SS4.06 Speciation, Bioavailability, and Impacts of Atmospheric Trace Metals in Aquatic Systems
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
Taub FB, University of Washington, Seattle, USA, taub@u.washington.edu
Butler, S, , University of Washington, Seattle, USA, sbutler@u.washington.edu
Conquest, L, L, University of Washington, Seattle, USA, conquest@u.washington.edu
 
PRODUCTION AND RESPIRATION RESPONSES OF AQUATIC MICROCOSMS TO TOXIC CONCENTRATIONS OF CUSO4
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The balance between photosynthesis and respiration determines an ecosystemís ability to harvest light energy and transform it to other trophic levels. CuSO4 both (1) selectively inhibits algal species and (2) kills grazers. At different concentrations and after various lags, CuSO4 treatment decreased or increased net primary production. Respiration was usually similar to production, with short term exceptions. Measures of (lighted) net primary production and (dark) respiration were better measures of system responses than the P:R ratio. A new variable, Accumulated Production, provided a measure to track the ecosystemís production over time as Cu was detoxified by increased pH and Dissolved Organic Matter produced by the most resistant algal species. The usefulness of some different statistical approaches will be considered, including repeated measures, cumulative functions, derived variables, and patterns in day-by-day ANOVAs.