Monitoring Changes in Stream Bottom Sediments and Benthic Invertebrates

About the report:

The study was conducted to determine whether the analysis of stream bottom sediments could be used to assess sediment pollution generated by highway construction. Most of the work completed to date has involved testing and refining methods for the collection and processing of sediment and benthic invertebrates; a transect procedure was used to characterize stream bed profiles. Two devices were tested for sampling bottom sediments: a coring tube and a small grab sampler. The grab proved to be more versatile and efficient. Laboratory processing of sediments was accomplished by standard methods of drying, sieving, and weighing. The mean grain size was calculated for each sample. Organisms were collected with a Surber sampler. A combination of traditional and novel methods was used to partition the organisms from the debris in the samples. These methods included sieving, decantation, and the use of a settling tube. The preliminary data indicated that sediment grain sizes differ spatially, but that temporal differences at specific sites are minimal. The community of invertebrates at the principal field site was characterized by low diversity. This finding suggests that the creek is moderately polluted.

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