Date of Award

Spring 5-10-2025

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Ecology and Environmental Sciences

First Committee Advisor

Matthew Chatfield

Second Committee Member

Caroline Noblet

Third Committee Member

Dianne Kopec

Abstract

Per- and polyfluoroalkyl substances (PFAS) are a group of ubiquitous synthetic chemicals that pose significant risks to both animals and humans. Of particular concern are their implications for sensitive species like the North American wood turtle (Glyptemys insculpta), designated as a Species of Greatest Conservation Need in Maine. Wood turtles exhibit seasonal movement between aquatic overwintering habitats and terrestrial summer foraging habitats, leading to different potential PFAS exposure routes throughout the year. Focusing on a population involved in a long-term monitoring project in central Maine, we collected water, sediment, diet, and nonlethal tissue samples to assess the severity of PFAS contamination in the turtles, their aquatic habitat, and their summer food web, as well as to identify potential exposure routes and quantify trophic transfer. Out of 54 potential PFAS compounds included in the analysis, 15 were detected in the stream water samples from our study site (n=10), showing a geographic gradient, with sum PFAS concentrations having a median of 66 ng/L and reaching 145 ng/L. Concentrations of individual PFOS and PFOA generally exceeded the EPA’s Draft Human Health Ambient Water Quality Criteria. PFAS were also detected in low concentrations in plant and snail samples collected from the sites. 10 PFAS compounds, all long-chain, were found in turtle blood serum (n=31), with the highest sum PFAS concentration >400 ng/mL and median concentration of 41 ng/mL, indicating bioaccumulation. Our study adds to the growing body of knowledge regarding PFAS contamination in the environment and their propensity for transfer and bioaccumulation in an imperiled species.

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