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Technical Report

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Algae, Streams, Periphyton, Sampling, Primary Productivity


The response of stream biota to changing water quality or other ecosystem perturbations is an important means of assessing water quality. The dynamic nature of streams induces significant sampling and measurement problems. In smaller streams a true algal plankton subcommunity is lacking and the major location for the production of algae is attachment onto stones and other stable surfaces at the substrate-water interface. Several artificial techniques have been developed to analyze the composition of a portion of the epiphytic periphyton (algae attached to stones) but not populations which are qualitatively and quantitatively similar to natural substrates. A newly developed substrate has been tested to determine residence time, qualitative similarity be- tween natural and sampler populations, methodologies for determining primary production rates, seasonal succession, and colonization rates. The new method has been applied, for comparative purposes, to two streams. One stream is influenced by treated municipal sewage while the other is a non-impacted stream.

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