Date of Award

8-31-2026

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Environmental Sciences

First Advisor

Helen C. Poynton

Abstract

From 1941 to 2003, the United States Navy and North Atlantic Treaty Organization (NATO) used Vieques, Puerto Rico, for military training, which led to long-term pollution from metals, organic chemicals, explosives, and per- and polyfluoroalkyl substances (PFAS). While earlier research found these contaminants in the environment and in living organisms, their combined effects on local ecosystems remain poorly understood.

This dissertation used a Genomic-Based Environmental Health Assessment (GEHA) framework to study the ecological risks from past military pollution in Vieques. The approach combined sediment toxicity tests, chemical analysis, gene expression studies, microbial community analysis, and community-based research. The four main goals were to (1) test sediment toxicity and chemistry in coastal and lagoon areas, (2) study gene expression changes in Parhyale hawaiensis after sediment exposure, (3) analyze bacterial and fungal communities using genetic sequencing, and (4) explore how community-based research can support ecotoxicology studies.

Acute toxicity testing revealed substantial variation among sites, with lagoon sediments generally exhibiting greater toxicity than coastal sediments. Toxicity patterns were influenced not only by contaminant concentrations but also by sediment characteristics, including organic carbon content and grain size. Transcriptomic analyses identified changes in genes associated with stress response, detoxification, protein folding, cuticle remodeling, and endocrine-related pathways, demonstrating that sediments with limited mortality effects could still induce measurable molecular stress responses. Microbial analyses revealed significant differences in bacterial and fungal community composition across sites, with diversity patterns associated with environmental conditions and contaminant gradients.

Collectively, these findings demonstrate that integrating toxicity testing, chemistry, genomics, microbial ecology, and community engagement provides a more comprehensive assessment of ecological health than any single line of evidence alone. The GEHA framework developed in this dissertation offers a transferable approach for evaluating ecological risk in historically contaminated environments and contributes to understanding the long-term environmental impacts of military activities in Vieques, Puerto Rico.

Comments

Free and open access to this work is made available to the UMass Boston community by ScholarWorks at UMass Boston. Those not on campus and those without a UMass Boston campus username and password may gain access to this work through Interlibrary Loan. If you have a UMass Boston campus username and password and would like to download this work from off-campus, click on the “Off-Campus Users” button.

Download

Share

COinS