Date of Award
5-2026
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Forestry and Environmental Conservation
Committee Chair/Advisor
Dr. Brandon Peoples
Committee Member
Dr. Zanethia Barnett
Committee Member
Dr. Troy Farmer
Abstract
Freshwater ecosystems in the South Carolina Coastal Plain are highly dynamic and increasingly impacted by land development, hydrologic variability (e.g., droughts and hurricanes), and declining water quality. This variability presents challenges for monitoring sensitive fish species and understanding stream fish community structure. We evaluated backpack electrofishing (BPEF) and environmental DNA (eDNA) detection methods using American Eel Anguilla rostrata, a catadromous species experiencing range-wide declines. Between June – December 2024, we surveyed 45 sites representing regional land cover types and conducted 3 – 4 repeated visits. At each site, we collected three 1-Liter eDNA samples and performed a 2-pass presence/absence BPEF survey. We found that eDNA detected eels more frequently than BPEF. However, both methods produced similar ecological conclusions on factors influencing eel distribution. Occupancy probability increased for both gears with higher minimum stream volume and decreased with cooler temperatures, acidic pH, and low conductivity. Detection probability for both gears increased with higher stream volume and warmer temperatures but declined with higher turbidity. Our results indicate that eDNA improves eel detection, but both methods provide comparable ecological insights. We also quantified intra-annual stream fish community variability using taxonomic and functional beta diversity components (replacement and richness difference). Taxonomic variability was driven by environmental factors interacting with stream network position, while functional variability was associated with local environmental filtering. These findings highlight the importance of dispersal, environmental filtering, and extreme conditions in structuring fish communities. Integrating effective monitoring approaches with taxonomic and functional perspectives improves our understanding of variable coastal plain community dynamics.
Recommended Citation
Fair, Brandon, "Signals in the Stream: Decoding American Eel Distribution and Freshwater Assemblages in the South Carolina Coastal Plain" (2026). All Theses. 4729.
https://open.clemson.edu/all_theses/4729