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Advantage: Information on the variability among similar habitats within the same reach. Disadvantage: Many more samples to process, which will increase costs substantially. Strategy two: Collect samples from similar habitat types throughout an individual reach and composite them into a single sample. Different locations would be sampled on each sampling trip to avoid continually sampling more or less productive areas. Advantage: There are fewer samples to process than strategy one. Retain information on the variability among habitat types within reaches. Disadvantage: This strategy provides no information on the variability within similar habitats within the same reach. Strategy three: Select a single representative location of each habitat type and collect multiple samples within this location and composite them into a single sample. Advantage: This strategy reduces some variability that will probably occur among different sampling dates using strategies one or two. Disadvantage: Like the previous strategy, this strategy does not allow for the determination of the variability among similar habitats within the same reach. Another disadvantage of this strategy is that it assumes a representative location of each habitat exists and that it was selected. Recommendation: I recommend carrying out strategy one on the initial sampling trip and strategy two on subsequent trips. Strategy one will give us an understanding of the variability in invertebrate communities among similar habitat types within the same reach and allow us to calculate appropriate sample sizes for each habitat type. Use of strategy two after this initial trip will save money and still provide substantial information on the variability in invertebrate assemblages among habitats and among reaches over time. Thus, during the initial sampling trip a subset of sampling locations of each habitat type within each reach would be sampled. All samples collected from the same habitat type within the same reach would be kept separate. This procedure would be repeated for each habitat type present in each reach. Within lengthy reaches sampling sites should be selected such that samples are collected from upper, mid, and lower sections of each reach. On subsequent trips, samples from like habitats within the same strata would be combined. The same locations need not be sampled on subsequent sampling trips. A summary of the number of samples to be collected is shown in Table 3. 5