A State-Of-The-Art Perspective on the Characterization of Subterranean Estuaries at the Regional Scale

authored by

Nils Moosdorf, Michael Ernst Böttcher, Dini Adyasari, Ercan Erkul, Benjamin S. Gilfedder, Janek Greskowiak, Anna Kathrina Jenner, Lech Kotwicki, Gudrun Massmann, Mike Müller-Petke, Till Oehler, Vincent Post, Ralf Prien, Jan Scholten, Bernhard Siemon, Cátia Milene Ehlert von Ahn, Marc Walther, Hannelore Waska, Tina Wunderlich, Ulf Mallast

Abstract

Subterranean estuaries the, subsurface mixing zones of terrestrial groundwater and seawater, substantially influence solute fluxes to the oceans. Solutes brought by groundwater from land and solutes brought from the sea can undergo biogeochemical reactions. These are often mediated by microbes and controlled by reactions with coastal sediments, and determine the composition of fluids discharging from STEs (i.e., submarine groundwater discharge), which may have consequences showing in coastal ecosystems. While at the local scale (meters), processes have been intensively studied, the impact of subterranean estuary processes on solute fluxes to the coastal ocean remains poorly constrained at the regional scale (kilometers). In the present communication, we review the processes that occur in STEs, focusing mainly on fluid flow and biogeochemical transformations of nitrogen, phosphorus, carbon, sulfur and trace metals. We highlight the spatio-temporal dynamics and measurable manifestations of those processes. The objective of this contribution is to provide a perspective on how tracer studies, geophysical methods, remote sensing and hydrogeological modeling could exploit such manifestations to estimate the regional-scale impact of processes in STEs on solute fluxes to the coastal ocean.

External Organisation(s)

Leibniz Centre for Tropical Marine Research (ZMT)
Kiel University
Southern Cross University
Leibniz Institute for Baltic Sea Research Warnemünde (IOW)
University of Greifswald
University of Rostock
University of Bayreuth
Carl von Ossietzky University of Oldenburg
Instytut Chemii Bioorganicznej Polskiej Akademii Nauk
Leibniz Institute for Applied Geophysics (LIAG)
Federal Institute for Geosciences and Natural Resources (BGR)
Technische Universität Dresden
Helmholtz Zentrum München - German Research Center for Environmental Health

Type

Review article

Journal

Frontiers in Earth Science

Volume

9

ISSN

2296-6463

Publication date

14.05.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

General Earth and Planetary Sciences

Sustainable Development Goals

SDG 15 - Life on Land

Electronic version(s)

https://doi.org/10.3389/feart.2021.601293 (Access: Open)