Parameters of Interstitial Water Collected by a New Sampler from the Biotopes of Cyathura polita (Isopoda) in Six Southeastern States

Abstract

A new, hand-operated sampler which collects interstitial water to a depth of 7.0 cm is described. To test the usefulness of the instrument, studies were made of 17 habitats ofCyathura polita in the southeastern United States. Measurements of physical-chemical parameters were made of interstitial and overlying waters, and associated plants and animals were noted to further characterize the cyathuran biotopes. Temperature and dissolved oxygen of interstitial water were determinedin situ with a galvanic oxygen analyzer and thermistor. Water pumped from the sampler was used to measure pH and salinity. The instrument performed well, and repeated sampling at one locality yielded consistent results. Based on the data from this study and that reported in the literature, a few general statements can be made. The amount of dissolved oxygen in overlying water is greater than in interstitial water. There is correlation between dissolved oxygen and type of substratum, the amount of oxygen decreasing as the particle size decreases and the proportion of mud and silt to sand increases. The pH values for interstitial water are lower than those for the overlying water.