ABSTRACT
Most methods that ecotoxicologists apply to determine lethality come from mammalian toxicology. As the field of ecotoxicology developed, adoption of established techniques and concepts allowed very rapid, initial advancement. Several exposure designs have been established for tests quantifying lethal effects of toxicants in waters. In static toxicity tests, individuals are placed into one of a series of exposure concentrations, and the exposure water is not changed during the test. Incipiency when referring to lethality of contaminants is the lowest concentration at which an increase in toxicant concentration begins to produce an increase in the measured effect. Consequently, estimation of lethal effect of mixtures is more difficult than described to this point for single toxicants. Lethality was framed around acute and chronic exposure contexts. The possibility of differences in toxic impact at different life stages of an individual was explored along with associated implications.
