Abstract |
Two microecosystem protocols, the Standardized Aquatic Microcosm (SAM) method (1982) and the Mixed Flask Culture (MFC) method (1981), were compared on the basis of their response to copper sulfate. These protocols differed in microcosm structure, age, and the variables monitored. Although responses were similar with both systems, the SAM procedure provided considerably more insight into the changes in population densities and nutrient cycling responsible for the observed ecosystem level changes. The SAM protocol was more repeatable and provided a much more complete picture of toxicant effects, but was extremely labor intensive. The MFC protocol lacked repeatability and provided no information to aid in interpreting ecosystem level effects, but was capable of displaying sensitivity equal to that of the SAM procedure and required a comparatively small time investment. (Copyright (c) 1987, American Society for Testing and Materials.) |