Journal article
Tropical Beaches Attenuate Groundwater Nitrogen Pollution Flowing to the Ocean
Environmental Science & Technology, Vol.55(12), pp.8432-8438
15/06/2021
PMID: 34086455
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Source: InCites
Abstract
Tropical urbanized coastal regions are hotspots for the discharge of nutrient-enriched groundwater, which can affect sensitive coastal ecosystems. Here, we investigated how a beach modifies groundwater nutrient loads in southern India (Varkala Beach), using flux measurements and stable isotopes. Fresh groundwater was highly enriched in NO3 from sewage or manure. Submarine groundwater discharge and nearshore groundwater discharge were equally important contributors to coastal NO3 fluxes with 303 mmol NO3 m–1 day–1 in submarine and 334 mmol NO3 m–1 day–1 in nearshore groundwater discharge. However, N/P ratios in nearshore groundwater discharge were up to 3 orders of magnitude greater than that in submarine groundwater, which can promote harmful algae blooms. As groundwater flowed through the beach, N/P ratios decreased toward Redfield ratios due to the removal of 30–50% of NO3 due to denitrification and production of PO4 due to mineralization of organic matter. Overall, tropical beaches can be important natural biogeochemical reactors that attenuate nitrogen pollution and modify N/P ratios in submarine groundwater discharge.
Details
- Title
- Tropical Beaches Attenuate Groundwater Nitrogen Pollution Flowing to the Ocean
- Creators
- Till Oehler - Leibniz Centre for Tropical Marine ResearchMurugan Ramasamy - National Centre for Earth Science StudiesMintu E George - National Centre for Earth Science StudiesSuresh D. S Babu - National Centre for Earth Science StudiesKirstin Dähnke - Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, 21502 Geesthacht, GermanyMarkus Ankele - Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, 21502 Geesthacht, GermanyMichael E Böttcher - Leibniz Institute for Baltic Sea Research WarnemündeIsaac R Santos - University of GothenburgNils Moosdorf - Leibniz Centre for Tropical Marine Research
- Publication Details
- Environmental Science & Technology, Vol.55(12), pp.8432-8438
- Publisher
- American Chemical Society
- Grant note
- This work was funded by the German Federal Ministry of Education and Research (BMBF Grant no. 01LN1307A to N.M.). The authors gratefully acknowledge the approval of the Mission SGD project and the funding received from the Ministry of Earth Sciences (MoES), Government of India.
- Identifiers
- 991012948576002368
- Copyright
- Copyright © 2021 American Chemical Society
- Academic Unit
- Faculty of Science and Engineering; School of Environment, Science and Engineering; National Marine Science Centre; Science
- Language
- English
- Resource Type
- Journal article