Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study
In open-ocean regions, as is the Eastern Tropical North Atlantic (ETNA), pelagic production is the main source of dissolved organic matter (DOM) and is affected by dissolved inorganic nitrogen (DIN) and phosphorus (DIP) concentrations. Changes in pelagic production under nutrient amendments were sho...
Published in: | Biogeosciences |
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Main Authors: | , , , , , |
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Language: | English |
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Copernicus Publications (EGU)
2015
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Online Access: | https://oceanrep.geomar.de/id/eprint/28809/ https://oceanrep.geomar.de/id/eprint/28809/29/bg-12-6897-2015.pdf https://oceanrep.geomar.de/id/eprint/28809/30/bg-12-6897-2015-supplement.pdf https://doi.org/10.5194/bg-12-6897-2015 |
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ftoceanrep:oai:oceanrep.geomar.de:28809 2023-05-15T17:32:09+02:00 Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study Loginova, Alexandra N. Borchard, Corinna Meyer, Judith Hauss, Helena Kiko, Rainer Engel, Anja 2015-11-02 text https://oceanrep.geomar.de/id/eprint/28809/ https://oceanrep.geomar.de/id/eprint/28809/29/bg-12-6897-2015.pdf https://oceanrep.geomar.de/id/eprint/28809/30/bg-12-6897-2015-supplement.pdf https://doi.org/10.5194/bg-12-6897-2015 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/28809/29/bg-12-6897-2015.pdf https://oceanrep.geomar.de/id/eprint/28809/30/bg-12-6897-2015-supplement.pdf Loginova, A. N. , Borchard, C., Meyer, J., Hauss, H. , Kiko, R. and Engel, A. (2015) Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study. Open Access Biogeosciences (BG), 12 . pp. 6897-6914. DOI 10.5194/bg-12-6897-2015 <https://doi.org/10.5194/bg-12-6897-2015>. doi:10.5194/bg-12-6897-2015 cc_by_3.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2015 ftoceanrep https://doi.org/10.5194/bg-12-6897-2015 2023-04-07T15:19:21Z In open-ocean regions, as is the Eastern Tropical North Atlantic (ETNA), pelagic production is the main source of dissolved organic matter (DOM) and is affected by dissolved inorganic nitrogen (DIN) and phosphorus (DIP) concentrations. Changes in pelagic production under nutrient amendments were shown to also modify DOM quantity and quality. However, little information is available about the effects of nutrient variability on chromophoric (CDOM) and fluorescent (FDOM) DOM dynamics. Here we present results from two mesocosm experiments ("Varied P" and "Varied N") conducted with a natural plankton community from the ETNA, where the effects of DIP and DIN supply on DOM optical properties were studied. CDOM accumulated proportionally to phytoplankton biomass during the experiments. Spectral slope (S) decreased over time indicating accumulation of high molecular weight DOM. In Varied N, an additional CDOM portion, as a result of bacterial DOM reworking, was determined. It increased the CDOM fraction in DOC proportionally to the supplied DIN. The humic-like FDOM component (Comp.1) was produced by bacteria proportionally to DIN supply. The protein-like FDOM component (Comp.2) was released irrespectively to phytoplankton or bacterial biomass, but depended on DIP and DIN concentrations. Under high DIN supply, Comp.2 was removed by bacterial reworking, leading to an accumulation of humic-like Comp.1. No influence of nutrient availability on amino acid-like FDOM component in peptide form (Comp.3) was observed. Comp.3 potentially acted as an intermediate product during formation or degradation of Comp.2. Our findings suggest that changes in nutrient concentrations may lead to substantial responses in the quantity and quality of optically active DOM and, therefore, might bias results of the applied in situ optical techniques for an estimation of DOC concentrations in open-ocean regions. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Biogeosciences 12 23 6897 6914 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
In open-ocean regions, as is the Eastern Tropical North Atlantic (ETNA), pelagic production is the main source of dissolved organic matter (DOM) and is affected by dissolved inorganic nitrogen (DIN) and phosphorus (DIP) concentrations. Changes in pelagic production under nutrient amendments were shown to also modify DOM quantity and quality. However, little information is available about the effects of nutrient variability on chromophoric (CDOM) and fluorescent (FDOM) DOM dynamics. Here we present results from two mesocosm experiments ("Varied P" and "Varied N") conducted with a natural plankton community from the ETNA, where the effects of DIP and DIN supply on DOM optical properties were studied. CDOM accumulated proportionally to phytoplankton biomass during the experiments. Spectral slope (S) decreased over time indicating accumulation of high molecular weight DOM. In Varied N, an additional CDOM portion, as a result of bacterial DOM reworking, was determined. It increased the CDOM fraction in DOC proportionally to the supplied DIN. The humic-like FDOM component (Comp.1) was produced by bacteria proportionally to DIN supply. The protein-like FDOM component (Comp.2) was released irrespectively to phytoplankton or bacterial biomass, but depended on DIP and DIN concentrations. Under high DIN supply, Comp.2 was removed by bacterial reworking, leading to an accumulation of humic-like Comp.1. No influence of nutrient availability on amino acid-like FDOM component in peptide form (Comp.3) was observed. Comp.3 potentially acted as an intermediate product during formation or degradation of Comp.2. Our findings suggest that changes in nutrient concentrations may lead to substantial responses in the quantity and quality of optically active DOM and, therefore, might bias results of the applied in situ optical techniques for an estimation of DOC concentrations in open-ocean regions. |
format |
Article in Journal/Newspaper |
author |
Loginova, Alexandra N. Borchard, Corinna Meyer, Judith Hauss, Helena Kiko, Rainer Engel, Anja |
spellingShingle |
Loginova, Alexandra N. Borchard, Corinna Meyer, Judith Hauss, Helena Kiko, Rainer Engel, Anja Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study |
author_facet |
Loginova, Alexandra N. Borchard, Corinna Meyer, Judith Hauss, Helena Kiko, Rainer Engel, Anja |
author_sort |
Loginova, Alexandra N. |
title |
Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study |
title_short |
Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study |
title_full |
Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study |
title_fullStr |
Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study |
title_full_unstemmed |
Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study |
title_sort |
effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the eastern tropical north atlantic: a mesocosm study |
publisher |
Copernicus Publications (EGU) |
publishDate |
2015 |
url |
https://oceanrep.geomar.de/id/eprint/28809/ https://oceanrep.geomar.de/id/eprint/28809/29/bg-12-6897-2015.pdf https://oceanrep.geomar.de/id/eprint/28809/30/bg-12-6897-2015-supplement.pdf https://doi.org/10.5194/bg-12-6897-2015 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/28809/29/bg-12-6897-2015.pdf https://oceanrep.geomar.de/id/eprint/28809/30/bg-12-6897-2015-supplement.pdf Loginova, A. N. , Borchard, C., Meyer, J., Hauss, H. , Kiko, R. and Engel, A. (2015) Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study. Open Access Biogeosciences (BG), 12 . pp. 6897-6914. DOI 10.5194/bg-12-6897-2015 <https://doi.org/10.5194/bg-12-6897-2015>. doi:10.5194/bg-12-6897-2015 |
op_rights |
cc_by_3.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-12-6897-2015 |
container_title |
Biogeosciences |
container_volume |
12 |
container_issue |
23 |
container_start_page |
6897 |
op_container_end_page |
6914 |
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1766130113333690368 |