Drivers of dissolved organic matter processing in subterranean estuaries
Abstract Subterranean estuaries (i.e., seawater‐fresh groundwater mixing zones at coastal aquifers) are highly reactive boundaries between continental groundwater and coastal surface seawater. Because particulate organic matter is retained in shallow sediments, internal microbial transformations rel...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2025-08-01
|
| Series: | Limnology and Oceanography Letters |
| Online Access: | https://doi.org/10.1002/lol2.70026 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849303958307209216 |
|---|---|
| author | Elisa Calvo‐Martin Xosé Antón Álvarez‐Salgado María José Pazó Fernández Vanesa Vieitez Dos Santos J. Severino P. Ibánhez |
| author_facet | Elisa Calvo‐Martin Xosé Antón Álvarez‐Salgado María José Pazó Fernández Vanesa Vieitez Dos Santos J. Severino P. Ibánhez |
| author_sort | Elisa Calvo‐Martin |
| collection | DOAJ |
| description | Abstract Subterranean estuaries (i.e., seawater‐fresh groundwater mixing zones at coastal aquifers) are highly reactive boundaries between continental groundwater and coastal surface seawater. Because particulate organic matter is retained in shallow sediments, internal microbial transformations rely on dissolved organic matter (DOM) supply and bioavailability. Here, we investigated DOM carbon content and optical characteristics in two nearby subterranean estuaries with contrasting oxygenation. Coastal organic carbon processing in the anoxic subterranean estuary resulted in the export of DOM enriched in recalcitrant compounds compared to the oxygenated one, which was a net sink of DOM. This contrasting behavior was not driven by opposite redox conditions but from the fast transfer of labile DOM and oxygen to the beach interior of the oxygenated subterranean estuary. There, heterotrophic processes, which rely almost exclusively on DOM, are enhanced, resulting in net DOM consumption prior discharge to surface waters. |
| format | Article |
| id | doaj-art-7c59255c341f4e3c81ab829ec00f874f |
| institution | Kabale University |
| issn | 2378-2242 |
| language | English |
| publishDate | 2025-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Limnology and Oceanography Letters |
| spelling | doaj-art-7c59255c341f4e3c81ab829ec00f874f2025-08-20T03:55:53ZengWileyLimnology and Oceanography Letters2378-22422025-08-0110453654610.1002/lol2.70026Drivers of dissolved organic matter processing in subterranean estuariesElisa Calvo‐Martin0Xosé Antón Álvarez‐Salgado1María José Pazó Fernández2Vanesa Vieitez Dos Santos3J. Severino P. Ibánhez4Organic Geochemistry Lab, Department of Oceanography Instituto de Investigacións Mariñas, Consejo Superior de Investigaciones Científicas (CSIC) Vigo SpainOrganic Geochemistry Lab, Department of Oceanography Instituto de Investigacións Mariñas, Consejo Superior de Investigaciones Científicas (CSIC) Vigo SpainOrganic Geochemistry Lab, Department of Oceanography Instituto de Investigacións Mariñas, Consejo Superior de Investigaciones Científicas (CSIC) Vigo SpainOrganic Geochemistry Lab, Department of Oceanography Instituto de Investigacións Mariñas, Consejo Superior de Investigaciones Científicas (CSIC) Vigo SpainOrganic Geochemistry Lab, Department of Oceanography Instituto de Investigacións Mariñas, Consejo Superior de Investigaciones Científicas (CSIC) Vigo SpainAbstract Subterranean estuaries (i.e., seawater‐fresh groundwater mixing zones at coastal aquifers) are highly reactive boundaries between continental groundwater and coastal surface seawater. Because particulate organic matter is retained in shallow sediments, internal microbial transformations rely on dissolved organic matter (DOM) supply and bioavailability. Here, we investigated DOM carbon content and optical characteristics in two nearby subterranean estuaries with contrasting oxygenation. Coastal organic carbon processing in the anoxic subterranean estuary resulted in the export of DOM enriched in recalcitrant compounds compared to the oxygenated one, which was a net sink of DOM. This contrasting behavior was not driven by opposite redox conditions but from the fast transfer of labile DOM and oxygen to the beach interior of the oxygenated subterranean estuary. There, heterotrophic processes, which rely almost exclusively on DOM, are enhanced, resulting in net DOM consumption prior discharge to surface waters.https://doi.org/10.1002/lol2.70026 |
| spellingShingle | Elisa Calvo‐Martin Xosé Antón Álvarez‐Salgado María José Pazó Fernández Vanesa Vieitez Dos Santos J. Severino P. Ibánhez Drivers of dissolved organic matter processing in subterranean estuaries Limnology and Oceanography Letters |
| title | Drivers of dissolved organic matter processing in subterranean estuaries |
| title_full | Drivers of dissolved organic matter processing in subterranean estuaries |
| title_fullStr | Drivers of dissolved organic matter processing in subterranean estuaries |
| title_full_unstemmed | Drivers of dissolved organic matter processing in subterranean estuaries |
| title_short | Drivers of dissolved organic matter processing in subterranean estuaries |
| title_sort | drivers of dissolved organic matter processing in subterranean estuaries |
| url | https://doi.org/10.1002/lol2.70026 |
| work_keys_str_mv | AT elisacalvomartin driversofdissolvedorganicmatterprocessinginsubterraneanestuaries AT xoseantonalvarezsalgado driversofdissolvedorganicmatterprocessinginsubterraneanestuaries AT mariajosepazofernandez driversofdissolvedorganicmatterprocessinginsubterraneanestuaries AT vanesavieitezdossantos driversofdissolvedorganicmatterprocessinginsubterraneanestuaries AT jseverinopibanhez driversofdissolvedorganicmatterprocessinginsubterraneanestuaries |