Abstract

Retention ponds are built in urban and suburban areas to catch the polluted runoff that would otherwise go into highly-valued freshwater ecosystems like the Great Lakes. They therefore make ideal model ecosystems to consider the effect of chemical, common pollution on aquatic communities. To understand the impact this aquatic pollution on both microbial community composition alongside green microbial physiological stress response, water column and sediment microbial communities were sampled from three retention ponds, and three non-retention, created ponds. The first part of this study focused on the microbial community composition. Using 16s amplicon sequencing on and subsequent analysis using Qiime2, PiCrust2, and the Vegan package in R, alpha and beta diversity metrics were examined across different variables. The impact of seasonality and year of sampling was considered across two seasons and years at two sites. The impact of individual site, retention vs non-retention sites, and  relationship of environmental gradients were al-so considered, alongside an examination of site-based functionality.  Results indicated that individual sites, particularly water communities, differ in community evenness/richness and presence, absence, and abundance of taxa. However, significant differences between retention and non-retention sites only occurred using an unnested Kruskal-Wallis approach for beta diversity metrics. Diversity was also well explained through variation in temperature and phosphate lev-els. Functionality analysis led to a lack of clear patterns. The second part of the study focused on the photosynthetic microbial response to determine how stress can affect wetland primary productivity. Green algal cultures were isolated from the same wetlands to test the hypothesis that isolates from ponds with more pollution exposure will have greater resilience under stress conditions, isolates were grown in four concentrations of Miracle Gro Lawn Food fertilizer, SALTSY MgCl2 road salt, and Morton SAFE-T-Salt NaCl road salt, and Roundup Weed and Grass Killer for one week to determine their relative growth under stress. A Chlorella vulgaris and a cyanobacteria isolate were also grown together in the same chemical treatments to compare cell counts under the same conditions. Growth response differed by retention and non-retention sites and taxonomical order for select treatments, though results highlighted a wide range in response across individual isolates. Competition assays showed that cyanobacteria dominated under all conditions except 150 mMol NaCl. Desmodesmus sp. isolates were found to consistently survive 5 mL/L of Roundup.

Library of Congress Subject Headings

Microbial ecology--New York (State)--Rochester; Microorganisms--Effect of water pollution on

Publication Date

6-22-2026

Document Type

Thesis

Student Type

Graduate

Degree Name

Environmental Science (MS)

College

College of Science

Advisor

Elena Lopez Peredo

Advisor/Committee Member

Christy Tyler

Advisor/Committee Member

Elle Barnes

Campus

RIT – Main Campus

Plan Codes

ENVS-MS

Download

Share

COinS