An apparatus which draws lake water, either filtered or unaltered, at a preestablished rate through four 40.75 L vessels incubated in situ is described. The system provides facilities for the synchronous addition of experimental liquids such as toxicants. All components are readily transportable. The system is self-powered for periods up to one month depending on the rate of flow chosen. This apparatus provides for the isolation of the zooplankton community from other compartments in the lake, incubation in natural conditions, experimental periods of from 1 to 30 d, maintenance of chosen concentrations of added materials continuously or non-continuously as appropriate, and entry of food organisms with concomitant dilution of wastes and metabolites.The responses of selected zooplankton species or of zooplankton communities to impoundment, manipulation of predator or prey organisms and the addition of nutrient or toxic materials can be assessed as they occur in the naturally varying conditions of a lake environment while the population is being held as a separate and defined part of the whole-lake ecosystem.Methods for the construction and use of the apparatus, and for collection of samples are described. Methods for enumerating organisms in several sizes of subsamples are assessed. Data generated in several experiments are analyzed using standard statistical methods and percent similarity indices.
A constant current triboelectric nanogenerator arising from electrostatic breakdown