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<br />Water temperature <br /> <br /> <br />Water temperature should be measured in major habitat types within each reach using <br /> <br /> <br />electronic temperature recordets (e.g., Onset Instruments, Inc. Hobo-Temp XT units). These <br /> <br /> <br />units should be programmed to collect data at a mainimum of 4 hr intervals. The recorders should <br /> <br /> <br />be swapped with a fresh unit eaCh time a site is visited. <br /> <br />Laboratory methods <br /> <br />Zoobenthos <br /> <br /> <br />Samples should be processed following Elliott (1971). Initially, the compo sited sample should <br /> <br /> <br />be searched for large and less-numerous organisms. If the sample appears to contain more than <br /> <br /> <br />250 organisms it should be subsampled. All organisms within a sub-sample should be removed <br /> <br />and identified. Additional sub-samples should be taken until a minimum of250 organisms is <br /> <br /> <br />removed. Organic matter from :the sorted portion of the sample should be combined back with <br /> <br /> <br />the unsorted portion of the sample and used to determine organic matter composition. <br /> <br />An effort should be made to identify organisms to a consistent taxonomic level. A <br /> <br />recommended list of taxonomic resolution for the major taxonomic groups is presented in <br />Appendix 1. At a minimum, insects should be identified to the genera level except Chironomidae <br />which should be identified too subfamily. Non-insect taxa can be identified to various taxonomic <br />levels depending on the availability of identification keys. Genera identifications of insects are <br />desired because much of the basic habitat reqOirements and life history information for insect <br />genera, except Chironomidae, are known. A list of sugg~ed identification keys and references <br />to be used is presented in Appendix 2. <br /> <br />9 <br />