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Qualters Middle School, Mansfield, Massachusetts


Mark DeGirolamo


The students of Qualters Middle School performed a study called “Rumford River Water Quality Assessment Utilizing Benthic Macro invertebrates”. The study was conducted on October 19, 2011 in Mansfield, Massachusetts. The study location consisted of one sampling site at the Fulton’s Pond Waterfall on West Street.

The purpose of this study was to introduce benthic macro invertebrates 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 macro invertebrates were studied and found to not be at a substantial risk of harm. The “Rumford River Water Quality Assessment Utilizing Benthic Macro invertebrates” study was performed to compare our results with those found in the EPA study of 2005 and the 2007 QMS Rumford River water study.

Benthic macro invertebrates 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 macro invertebrates 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 macro invertebrates 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 Macro invertebrates 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 3.44. This value falls between the HBI range of 0.00-3.75, which indicates “excellent” water quality. The 2011 sampling site showed a better water quality rating of 3.44 on the HBI scale as compared to the 2007 study which showed a water quality rating of 5.43, or “fair” water quality, utilizing the same scale.

The “Rumford River Water Quality Assessment Utilizing Benthic Macro invertebrates” sampling program detailed a diverse macro invertebrate community. It also showed that the Rumford River appears to be in excellent condition as indicated by the macro invertebrate community. Our data appears to support the findings from the above-mentioned 2005 EPA report and exceeds the results identified within the 2007 QMS study.

Annual water quality monitoring is planned for the Rumford River. The goal is to expand the study to multiple sampling sites along the Rumford River. Future students will have the opportunity to review past studies, design their own Rumford River studies, perform sampling activities, identify organisms, record/analyze data, summarize data, and present findings.

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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.


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