Name: Taylor Breton
Date: 07/14/2026
Time (EST/EDT): 09:00 AM
Location: Appalachian Laboratory, IVN Room 109
Remote Access: email: mees@umd.edu

Committee Chair: Katia Engelhardt
Committee Members: Magdalene Ngeve and Bill Dennison

Title: Vallisneria americana in the Hudson River Estuary: Incorporating
Genotypic Identity and Richness into Restoration Design

Abstract: Dynamic tidal estuaries are characterized by fluctuating
environmental conditions that can hinder the recovery and long-term persistence
of submerged aquatic vegetation (SAV) beds. Within the Hudson River,
Vallisneria americana populations have struggled to recover following major
storm events in 2011 and continue to be affected by the loss of shallow-water
habitat. Incorporating fine-scale genetic variation enhances adaptive capacity
and recovery of SAV beds following disturbance. To evaluate the role genotypic
diversity can play in restoration, I conducted controlled greenhouse
experiments examining the growth and reproductive responses of four Hudson
River-native Vallisneria americana genotypes to common environmental drivers.
The same genotypes were subsequently planted at Stockport Flats, a freshwater
tidal reach of Hudson River estuary, to evaluate survival and growth under
field conditions. Greenhouse experiments revealed significant genotypic
differences in clonal expansion, sexual reproduction, and overwintering turion
formation across substrate, aeration, and fertilization treatments. In
contrast, field trials demonstrated that habitat conditions largely masked
underlying genetic differences and were the primary drivers of plant survival
and growth. These findings suggest that greenhouse screening can identify
robust, high-performing genotypes for restoration; however, the benefits of
genotype selection may not be seen in the field until habitat stressors and
unfavorable conditions are addressed. Findings from this work were synthesized
into a handbook for practitioners that provides guidance on genotype sourcing,
greenhouse propagation, and field deployment techniques for genotype-guided SAV
restoration in estuarine systems.