Date of Award
Summer 2025
Document Type
Open Access Dissertation
Department
Environmental Health Sciences
First Advisor
Geoffrey I. Scott
Abstract
This dissertation employed a mixed-methods approach that integrated field-based toxicity assessments, laboratory analyses, and qualitative community engagement to investigate the ecological and public health implications of harmful algal blooms (HABs) in Lake Wateree, a freshwater reservoir in South Carolina. HABs, particularly those caused by cyanobacteria, represent a growing global concern due to their capacity to produce toxins harmful to humans, pets, and aquatic life. These blooms are influenced by multiple environmental stressors, including nutrient enrichment, climate change, and hydrological shifts, which complicate efforts to predict their occurrence and toxicity. In Lake Wateree, the benthic cyanobacterium Microseira wollei (formerly Lyngbya wollei) has been observed for over a decade and is of increasing concern due to the formation of persistent algal mats, especially in shallow coves. Despite years of monitoring by local volunteers and researchers, substantial gaps remained in understanding the ecological hazards and community awareness associated with these blooms. This dissertation addressed these gaps through the integration of toxicological bioassays and qualitative data, providing a comprehensive foundation for evaluating both environmental and public health risks.
The first aim of this research was to assess the acute toxicity of Microseira wollei to adult fathead minnows (Pimephales promelas), a standard species in aquatic toxicology. Sub-aims included: (1.1) conducting in situ toxicity testing at HAB and non-HAB sites; (1.2) evaluating interactions between Microseira wollei and co-occurring environmental toxicants, specifically tire wear particles, through laboratory-based mixture toxicity assays; and (1.3) comparing field and laboratory outcomes to assess differences in toxicological response under natural and controlled conditions. This integrated approach allowed for a more nuanced understanding of both individual and combined stressor effects on aquatic organisms.
The second aim was to examine local perceptions, knowledge, and communication needs regarding HABs through semi-structured interviews with Lake Wateree residents. Interviews were transcribed, coded, and analyzed using both a priori and inductive approaches to explore themes related to lake usage, environmental health literacy, and risk communication. Sub-aim 2.1 focused on synthesizing community insights to generate actionable recommendations for water quality education and HAB risk communication tailored to local concerns and information preferences.
Collectively, the findings from this dissertation advanced understanding of the ecological dynamics and human health implications of benthic freshwater harmful algal blooms. This work contributes novel insights into the toxicological effects of Microseira wollei and offers community-informed guidance to improve environmental communication, public health strategies, and freshwater lake management HAB-affected regions.
Rights
© 2025, Margaret Ann Carson
Recommended Citation
Carson, M. A.(2025). Harmful Algal Blooms and Lake Wateree: The Assessment of Microseira Wollei and Associated Toxins on the Fathead Minnow (Pimephales Promelas) and the Potential Public Health Implications on the Lake Wateree Residential Community. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/8339