Hydrodynamic Drivers of Dissolved Oxygen Variability within a Tidal Creek in Myrtle Beach, South Carolina

Abstract

Beach erosion and water quality degradation have been observed in Singleton Swash, a tidal creek that traverses the beach-face connecting land and ocean in Myrtle Beach, SC. The objective of this study in Singleton Swash is to explore relationships between water quality and hydrodynamics, where the latter are influenced by beach face morphology. We measure water velocities, water levels, and dissolved oxygen concentrations (DO) (a proxy for water quality) and apply correlation analysis to examine the relationships between physical processes and dissolved oxygen variations. Results show that larger tidal ranges are associated with higher mean levels of DO in the tidal creek. The larger tidal ranges are linked to larger magnitude currents, which increase both the DO transport via larger fluxes of oxygenated oceanic water into the swash and the magnitude of Reynolds shear stresses; due to tidal asymmetries, flood currents are stronger than ebb currents in this system. Based on these results, it is concluded that the combined transport of oxygenated waters into the tidal creek from the ocean on large flood tides and subsequent mixing due to large Reynolds shear stresses result in the observed net DO concentration increases in the creek over tidal cycles.

Numerical simulation of Dissolved Oxygen as a water quality indicator in artificial lagoons—Case​ study El Gouna, Egypt

“…They concluded that their studied domain suffered from several fish-kill catastrophes in recent years due to a lack of oxygen (Bacon et al, 2017). Recently, researchers have tended to capture the complexities of the relation between the hydrodynamics of water bodies and the water quality parameters using field observations or numerical techniques (e.g., Huang et al, 2019;Marlina & Melyta, 2019;Pastore et al, 2019;Seiler et al, 2020). Huang et al (2019) investigated the effect of three physical parameters of flow discharge, tide and wind data on the DO and the hypoxia events in the Pearl River estuary in China.…”

“…They found that the three studied parameters had a minor or no effect on BOD and DO, except the water temperature had a high effect on DO concentrations. Pastore et al (2019) studied the relationship between the flow hydrodynamics from tidal waves and the water quality. Results show that higher values of DO were observed when larger tidal ranges were applied.…”

The Role of a Permeable Sand Column in Modifying Tidal Creek Nutrient Inputs into the Coastal Ocean

“…The landward station is rarely characterized by the freshest water (Table 2), with freshwater entering the swash at surface discharges or potentially through groundwater seepage throughout the tidal cycle. Moreover, salinity gradients along the primary channel are further muted by stronger flood currents than ebb currents that rapidly mix an accumulating water mass within the marsh tidal creek and emptying out during low tide [25]. Tidal-or diurnal-period processes are nested within seasonal or annual processes.…”