Currently, protocols for investigating the effects of
chemical pollutants on periphyton communities under natural
conditions are statistically flawed and/or potentially harmful
to the ecosystems in which the studies are conducted.
Toxicant-releasing substrates have been proposed to allow the
delivery of different levels of chemical pollutants to
replicate microbial communities in situ while minimizing the
amount of toxicant released into the aquatic ecosystems under
investigation. The purpose of this research was to compare
the copper-induced responses of laboratory periphyton
communities in artificial streams to those generated using
standard, laboratory toxicity testing protocols during a
summer and winter experiment. Chemical-releasing substrates
were successfully used to deliver copper to periphyton
communities in a predictable manner, over a broad range of
doses, and at fairly constant rates during one week exposure periods.
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