia, the United States and much of Europe. Once ingested, microcystin travels to the liver.
Mixolimnion: The upper layer of less-saline water that can mix completely at least once a year in a meromictic lake.
Nitrification: Bacterial metabolism in which ammonium ion (NH4+) is oxidized to nitrite (NO2-) and then to nitrate (NO3-) in order to yield chemical energy that is used to fix carbon dioxide into organic carbon. The process is a type of chemosynthesis which is comparable to photosynthesis except that chemical energy rather than light energy is used. These bacteria are aerobic and so require dissolved oxygen in order to survive.
Nitrogen Fixation: The conversion of elemental nitrogen in the atmosphere (N2) to a form (e.g., ammonia) that can be used as a nitrogen source by organisms. Biological nitrogen fixation is carried out by a variety of organisms; however, those responsible for most of the fixation in lakes are certain species of bluegreen algae.
Non-motile: Not able to move at will.
Non-polar Molecule: A molecule that does not have electrically charged areas (poles).
Nonpoint source: Diffuse source of pollutant(s); not discharged from a pipe; associated with land use such as agriculture or contaminated groundwater flow or on-site septic systems.
Nuisance blooms: Referring to obnoxious and excessive growths of algae caused by excessive nutrient loading; often due to scum forming cyanobacteria (bluegreen algae) that can regulate their buoyancy to float high in the water column to obtain sunlight.
Nutrient loading: Discharging of nutrients from the watershed (basin) into a receiving water body (lake, stream, wetland); expressed usually as mass per unit area per unit time (kg/ha/yr or lbs/acre/year.
Oligotrophic: Very unproductive; lakes low in nutrients and algae, usually very transparent with abundant hypolimnetic oxygen if stratified.
Omnivorous: Capable of eating plants, fungi and animals.
Organic: Substances which contain carbon atoms and carbon-carbon bonds.
Outflow: Water flowing out of a lake.
Oxygen: An odorless, colorless gas; combines to form water; essential for aerobic respiration
Oxygen Solubility: The ability of oxygen gas to dissolve into water.
Pelagic: Refers to the offshore open water, and often deep water, zone of a lake as opposed to the nearshore fringe. Also referred to as the limnetic zone, in contrast to the (usually) nearshore littoral zone which is usually defined either by the depth to which there is sufficient light availble for submersed aquatic plants to grow, or by the depth to which light penetration is 1% of surface light irradiance.
Periphyton: Attached algae; the green slime that attaches shoreline and bottom vegetation and the brown stuff attached to rock surfaces.
pH A measure of the concentration of hydrogen ions.
pH Scale: A scale used to determine the alkaline or acidic nature of a substance. The scale ranges from 1-14 with 1 being the most acidic and 14 the most basic. Pure water is neutral with a pH of 7.
Phosphorus: Key nutrient influencing plant growth in lakes. Soluble reactive phosphorus (PO4-3) is the amount of phosphorus in solution that is available to plants. Total phosphorus includes the amount of phosphorus in solution (reactive) and in particulate form.
Photosynthesis: The process by which green plants convert carbon dioxide
(CO2) dissolved in water to sugars and oxygen using sunlight for energy. Photosynthesis is essential in producing a lake's food base, and is an important source of oxygen for many lakes.
Photosynthesizers: Organisms that produce their energy via phtosynthesis.
Phytoplankton: Microscopic floating plants, mainly algae, that live suspended in bodies of water and that drift about because they cannot move by themselves or because they are too small or too weak to swim effectively against a current.
Planktivores: Animals that eat plankton; usually refers to fish that feed on zooplankton but can also refer to fish that graze on algae; includes invertebrate predators, such as the phantom midge.
Polar molecule: A molecule in which one structural end (an atom or atoms) possesses a slight negative charge and another structural end possesses a slight positive charge but the charges do not cancel one another out but rather create two separate poles.
Polymictic: Mixes completely intermittently.
ppb: Part-per-billion; equivalent to a microgram per liter (ug/l).
ppm: Part-per-million; equivalent to a milligram per liter (mg/l).
Primary consumers: First level of consumers according to the ecological pyramid concept; organisms that eat herbivorous grazers.
Primary producers: Organisms that convert CO2 to biomass. Usually refers to photosynthesizers, but also includes the chemosynthetic bacteria that use chemical instead of light energy to fixCO2 to biomass.
Primary Productivity: The productivity of the photosynthetic organisms at the base of the food chain in ecosystems. This refers to the yield of new biomass (plant) growth during a specified time period. The entire year’s accumulation is termed annual production. In the open water of lakes it is typically estimated by measured growth rates of phytoplankton (algae), either via O2 accumulation in light relative to dark bottles of lake water or by the uptake of added radioactive carbon dioxide in sealed bottles of lake water.
Productivity: The time rate of production of biomass for a given group of organisms; essentially the net growth rate of organisms.
Profile: A vertical, depth by depth characterization of a water column, usually at the deepest part of a lake.
Respiration: The metabolic process by which organic carbon molecules are oxidized to carbon dioxide and water with a net release of energy. Aerobic respiration requires, and therefore consumes, molecular oxygen (algae, weeds, zooplankton, benthic invertebrates, fish, many bacteria, people). Certain bacteria can use nitrate in place of oxygen (denitrifiers) or sulfate (sulfate reducers), but only under anaerobic (anoxic) conditions - typically present only in the sediments or in the hypolimnion after prolonged oxygen depletion has occurred.
Saturation: The point at which a substance has the maximum amount of another substance at a given temperature and pressure; also see supersaturation.
Secchi Disk: A disk with a 4-6 inch radius that is divided into 4 equal quadrates of alternating black and white colors. It is lowered into a section of shaded water until it can no longer be seen and then lifted back up until it can be seen once again. Averaging the two depths gives the clarity of the water; see also clarity.
Secondary consumers: Consumers such as plankton eating fish or predaceous zooplankton that eat other zooplankton.
Secondary contaminants: substances which are not directly health concerns, but may affect the taste, color, odor or some other aesthetic aspect of drinking water.
Sedimentation: The removal, transport, and deposition of detached soil particles by flowing water or wind. Accumulated organic and inorganic matter on the lake bottom. Sediment includes decaying algae and weeds, precipitated calcium carbonate (marl), and soil and organic matter eroded from the lake's watershed.
Sewage sludge: The solid portion of sewage that contains organic matter, and a whole community of algae, fungi, bacteria and protozoans that consume it. The terms biosolids, sludge, and sewage sludge are often used interchangeably.
Solubility: The ability of a substance to dissolve into another; also see gas solubility.
Solute: A substance which can be dissolved into another substance.
Solution: A homogenous mixture of two substances.
Solvent: A substance which has the ability to dissolve another.
Specific conductance: A measure of the ability of water to conduct an electrical current as measured using a 1-cm cell and expressed in units of electrical conductance (EC), i.e. siemans (u or mS) at 25 C.
Stormwater discharge: Precipitation and snowmelt runoff from roadways, parking lots, roof drains that is collected in gutters and drains; a major source of nonpoint source pollution to water bodies and a major headache to sewage treatment plants in municipalities where the stormwater is combined with the flow of domestic wastewater (sewage) before entering the wastewater treatment plant.
Stratification: An effect where a substance or material is broken into distinct horizontal layers due to different characteristics such as density or temperature.
Substrate: Attachment surface or bottom material in which organisms can attach or live-within; such as rock substrate or sand or muck substrate or woody debris or living macrophytes.
Surface Tension: A phenomenon caused by a strong attraction towards the interior of the liquid action on liquid molecules in or near the surface in such a way to reduce the surface area.
Suspended Sediment (SS or Total SS[TSS]): Very small particles which remain distributed throughout the water column due to turbulent mixing exceeding gravitational sinking; also see turbidity.
TDS: Total dissolved salts or solids in a volume of water; usually in mg/l; estimated by EC (electrical conductivity).
Temperate: Refers to lakes located in a climate where the summers are warm and the winters moderately cold. The Temperate Zone is between the Tropic of Cancer and the Arctic Circle.
Temperature: A measure of whether a substance is hot or cold.
Temperature Profile: A graph of the temperature per depth; where the depth is on the z-axis and temperature is on the x-axis.
Tertiary consumers: Larger consumers in the fourth trophic level like adult northern pike, ospreys and humans that eat fish.
Thermal stratification: Existence of a turbulently mixed layer of warm water (epilimnion) overlying a colder mass of relatively stagnant water (hypolimnion) in a water body due to cold water being denser than warm water coupled with the damping effect of water depth on the intensity of wind mixing.
Thermocline: The depth at which the temperature gradient is steepest during the summer; usually this gradient must be at least 10C per meter of depth.
Total Dissolved Solids (TDS): The amount of dissolved substances, such as salts or minerals, in water remaining after evaporating the water and weighing the residue.
Total Maximum Daily Loads (TMDL’s): A Total Maximum Daily Load (TMDL) is a regulatory term in the U.S. Clean Water Act (CWA), describing a value of the maximum amount of a pollutant that a water body can receive while still meeting water quality standards.
Trophic State: Eutrophication is the process by which lakes are enriched with nutrients, increasing the production of rooted aquatic plants and algae. The extent to which this process has occurred is reflected in a lake's trophic classification or state: oligotrophic (nutrient poor), mesotrophic (moderately productive), and eutrophic (very productive and fertile).
Trophic State Index: The quantities of nitrogen, phosphorus, and other biologically useful nutrients are the primary determinants of a lake's trophic state index (TSI). Nutrients such as nitrogen and phosphorus tend to be limiting resources in standing water bodies, so increased concentrations tend to result in increased plant growth, followed by corollary increases in subsequent trophic levels. Consequently, a lake's Trophic State Index provides a rough estimate of its biological condition.
Trophic webs: Conceptual model of the interconnections of species of organisms according to their different feeding groups.
Turbidity: A measure of the degree to which light is scattered by suspended particulate material and soluble colored compounds in the water. It provides an estimate of the the muddiness or cloudiness of the water due to clay, silt, finely divided organic and inorganic matter, soluble colored organic compounds, plankton, and microscopic organisms.
Turnover: Fall cooling and spring warming of surface water act to make density uniform throughout the water column. This allows wind and wave action to mix the entire lake. Mixing allows bottom waters to contact the atmosphere, raising the water's oxygen content. However, warming may occur too rapidly in the spring for mixing to be effective, especially in small sheltered kettle lakes.
Water column: A conceptual column of water from lake surface to bottom sediments.
Water Density: The ratio of water's mass to its volume; water is the most dense at four degrees Celsius.
Watershed: All land and water areas that drain toward a river or lake; also called Drainage Basin or Water Basin.
Watershed area: lake surface area ratio: Aw:a0 ; a measure relating to how much land area is there relative to lake area in a given watershed.
Zooplankton: The animal portion of the living particles in water that freely float in open water, eat bacteria, algae, detritus and sometimes other zooplankton and are in turn eaten by planktivorous fish. Zooplankton can be holoplanktonic (live entire lives as plankton) or meroplanktonic (spend only a part of their life cycle in the water column).
AquaFiber News
Read the latest news on AquaFiber Technologies Corporation
aqualutions™
Patent pending technology that removes phosphorus, nitrogen, carbon, and other harmful pollutants from surface waters.
aquaknight™
A mobile water treatment unit that can be delivered to field locations.
partners
AquaFiber is working with the following organizations.