Submarine Groundwater Discharge helps making nearshore waters heterotrophic

Abstract

Submarine groundwater discharge (SGD) is the submarine seepage of all fluids from coastal sediments into the overlying coastal seas. It has been well documented that the SGD may contribute a great deal of allochthonous nutrients to the coastlines. It is, however, less known how much carbon enters the ocean via the SGD. Nutrients (NO3, NO2, NH4, PO4, SiO2), alkalinity and dissolved inorganic carbon (DIC) in the submarine groundwater were measured at 20 locations around Taiwan for the first time. The total N/P/Si yields from the SGD in Taiwan are respectively 3.28 ± 2.3 × 104, 2.6 ± 1.8 × 102 and 1.89 ± 1.33 × 104 mol/km2/a, compared with 9.5 ± 6.7 × 105 mol/km2/a for alkalinity and 8.8 ± 6.2 × 105 mol/km2/a for DIC. To compare with literature data, yields for the major estuary across the Taiwan Strait (Jiulong River) are comparable except for P which is extremely low. Primary production supported by these nutrient outflows is insufficient to compensate the DIC supplied by the SGD. As a result, the SGD helps making the coastal waters in Taiwan and Jiulong River heterotrophic.

Scrutinizing Relationships between Submarine Groundwater Discharge and Upstream Areas Using Thermal Remote Sensing: A Case Study in the Northern Persian Gulf

“…Additionally, the use of geomorphometric and topo-hydrological indices can facilitate the investigation of hydrological attributes and processes governing the SGD from (upstream) terrestrial zones into the coastal lands. Whereas previously recorded in other parts of the world such as Turkey [66], Spain [21], Australia [67], USA [68], Taiwan [69], and Portugal [70] revealed that presence of SGD is related to upland karstic zones, they rarely established quantitative relationships and indices. Therefore, the findings may be generalized into the other similar regions for distinguishing the potential of SGD sites.…”

Chromophoric dissolved organic matter in summer in a coastal mariculture region of northern Shandong Peninsula, North Yellow Sea

“…River/sewage inputs can play a significant role in DOM dynamics in coastal waters (Yang et al, 2015;Wang et al, 2018). In the study area, there are two important cities along the coastline, i.e.…”

Estimation of coastal aquifer properties: A review of the tidal method based on theoretical solutions

“…Therefore, application of the tidal method may be limited to relatively narrow areas of less than 5 km from the coastline for a perfectly confined coastal aquifer. It should be noted that earth tides (Liao & Wang, 2018; Wang, Doan, et al, 2018; Wang, Chen, et al, 2018) and changes in local atmospheric pressure (Acworth, Halloran, Rau, Cuthbert, & Bernardi, 2016) may also induce similar tidal fluctuations in the hydraulic head within an inland observation well. Therefore, cautions should be taken into account when performing tidal hydraulic characterization in areas several kilometers away from the coastline.…”

“…The hydraulic properties of coastal aquifer systems are relevant to various hydrogeological, hydro-ecological, and engineering problems, such as seawater intrusion (Carr, 1969;Kuan et al, 2012;Werner et al, 2013), submarine groundwater discharge (Moore, 1996;Taniguchi, 2002;Prieto & Destouni, 2011;Wang, Doan, et al, 2018;Wang, Chen, et al, 2018), migration of contaminants and/or nutrients (Chan & Mohsen, 1992;Gallagher, Dietrich, Reay, Hayes, & Simmons Jr, 1996;Uchiyama, Nadaoka, Roelke, Adachi, & Yagi, 2000), and stability of coastal engineering structures (Farrell, 1994). Although mass transport in a coastal aquifer system can be controlled by many processes, such as advection, dispersion and reaction, understanding the hydraulic properties of a coastal aquifer system is of fundamental importance when evaluating advection.…”