To access this work you must either be on the Smith College campus OR have valid Smith login credentials.

On Campus users: To access this work if you are on campus please Select the Download button.

Off Campus users: To access this work from off campus, please select the Off-Campus button and enter your Smith username and password when prompted.

Non-Smith users: You may request this item through Interlibrary Loan at your own library.

Publication Date

2025-5

First Advisor

Amy L. Rhodes

Document Type

Honors Project

Degree Name

Bachelor of Arts

Department

Geosciences

Keywords

macroinvertebrates, geochemistry, biology, geology, water quality

Abstract

The Mill River Watershed in Northampton, Massachusetts, has long served as a site for ecological research for Smith College faculty and students, particularly focusing on the impacts of the Paradise Pond dam. Building on prior studies by Smith College faculty and students, this study looks at how damming affects aquatic benthic macroinvertebrate organisms as indicators of water quality. Unlike previous research, which has concentrated on studying areas directly above or downstream of Paradise Pond, this project expands the scope by sampling sites several miles upstream and within more remote regions of the watershed. By analyzing these less-studied upstream locations, this study aims to characterize the baseline conditions of macroinvertebrate biodiversity and water chemistry and to identify whether varying human land uses may be playing a role on the river ecological health, in addition to direct effects of the dam, to offer a more comprehensive understanding of the health of this watershed and the impact of Smith’s sediment management of Paradise Pond. Results show a steady decline in water quality downstream in the Mill River Watershed, likely due to the introduction of nonpoint source pollutants like fertilizers and road salt. However, when sampling near Paradise Pond, water quality is especially poor in terms of both geochemistry and in macroinvertebrate health. Salt concentrations are highest near Paradise Pond, likely due to the increased population in Northampton, requiring increased road salting. Additionally, at the location most downstream, Site “MD”, total abundance of macroinvertebrates increases rapidly, but biodiversity plummets. The percentage of low tolerance macroinvertebrates also decreases near Paradise Pond, though the tolerance levels of the midges at site “MD” could not be determined. Ranges of different tolerance levels also were lower downstream relative to upstream locations. However, small increases in tolerance levels 5 and 4 suggest some positive changes in the ecosystem directly downstream of the dam, possibly due to increased nutrients being supplied by the sediment redistribution project. Overall, these results are concerning in terms of water quality, and are likely due to the presence of the dam. Previous studies on macroinvertebrate populations by Pratt (Pratt 2025) interpreted that Smith College’s sediment redistribution project has mitigated the effects of the dam on macroinvertebrates. However, the results of this study suggest that the dam's presence is likely having a negative effect on water quality in general, as the rate of biodiversity decline of water quality increases in this area.

Rights

©2025 Isabel Espinosa. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.

Language

English

Comments

v, 38 pages : color illustrations, charts. Includes bibliographical references (pages 36-38).

Download

Smith Only:
Off Campus Download

Share

COinS