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IMPORTANCE OF PHYSICAL SCALING FACTORS TO BENTHIC MARINE INVERTEBRATE RECOLONIZATION OF LABORATORY MICROCOSMS
Citation:
Flemer, D., J. Clark, R. Stanley, C. Bundrick, AND G. Plaia. IMPORTANCE OF PHYSICAL SCALING FACTORS TO BENTHIC MARINE INVERTEBRATE RECOLONIZATION OF LABORATORY MICROCOSMS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/114 (NTIS PB94155538).
Description:
Five laboratory studies of benthic macroinvertebrate recolonization were conducted for 6-wk periods to evaluate the effects of physical factors (i.e., microcosm size, seawater flow rates and sediment depth) on benthic community structure. esign variables included4 open-faced acrylic containers of size 7, 12, 20 and 32 cm sq; seawater flow rate - approximately 0.7 or 1.6 liters/min, and sediment depth of 2.5 or 5.0 cm. esponse variables included: total number of organisms (TNO), and taxa (TNT), Brillouin's and Shannon-Weiner diversity indexes, and Simpson's diversity index (dominance sensitive index). Effects of seawater flow rates were more apparent than those related to microcosm size and sediment depth. oth TNO and TNT gave significant positive responses to increasing flow. ize effects were non-linear, size-20 microcosms tended to average more organisms than size-32 but effects were often not significant (P > 0.05). ize-20 microcosms averaged higher numbers of taxa than size-32 and responses were usually significant (P < 0.05). The various indices usually did not vary significantly with physical scaling factors. urvival individual taxa responded significantly to one or more design variables. tatistical power analysis based on a representative data set of no-mobile macroinvertebrates which provided an increased number of degrees of freedom detected a 20% difference from the means of responses variables but a doubling or larger sample size would be required to detect a 10% difference at a power > 0.9 for in alpha = 0.05. hese results provide a basis for setting minimum experimental unit parameters and should lead to cost savings through physical scale reduction (depth of sediment and surface area) and less time to process smaller volumes of sediment and generation of smaller waste volumes.
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IMPORTANCE OF PHYSICAL SCALING FACTORS TO BENTHIC MARINE INVERTEBRATE RECOLONIZATION OF LABORATORY MICROCOSMS