Term of Award
Fall 2023
Degree Name
Master of Science in Biology (M.S.)
Document Type and Release Option
Thesis (open access)
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution 4.0 License.
Department
Department of Biology
Committee Chair
J. Checo Colon-Gaud
Committee Member 1
Stephen P. Vives
Committee Member 2
John Carroll
Abstract
Coastal wetlands are threatened by the compounding effects of sea level rise and historical land modification. Historically, much of Sapelo Island, Georgia was deforested and drained using a series of ditches and canals to create arable land fit for agriculture and to provide drainage to the inhabited parts of the island. Today, this network of artificial channels is believed to be facilitating the movement of saltwater from the nearby estuary into freshwater areas on the interior of the island. This study aimed to better understand the frequency and magnitude of salinity intrusion events along with their resulting impacts to the ecology of benthic macroinvertebrate communities on Sapelo Island. I utilized a water sensor network to monitor the hydrology of Oakdale Creek, one of Sapelo’s primary artificial channels. I coupled this with seasonal assessments of benthic macroinvertebrate community composition and function by using rapid bioassessment protocols (RBP) and leaf pack deployments. Results indicated that of the four sites, Dixie, was tidally influenced and had significantly higher decomposition rates than all other sites. Dixie also had a significantly different macroinvertebrate community composition when compared to non-tidal sites. All sites were regularly exposed to salinities >5 ppt, which can cause negative impacts to the survival and productivity of freshwater aquatic organisms. RBP scores were relatively low at all sites when compared to reference values indicating impairment. Findings highlight the ability of small artificial channels to transport saline water, especially during large weather events (i.e., hurricanes). Additionally, I showed that interior sites on Sapelo Island that are distant from the estuarine interface are being regularly exposed to saline water which prevented the development of a robust macroinvertebrate community. Results of this study will inform local land managers on the current state of artificial channels on the island especially as it relates to future management in the face of rising sea levels and continued land use change on the island.
Recommended Citation
KIDDER, RAYMOND PAUL II, "Investigating Salinity Intrusion Effects on Sapelo Island, Georgia Using Benthic Macroinvertebrate Bioindicators" (2023). Electronic Theses and Dissertations. 2673.
https://digitalcommons.georgiasouthern.edu/etd/2673
Research Data and Supplementary Material
No
