Cross-shore transport and eddies promote large scale response to urban eutrophication [+ Correction, 1 p.]

2024

Article référencé dans le Web of Science WOS:001196356400095

Kessouri F., Sutula M. A., Bianchi D., Ho M. N., Damien P., McWilliams J. C., Frieder C. A., Renault Lionel, Frenzel H., McLaughlin K., Deutsch C.

Scientific Reports - Nature, 2024, 14 (1), 7240 [17 p.] + [Correction, 1 p., vol. 14, 22896, 2024] ISSN 2045-2322

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 (O2 ) 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

Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Ecologie, systèmes aquatiques [036] ; Pollution [038] ; Urbanisation et sociétés urbaines [102]

ETATS UNIS ; PACIFIQUE

Fonds IRD [F B010090561]

fdi:010090561