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...
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2015
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00014615 2023-05-15T17:31:59+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, A. N. Borchard, C. Meyer, J. Hauss, H. Kiko, R. Engel, A. 2015-12 electronic https://doi.org/10.5194/bg-12-6897-2015 https://noa.gwlb.de/receive/cop_mods_00014615 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00014570/bg-12-6897-2015.pdf https://bg.copernicus.org/articles/12/6897/2015/bg-12-6897-2015.pdf eng eng Copernicus Publications Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-12-6897-2015 https://noa.gwlb.de/receive/cop_mods_00014615 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00014570/bg-12-6897-2015.pdf https://bg.copernicus.org/articles/12/6897/2015/bg-12-6897-2015.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2015 ftnonlinearchiv https://doi.org/10.5194/bg-12-6897-2015 2022-02-08T22:55:00Z 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 Niedersächsisches Online-Archiv NOA Biogeosciences 12 23 6897 6914 |
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article Verlagsveröffentlichung Loginova, A. N. Borchard, C. Meyer, J. Hauss, H. Kiko, R. Engel, A. Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study |
topic_facet |
article Verlagsveröffentlichung |
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, A. N. Borchard, C. Meyer, J. Hauss, H. Kiko, R. Engel, A. |
author_facet |
Loginova, A. N. Borchard, C. Meyer, J. Hauss, H. Kiko, R. Engel, A. |
author_sort |
Loginova, A. 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 |
publishDate |
2015 |
url |
https://doi.org/10.5194/bg-12-6897-2015 https://noa.gwlb.de/receive/cop_mods_00014615 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00014570/bg-12-6897-2015.pdf https://bg.copernicus.org/articles/12/6897/2015/bg-12-6897-2015.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-12-6897-2015 https://noa.gwlb.de/receive/cop_mods_00014615 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00014570/bg-12-6897-2015.pdf https://bg.copernicus.org/articles/12/6897/2015/bg-12-6897-2015.pdf |
op_rights |
uneingeschränkt 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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1766129889334788096 |