Glossary

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Acidity - the quantitative capacity of a water to react with a strong base to a designated pH.

Acute toxicity - rapid adverse effect (e.g. death) caused by a substance in a living organism. Can be used to define either the exposure or the response to an exposure (effect).

AFFA - Agriculture, Fisheries and Forestry Australia.

Algae - comparatively simple chlorophyll-bearing plants, most of which are aquatic and microscopic in size.

Alkalinity - the acid-neutralising capacity of an aqueous system; the sum of all titratable bases.

Ambient – surrounding.

ANCA - Australian Nature Conservation Agency.

Anion - a negatively-charged ion.

ANZECC - Australian and New Zealand Environment and Conservation Council.

Aquatic ecosystem - any water environment from small to large, from pond to ocean, in which plants and animals interact with the chemical and physical features of the environment.

Aquifer - an underground layer of permeable rock, sand or gravel that carries water, allowing it free passage through pore spaces.

ARMCANZ - Agriculture and Resource Management Council of Australia and New Zealand.

AUSRIVAS - Australian River Assessment Scheme.

BACI - Before-after, control-impact.

Benchmark - a standard or point of reference.

Benthic - referring to organisms living in or on the sediments of aquatic habitats.

Bioaccumulation - a general term describing a process by which chemical substances are accumulated by aquatic organisms from water directly or through consumption of food containing the chemicals.

Bioassay - a test used to evaluate the relative potency of a chemical by measuring its effect on a living organism relative to a control.

Bioavailable - able to be taken up by organisms.

Biochemical oxygen demand (BOD) - the decrease in oxygen content in a sample of water that is brought about by the bacterial breakdown of Organic matter in the water.

Bioconcentration - a process by which there is a net accumulation of a chemical directly from water into aquatic organisms, resulting from simultaneous uptake (e.g. by gill or epithelial tissue) and elimination.

Biomagnification - result of the processes of bioconcentration and bioaccumulation by which tissue concentrations of bioaccumulated chemicals increase as the chemical passes up through two or more trophic levels. The term implies an efficient transfer of chemicals from food to consumer so that the residue concentrations increase systematically from one trophic level to the next.

Bivalve - mollusc with a shell in two parts, hinged together.

Bloom - an unusually large number of organisms of one or a few species, usually algae, per unit of water.

BOD - Biochemical oxygen demand or biological oxygen demand.

BOD test - an empirical test that measures the relative oxygen requirements of waste-waters, effluents and contaminated waters by incubating samples in the dark at a certain temperature for a fixed number of days usually designated by a subscript, e.g. BODs test.

Cation - a positively-charged ion.

Chemical oxygen demand (COD) - the oxygen equivalent of the organic matter content of a sample that is susceptible to oxidation by a strong chemical oxidant.

Chronic toxicity - toxicity that acts over a long period of time and that typically affects a life stage (e.g. reproductive capacity); it can also refer to toxicity resulting from a long-term exposure.

COAG - Council of Australian Governments.

COD - Chemical oxygen demand.

Community - assemblage of organisms characterised by a distinctive combination of species occupying a common environment and interacting with one another.

Community composition - all the types of taxa present in a community.

Concentration - the quantifiable amount of a substance in water, food or sediment.

Contaminants - biological or chemical substances or entities, not normally present in a system, capable of producing an adverse effect in a biological system, seriously injuring structure or function.

Control - part of an experimental procedure that is ideally exactly like the treated part except that it is not subject to the test conditions. It is used as a standard of comparison, to check that the outcome of the experiment is a reflection of the test conditions and not of some unknown general factor.

CRCFE - Cooperative Research Centre for Freshwater Ecology Criteria (water quality). Scientific data is evaluated to derive the recommended quality of water for different uses.

CSIRO - Commonwealth Scientific and Industrial Research Organisation.

DEST - Department of Environment, Sport and Territories.

Detection limit - method detection limit is the concentration of a substance that when processed through the complete analytical method produces a signal that has a 99% probability of being different from the blank.

DO - Dissolved oxygen.

DOC - Dissolved organic carbon.

Duplicate samples - obtained by dividing a sample into two or more sub samples, to reveal the sizes of random and/or systematic errors due to contamination.

EA - Environment Australia.

EC - Electrical conductivity.

Ecologically Sustainable Development  (ESD) - development that improves the total quality of life, both now and in the future, in a way that maintains the ecological processes on which life depends.

Electrical conductivity - the ability of water or soil solution to conduct an electric current; commonly used as a measure of salinity or total dissolved salts.

Environmental values - particular values or uses of the environment that are important for a healthy ecosystem or for public benefit, welfare, safety or health and that require protection from the effects of contaminants, waste discharges and deposits. Several environmental values may be designated for a specific water body.

EPA - Environment Protection Authority.

Epilimnion - the uppermost layer of water in a lake, characterised by an essentially uniform temperature that is generally warmer than elsewhere in the lake, and by relatively uniform mixing by wind and wave action.

ERISS - Environmental Research Institute of the Supervising Scientist.

ESD - Ecologically sustainable development.

Euphotic - surface waters to a depth of approximately 80-100 m; the lit region that extends virtually from the water surface to the level at which photosynthesis fails to occur because of reduced light penetration.

Eutrophication - enrichment of waters with nutrients, primarily phosphorus, causing abundant aquatic plant growth and often leading to seasonal deficiencies in dissolved oxygen.

Fate - disposition of a material in various environmental compartments (e.g. soil or sediment, water, air, biota) after transport, transformation and degradation.

FNARH - First National Assessment of River Health.

Guideline - numerical concentration limit or narrative statement recommended to support and maintain a designated water use.

Guideline trigger levels - the concentrations (or loads) for each water quality parameter, below which there exists a low risk that adverse biological (or ecological) effects will occur. They are the levels that trigger some action, either continued monitoring in the case of low risk situations or further ecosystem-specific investigations in the case of high risk situations.

Hardness - measure of the sum of the concentrations of calcium and magnesium ions in water, both expressed as g/L calcium carbonate equivalent.

Humic substances - heterogeneous yellow-black organic materials that include most of the naturally dissolved organic matter in water. They are classified as huin (not soluble at any pH), humic acid (not soluble at pH <2) and fulvic acid (soluble at all pH values).

Hydrograph - graphical representation of either surface stream discharges or water-level fluctuations in wells.

Hypolimnion - the region of a water body that extends from below the thermocline to the bottom of a lake; it is thus removed from much of the surface influence, and is usually cold and relatively undisturbed.

Hypothesis - supposition drawn from known facts, made as a starting point for further investigation.

Index (indices) - composite value(s) that can give a quick ranking to a water body or other ecosystem feature, derived via a formula that combines measurements of important ecosystem characteristics; typically used to rank ‘health' or naturalness.

Indicator - measurement parameter or combination of parameters that can be used to assess the quality of water.

Invertebrates - animals lacking a dorsal column of vertebrae or a notochord.

Ion - an electrically charged atom.

Leaching - the dissolution of a material, by water or another solvent mixing with a solid phase, and its downward or outward movement from the solid in solution.

ICM - Integrated Catchment Management.

Level of protection - the acceptable level of change from a defined reference condition.

Management goals - long-term management objectives that can be used to assess whether the corresponding environmental value is being maintained. They should reflect the desired levels of protection for the aquatic system and any relevant environmental problems.

MBACI - Multiple before-after, control-impact.

MBACIP - Multiple before-after, control-impact, paired.

MDBC - Murray-Darling Basin Commission.

Measurement parameter - any parameter or variable that is measured to find something out about an ecosystem.

Methylation - the introduction of methyl (CH₃) groups into organic and inorganic compounds.

NATA - National Association of Testing Authorities of Australia.

NHMRC - National Health and Medical Research Council.

Not detectable - below the limit of detection of a specified method of analysis.

NRC - National Research Council.

NRHP - National River Health Program.

NWQMS - National Water Quality Management Strategy.

OH&S - occupational health & safety.

Organism - any living animal or plant; anything capable of carrying on life processes.

Oxidation - the combination of oxygen with a substance, or the removal of hydrogen from it, or, more generally, any reaction in which an atom loses electrons.

PAH’s - polycyclic aromatic hydrocarbons.

Parameter - a measurable or quantifiable characteristic or feature.

Pathogen - an organism capable of eliciting disease symptoms in another organism.

Pelagic - term applied to organisms of the plankton and nekton which inhabit the open water of a sea or lake.

Performance indicators - indicators used to assess the risk that a particular issue will occur (they are used in the guideline packages 0 compare against the trigger levels). They are generally median (or mean) concentrations in the ambient water, and may be stress and/or condition indicators.

Periphyton - organisms attached to submerged plants.

Pesticide - substance or mixture of substances used to kill unwanted species of plants or animals.

pH - the intensity of the acidic or basic character of a solution, defined as the negative logarithm of the hydrogen ion concentration of a solution.

Plankton - plants (phytoplankton) and animals (zooplankton), usually microscopic, floating in aquatic systems.

Precipitation - the settling out of water from cloud, in the form of rain, hail, fog, snow, etc. (also the formation and settling out of solid particles in solution).

Producers - organisms that can build up their body substance from inorganic materials.

Protocol - a formally agreed method and procedure for measuring an indicator, including sampling, sample handling procedures and sample analysis.

Pseudoreplication - replication in which the samples are not independent but instead are from sub-populations of a population: replicates that are actually sub samples of one sample are pseudoreplicates; and samples from various sites along a stretch of river are pseudoreplicates because the water is the same, moving between sites.

Quality assurance (QA) - the implementation of checks on the success of quality control (e.g. replicate samples, analysis of samples of known concentration).

Quality control (QC) - the implementation of procedures to maximise the integrity of monitoring data (e.g. cleaning procedures, contamination avoidance, sample preservation methods).

Redox - simultaneous (chemical) reduction and oxidation: reduction is the transfer of electrons to an atom or molecule; oxidation is the removal of electrons from an atom or molecule.

Reference condition - an environmental quality or condition that is defined from as many similar systems as possible and used as one benchmark for determining the environmental quality or condition to be achieved and/or maintained in a particular system of equivalent type.

Risk - a statistical concept defined as the expected frequency or probability of undesirable effects resulting from a specified exposure to known or potential environmental concentrations of a material, organism or condition.  A material is considered safe if the risks associated with its exposure are judged to be acceptable. Estimates of risk may be expressed in absolute or relative terms. Absolute risk is the excess risk due to exposure. Relative risk is the ratio of the risk in the exposed population to the risk in the unexposed population.

RIVPACS - River Invertebrate Prediction and Classification System.

SAA - Standards Association of Australia.

Salinity - the presence of soluble salts in water or soils.

Sediment - unconsolidated mineral and organic particulate material that has settled to the bottom of aquatic environments.

SOE - State of the Environment.

Solution concentration - concentration of contaminants in the liquid phase.

Speciation - measurement of different chemical forms or species of an element in a solution or solid.

Species - generally regarded as a group of organisms that resemble each other to a greater degree than members of other groups and that form a reproductively isolated group that will not normally breed with members of another group. (Chemical species are differing compounds of an element.)

Species richness - the number of species present (generally applied to a sample or community).

Stakeholder - a person or group (e.g. an industry, a government jurisdiction, a community group, the public, etc.) that has an interest or concern in something.

Standard - an objective that is recognised in environmental control laws, enforceable by a level of government. e.g. water quality standard.

Stressors - the physical, chemical or biological factors that can cause an adverse effect on an aquatic ecosystem as measured by the condition indicators.

Sub-lethal - involving a stimulus below the level that causes death.

Suspension - very small particles (solid, semi-solid, or liquid) more or less uniformly dispersed in a liquid or gaseous medium.

Taxon (taxa) - any group of organisms considered to be sufficiently distinct from other such groups to be treated as a separate unit (e.g. species, genera, families).

Taxa richness - number of taxa present.

TCM - Total Catchment Management.

TDS - Total Dissolved Solids.

Thermocline - a region or layer of water in a lake, between the well-mixed surface layer and the cold still bottom layer, where the temperature changes rapidly with respect to depth.

TIE - Toxicity Identification and Evaluation.

Toxicant - a chemical capable of producing an adverse response (effect), seriously injuring the structure or function or producing death in a biological system. Examples include pesticides, heavy metals and biotoxins (i.e. domoic acid, ciguatoxin and saxitoxins).

Toxicity - the inherent potential or capacity of a material to cause adverse effects in a living organism.

Toxicity test - the means by which the toxicity of a chemical or other test material is determined. A toxicity test is used to measure the degree of response produced by exposure to a specific level of stimulus (or concentration of chemical).

Trophic level - a notional stage in the 'food chain' that transfers matter and energy through a community; primary producers, herbivores, carnivores and decomposers each occupy a different trophic level.

True colour - the colour of water resulting from substances that are totally in solution; not to be mistaken for apparent colour, which includes the effect of colloidal or suspended matter.

UC - University of Canberra.

Uptake - a process by which materials are absorbed and incorporated into a living organism.

USEPA - United States Environmental Protection Agency.

UWRAA - Urban Water Research Association of Australia.

WHO - World Health Organization.

WMO - World Meteorological Organization.

Zooplankton - see plankton.