Comparison of test results in the evaluation of the WSF of several jet fuels using the standardized aquatic microcosm and the mixed flask culture protocols

The water soluble fraction of the turbine fuels Jet-A, JP-4 and JP-8 have been examines as stressors for two microcosm protocols, the standardized aquatic microcosm (SAM) and the mixed flask culture (MFC). The SAM is a 3 L system inoculated with standard cultures of algae, zooplankton, bacteria, protozoa. In contrast, the MFC is 1 L and is inoculated with a complex mixture of organisms derived from a natural source. Analysis of the organism counts and physical data were conducted using conventional and newly derived multivariate methods. Physical parameters, such as pH and oxygen metabolism, were often not as sensitive as species and bacterial counts. Like the SAM system, species numbers and other variables that determined clusters varied among sampling dates. Compared to the larger yet simpler system, the MFC exhibits more violent dynamics and is more likely to become catastrophically fixated, as in systems dominated by cyanobacteria. The combination of greater diversity and smaller volume may contribute to the volatile or chaotic dynamics of the MFC system