Cross-shore transport and eddies promote large scale response to urban eutrophication.

Autor: Kessouri F; Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA. faycalk@sccwrp.org.; Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA. faycalk@sccwrp.org., Sutula MA; Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA., Bianchi D; Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA., Ho M; Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA.; Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA., Damien P; Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA., McWilliams JC; Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA., Frieder CA; Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA., Renault L; Laboratoire d'Études en Géophysique et Océanographie Spatiale, IRD, CNRS, CNES, UPS, Toulouse, 31400, France., Frenzel H; School of Oceanography, Seattle, WA, 98195, USA.; CICOES, University of Washington and NOAA PMEL, Seattle, WA, 98105, USA., McLaughlin K; Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA., Deutsch C; Department of Geosciences, High Meadows Environmental Institute, Princeton University, Princeton, NJ, 08544, USA.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2024 Mar 27; Vol. 14 (1), pp. 7240. Date of Electronic Publication: 2024 Mar 27.
DOI: 10.1038/s41598-024-57626-6
Abstrakt: A key control on the magnitude of coastal eutrophication is the degree to which currents quickly transport nitrogen derived from human sources away from the coast to the open ocean before eutrophication develops. In the Southern California Bight (SCB), an upwelling-dominated eastern boundary current ecosystem, anthropogenic nitrogen inputs increase algal productivity and cause subsurface acidification and oxygen (O 2 ) loss along the coast. However, the extent of anthropogenic influence on eutrophication beyond the coastal band, and the physical transport mechanisms and biogeochemical processes responsible for these effects are still poorly understood. Here, we use a submesoscale-resolving numerical model to document the detailed biogeochemical mass balance of nitrogen, carbon and oxygen, their physical transport, and effects on offshore habitats. Despite management of terrestrial nutrients that has occurred in the region over the last 20 years, coastal eutrophication continues to persist. The input of anthropogenic nutrients promote an increase in productivity, remineralization and respiration offshore, with recurrent O 2 loss and pH decline in a region located 30-90 km from the mainland. During 2013 to 2017, the spatially averaged 5-year loss rate across the Bight was 1.3 mmol m - 3 O 2 , with some locations losing on average up to 14.2 mmol m - 3 O 2 . The magnitude of loss is greater than model uncertainty assessed from data-model comparisons and from quantification of intrinsic variability. This phenomenon persists for 4 to 6 months of the year over an area of 278,40 km 2 ( ∼ 30% of SCB area). These recurrent features of acidification and oxygen loss are associated with cross-shore transport of nutrients by eddies and plankton biomass and their accumulation and retention within persistent eddies offshore within the SCB.
(© 2024. The Author(s).)
Databáze: MEDLINE
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