ORCID
0000-0003-2422-3252 (Tamborski), 0000-0001-8819-189X (Mulholland)
Document Type
Article
Publication Date
2024
DOI
10.1002/lno.12772
Publication Title
Limnology and Oceanography
Volume
Article in Press
Pages
1-17
Abstract
The tidal tributaries of the lower Chesapeake Bay experience seasonally recurring harmful algal blooms and the significance of submarine groundwater discharge (SGD) as a nutrient vector is largely unknown. Here, we determined seasonal SGD nutrient loads in two tributaries with contrasting hydrodynamic conditions, river-fed (York River) vs. tidally dominated (Lafayette River). Radon surveys were performed in each river to quantify SGD at the embayment-scale during spring and fall 2021. Total SGD was determined from a ²²²Rn mass balance and Monte Carlo simulations. Submarine groundwater discharge rates differed by a factor of two during spring (Lafayette = 11 ± 17 cm d⁻¹; York = 6 ± 10 cm d⁻¹) and a factor of six during fall (Lafayette = 19 ± 27 cm d⁻¹; York = 3 ± 7 cm d⁻¹). Groundwater N concentrations and fluxes varied seasonally in the York (4–7 mmol N m⁻² d⁻¹). In the Lafayette River, seasonal N fluxes (22–37 mmol N m⁻² d⁻¹) were driven by seasonal water exchange rates, likely due to recurrent saltwater intrusion. Submarine groundwater discharge–derived nutrient fluxes were orders of magnitude greater than riverine inputs and runoff in each system. Additionally, sediment N removal by denitrification and anaerobic ammonium oxidation would only remove ~ 1–11% of dissolved inorganic nitrogen supplied through SGD. The continued recurrence of harmful algal blooms in the Bay’s tidal tributaries may be indicative of an under-accounting of submarine groundwater-borne nutrient sources. This study highlights the importance of including SGD in water quality models used to advise restoration efforts in the Chesapeake Bay region and beyond.
Rights
© The Authors 2024.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Data Availability
Article states: "Data described in this manuscript are available via the HydroShare repository (http://www.hydroshare.org/resource/da51227edc2e4e72ba178b5fc30480de) and the National Science Foundation's BCO-DMO Website (https://www.bco-dmo.org/project/805722). Any other data are available to the reader upon request to the corresponding authors."
Original Publication Citation
Wilson, S. J., Tamborski, J. J., Song, B., Bernhardt, P., & Mulholland, M. R. (2024). Submarine groundwater discharge as a major nutrient source in river-fed vs. tidally dominated estuaries. Limnology and Oceanography. Advance online publication. https://doi.org/10.1002/lno.12772
Repository Citation
Wilson, Stephanie J.; Tamborski, Joseph J.; Song, Bongkeun; Bernhardt, Peter; and Mulholland, Margaret R., "Submarine Groundwater Discharge as a Major Nutrient Source in River-Fed vs. Tidally Dominated Estuaries" (2024). OES Faculty Publications. 529.
https://digitalcommons.odu.edu/oeas_fac_pubs/529
