Evaluation of origin-depended nitrogen input through atmospheric deposition and its effect on primary production in coastal areas of western Kyusyu, Japan

2021 ◽  
Vol 291 ◽  
pp. 118034
Author(s):  
Yu Umezawa ◽  
Kanae Toyoshima ◽  
Yu Saitoh ◽  
Shigenobu Takeda ◽  
Kei Tamura ◽  
...  
Keyword(s):  
Primary Production ◽  
Atmospheric Deposition ◽  
Coastal Areas ◽  
Nitrogen Input

scholarly journals Box-modeling of the impacts of atmospheric nitrogen deposition and benthic remineralization on the nitrogen cycle of the eastern tropical South Pacific

2015 ◽  
Vol 12 (17) ◽  
pp. 14441-14479
Author(s):  
B. Su ◽  
M. Pahlow ◽  
A. Oschlies
Keyword(s):  
Nitrogen Fixation ◽  
Primary Production ◽  
Atmospheric Deposition ◽  
Water Column ◽  
Nitrogen Deposition ◽  
Nitrogen Cycle ◽  
South Pacific ◽  
Atmospheric Nitrogen Deposition ◽  
Atmospheric Nitrogen ◽  
Model Domain

Abstract. Both atmospheric deposition and benthic remineralization influence the marine nitrogen cycle, and hence ultimately also marine primary production. The biological and biogeochemical relations of the eastern tropical South Pacific (ETSP) to nitrogen deposition, benthic denitrification and phosphate regeneration are analysed in a prognostic box model of the oxygen, nitrogen and phosphorus cycles in the ETSP. In the model, atmospheric nitrogen deposition based on estimates for the years 2000–2009 is offset by half by reduced N2 fixation, with the other half transported out of the model domain. Both model- and data-based benthic denitrification are found to trigger nitrogen fixation, partly compensating for the NO3− loss. Since phosphate is the ultimate limiting nutrient in the model, enhanced sedimentary phosphate regeneration under suboxic conditions stimulates primary production and subsequent export production and NO3− loss in the oxygen minimum zone (OMZ). A sensitivity analysis of the local response to both atmospheric deposition and benthic remineralization indicates dominant stabilizing feedbacks in the ETSP, which tend to keep a balanced nitrogen inventory, i.e., nitrogen input by atmospheric deposition is counteracted by decreasing nitrogen fixation; NO3− loss via benthic denitrification is partly compensated by increased nitrogen fixation; enhanced nitrogen fixation stimulated by phosphate regeneration is partly removed by the stronger water-column denitrification. Even though the water column in our model domain acts as a NO3− source, the ETSP including benthic denitrification might become a NO3− sink.

Atmospheric deposition of polybrominated diphenyl ethers (PBDEs) in coastal areas in Korea

Chemosphere ◽  
2007 ◽  
Vol 66 (4) ◽  
pp. 585-593 ◽  
Author(s):  
Hyo-Bang Moon ◽  
Kurunthachalam Kannan ◽  
Su-Jeong Lee ◽  
Minkyu Choi
Keyword(s):  
Atmospheric Deposition ◽  
Polybrominated Diphenyl Ethers ◽  
Coastal Areas ◽  
Diphenyl Ethers

scholarly journals Testing the robustness of primary production models in shallow coastal areas: a case study

2004 ◽  
Vol 179 (2) ◽  
pp. 221-233 ◽  
Author(s):  
R. Pastres ◽  
D. Brigolin ◽  
A. Petrizzo ◽  
M. Zucchetta
Keyword(s):  
Primary Production ◽  
Coastal Areas ◽  
Production Models

scholarly journals Atmospheric Deposition of Macronutrients (Dissolved Inorganic Nitrogen and Phosphorous) onto the Black Sea and Implications on Marine Productivity*

2016 ◽  
Vol 73 (4) ◽  
pp. 1727-1739 ◽  
Author(s):  
M. Koçak ◽  
N. Mihalopoulos ◽  
E. Tutsak ◽  
K. Violaki ◽  
C. Theodosi ◽  
...  
Keyword(s):  
Primary Production ◽  
Atmospheric Deposition ◽  
Black Sea ◽  
Inorganic Nitrogen ◽  
Phosphate Concentration ◽  
Rural Site ◽  
The Black Sea ◽  
Dissolved Inorganic Nitrogen ◽  
N:P Ratios ◽  
The Mean

Abstract Two-sized aerosol samples were obtained from a rural site located close to Sinop on the south coastline of the Black Sea. In addition, bulk deposition samples were collected at Varna, located on the west coastline of the Black Sea. Both aerosol and deposition samples were analyzed for the main macronutrients, NO3−, NH4+, and PO43−. The mean aerosol nitrate and ammonium concentrations were 7.1 ± 5.5 and 22.8 ± 17.8 nmol m−3, respectively. The mean aerosol phosphate concentration was 0.69 ± 0.31 nmol m−3, ranging from 0.21 to 2.36 nmol m−3. Interestingly, phosphate concentration over Sinop was substantially higher than those of most Mediterranean sites. Comparison of the atmospheric and riverine inputs for the Black Sea revealed that atmospheric dissolved inorganic nitrogen (DIN) only ranged between 4% and 13%, while the atmospheric dissolved inorganic phosphorus (DIP) fluxes had significantly higher contributions with values ranging from 12% to 37%. The molar N:P ratios in atmospheric deposition for Sinop and Varna were 13 and 14, respectively, both of which were lower than the Redfield ratio (16). The atmospheric molar N:P ratios over the Black Sea were considerably lower than those reported for riverine fluxes (41) and the Mediterranean region (more than 200). The atmospheric P flux can sustain 0.5%–5.2% of the primary production, whereas the N flux can sustain 0.4%–4.8% of the primary production. The contribution of the atmospheric flux may enhance by 2.6 when the new production is considered.

scholarly journals Box-modelling of the impacts of atmospheric nitrogen deposition and benthic remineralisation on the nitrogen cycle of the eastern tropical South Pacific

2016 ◽  
Vol 13 (17) ◽  
pp. 4985-5001
Author(s):  
Bei Su ◽  
Markus Pahlow ◽  
Andreas Oschlies
Keyword(s):  
Nitrogen Fixation ◽  
Primary Production ◽  
Atmospheric Deposition ◽  
Water Column ◽  
Nitrogen Deposition ◽  
Nitrogen Cycle ◽  
Atmospheric Nitrogen Deposition ◽  
Atmospheric Nitrogen ◽  
Model Domain ◽  
Phosphorus Regeneration

Abstract. Both atmospheric deposition and benthic remineralisation influence the marine nitrogen cycle, and hence ultimately also marine primary production. The biological and biogeochemical relations in the eastern tropical South Pacific (ETSP) among nitrogen deposition, benthic denitrification and phosphorus regeneration are analysed in a prognostic box model of the oxygen, nitrogen and phosphorus cycles in the ETSP. Atmospheric nitrogen deposition ( ≈ 1.5 Tg N yr−1 for the years 2000–2009) is offset by half in the model by reduced N2 fixation, with the other half transported out of the model domain. Model- and data-based benthic denitrification in our model domain are responsible for losses of 0.19 and 1.0 Tg Tg N yr−1, respectively, and both trigger nitrogen fixation, partly compensating for the NO3− loss. Model- and data-based estimates of enhanced phosphate release via sedimentary phosphorus regeneration under suboxic conditions are 0.062 and 0.11 Tg N yr−1, respectively. Since phosphate is the ultimate limiting nutrient in the model, even very small additional phosphate inputs stimulate primary production and subsequent export production and NO3− loss in the oxygen minimum zone (OMZ). A sensitivity analysis of the local response to both atmospheric deposition and benthic remineralisation indicates dominant stabilising feedbacks in the ETSP, which tend to keep a balanced nitrogen inventory; i.e. nitrogen input by atmospheric deposition is counteracted by decreasing nitrogen fixation; NO3− loss via benthic denitrification is partly compensated for by increased nitrogen fixation; enhanced nitrogen fixation stimulated by phosphate regeneration is partly counteracted by stronger water-column denitrification. Even though the water column in our model domain acts as a NO3− source, the ETSP including benthic denitrification might be a NO3− sink.

scholarly journals Nitrogen budgets following a Lagrangian strategy in the Western Tropical South Pacific Ocean: the prominent role of N<sub>2</sub> fixation (OUTPACE cruise)

2017 ◽  
Author(s):  
Mathieu Caffin ◽  
Thierry Moutin ◽  
Rachel Ann Foster ◽  
Pascale Bouruet-Aubertot ◽  
Andrea Michelangelo Doglioli ◽  
...  
Keyword(s):  
Primary Production ◽  
Atmospheric Deposition ◽  
N2 Fixation ◽  
High Efficiency ◽  
Nifh Gene ◽  
Austral Summer ◽  
South Pacific ◽  
Eddy Diffusion ◽  
Sediment Traps ◽  
Nitrogen Budgets

Abstract. We performed N budgets at three stations in the western tropical South Pacific (WTSP) Ocean during austral summer conditions (Feb. Mar. 2015) and quantified all major N fluxes both entering the system (N2 fixation, nitrate eddy diffusion, atmospheric deposition) and leaving the system (PN export). Thanks to a Lagrangian strategy, we sampled the same water mass for the entire duration of each long duration (5 days) station, allowing to consider only vertical exchanges. Two stations located at the western end of the transect (Melanesian archipelago (MA) waters, LD A and LD B) were oligotrophic and characterized by a deep chlorophyll maximum (DCM) located at 51 ± 18 m and 81 ± 9 m at LD A and LD B. Station LD C was characterized by a DCM located at 132 ± 7 m, representative of the ultra-oligotrophic waters of the South Pacific gyre (SPG water). N2 fixation rates were extremely high at both LD A (593 ± 51 µmol N m−2 d−1) and LD B (706 ± 302 µmol N m−2 d−1), and the diazotroph community was dominated by Trichodesmium. N2 fixation rates were lower (59 ± 16 µmol N m−2 d−1) at LD C and the diazotroph community was dominated by unicellular N2-fixing cyanobacteria (UCYN). At all stations, N2 fixation was the major source of new N (> 90 %) before atmospheric deposition and upward nitrate fluxes induced by turbulence. N2 fixation contributed circa 8–12 % of primary production in the MA region and 3 % in the SPG water and sustained nearly all new primary production at all stations. The e-ratio (e-ratio = PC export/PP) was maximum at LD A (9.7 %) and was higher than the e-ratio in most studied oligotrophic regions (~ 1 %), indicating a high efficiency of the WTSP to export carbon relative to primary production. The direct export of diazotrophs assessed by qPCR of the nifH gene in sediment traps represented up to 30.6 % of the PC export at LD A, while there contribution was 5 and

scholarly journals N<sub>2</sub> fixation as a dominant new N source in the western tropical South Pacific Ocean (OUTPACE cruise)

2018 ◽  
Vol 15 (8) ◽  
pp. 2565-2585 ◽  
Author(s):  
Mathieu Caffin ◽  
Thierry Moutin ◽  
Rachel Ann Foster ◽  
Pascale Bouruet-Aubertot ◽  
Andrea Michelangelo Doglioli ◽  
...  
Keyword(s):  
Primary Production ◽  
Atmospheric Deposition ◽  
N2 Fixation ◽  
High Efficiency ◽  
Nifh Gene ◽  
South Pacific ◽  
Particulate Carbon ◽  
Trophic Conditions ◽  
N Accumulation ◽  
Photic Layer

Abstract. We performed nitrogen (N) budgets in the photic layer of three contrasting stations representing different trophic conditions in the western tropical South Pacific (WTSP) Ocean during austral summer conditions (February–March 2015). Using a Lagrangian strategy, we sampled the same water mass for the entire duration of each long-duration (5 days) station, allowing us to consider only vertical exchanges for the budgets. We quantified all major vertical N fluxes both entering (N2 fixation, nitrate turbulent diffusion, atmospheric deposition) and leaving the photic layer (particulate N export). The three stations were characterized by a strong nitracline and contrasted deep chlorophyll maximum depths, which were lower in the oligotrophic Melanesian archipelago (MA, stations LD A and LD B) than in the ultra-oligotrophic waters of the South Pacific Gyre (SPG, station LD C). N2 fixation rates were extremely high at both LD A (593 ± 51 µmol N m−2 d−1) and LD B (706 ± 302 µmol N m−2 d−1), and the diazotroph community was dominated by Trichodesmium. N2 fixation rates were lower (59 ± 16 µmol N m−2 d−1) at LD C, and the diazotroph community was dominated by unicellular N2-fixing cyanobacteria (UCYN). At all stations, N2 fixation was the major source of new N (> 90 %) before atmospheric deposition and upward nitrate fluxes induced by turbulence. N2 fixation contributed circa 13–18 % of primary production in the MA region and 3 % in the SPG water and sustained nearly all new primary production at all stations. The e ratio (e ratio = particulate carbon export ∕ primary production) was maximum at LD A (9.7 %) and was higher than the e ratio in most studied oligotrophic regions (< 5 %), indicating a high efficiency of the WTSP to export carbon relative to primary production. The direct export of diazotrophs assessed by qPCR of the nifH gene in sediment traps represented up to 30.6 % of the PC export at LD A, while their contribution was 5 and < 0.1 % at LD B and LD C, respectively. At the three studied stations, the sum of all N input to the photic layer exceeded the N output through organic matter export. This disequilibrium leading to N accumulation in the upper layer appears as a characteristic of the WTSP during the summer season.

scholarly journals Dust deposition in an oligotrophic marine environment: impact on the carbon budget

2014 ◽  
Vol 11 (1) ◽  
pp. 1707-1738 ◽  
Author(s):  
C. Guieu ◽  
C. Ridame ◽  
E. Pulido-Villena ◽  
M. Bressac ◽  
K. Desboeufs ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Atmospheric Deposition ◽  
Mediterranean Sea ◽  
Carbon Budget ◽  
Net Primary Production ◽  
Saharan Dust ◽  
Surface Mixed Layer ◽  
Dust Deposition ◽  
The Mediterranean

Abstract. By bringing new nutrients and particles to the surface ocean, atmospheric deposition impacts biogeochemical cycles. The extent to which those changes are modifying the carbon balance in oligotrophic environments such as the Mediterranean Sea that receives important Saharan dust fluxes is unknown. DUNE project provides the first attempt to evaluate the changes induced in the carbon budget of an oligotrophic system after simulated Saharan dust wet and dry deposition events. Here we report the results for the 3 distinct artificial dust seeding experiments in large mesocosms that were conducted in the oligotrophic waters of the Mediterranean Sea in summer 2008 and 2010. Simultaneous measurements of the metabolic rates (C fixation, C respiration) in the water column have shown that the dust deposition did not change drastically the metabolic balance as the tested waters remained net heterotroph (i.e. net primary production to bacteria respiration ratio < 1) and in some cases the net heterotrophy was even enhanced by the dust deposition. Considering the different terms of the carbon budget, we estimate that it was balanced with a dissolved organic carbon (DOC) consumption of at least 10% of the initial stock. This corresponds to a fraction of the DOC stock of the surface mixed layer that consequently will not be exported during the winter mixing. Although heterotrophic bacteria were found to be the key players in the response to dust deposition, net primary production increased about twice in case of simulated wet deposition (that includes anthropogenic nitrogen) and a small fraction of particulate organic carbon was still exported. Our estimated carbon budgets are an important step forward in the way we understand dust deposition and associated impacts on the oceanic cycles. They are providing knowledge about the key processes (i.e. bacteria respiration, aggregation) that need to be considered for an integration of atmospheric deposition in marine biogeochemical modeling.

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