Though ample evidence supports the detrimental effects of residual chlorine to many aquatic biota, the on-site response of macroinvertebrates has hitherto been little documented. Accordingly, year-long in-stream collections were undertaken to assess and characterize the response of the macroinvertebrate community inhabiting Lampson Brook, Belchertown, Massachusetts. Artificial substrates (limestone chips) were used in the data gathering and a new methodology, Wrona's, was applied to the data analysis. One control station and four downstream stations extending for 3000 meters along the stream were established. All the macroinvertebrates captured at these stations were counted and identified to their lowest taxonomic group. These data were employed to evaluate several diversity indices as well as qualitative and quantitative community comparison indices. The implications of the respective mathematical formulae applied to biological collections were examined and revisions of certain of the formulae are proposed. The combination of density estimates, species richness, EPT value (a value derived from total identified species of Ephemeroptera, Plecoptera and Tricoptera), and a number of selected indices was chosen to describe the impact of chlorinated/non-chlorinated sewage. A list of macroinvertebrate species has been designated as chlorine sensitive/tolerant with the respective total residual chlorine (TRC) concentration. The results indicate that community comparison indices are more sensitive than diversity indices in measuring pollution effects. Community comparison indices, however, showed considerable variations in assessing the severity of the impact. The macroinvertebrate community structures of all the downstream stations were altered due to changes in environmental conditions with regard to all aspects of community parameters. The suspected causes of such disruption in aquatic macroinvertebrate community may be attributed to either the immediate impact of TRC in the water column at station 2 or the chronic effects of stable chlorinated by-products associated with the sediments at stations 3, 4, and 5. The level of impact with regard to each station is a matter of subjective definition as to which are the most important parameters in describing community structure. Different aspects of change in relation to water quality need to be further tested before imposing any judgement on the extent of impact at each station.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-9066 |
| Date | 01 January 1995 |
| Creators | Coler, Ming-Jung |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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