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- Rocha, C., et al.
(författare)
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A place for subterranean estuaries in the coastal zone
- 2021
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Ingår i: Estuarine Coastal and Shelf Science. - : Elsevier BV. - 0272-7714. ; 250
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Tidskriftsartikel (refereegranskat)abstract
- Willard S. Moore coined the term subterranean estuary (STE) as that part of the coastal aquifer 'where groundwater derived from land drainage measurably dilutes seawater that has invaded the aquifer through a free connection to the sea' more than two decades ago (Moore, 1999). In doing so, Moore was calling attention to the potential importance of this zone, long studied by terrestrial hydrologists, to marine systems. Since then, we have accumulated indisputable evidence of the importance of STEs and their associated submarine groundwater discharge (SGD) in coastal ecosystem function. Yet, subterranean estuaries are often not considered distinct systems in the land-ocean continuum either from an academic viewpoint or for developing integrative monitoring and management. This invisibility means that the impact of STEs on ecosystem state has been neglected when environmental assessments that aim to meet coastal water quality and ecosystem health targets are performed. It is possible that our current broad definition of STEs, as well as misuse and misunderstanding of terminology, partly explain their de-facto transparency to the wider coastal scientific community. Here, we argue for the inclusion of STEs as important, interconnected systems driving water quality, ecology, and biogeochemical cycles in nearby coastal ecosystems. To achieve broader recognition, we first need to address the perceived compartmentalization of surface and groundwater systems, as well as overcome a pigeon-holed approach to research often confined within narrow disciplinary boundaries. The establishment of open-water estuarine science over the last several decades shows that such obstacles are surmountable. A lack of awareness and recognition of STE functions impedes a holistic understanding of coastal ecosystems and slows down the development of cause-effect relationships for a science-based approach to ecosystem management.
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| 2. |
- Wilson, Stephanie J., et al.
(författare)
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Global subterranean estuaries modify groundwater nutrient loading to the ocean
- 2024
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Ingår i: Limnology And Oceanography Letters. - 2378-2242.
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Tidskriftsartikel (refereegranskat)abstract
- Terrestrial groundwater travels through subterranean estuaries before reaching the sea. Groundwater-derived nutrients drive coastal water quality, primary production, and eutrophication. We determined how dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and dissolved organic nitrogen (DON) are transformed within subterranean estuaries and estimated submarine groundwater discharge (SGD) nutrient loads compiling > 10,000 groundwater samples from 216 sites worldwide. Nutrients exhibited complex, nonconservative behavior in subterranean estuaries. Fresh groundwater DIN and DIP are usually produced, and DON is consumed during transport. Median total SGD (saline and fresh) fluxes globally were 5.4, 2.6, and 0.18 Tmol yr−1 for DIN, DON, and DIP, respectively. Despite large natural variability, total SGD fluxes likely exceed global riverine nutrient export. Fresh SGD is a small source of new nutrients, but saline SGD is an important source of mostly recycled nutrients. Nutrients exported via SGD via subterranean estuaries are critical to coastal biogeochemistry and a significant nutrient source to the oceans.
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