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Mansfield High School, Mansfield, Massachusetts


Mark DeGirolamo


The students of Mansfield High School performed a water quality study on the Rumford River on Tuesday, November 12, 2013 in Mansfield, Massachusetts. The study location consisted of one site on the Town of Mansfield Conservation Commission property on Fischer Lane.

The purpose of this study was to introduce benthic macroinvertebrates and their role as indicators for evaluating stream water quality. Students utilized state of the art methods and techniques during all aspects of this study.

The Rumford River is listed on the Environmental Protection Agencies (EPA) National Priority List (NPL). The river was polluted with dioxins, furans and phenols by a wood treating company from 1953-1993. The amounts of pollutants and the frequency of their release are not known. As part of an EPA ecological study, benthic macroinvertebrates were studied and found to not be at a substantial risk of harm. The student led study was performed to compare our results with those found in the EPA study of 2005 as well as other student led studies in 2007, 2011, and 2012.

Benthic macroinvertebrates were collected utilizing the “kick net” method. A total of four samples were collected at the site. Each of which consisted of two low-flow and two high-flow sub-samples to ensure an accurate and diverse collection. Physical habitat data was also collected to document specific habitat information at the site. This data was evaluated against the types of organisms found to see if there were any discrepancies between habitat and macroinvertebrates within the stream study location. All physical habitat data was recorded utilizing the “Stream Biomonitoring: Physical Habitat Data Field Sheet” which was modified from CABIN.

Benthic macroinvertebrates were then identified to the “order” level. This was accomplished by viewing the specimens under stereomicroscopes. Dichotomous keys found in the “Living Waters: Using Benthic Macroinvertebrates and Habitat to Assess Your River’s Health. River Watch, A Program of River Network, 1997 and Aquatic Entomology: The Fishermen’s and Ecologist’s Illustrated Guide to Insects and Their Relatives. McCafferty, Patrick, W. 1998.” were utilized for the identification piece of the project. Order level data was recorded on the “Stream Biomonitoring: Level 1 Major Group Biotic Index” data sheet.

Necessary calculations were performed to indicate the overall Major Group Biotic Index (MGBI). The calculations are as follows: average count, average organism density and group percent. These calculations were performed on an excel spreadsheet. The MGBI was then compared to the Hilsenhoff Biotic Index (HBI) to give a water quality rating. The calculated MGBI for the sample location was 6.25. This value falls between the HBI range of 5.76-6.50, which indicates a “Fairly Poor” water quality rating.

The “Benthic Macroinvertebrate Exploration in the Rumford River” sampling program detailed a fairly diverse macroinvertebrate community. It also showed that the Rumford River water quality appears to be fairly poor as indicated by the macroinvertebrate community. Our data appears to support the findings from the above-mentioned 2005 EPA report and prior student studies.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Mansfield-Rumford-2013-Brochure.pdf (422 kB)
Stream Ecology Brochure


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