Contribution of Submarine Groundwater Discharge to Select Biogeochemical Fluxes in St. Louis Bay, Mississippi

<p>This thesis assesses the role of submarine groundwater discharge (SGD) in St. Louis Bay, Mississippi. Located along the northern Gulf of Mexico, St. Louis Bay (SLB) is a semi-enclosed bay that is important to the local area for recreation and tourism. SGD is the movement of any water into the water column across the sediment-water interface. In coastal environments, SGD can be a source of a variety of substances including nutrients and pollutants. In this study, a steady state mass balance approach was used to quantify SGD flux for SLB using ²²³Ra, ²²⁴Ra, and Ba. Using the water volume flux data calculated from the mass balances and groundwater endmembers for CH₄, NO₃, NO₂, NH₄, PO₄, and SiO₃, fluxes from SGD of these select substances were calculated. It was found that the average water volume flux of SGD was 5.3 · 10⁵ m³ d^-1 and delivers approximately 1300 mol d^-1 during the sampling period. SGD was also found to be a significant source of NO₃ (17-60 kmol d^-1) and PO₄ (12-42 kmol d^-1) into the bay. Since nutrient loading is a concern in St. Louis Bay for eutrophication, understanding the role SGD plays is an important consideration for managing this environmental issue.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2020

Author dc:creator

• Spaid, Haley

Contributors dc:contributor

• Alan Shiller
• Christopher Hayes
• Davin Wallace

• submarine groundwater discharge
• methane
• nutrients
• St. Louis
• radium
• barium Bay
• Biogeochemistry

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/780

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1833