Accession Number : ADA290415

Title :   Measuring Variation in Ecosystem Sensitivity to Stress.

Descriptive Note : Final rept. 1 Sep 91-31 Oct 94,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG UNIV CENTER FOR ENVIRON- MENTAL/HAZARDOUS MATERIALS STUDIES

Personal Author(s) : Cairns, John, Jr. ; McCormick, Paul V. ; Arnegard, Matthew ; Smith, Eric P.

PDF Url : ADA290415

Report Date : 28 DEC 1994

Pagination or Media Count : 96

Abstract : Chemical-releasing substrates that allow the effects of certain pollutants on attached algal communities to be studied under natural stream conditions without impacting the stream ecosystems were developed. Several investigations in both artificial streams and in the field were conducted with these substrates; in them algal communities were first allowed to colonize and develop on the diffusing surface of these substrates for several weeks, after which time toxicant solutions were added to the flasks and allowed to diffuse through the attached algal communities. Laboratory studies revealed that the responses of algal communities to substrate-released copper were not different from responses generated in traditional toxicity tests. The experimental substrates may be useful in validating the results of laboratory toxicity tests under natural environmental conditions, confirming the results of upstream-downstream pollution studies, which are flawed by the lack of rigorous controls, and measuring the variation in algal community sensitivity to stress. Field studies focusing on the last application failed to reject the null hypothesis that communities in polluted streams respond to copper differently from those in unpolluted streams, but they were flawed by unpredicted methodological problems. -BKA

Descriptors :   *WATER POLLUTION ABATEMENT, *WASTE WATER, *ECOSYSTEMS, *ALGAE, STRESSES, METHODOLOGY, TOXICITY, SPECTROMETRY, ENVIRONMENTAL IMPACT, DRAINAGE, COPPER, DIATOMIC MOLECULES, EXPOSURE(PHYSIOLOGY), SITE INVESTIGATIONS, WATER QUALITY, HABITATS, SEDIMENTS, WASTE TREATMENT, CONCENTRATION(CHEMISTRY), RUNOFF, STREAMS, HAZARDOUS MATERIALS, BIOMASS CONVERSION, WATER CHEMISTRY.

Subject Categories : Ecology
      Solid Wastes Pollution and Control
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE