Radium and radon radioisotopes in regional groundwater, intertidal groundwater, and seawater in the Adelaide Coastal Waters Study area: Implications for the evaluation of submarine groundwater discharge

Fresh groundwater quality and accessibility in coastal zones is influenced via seawater interruption into coastal aquifers, and coastal water quality and biological community status might be altogether influenced by groundwater pollutants that are transported into coastal waters by submarine groundwater discharge (SGD). SGD and its pertinent evaluation as one associating part among the different principle local pathways of freshwater and tracer/poison contributions from land to sea and the coordinated framework working of both and as primary segments of the same coastal groundwater framework. An elective technique might be to control seawater interruption through fake groundwater revive, for example by adequately treated wastewater, which may impressively decrease long haul patterns of saltiness increment in pumped groundwater, notwithstanding for little simulated energize rates contrasted with pumping rates. Both the outside sources and the interior wellsprings of water seepage might be distinguished via doing infrared thermo-realistic assessments subsequent to directing water snugness tests, flooding tests or pressure driven tests as suitable. A contextual investigation was led to discover the examinations on groundwater issues in a region subjected to sea water ingression and seepage into groundwater in Karaikal

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Has Submarine Groundwater Discharge Been Overlooked as a Source of Mercury to Coastal Waters?

Environmental Science & Technology ◽

10.1021/es0622453 ◽

2007 ◽

Vol 41 (9) ◽

pp. 3090-3095 ◽

Cited By ~ 74

Author(s):

Sharon E. Bone ◽

Matthew A. Charette ◽

Carl H. Lamborg ◽

Meagan Eagle Gonneea

Keyword(s):

Coastal Waters ◽

Submarine Groundwater Discharge ◽

Groundwater Discharge ◽

Submarine Groundwater

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Submarine groundwater discharge is an important net source of light and middle REEs to coastal waters of the Indian River Lagoon, Florida, USA

Geochimica et Cosmochimica Acta ◽

10.1016/j.gca.2010.11.005 ◽

2011 ◽

Vol 75 (3) ◽

pp. 825-843 ◽

Cited By ~ 72

Author(s):

Karen H. Johannesson ◽

Darren A. Chevis ◽

David J. Burdige ◽

Jaye E. Cable ◽

Jonathan B. Martin ◽

...

Keyword(s):

Coastal Waters ◽

Submarine Groundwater Discharge ◽

Groundwater Discharge ◽

Indian River Lagoon ◽

Submarine Groundwater ◽

Indian River

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Assessment of Submarine Groundwater Discharge (SGD) as a Source of Dissolved Radium and Nutrients to Moorea (French Polynesia) Coastal Waters

Estuaries and Coasts ◽

10.1007/s12237-016-0108-y ◽

2016 ◽

Vol 39 (6) ◽

pp. 1651-1668 ◽

Cited By ~ 21

Author(s):

Karen L. Knee ◽

Elizabeth D. Crook ◽

James L. Hench ◽

James J. Leichter ◽

Adina Paytan

Keyword(s):

Coastal Waters ◽

Submarine Groundwater Discharge ◽

Groundwater Discharge ◽

French Polynesia ◽

Submarine Groundwater

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Submarine Groundwater Discharge (SGD) to Coastal Waters of Saipan (Commonwealth of the Northern Mariana Islands, USA): Implications for Nitrogen Sources, Transport and Ecological Effects

Water ◽

10.3390/w12113029 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3029

Author(s):

Melissa A. Knapp ◽

Naomi Geeraert ◽

Kiho Kim ◽

Karen L. Knee

Keyword(s):

Water Quality ◽

Primary Production ◽

Coastal Waters ◽

Submarine Groundwater Discharge ◽

Nutrient Loading ◽

Groundwater Discharge ◽

Seagrass Meadows ◽

Nitrogen Inputs ◽

Submarine Groundwater ◽

Primary Producer

Seagrass meadows and coral reefs along the coast of Saipan, a US commonwealth in the Northern Pacific, have been declining since the 1940s, possibly due to nutrient loading. This study investigated whether submarine groundwater discharge (SGD) contributes to nutrient loading and supports primary production on Saipan’s coast. SGD can be an important source of freshwater, nutrients, and other pollutants to coastal waters, especially in oceanic islands without well-developed stream systems. Ra and Rn isotopes were used as natural tracers of SGD. Nitrate, phosphate, and ammonium concentrations, ancillary water quality parameters, δ15N and δ18O of dissolved nitrate, and δ15N of primary producer tissue were measured. Our results pointed to discharge of low-salinity groundwater containing elevated concentrations of sewage-derived N at specific locations along Saipan’s coast. High SGD areas had lower salinity and pH, higher dissolved inorganic nitrogen concentrations, and elevated primary producer δ15N, indicative of sewage nitrogen inputs. We estimated that SGD could support 730–6400 and 3000–15,000 mol C d−1 of primary production in Tanapag and Garapan Lagoons, respectively, or up to approximately 60% of primary production in Garapan Lagoon. Efforts to improve water quality, reduce nutrient loading, and preserve coastal ecosystems must account for groundwater, since our results demonstrate that it is an important pathway of nitrogen delivery.

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Temporal Variations of Submarine Groundwater Discharge into a Tide-Dominated Coastal Wetland (Gaomei Wetland, Western Taiwan) Indicated by Radon and Radium Isotopes

Water ◽

10.3390/w12061806 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1806 ◽

Cited By ~ 1

Author(s):

Feng-Hsin Hsu ◽

Chih-Chieh Su ◽

Pei-Ling Wang ◽

In-Tian Lin

Keyword(s):

Coastal Waters ◽

Seasonal Changes ◽

Submarine Groundwater Discharge ◽

Coastal Wetland ◽

Groundwater Discharge ◽

High Tide ◽

Dry Season ◽

Wet Season ◽

Submarine Groundwater ◽

Δd And Δ18o

Submarine groundwater discharge (SGD) is evidenced around Taiwan, but the seasonal/temporal changes of SGD have not been fully examined. Here, we report a time-series investigation of SGD into a tide-dominated coastal wetland, the Gaomei Wetland, located to the south of the Da-Chia River’s mouth, western Taiwan, by using environmental tracers (222Rn, 224Raex, 228Ra, δD, and δ18O). Our results showed that regardless of dry and wet seasons, the 222Rn activities in coastal waters were high at low tide but low at high tide. It represents the continuous input of 222Rn-enriched groundwater. However, the 224Raex and 228Ra activities showed seasonal changes with tide conditions. In the dry season, the 224Raex and 228Ra activities in coastal waters were low at low tide but high at high tide; whereas in the wet season, an opposite relation was observed with quite high 224Raex and 228Ra activities in the low-tide waters. Coupled with the lower δD and δ18O values of coastal and pore waters in the dry season, in comparison to those in the wet season, it is suggested that these phenomena probably reflected a seasonal difference in the main SGD component with fresh SGD in the dry season, but saline ones in the wet season. Based on a 222Rn mass balance model, the estimated SGD fluxes into the Gaomei Wetland varied with tidal fluctuations and ranged from 0.2 to 25 cm d−1 and from 0.1 to 47 cm d−1 for the dry and wet seasons, respectively. A slightly high SGD flux occurring during the wet season at spring tide, implied a stronger tidal pumping coupled with a larger hydraulic gradient between land and sea. In this study, we demonstrated that the variation of SGD into the Gaomei Wetland is not only controlled by the seasonal changes of groundwater recharge, but also by the tidal pumping process.

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Controls on submarine groundwater discharge in an urbanized bay of the southern Baltic Sea: An isotope and trace metal perspective.

10.5194/egusphere-egu21-2470 ◽

2021 ◽

Author(s):

Catia Milene Ehlert von Ahn ◽

Jan Scholten ◽

Christoph Malik ◽

Peter Feldens ◽

Bo Liu ◽

...

Keyword(s):

Coastal Waters ◽

Water Samples ◽

Coastal Aquifer ◽

Submarine Groundwater Discharge ◽

Surface Sediments ◽

Groundwater Discharge ◽

Water Interface ◽

Mixing Zone ◽

Submarine Groundwater ◽

The Impact

Submarine groundwater discharge (SGD) acts as a source of fresh water and dissolved substances for coastal ecosystems. Evaluation of the actual controls on SGD and corresponding chemical fluxes require a closer understanding of the processes that take place in the mixing zone between SGD and the coastal waters. It is hypothesized that artificial infrastructures, like sediment channeling, may ease the hydrological connection between coastal aquifer and coastal bottom water. The resultant, increase of SGD, changes the residence time in the mixing zone, and thereby, reduces the impact of early diagenesis. The present study focuses on the distribution of SGD, including the characterization of different mixing zones in the urbanized Wismar Bay (WB), southern Baltic Sea. Short sediment cores were retrieved for geochemical porewaters and sediment analyses. Surface sea water samples were collected along across-shore transects in the WB.&#160; Besides major ions, Ba, Fe, and Mn, the water samples were analyzed for nutrients, dissolved inorganic carbon (DIC), stable isotopes (H, O, C, S), and Ra isotopes. Sediments were analyzed for C, N, S, Hg contents as well as reactive components (e.g. Fe, Mn, P) by HCl extractions. Organic matter mineralization rates, DIC, and SO4 fluxes for the sediment-water interface were modeled from porewater profiles. Shallow seismic techniques were applied to identify potential litho-morphological controls on SGD. Geochemical porewater data allow identification of active SGD sites in the WB. In the central part, the freshening of porewaters in the top surface sediments indicates the upward flow of SGD originating from a coastal aquifer. The acoustic profiles show that the bottom sediments in the central bay are under local impact of excavation, reducing the sediment thickness above the coastal aquifer. Overall, the impact of SGD on the coastal water body of the WB is diffuse and promoted by local anthropogenic activity. The water isotope composition of porewaters at this site are close to the local meteoric water line at Warnem&#252;nde (located 50 km east of the WB), suggesting a discharge of relatively modern fresh waters. The (isotope) hydrochemical composition of the fresh water discharging is controlled by water-rock interactions in the aquifer and modulated by intense diagenesis in the brackish surface sediments. Furthermore, the SGD facilitates the upward migration of elements and enhances their fluxes across the sediment-water interface, e.g. DIC concentrations in the fresh groundwater are further enhanced in the mixing zone, indicating that SGD is a potential source of excess CO2 in the investigated coastal waters.The investigations are supported by the DAAD, DFG RTS Baltic TRANSCOAST, KiSnet project, BONUS SEAMOUNT, FP7 EU Marie Curie career integration grant, DAM-MFG, and IOW.

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