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Kalvelage T., Lavik G., Lam P., Contreras S., Arteaga L., Löscher C.R., Oschlies A., Paulmier Aurélien, Stramma L., Kuypers M.M.M. (2013). Nitrogen cycling driven by organic matter export in the South Pacific oxygen minimum zone. Nature Geoscience, 6 (3), p. 228-234. ISSN 1752-0894.

Titre du document
Nitrogen cycling driven by organic matter export in the South Pacific oxygen minimum zone
Année de publication
2013
Type de document
Article référencé dans le Web of Science WOS:000316945800026
Auteurs
Kalvelage T., Lavik G., Lam P., Contreras S., Arteaga L., Löscher C.R., Oschlies A., Paulmier Aurélien, Stramma L., Kuypers M.M.M.
Source
Nature Geoscience, 2013, 6 (3), p. 228-234 ISSN 1752-0894
Oxygen minimum zones are expanding globally, and at present account for around 20-40% of oceanic nitrogen loss. Heterotrophic denitrification and anammox-anaerobic ammonium oxidation with nitrite-are responsible for most nitrogen loss in these low-oxygen waters. Anammox is particularly significant in the eastern tropical South Pacific, one of the largest oxygen minimum zones globally. However, the factors that regulate anammox-driven nitrogen loss have remained unclear. Here, we present a comprehensive nitrogen budget for the eastern tropical South Pacific oxygen minimum zone, using measurements of nutrient concentrations, experimentally determined rates of nitrogen transformation and a numerical model of export production. Anammox was the dominant mode of nitrogen loss at the time of sampling. Rates of anammox, and related nitrogen transformations, were greatest in the productive shelf waters, and tailed off with distance from the coast. Within the shelf region, anammox activity peaked in both upper and bottom waters. Overall, rates of nitrogen transformation, including anammox, were strongly correlated with the export of organic matter. We suggest that the sinking of organic matter, and thus the release of ammonium into the water column, together with benthic ammonium release, fuel nitrogen loss from oxygen minimum zones.
Plan de classement
Milieux physico-chimique [032MILPHY]
Descripteurs
CYCLE BIOGEOCHIMIQUE ; CYCLE DE L'AZOTE ; UPWELLING ; OXYGENE ; NITRIFICATION ; OCEAN
Description Géographique
PACIFIQUE
Localisation
Fonds IRD [F B010070126]
Identifiant IRD
fdi:010070126
Contact