Biological Condition Assessment
The biological condition of Tributary 7 has been evaluated through an assessment of the benthic macroinvertebrate community. Suitable riffle habitat was identified just below the study neighborhoods, and field sampling was completed in the fall of 2004. We used the methods documented in Vermont Department of Environmental Conservation Field Methods Manual (VTDEC 2003) to collect and process the aquatic macroinvertebrate samples.
Laboratory sorting of the samples identification of the organisms took place in early 2005. As anticipated, the benthic macroinvertebrate community in Tributary 7 is characterized by low-diversity and a high percentage of pollution-tolerant species. These findings indicate an impaired status, which is consistent with the assessments performed in other urbanizing watersheds as part of the functional assessment study (described below). The benthic macroinvertebrate sampling results for all of the study locations - including Tributary 7 and the functional assessment sites - are presented in the following figures.
To learn more about the invertebrate sampling methodologies and for more information on how the Vermont Department of Environmental Conservation (VT DEC) utilizes biological condition assessments to assess stream health, please take a look at the biomonitoring webpage.