Simple Alternative Methods for the Biological Component of Watershed Assessments

Bioassessments have become useful tools for understanding and rating stream health. The most widely used bioassessments analyze macroinvertebrate communities in order to reach conclusions about water quality. Many state agencies have designed protocols for macroinvertebrate bioassessments and non-government organizations also have adopted their own protocols that are simplified but still effectively measuring stream health. We will compare results from two simplified bioassessment protocols to those produced by the Georgia EPD bioassessment protocol. Our objectives are to determine whether or not the simplified methods produce the same quality data and some inference as that of the EPD methods. We also look at seasonal differences in results to determine whether time of sampling influences results. Currently, our data is limited to four sampling sites in Statham, GA that have been sampled over the fall and winter seasons. We intend to add 11 more sites for fall and winter, and also include spring samples for all 15 sites. Assessment scores varied little over the five sites, and with this limited data set there are inconsistencies of ratings between the two simplified methods compared to the EPD methods. We have also not yet produced any evidence of water quality ratings being affected by sampling in different seasons. Previous studies have shown that at least one of the simple methods produces results consistent to more complex methods, and that macroinvertebrate community structure does undergo seasonal changes. Due to the insufficient amount of data collected at this time, we are unable to reach solid conlusions.