Loyola University Chicago

Department of Biology

Anna Vincent Project Description

Title: Plastic in Urban Streams: Distribution, Transport, and Influence on Biofilm Community Composition


Accelerated production and disposal of plastic is generating global accumulations of plastic litter in natural ecosystems. The capacity for plastic to undergo physical, chemical, and biological processes within freshwaters is understudied, and remains a critical component of global plastic budgets and future management interventions. Our objectives were to: (1) quantify the abundance of microplastic within different river habitats, (2) adapt organic matter ‘spiraling’ metrics to measure microplastic transport concurrent with fine particulate organic matter (FPOM), and (3) measure the influence of plastic polymer type on biofilm community composition and function in urban streams spanning a geographic gradient. We quantified microplastic and FPOM abundance by habitat (surface water, water column, benthos), and calculated downstream particle velocity, index of retention, turnover rate, and spiraling length for both particle types. Downstream particle velocity and indices of retention were similar. However, microplastic showed lower turnover rates and longer spiraling lengths relative to FPOM, attributed to the slow rates of plastic degradation. Overall, results suggest that the same microplastic particles can be retained, transported long distances, and released into larger bodies of water. In our biofilm analysis, we documented robust microbial growth on natural and synthetic substrata. Biofilm activity was somewhat affected by plastic surfaces, including enhanced biomass and reduced taxonomic (OTU) richness. Community composition was driven most strongly by the environmental conditions at each site, and not by the chemical composition of the plastic growth substrate. These projects provide insight on the pervasive nature of plastic pollution and contribute to global plastic budgets.



This research was funded by a National Science Foundation grant (CAREER 1553835) to Timothy Hoellein. Thank you to my thesis advisor, Timothy Hoellein, and committee members Martin Berg, John Kelly, and Samuel Dunn for their guidance during the research process and comments on this thesis. Many thanks to Raúl Lazcano, Paul Risteca, Elizabeth (Bizzy) Berg, Drew Eppehimer, Lisa Kim, Loren Hou, Lauren Wisbrock, Catherine Rovegno, Deeb Omari, Naiha Sharma, Amy Fetters, Stuti Desai, Jennifer Piacente, Wesley Heal, Justine Nguyen, and Kelsey Hollien for their assistance with field collection and laboratory processing. Thank you to collaborators Michael Bogan, Katherine Lynch, Rick Campbell, and Rob Sperl for their assistance with site selection and sampling logistics. Finally, thank you to my family and friends for their support and reassurance throughout the course of this program.



Anna Vincent was born and raised in Palm Beach Gardens, Florida. She earned a Bachelor of Science degree in Biology (Ecology emphasis) with a minor in Environmental Science from Loyola University Chicago in 2017. During her undergraduate studies, Anna studied abroad at the Universidad San José in San Ramón, Costa Rica and completed the Interdisciplinary Honors Program. She entered graduate school in 2017. Since beginning graduate school, Anna has held leadership positions with the Student Resource Committee of the Society for Freshwater Science and Loyola’s Biology Graduate Student Association. In addition to her research, she engaged in multiple educational outreach initiatives and maintained ongoing relationships with Chicago-area nonprofits. Anna was a teaching assistant for general ecology and limnology courses.


Committee Members

Dr. Timothy J. Hoellein,

Dr. Marty B. Berg,

Dr. John J. Kelly,

Dr. Samuel T. Dunn