Abstract
Water microbiological and physicochemical characterizations at various depths of aquatic ecosystems are basic requirements in several fields of research. A chief difficulty in hydrobiology, limnology, biological oceanography and water environmental microbiology is that of taking accurate field collections that are representative of the natural environment and population at various depths of aquatic ecosystems. Gathering water/plankton samples in a level just below the surface of the water body upon rising in columns from various depths due to hydrostatic pressure variations provided a simple approach for water and plankton sampling. Based on this approach, several forms of simple devices for water and plankton sampling were developed for water microbiological and physicochemical characterizations at various depths of aquatic ecosystems. The described approach showed less sampling errors in comparison to Van Dorn bottle and was comparable to water pumping but requires no external source of power. The described samplers are inexpensive and can be self constructed.