5.1 A microcosm test is conducted to obtain information concerning toxicity or other effects of a test material on the interactions among three trophic levels (primary, secondary, and detrital) and the competitive interactions within each trophic level. As with most natural aquatic ecosystems, the microcosms depend upon algal production (primary production) to support the grazer trophic level (secondary production), which along with the microbial community are primarily responsible for the nutrient recycling necessary to sustain primary production. Microcosm initial condition includes some detritus (chitin and cellulose) and additional detritus is produced by the system. The microcosms include ecologically important processes and organisms representative of ponds and lakes, but are non-site specific.
5.2 The species used are easy to culture in the laboratory and some are routinely used for single species toxicity tests (Guide E729; Practice D3978, Guides E1192 and E1193). Presumably acute toxicity test results with some of these species would be available prior to the decision to undertake the microcosm test. If available, single species toxicity results would aid in distinguishing between indirect and direct effects.
5.3 These procedures are based mostly on previously published methods (4-6), interlaboratory testing (7-10), intermediate studies (11-22), statistical studies (23-25) and mathematical simulation results (26). Newer studies on jet fuels have been reported (27)(See 15.1 for multivariate statistical analyses) and on the implications of multispecies testing for pesticide registration (28). Environmental Protection Agency, (EPA) and Food and Drug Administration, (FDA) published similar microcosm tests (29). The methods described here were used to determine the criteria for Acceptable Tests (Section 16).
5.4 Concur......ASTM E1366-11(2016) Referenced Document
ASTM E1366-11(2016) history
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