Publications archive - Coasts and Oceans
Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.
Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.
Final Report for the Department of the Environment and Heritage
S Duda, JH Myers and S Hoffman
Victorian Department of Natural Resources and Environment, 2003
Note: All definitions are given in the context of the procedures in this report, and may not be appropriate in another context.
Acute denotes events that occur within a short period (seconds, minutes, hours or a few days) in relation to the life span of the test organism.
Acute toxicity means a discernible adverse effect (lethal or sublethal) induced in the test organism(s) within a period of exposure to a test material. The period of exposure is short relative to the life span of the test organism.
Bioassay is an experiment for estimating the nature, constitution or potency of a material (or a process) by means of the reaction that follows its application to living matter (Rand 1995). Bioassays are used to assess the relative potency of a chemical(s) by comparing its effects on a living organism with effects of a standard preparation on the same type of organism.
Chemical is any element, compound, formulation or mixture of chemical substances that might be mixed with, deposited or found in association with sediment or water.
Chronic denotes events that occur within a relatively long period of exposure, usually a significant portion of the life span of the organism (eg: 10% or more).
Chronic toxicity implies long-term effects that are related to changes in such things as metabolism, growth, reproduction, or ability to survive.
Coefficient of variation (CV) is the standard deviation (SD) of a sample expressed as a percentage of the mean (100SD/x).
Concentration-response curve a graph describing the relationship between different exposure concentrations of a particular chemical (s) and percent of the exposed test population.
Contaminant is a foreign agent that is present that may cause a physical or chemical change but may not cause adverse biological effects.
Control is a treatment in an investigation or study that duplicates the conditions and factors that might affect the results of the investigation, except the specific condition that is being studied. In an aquatic toxicity test, the control must duplicate the conditions of the exposure treatment(s), but contain essentially no test substance (eg: trace levels may be present). The control is used to determine the absence of measurable toxicity due to basic test conditions (eg: temperature, health of test organisms, or effects due to their handling). In the event that a solvent must be used to dissolve the test toxicant, a spiked-solvent control is established in addition to the unspiked control treatment.
Deionised water is freshwater that has been purified to remove ions from solution by passing it through resin columns and/or a reverse osmosis system.
Distilled water is water that has been passed through a distillation apparatus of borosilicate or quartz glass, or other material, to remove non-volatile impurities.
Dilution/Control water is the water used to prepare test solutions with specific concentrations of a reference toxicant or other test chemicals for waterborne exposures of test organisms. This water is also used for the control water.
EC50 is the median effective concentration. That is, the concentration of material in the water (mgL-1) that is estimated to cause a discernible sublethal toxic effect to 50% of the test organisms. In most instances the EC50 (together with its 95% confidence intervals) is statistically derived by analysis of an observed sublethal response (eg: germination, rhizoid elongation) for various test concentrations, after a fixed period of exposure. The duration of exposure must be specified (eg: 48h, 72h).
Endpoint(s) is (are) the variable(s) (i.e.: time, the reaction of the organisms, etc) that indicate(s) the termination of a test. Endpoint can also refer to the measurement(s) or value(s) derived that characterises the results of the test (eg: EC50, LC50).
Equilibrium This indicates that both a steady state of flux and an equivalence in chemical activity have been reached in compartments or phases separated by a membrane or boundary across which the chemical fluxes over. LOEC is the lowest-observed-effect concentration. This is the lowest concentration of a test material to which organisms are exposed, that causes adverse effects on the organisms. Effects are detected by the observer and are statistically significant.
Macroalgae are algal species that have a life history stage that is visible to the naked eye.
NOEC is the no-observed-effect concentration. This is the highest concentration of test material to which organisms are exposed, that does not cause any observed and statistically significant adverse effect on the organisms.Range finder is a test conducted to estimate the concentrations to be used for a definitive test. Receptacle A fertile area on which gametangia or sporangia arise.
Reference test refers to a waterborne toxicity test in which a reference toxicant is added to control/dilution water.
Reference toxicant is a standard chemical used to assess the sensitivity of organisms to establish confidence in the toxicity data obtained for a test material. In most instances, a toxicity test with a reference toxicant is performed to assess the sensitivity of the organisms at the time the test material is evaluated, and to assess the precision of results obtained by the laboratory over time. The toxicity test with the reference toxicant is performed in a manner consistent with that of the toxicity test for which test precision is of interest.
Static tests describes toxicity tests in which test waters or solutions are not renewed during the test. Stock solution is a concentrated aqueous solution of a reference toxicant or test toxicant. Measured volumes of a stock solution are added to a carrier (eg: acetone) or dilution water to prepare the required concentrations of test solution for experiment.
Sublethal is detrimental to the test organism, but below the level that directly causes death within the test period.
Sublethal effect is an adverse effect on a test organism, below the level that directly causes death within the test period.
Sublethal concentration is a concentration of test material that does not cause death under the defined test conditions.
Toxicant an agent or material capable of producing an adverse response (effect) in a biological system, seriously injuring the structure and/or function or producing death.
Toxicity is the inherent potential or capacity of a material to cause adverse effects toward the exposed organism.
Toxicity test means a determination of the effect of a material on a group of selected test organisms of a single species, under defined conditions. An aquatic toxicity test usually measures either (a) the proportion of organisms affected (quantal) or (b) the degree of effect shown (graded or quantitative), after exposure to a specific test material.
Warning chart is synonymous with control chart and refers to a chart of mean toxicity values prepared for reference toxicant tests by plotting the results of a successive series of tests on a chart where the x-axis represents the test date and the y-axis indicates the endpoint concentration (eg: EC50). The chart also indicates a measure of the variability expected in the test results.