Articles | Volume 19, issue 22
https://doi.org/10.5194/bg-19-5237-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-19-5237-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
18 Nov 2022
Research article |
| 18 Nov 2022
The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific
Zuozhu Wen
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean
Research Kiel, Kiel, Germany
Thomas J. Browning
Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean
Research Kiel, Kiel, Germany
Rongbo Dai
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Wenwei Wu
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Weiying Li
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
present address: Key Laboratory of Marine Ecosystem Dynamics, Second
Institute of Oceanography, Ministry of Natural Resources, Hangzhou,
Zhejiang, PR China
Xiaohua Hu
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Wenfang Lin
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Lifang Wang
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Zhimian Cao
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Haizheng Hong
CORRESPONDING AUTHOR
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
Dalin Shi
CORRESPONDING AUTHOR
State Key Laboratory of Marine Environmental Science, Xiamen
University, Xiamen, Fujian, PR China
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Guang Gao, Tifeng Wang, Jiazhen Sun, Xin Zhao, Lifang Wang, Xianghui Guo, and Kunshan Gao
Biogeosciences, 19, 2795–2804, https://doi.org/10.5194/bg-19-2795-2022, https://doi.org/10.5194/bg-19-2795-2022, 2022
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After conducting large-scale deck-incubation experiments, we found that seawater acidification (SA) increased primary production (PP) in coastal waters but reduced it in pelagic zones, which is mainly regulated by local pH, light intensity, salinity, and community structure. In future oceans, SA combined with decreased upward transports of nutrients may synergistically reduce PP in pelagic zones.
Neil J. Wyatt, Angela Milne, Eric P. Achterberg, Thomas J. Browning, Heather A. Bouman, E. Malcolm S. Woodward, and Maeve C. Lohan
Biogeosciences, 18, 4265–4280, https://doi.org/10.5194/bg-18-4265-2021, https://doi.org/10.5194/bg-18-4265-2021, 2021
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Using data collected during two expeditions to the South Atlantic Ocean, we investigated how the interaction between external sources and biological activity influenced the availability of the trace metals zinc and cobalt. This is important as both metals play essential roles in the metabolism and growth of phytoplankton and thus influence primary productivity of the oceans. We found seasonal changes in both processes that helped explain upper-ocean trace metal cycling.
Maximiliano J. Vergara-Jara, Mark J. Hopwood, Thomas J. Browning, Insa Rapp, Rodrigo Torres, Brian Reid, Eric P. Achterberg, and José Luis Iriarte
Ocean Sci., 17, 561–578, https://doi.org/10.5194/os-17-561-2021, https://doi.org/10.5194/os-17-561-2021, 2021
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Ash from the Calbuco 2015 eruption spread across northern Patagonia, the SE Pacific and the SW Atlantic. In the Pacific, a phytoplankton bloom corresponded closely to the volcanic ash plume, suggesting that ash fertilized this region of the ocean. No such fertilization was found in the Atlantic where nutrients plausibly supplied by ash were likely already in excess of phytoplankton demand. In Patagonia, the May bloom was more intense than usual, but the mechanistic link to ash was less clear.
Robyn E. Tuerena, Raja S. Ganeshram, Matthew P. Humphreys, Thomas J. Browning, Heather Bouman, and Alexander P. Piotrowski
Biogeosciences, 16, 3621–3635, https://doi.org/10.5194/bg-16-3621-2019, https://doi.org/10.5194/bg-16-3621-2019, 2019
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The carbon isotopes in algae can be used to predict food sources and environmental change. We explore how dissolved carbon is taken up by algae in the South Atlantic Ocean and how this affects their carbon isotope signature. We find that cell size controls isotope fractionation. We use our results to investigate how climate change may impact the carbon isotopes in algae. We suggest a shift to smaller algae in this region would decrease the carbon isotope ratio at the base of the food web.
Yangyang Lu, Zuozhu Wen, Dalin Shi, Mingming Chen, Yao Zhang, Sophie Bonnet, Yuhang Li, Jiwei Tian, and Shuh-Ji Kao
Biogeosciences, 15, 1–12, https://doi.org/10.5194/bg-15-1-2018, https://doi.org/10.5194/bg-15-1-2018, 2018
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We investigated the light response of field Trichodesmium N2 fixation and net dissolved nitrogen release behavior. Our results suggest that N2 fixation was a function of light intensity, and the light requirement of Trichodesmium nitrogen fixation was high relative to its photosynthetic light demand. Meanwhile, light is a crucial parameter driving the physiological state of Trichodesmium, which subsequently determined the C / N metabolism and net dissolved nitrogen release.
Jianzhong Su, Minhan Dai, Biyan He, Lifang Wang, Jianping Gan, Xianghui Guo, Huade Zhao, and Fengling Yu
Biogeosciences, 14, 4085–4099, https://doi.org/10.5194/bg-14-4085-2017, https://doi.org/10.5194/bg-14-4085-2017, 2017
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We provide direct and quantitative assessments showing the marine organic matter from eutrophication-induced primary production dominated oxygen consumption in the hypoxic zone, while the terrestrially sourced organic matter also significantly contributed to the formation and maintenance of hypoxia in the lower Pearl River Estuary (PRE) and the adjacent coastal water.
T. Shiozaki, S. Takeda, S. Itoh, T. Kodama, X. Liu, F. Hashihama, and K. Furuya
Biogeosciences, 12, 6931–6943, https://doi.org/10.5194/bg-12-6931-2015, https://doi.org/10.5194/bg-12-6931-2015, 2015
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The high abundance of Trichodesmium and active nitrogen fixation in the Kuroshio were not explained by the nutrient (nitrate, phosphate, and iron) distribution. We observed a Trichodesmium bloom and high nitrogen fixation near islands situated along the Kuroshio. Numerical particle-tracking experiments simulated the transportation of water around the Ryukyu Islands to the Kuroshio. Our results indicate that Trichodesmium growing around the Ryukyu Islands could be advected into the Kuroshio.
Z. Cao, M. Dai, W. Evans, J. Gan, and R. Feely
Biogeosciences, 11, 6341–6354, https://doi.org/10.5194/bg-11-6341-2014, https://doi.org/10.5194/bg-11-6341-2014, 2014
C. Du, Z. Liu, M. Dai, S.-J. Kao, Z. Cao, Y. Zhang, T. Huang, L. Wang, and Y. Li
Biogeosciences, 10, 6419–6432, https://doi.org/10.5194/bg-10-6419-2013, https://doi.org/10.5194/bg-10-6419-2013, 2013
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Iron is a key nutrient for ocean primary productivity. Hydrothermal vents are a source of iron to the oceans, but the size of this source is poorly understood. This study examines the variability in iron inputs between hydrothermal vents in different geological settings. The vents studied release different amounts of Fe, resulting in plumes with similar dissolved iron concentrations but different particulate concentrations. This will help to refine modelling of iron-limited ocean productivity.
Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, and Karen L. Casciotti
Biogeosciences, 20, 325–347, https://doi.org/10.5194/bg-20-325-2023, https://doi.org/10.5194/bg-20-325-2023, 2023
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Natacha Le Grix, Jakob Zscheischler, Keith B. Rodgers, Ryohei Yamaguchi, and Thomas L. Frölicher
Biogeosciences, 19, 5807–5835, https://doi.org/10.5194/bg-19-5807-2022, https://doi.org/10.5194/bg-19-5807-2022, 2022
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Biogeosciences, 19, 5689–5705, https://doi.org/10.5194/bg-19-5689-2022, https://doi.org/10.5194/bg-19-5689-2022, 2022
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Margot C. F. Debyser, Laetitia Pichevin, Robyn E. Tuerena, Paul A. Dodd, Antonia Doncila, and Raja S. Ganeshram
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We focus on the exchange of key nutrients for algae production between the Arctic and Atlantic oceans through the Fram Strait. We show that the export of dissolved silicon here is controlled by the availability of nitrate which is influenced by denitrification on Arctic shelves. We suggest that any future changes in the river inputs of silica and changes in denitrification due to climate change will impact the amount of silicon exported, with impacts on Atlantic algal productivity and ecology.
Emily J. Zakem, Barbara Bayer, Wei Qin, Alyson E. Santoro, Yao Zhang, and Naomi M. Levine
Biogeosciences, 19, 5401–5418, https://doi.org/10.5194/bg-19-5401-2022, https://doi.org/10.5194/bg-19-5401-2022, 2022
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Given the sparsity of observational constraints on micronutrients such as zinc (Zn), we assess the sensitivities of a framework for objective parameter optimisation in an oceanic Zn cycling model. Our ensemble of optimisations towards synthetic data with varying kinds of uncertainty shows that deficiencies related to model complexity and the choice of the misfit function generally have a greater impact on the retrieval of model Zn uptake behaviour than does the limitation of data coverage.
Alban Planchat, Lester Kwiatkwoski, Laurent Bopp, Olivier Torres, James R. Christian, Momme Butenschön, Tomas Lovato, Roland Séférian, Matthew A. Chamberlain, Olivier Aumont, Michio Watanabe, Akitomo Yamamoto, Andrew Yool, Tatiana Ilyina, Hiroyuki Tsujino, Kristen M. Krumhardt, Jörg Schwinger, Jerry Tjiputra, John P. Dunne, and Charles Stock
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Biogeosciences, 19, 4865–4882, https://doi.org/10.5194/bg-19-4865-2022, https://doi.org/10.5194/bg-19-4865-2022, 2022
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Jens Terhaar, Thomas L. Frölicher, and Fortunat Joos
Biogeosciences, 19, 4431–4457, https://doi.org/10.5194/bg-19-4431-2022, https://doi.org/10.5194/bg-19-4431-2022, 2022
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Estimates of the ocean sink of anthropogenic carbon vary across various approaches. We show that the global ocean carbon sink can be estimated by three parameters, two of which approximate the ocean ventilation in the Southern Ocean and the North Atlantic, and one of which approximates the chemical capacity of the ocean to take up carbon. With observations of these parameters, we estimate that the global ocean carbon sink is 10 % larger than previously assumed, and we cut uncertainties in half.
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Biogeosciences, 19, 3209–3224, https://doi.org/10.5194/bg-19-3209-2022, https://doi.org/10.5194/bg-19-3209-2022, 2022
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The remineralisation proxy, barite, was measured along 30°E in the southern Indian Ocean during early austral winter. To our knowledge this is the first reported Southern Ocean winter study. Concentrations throughout the water column were comparable to observations during spring to autumn. By linking satellite primary production to this proxy a possible annual timescale is proposed. These findings also suggest possible carbon remineralisation from satellite data on a basin scale.
Zhibo Shao and Ya-Wei Luo
Biogeosciences, 19, 2939–2952, https://doi.org/10.5194/bg-19-2939-2022, https://doi.org/10.5194/bg-19-2939-2022, 2022
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Non-cyanobacterial diazotrophs (NCDs) may be an important player in fixing N2 in the ocean. By conducting meta-analyses, we found that a representative marine NCD phylotype, Gamma A, tends to inhabit ocean environments with high productivity, low iron concentration and high light intensity. It also appears to be more abundant inside cyclonic eddies. Our study suggests a niche differentiation of NCDs from cyanobacterial diazotrophs as the latter prefers low-productivity and high-iron oceans.
Coraline Leseurre, Claire Lo Monaco, Gilles Reverdin, Nicolas Metzl, Jonathan Fin, Claude Mignon, and Léa Benito
Biogeosciences, 19, 2599–2625, https://doi.org/10.5194/bg-19-2599-2022, https://doi.org/10.5194/bg-19-2599-2022, 2022
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Decadal trends of fugacity of CO2 (fCO2), total alkalinity (AT), total carbon (CT) and pH in surface waters are investigated in different domains of the southern Indian Ocean (45°S–57°S) from ongoing and station observations regularly conducted in summer over the period 1998–2019. The fCO2 increase and pH decrease are mainly driven by anthropogenic CO2 estimated just below the summer mixed layer, as well as by a warming south of the polar front or in the fertilized waters near Kerguelen Island.
Priscilla Le Mézo, Jérôme Guiet, Kim Scherrer, Daniele Bianchi, and Eric Galbraith
Biogeosciences, 19, 2537–2555, https://doi.org/10.5194/bg-19-2537-2022, https://doi.org/10.5194/bg-19-2537-2022, 2022
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Rebecca Chmiel, Nathan Lanning, Allison Laubach, Jong-Mi Lee, Jessica Fitzsimmons, Mariko Hatta, William Jenkins, Phoebe Lam, Matthew McIlvin, Alessandro Tagliabue, and Mak Saito
Biogeosciences, 19, 2365–2395, https://doi.org/10.5194/bg-19-2365-2022, https://doi.org/10.5194/bg-19-2365-2022, 2022
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Dissolved cobalt is present in trace amounts in seawater and is a necessary nutrient for marine microbes. On a transect from the Alaskan coast to Tahiti, we measured seawater concentrations of dissolved cobalt. Here, we describe several interesting features of the Pacific cobalt cycle including cobalt sources along the Alaskan coast and Hawaiian vents, deep-ocean particle formation, cobalt activity in low-oxygen regions, and how our samples compare to a global biogeochemical model’s predictions.
Nicolas Metzl, Claire Lo Monaco, Coraline Leseurre, Céline Ridame, Jonathan Fin, Claude Mignon, Marion Gehlen, and Thi Tuyet Trang Chau
Biogeosciences, 19, 1451–1468, https://doi.org/10.5194/bg-19-1451-2022, https://doi.org/10.5194/bg-19-1451-2022, 2022
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During an oceanographic cruise conducted in January 2020 in the south-western Indian Ocean, we observed very low CO2 concentrations associated with a strong phytoplankton bloom that occurred south-east of Madagascar. This biological event led to a strong regional CO2 ocean sink not previously observed.
Darren R. Clark, Andrew P. Rees, Charissa M. Ferrera, Lisa Al-Moosawi, Paul J. Somerfield, Carolyn Harris, Graham D. Quartly, Stephen Goult, Glen Tarran, and Gennadi Lessin
Biogeosciences, 19, 1355–1376, https://doi.org/10.5194/bg-19-1355-2022, https://doi.org/10.5194/bg-19-1355-2022, 2022
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Measurements of microbial processes were made in the sunlit open ocean during a research cruise (AMT19) between the UK and Chile. These help us to understand how microbial communities maintain the function of remote ecosystems. We find that the nitrogen cycling microbes which produce nitrite respond to changes in the environment. Our insights will aid the development of models that aim to replicate and ultimately project how marine environments may respond to ongoing climate change.
Martí Galí, Marcus Falls, Hervé Claustre, Olivier Aumont, and Raffaele Bernardello
Biogeosciences, 19, 1245–1275, https://doi.org/10.5194/bg-19-1245-2022, https://doi.org/10.5194/bg-19-1245-2022, 2022
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Part of the organic matter produced by plankton in the upper ocean is exported to the deep ocean. This process, known as the biological carbon pump, is key for the regulation of atmospheric carbon dioxide and global climate. However, the dynamics of organic particles below the upper ocean layer are not well understood. Here we compared the measurements acquired by autonomous robots in the top 1000 m of the ocean to a numerical model, which can help improve future climate projections.
Marie Barbieux, Julia Uitz, Alexandre Mignot, Collin Roesler, Hervé Claustre, Bernard Gentili, Vincent Taillandier, Fabrizio D'Ortenzio, Hubert Loisel, Antoine Poteau, Edouard Leymarie, Christophe Penkerc'h, Catherine Schmechtig, and Annick Bricaud
Biogeosciences, 19, 1165–1194, https://doi.org/10.5194/bg-19-1165-2022, https://doi.org/10.5194/bg-19-1165-2022, 2022
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This study assesses marine biological production in two Mediterranean systems representative of vast desert-like (oligotrophic) areas encountered in the global ocean. We use a novel approach based on non-intrusive high-frequency in situ measurements by two profiling robots, the BioGeoChemical-Argo (BGC-Argo) floats. Our results indicate substantial yet variable production rates and contribution to the whole water column of the subsurface layer, typically considered steady and non-productive.
Filippa Fransner, Friederike Fröb, Jerry Tjiputra, Nadine Goris, Siv K. Lauvset, Ingunn Skjelvan, Emil Jeansson, Abdirahman Omar, Melissa Chierici, Elizabeth Jones, Agneta Fransson, Sólveig R. Ólafsdóttir, Truls Johannessen, and Are Olsen
Biogeosciences, 19, 979–1012, https://doi.org/10.5194/bg-19-979-2022, https://doi.org/10.5194/bg-19-979-2022, 2022
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Ocean acidification, a direct consequence of the CO2 release by human activities, is a serious threat to marine ecosystems. In this study, we conduct a detailed investigation of the acidification of the Nordic Seas, from 1850 to 2100, by using a large set of samples taken during research cruises together with numerical model simulations. We estimate the effects of changes in different environmental factors on the rate of acidification and its potential effects on cold-water corals.
Guorong Zhong, Xuegang Li, Jinming Song, Baoxiao Qu, Fan Wang, Yanjun Wang, Bin Zhang, Xiaoxia Sun, Wuchang Zhang, Zhenyan Wang, Jun Ma, Huamao Yuan, and Liqin Duan
Biogeosciences, 19, 845–859, https://doi.org/10.5194/bg-19-845-2022, https://doi.org/10.5194/bg-19-845-2022, 2022
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A predictor selection algorithm was constructed to decrease the predicting error in the surface ocean partial pressure of CO2 (pCO2) mapping by finding better combinations of pCO2 predictors in different regions. Compared with previous research using the same combination of predictors in all regions, using different predictors selected by the algorithm in different regions can effectively decrease pCO2 predicting errors.
Shantelle Smith, Katye E. Altieri, Mhlangabezi Mdutyana, David R. Walker, Ruan G. Parrott, Sedick Gallie, Kurt A. M. Spence, Jessica M. Burger, and Sarah E. Fawcett
Biogeosciences, 19, 715–741, https://doi.org/10.5194/bg-19-715-2022, https://doi.org/10.5194/bg-19-715-2022, 2022
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Ammonium is a crucial yet poorly understood component of the Southern Ocean nitrogen cycle. We attribute our finding of consistently high ammonium concentrations in the winter mixed layer to limited ammonium consumption and sustained ammonium production, conditions under which the Southern Ocean becomes a source of carbon dioxide to the atmosphere. From similar data collected over an annual cycle, we propose a seasonal cycle for ammonium in shallow polar waters – a first for the Southern Ocean.
Jannes Koelling, Dariia Atamanchuk, Johannes Karstensen, Patricia Handmann, and Douglas W. R. Wallace
Biogeosciences, 19, 437–454, https://doi.org/10.5194/bg-19-437-2022, https://doi.org/10.5194/bg-19-437-2022, 2022
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In this study, we investigate oxygen variability in the deep western boundary current in the Labrador Sea from multiyear moored records. We estimate that about half of the oxygen taken up in the interior Labrador Sea by air–sea gas exchange during deep water formation is exported southward the same year. Our results underline the complexity of the oxygen uptake and export in the Labrador Sea and highlight the important role this region plays in supplying oxygen to the deep ocean.
Céline Ridame, Julie Dinasquet, Søren Hallstrøm, Estelle Bigeard, Lasse Riemann, France Van Wambeke, Matthieu Bressac, Elvira Pulido-Villena, Vincent Taillandier, Fréderic Gazeau, Antonio Tovar-Sanchez, Anne-Claire Baudoux, and Cécile Guieu
Biogeosciences, 19, 415–435, https://doi.org/10.5194/bg-19-415-2022, https://doi.org/10.5194/bg-19-415-2022, 2022
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We show that in the Mediterranean Sea spatial variability in N2 fixation is related to the diazotrophic community composition reflecting different nutrient requirements among species. Nutrient supply by Saharan dust is of great importance to diazotrophs, as shown by the strong stimulation of N2 fixation after a simulated dust event under present and future climate conditions; the magnitude of stimulation depends on the degree of limitation related to the diazotrophic community composition.
Matthew P. Humphreys, Erik H. Meesters, Henk de Haas, Szabina Karancz, Louise Delaigue, Karel Bakker, Gerard Duineveld, Siham de Goeyse, Andreas F. Haas, Furu Mienis, Sharyn Ossebaar, and Fleur C. van Duyl
Biogeosciences, 19, 347–358, https://doi.org/10.5194/bg-19-347-2022, https://doi.org/10.5194/bg-19-347-2022, 2022
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A series of submarine sinkholes were recently discovered on Luymes Bank, part of Saba Bank, a carbonate platform in the Caribbean Netherlands. Here, we investigate the waters inside these sinkholes for the first time. One of the sinkholes contained a body of dense, low-oxygen and low-pH water, which we call the
acid lake. We use measurements of seawater chemistry to work out what processes were responsible for forming the acid lake and discuss the consequences for the carbonate platform.
Gerhard Fischer, Oscar E. Romero, Johannes Karstensen, Karl-Heinz Baumann, Nasrollah Moradi, Morten Iversen, Götz Ruhland, Marco Klann, and Arne Körtzinger
Biogeosciences, 18, 6479–6500, https://doi.org/10.5194/bg-18-6479-2021, https://doi.org/10.5194/bg-18-6479-2021, 2021
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Low-oxygen eddies in the eastern subtropical North Atlantic can form an oasis for phytoplankton growth. Here we report on particle flux dynamics at the oligotrophic Cape Verde Ocean Observatory. We observed consistent flux patterns during the passages of low-oxygen eddies. We found distinct flux peaks in late winter, clearly exceeding background fluxes. Our findings suggest that the low-oxygen eddies sequester higher organic carbon than expected for oligotrophic settings.
Matthieu Bressac, Thibaut Wagener, Nathalie Leblond, Antonio Tovar-Sánchez, Céline Ridame, Vincent Taillandier, Samuel Albani, Sophie Guasco, Aurélie Dufour, Stéphanie H. M. Jacquet, François Dulac, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 18, 6435–6453, https://doi.org/10.5194/bg-18-6435-2021, https://doi.org/10.5194/bg-18-6435-2021, 2021
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Phytoplankton growth is limited by the availability of iron in about 50 % of the ocean. Atmospheric deposition of desert dust represents a key source of iron. Here, we present direct observations of dust deposition in the Mediterranean Sea. A key finding is that the input of iron from dust primarily occurred in the deep ocean, while previous studies mainly focused on the ocean surface. This new insight will enable us to better represent controls on global marine productivity in models.
Léo Berline, Andrea Michelangelo Doglioli, Anne Petrenko, Stéphanie Barrillon, Boris Espinasse, Frederic A. C. Le Moigne, François Simon-Bot, Melilotus Thyssen, and François Carlotti
Biogeosciences, 18, 6377–6392, https://doi.org/10.5194/bg-18-6377-2021, https://doi.org/10.5194/bg-18-6377-2021, 2021
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While the Ionian Sea is considered a nutrient-depleted and low-phytoplankton biomass area, it is a crossroad for water mass circulation. In the central Ionian Sea, we observed a strong contrast in particle distribution across a ~100 km long transect. Using remote sensing and Lagrangian simulations, we suggest that this contrast finds its origin in the long-distance transport of particles from the north, west and east of the Ionian Sea, where phytoplankton production was more intense.
Anna Teruzzi, Giorgio Bolzon, Laura Feudale, and Gianpiero Cossarini
Biogeosciences, 18, 6147–6166, https://doi.org/10.5194/bg-18-6147-2021, https://doi.org/10.5194/bg-18-6147-2021, 2021
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During summer, maxima of phytoplankton chlorophyll concentration (DCM) occur in the subsurface of the Mediterranean Sea and can play a relevant role in carbon sequestration into the ocean interior. A numerical model based on in situ and satellite observations provides insights into the range of DCM conditions across the relatively small Mediterranean Sea and shows a western DCM that is 25 % shallower and with a higher phytoplankton chlorophyll concentration than in the eastern Mediterranean.
Elvira Pulido-Villena, Karine Desboeufs, Kahina Djaoudi, France Van Wambeke, Stéphanie Barrillon, Andrea Doglioli, Anne Petrenko, Vincent Taillandier, Franck Fu, Tiphanie Gaillard, Sophie Guasco, Sandra Nunige, Sylvain Triquet, and Cécile Guieu
Biogeosciences, 18, 5871–5889, https://doi.org/10.5194/bg-18-5871-2021, https://doi.org/10.5194/bg-18-5871-2021, 2021
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We report on phosphorus dynamics in the surface layer of the Mediterranean Sea. Highly sensitive phosphate measurements revealed vertical gradients above the phosphacline. The relative contribution of diapycnal fluxes to total external supply of phosphate to the mixed layer decreased towards the east, where atmospheric deposition dominated. Taken together, external sources of phosphate contributed little to total supply, which was mainly sustained by enzymatic hydrolysis of organic phosphorus.
Zouhair Lachkar, Michael Mehari, Muchamad Al Azhar, Marina Lévy, and Shafer Smith
Biogeosciences, 18, 5831–5849, https://doi.org/10.5194/bg-18-5831-2021, https://doi.org/10.5194/bg-18-5831-2021, 2021
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This study documents and quantifies a significant recent oxygen decline in the upper layers of the Arabian Sea and explores its drivers. Using a modeling approach we show that the fast local warming of sea surface is the main factor causing this oxygen drop. Concomitant summer monsoon intensification contributes to this trend, although to a lesser extent. These changes exacerbate oxygen depletion in the subsurface, threatening marine habitats and altering the local biogeochemistry.
France Van Wambeke, Vincent Taillandier, Karine Desboeufs, Elvira Pulido-Villena, Julie Dinasquet, Anja Engel, Emilio Marañón, Céline Ridame, and Cécile Guieu
Biogeosciences, 18, 5699–5717, https://doi.org/10.5194/bg-18-5699-2021, https://doi.org/10.5194/bg-18-5699-2021, 2021
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Simultaneous in situ measurements of (dry and wet) atmospheric deposition and biogeochemical stocks and fluxes in the sunlit waters of the open Mediterranean Sea revealed complex physical and biological processes occurring within the mixed layer. Nitrogen (N) budgets were computed to compare the sources and sinks of N in the mixed layer. The transitory effect observed after a wet dust deposition impacted the microbial food web down to the deep chlorophyll maximum.
Frédéric Gazeau, France Van Wambeke, Emilio Marañón, Maria Pérez-Lorenzo, Samir Alliouane, Christian Stolpe, Thierry Blasco, Nathalie Leblond, Birthe Zäncker, Anja Engel, Barbara Marie, Julie Dinasquet, and Cécile Guieu
Biogeosciences, 18, 5423–5446, https://doi.org/10.5194/bg-18-5423-2021, https://doi.org/10.5194/bg-18-5423-2021, 2021
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Our study shows that the impact of dust deposition on primary production depends on the initial composition and metabolic state of the tested community and is constrained by the amount of nutrients added, to sustain both the fast response of heterotrophic prokaryotes and the delayed one of phytoplankton. Under future environmental conditions, heterotrophic metabolism will be more impacted than primary production, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.
Loes J. A. Gerringa, Martha Gledhill, Indah Ardiningsih, Niels Muntjewerf, and Luis M. Laglera
Biogeosciences, 18, 5265–5289, https://doi.org/10.5194/bg-18-5265-2021, https://doi.org/10.5194/bg-18-5265-2021, 2021
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For 3 decades, competitive ligand exchange–adsorptive cathodic stripping voltammetry was used to estimate the Fe-binding capacity of organic matter in seawater. In this paper the performance of the competing ligands is compared through the analysis of a series of model ligands.
The main finding of this paper is that the determined speciation parameters are not independent of the application, making interpretation of Fe speciation data more complex than it was thought before.
Frédéric Gazeau, Céline Ridame, France Van Wambeke, Samir Alliouane, Christian Stolpe, Jean-Olivier Irisson, Sophie Marro, Jean-Michel Grisoni, Guillaume De Liège, Sandra Nunige, Kahina Djaoudi, Elvira Pulido-Villena, Julie Dinasquet, Ingrid Obernosterer, Philippe Catala, and Cécile Guieu
Biogeosciences, 18, 5011–5034, https://doi.org/10.5194/bg-18-5011-2021, https://doi.org/10.5194/bg-18-5011-2021, 2021
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This paper shows that the impacts of Saharan dust deposition in different Mediterranean basins are as strong as those observed in coastal waters but differed substantially between the three tested stations, differences attributed to variable initial metabolic states. A stronger impact of warming and acidification on mineralization suggests a decreased capacity of Mediterranean surface communities to sequester CO2 following the deposition of atmospheric particles in the coming decades.
Carolin R. Löscher
Biogeosciences, 18, 4953–4963, https://doi.org/10.5194/bg-18-4953-2021, https://doi.org/10.5194/bg-18-4953-2021, 2021
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The Bay of Bengal (BoB) is classically seen as an ocean region with low primary production, which has been predicted to decrease even further. Here, the importance of such a trend is used to explore what could happen to the BoB's low-oxygen core waters if primary production decreases. Lower biological production leads to less oxygen loss in deeper waters by respiration; thus it could be that oxygen will not further decrease and the BoB will not become anoxic, different to other low-oxygen areas.
Bo Liu, Katharina D. Six, and Tatiana Ilyina
Biogeosciences, 18, 4389–4429, https://doi.org/10.5194/bg-18-4389-2021, https://doi.org/10.5194/bg-18-4389-2021, 2021
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We incorporate a new representation of the stable carbon isotope 13C in a global ocean biogeochemistry model. The model well reproduces the present-day 13C observations. We find a recent observation-based estimate of the oceanic 13C Suess effect (the decrease in 13C/12C ratio due to uptake of anthropogenic CO2; 13CSE) possibly underestimates 13CSE by 0.1–0.26 per mil. The new model will aid in better understanding the past ocean state via comparison to 13C/12C measurements from sediment cores.
Neil J. Wyatt, Angela Milne, Eric P. Achterberg, Thomas J. Browning, Heather A. Bouman, E. Malcolm S. Woodward, and Maeve C. Lohan
Biogeosciences, 18, 4265–4280, https://doi.org/10.5194/bg-18-4265-2021, https://doi.org/10.5194/bg-18-4265-2021, 2021
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Using data collected during two expeditions to the South Atlantic Ocean, we investigated how the interaction between external sources and biological activity influenced the availability of the trace metals zinc and cobalt. This is important as both metals play essential roles in the metabolism and growth of phytoplankton and thus influence primary productivity of the oceans. We found seasonal changes in both processes that helped explain upper-ocean trace metal cycling.
Hannah L. Bourne, James K. B. Bishop, Elizabeth J. Connors, and Todd J. Wood
Biogeosciences, 18, 3053–3086, https://doi.org/10.5194/bg-18-3053-2021, https://doi.org/10.5194/bg-18-3053-2021, 2021
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To learn how the biological carbon pump works in productive coastal upwelling systems, four autonomous carbon flux explorers measured carbon flux through the twilight zone beneath an offshore-flowing filament of biologically productive water. Strikingly different particle classes dominated the carbon fluxes during successive stages of the filament evolution over 30 d. Both flux and transfer efficiency were far greater than expected, suggesting an outsized filament impact in California waters.
Matthieu Roy-Barman, Lorna Foliot, Eric Douville, Nathalie Leblond, Fréderic Gazeau, Matthieu Bressac, Thibaut Wagener, Céline Ridame, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 18, 2663–2678, https://doi.org/10.5194/bg-18-2663-2021, https://doi.org/10.5194/bg-18-2663-2021, 2021
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The release of insoluble elements such as aluminum (Al), iron (Fe), rare earth elements (REEs), thorium (Th) and protactinium (Pa) when Saharan dust falls over the Mediterranean Sea was studied during tank experiments under present and future climate conditions. Each element exhibited different dissolution kinetics and dissolution fractions (always lower than a few percent). Changes in temperature and/or pH under greenhouse conditions lead to a lower Th release and a higher light REE release.
Stéphanie H. M. Jacquet, Dominique Lefèvre, Christian Tamburini, Marc Garel, Frédéric A. C. Le Moigne, Nagib Bhairy, and Sophie Guasco
Biogeosciences, 18, 2205–2212, https://doi.org/10.5194/bg-18-2205-2021, https://doi.org/10.5194/bg-18-2205-2021, 2021
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We present new data concerning the relation between biogenic barium (Baxs, a tracer of carbon remineralization at mesopelagic depths), O2 consumption and prokaryotic heterotrophic production (PHP) in the Mediterranean Sea. The purpose of this paper is to improve our understanding of the relation between Baxs, PHP and O2 and to test the validity of the Dehairs transfer function in the Mediterranean Sea. This relation has never been tested in the Mediterranean Sea.
Natacha Le Grix, Jakob Zscheischler, Charlotte Laufkötter, Cecile S. Rousseaux, and Thomas L. Frölicher
Biogeosciences, 18, 2119–2137, https://doi.org/10.5194/bg-18-2119-2021, https://doi.org/10.5194/bg-18-2119-2021, 2021
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Marine ecosystems could suffer severe damage from the co-occurrence of a marine heat wave with extremely low chlorophyll concentration. Here, we provide a first assessment of compound marine heat wave and
low-chlorophyll events in the global ocean from 1998 to 2018. We reveal hotspots of these compound events in the equatorial Pacific and in the Arabian Sea and show that they mostly occur in summer at high latitudes and their frequency is modulated by large-scale modes of climate variability.
Christopher Holder and Anand Gnanadesikan
Biogeosciences, 18, 1941–1970, https://doi.org/10.5194/bg-18-1941-2021, https://doi.org/10.5194/bg-18-1941-2021, 2021
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A challenge for marine ecologists in studying phytoplankton is linking small-scale relationships found in a lab to broader relationships observed on large scales in the environment. We investigated whether machine learning (ML) could help connect these small- and large-scale relationships. ML was able to provide qualitative information about the small-scale processes from large-scale information. This method could help identify important relationships from observations in future research.
Paul J. Tréguer, Jill N. Sutton, Mark Brzezinski, Matthew A. Charette, Timothy Devries, Stephanie Dutkiewicz, Claudia Ehlert, Jon Hawkings, Aude Leynaert, Su Mei Liu, Natalia Llopis Monferrer, María López-Acosta, Manuel Maldonado, Shaily Rahman, Lihua Ran, and Olivier Rouxel
Biogeosciences, 18, 1269–1289, https://doi.org/10.5194/bg-18-1269-2021, https://doi.org/10.5194/bg-18-1269-2021, 2021
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Silicon is the second most abundant element of the Earth's crust. In this review, we show that silicon inputs and outputs, to and from the world ocean, are 57 % and 37 % higher, respectively, than previous estimates. These changes are significant, modifying factors such as the geochemical residence time of silicon, which is now about 8000 years and 2 times faster than previously assumed. We also update the total biogenic silica pelagic production and provide an estimate for sponge production.
Caroline Ulses, Claude Estournel, Marine Fourrier, Laurent Coppola, Fayçal Kessouri, Dominique Lefèvre, and Patrick Marsaleix
Biogeosciences, 18, 937–960, https://doi.org/10.5194/bg-18-937-2021, https://doi.org/10.5194/bg-18-937-2021, 2021
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We analyse the seasonal cycle of O2 and estimate an annual O2 budget in the north-western Mediterranean deep-convection region, using a numerical model. We show that this region acts as a large sink of atmospheric O2 and as a major source of O2 for the western Mediterranean Sea. The decrease in the deep convection intensity predicted in recent projections may have important consequences on the overall uptake of O2 in the Mediterranean Sea and on the O2 exchanges with the Atlantic Ocean.
Fuminori Hashihama, Hiroaki Saito, Taketoshi Kodama, Saori Yasui-Tamura, Jota Kanda, Iwao Tanita, Hiroshi Ogawa, E. Malcolm S. Woodward, Philip W. Boyd, and Ken Furuya
Biogeosciences, 18, 897–915, https://doi.org/10.5194/bg-18-897-2021, https://doi.org/10.5194/bg-18-897-2021, 2021
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We investigated the nutrient assimilation characteristics of deep-water-induced phytoplankton blooms across the subtropical North and South Pacific Ocean. Nutrient drawdown ratios of dissolved inorganic nitrogen to phosphate were anomalously low in the western North Pacific, likely due to the high phosphate uptake capability of low-phosphate-adapted phytoplankton. The anomalous phosphate uptake might influence the maintenance of chronic phosphate depletion in the western North Pacific.
Florian Ricour, Arthur Capet, Fabrizio D'Ortenzio, Bruno Delille, and Marilaure Grégoire
Biogeosciences, 18, 755–774, https://doi.org/10.5194/bg-18-755-2021, https://doi.org/10.5194/bg-18-755-2021, 2021
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This paper addresses the phenology of the deep chlorophyll maximum (DCM) in the Black Sea (BS). We show that the DCM forms in March at a density level set by the winter mixed layer. It maintains this location until June, suggesting an influence of the DCM on light and nutrient profiles rather than mere adaptation to external factors. In summer, the DCM concentrates ~55 % of the chlorophyll in a 10 m layer at ~35 m depth and should be considered a major feature of the BS phytoplankton dynamics.
Robyn E. Tuerena, Joanne Hopkins, Raja S. Ganeshram, Louisa Norman, Camille de la Vega, Rachel Jeffreys, and Claire Mahaffey
Biogeosciences, 18, 637–653, https://doi.org/10.5194/bg-18-637-2021, https://doi.org/10.5194/bg-18-637-2021, 2021
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The Barents Sea is a rapidly changing shallow sea within the Arctic. Here, nitrate, an essential nutrient, is fully consumed by algae in surface waters during summer months. Nitrate is efficiently regenerated in the Barents Sea, and there is no evidence for nitrogen loss from the sediments by denitrification, which is prevalent on other Arctic shelves. This suggests that nitrogen availability in the Barents Sea is largely determined by the supply of nutrients in water masses from the Atlantic.
David Ford
Biogeosciences, 18, 509–534, https://doi.org/10.5194/bg-18-509-2021, https://doi.org/10.5194/bg-18-509-2021, 2021
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Biogeochemical-Argo floats are starting to routinely measure ocean chlorophyll, nutrients, oxygen, and pH. This study generated synthetic observations representing two potential Biogeochemical-Argo observing system designs and created a data assimilation scheme to combine them with an ocean model. The proposed system of 1000 floats brought clear benefits to model results, with additional floats giving further benefit. Existing satellite ocean colour observations gave complementary information.
Mark Hague and Marcello Vichi
Biogeosciences, 18, 25–38, https://doi.org/10.5194/bg-18-25-2021, https://doi.org/10.5194/bg-18-25-2021, 2021
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This paper examines the question of what causes the rapid spring growth of microscopic marine algae (phytoplankton) in the ice-covered ocean surrounding Antarctica. One prominent hypothesis proposes that the melting of sea ice is the primary cause, while our results suggest that this is only part of the explanation. In particular, we show that phytoplankton are able to start growing before the sea ice melts appreciably, much earlier than previously thought.
Cited articles
Arrigo, K. R.: Marine microorganisms and global nutrient cycles, Nature,
437, 349–355, https://doi.org/10.1038/nature04158, 2005.
Berman-Frank, I., Cullen, J. T., Shaked, Y., Sherrell, R. M., and Falkowski,
P.: Iron availability, cellular iron quotas, and nitrogen fixation in
Trichodesmium, Limnol. Oceanogr., 46, 1249–1260, https://doi.org/10.4319/lo.2001.46.6.1249, 2001.
Bonnet, S., Baklouti, M., Gimenez, A., Berthelot, H., and Berman-Frank, I.: Biogeochemical and biological impacts of diazotroph blooms in a low-nutrient, low-chlorophyll ecosystem: synthesis from the VAHINE mesocosm experiment (New Caledonia), Biogeosciences, 13, 4461–4479, https://doi.org/10.5194/bg-13-4461-2016, 2016.
Bonnet, S., Caffin, M., Berthelot, H., Grosso, O., Benavides, M., Helias-Nunige, S., Guieu, C., Stenegren, M., and Foster, R. A.: In-depth characterization of diazotroph activity across the western tropical South Pacific hotspot of N2 fixation (OUTPACE cruise), Biogeosciences, 15, 4215–4232, https://doi.org/10.5194/bg-15-4215-2018, 2018.
Böttjer, D., Dore, J. E., Karl, D. M., Letelier, R. M., Mahaffey, C.,
Wilson, S. T., Zehr, J. P., and Church, M. J.: Temporal variability of
nitrogen fixation and particulate nitrogen export at Station ALOHA, Limnol.
Oceanogr., 62, 200–216, https://doi.org/10.1002/lno.10386, 2016.
Browning, T. J., Achterberg, E. P., Yong, J. C., Rapp, I., Utermann, C.,
Engel, A., and Moore, C. M.: Iron limitation of microbial phosphorus
acquisition in the tropical North Atlantic, Limnol. Oceanogr. Lett., 8,
15465, https://doi.org/10.1038/ncomms15465, 2017.
Cerdan-Garcia, E., Baylay, A., Polyviou, D., Woodward, E. M. S., Wrightson,
L., Mahaffey, C., Lohan, M. C., Moore, C. M., Bibby, T. S., and Robidart, J.
C.: Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P
availability, ISME J., 16, 1055–1064, https://doi.org/10.1038/s41396-021-01151-1, 2022.
Chen, M., Lu, Y., Jiao, N., Tian, J., Kao, S. J., and Zhang, Y.:
Biogeographic drivers of diazotrophs in the western Pacific Ocean, Limnol.
Oceanogr., 64, 1403–1421, https://doi.org/10.1002/lno.11123, 2019.
Chen, Y. L. L., Chen, H. Y., and Lin, Y. H.: Distribution and downward flux
of Trichodesmium in the South China Sea as influenced by the transport from the Kuroshio
Current, Mar. Ecol.-Prog. Ser., 259, 47–57, https://doi.org/10.3354/meps259047, 2003.
Chen, Y. L. L., Chen, H. Y., Tuo, S. H., and Ohki, K.: Seasonal dynamics of
new production from Trichodesmium N2 fixation and nitrate uptake in the upstream
Kuroshio and South China Sea basin, Limnol. Oceanogr., 53, 1705–1721,
https://doi.org/10.4319/lo.2008.53.5.1705, 2008.
Chen, Y. L. L., Chen, H. Y., Lin, Y. H., Yong, T. C., Taniuchi, Y., and Tuo,
S. H.: The relative contributions of unicellular and filamentous diazotrophs
to N2 fixation in the South China Sea and the upstream Kuroshio, Deep-Sea Res. Pt. I, 85, 56–71, https://doi.org/10.1016/j.dsr.2013.11.006, 2014.
Church, M. J., Jenkins, B. D., Karl, D. M., and Zehr, J. P.: Vertical
distributions of nitrogen fixing phylotypes at Stn ALOHA in the oligotrophic
North Pacific Ocean, Aquat. Microb. Ecol., 38, 3–14, https://doi.org/10.3354/ame038003
2005a.
Church, M. J., Short, C. M., Jenkins, B. D., Karl, D. M., and Zehr, J. P.:
Temporal patterns of nitrogenase gene (nifH) expression in the oligotrophic
North Pacific Ocean, Appl. Environ. Microb., 71, 5362–5370,
https://doi.org/10.1128/AEM.71.9.5362-5370.2005, 2005b.
Church, M. J., Björkman, K., and Karl, D.: Regional distributions of
nitrogen-fixing bacteria in the Pacific Ocean, Limnol. Oceanogr., 53, 63–77,
2008.
Dekaezemacker, J., Bonnet, S., Grosso, O., Moutin, T., Bressac, M., and
Capone, D. G.: Evidence of active dinitrogen fixation in surface waters of
the eastern tropical South Pacific during El Niño and La Niña events
and evaluation of its potential nutrient controls, Global Biogeochem.
Cy., 27, 768–779, https://doi.org/10.1002/gbc.20063, 2013.
Du, C., Liu, Z., Dai, M., Kao, S.-J., Cao, Z., Zhang, Y., Huang, T., Wang, L., and Li, Y.: Impact of the Kuroshio intrusion on the nutrient inventory in the upper northern South China Sea: insights from an isopycnal mixing model, Biogeosciences, 10, 6419–6432, https://doi.org/10.5194/bg-10-6419-2013, 2013.
Duce, R. A., Liss, P. S., Merrill, J. T., Atlas, E. L., Buat-Menard, P.,
Hicks, B. B., Miller, J. M., Prospero, J. M., Arimoto, R., Church, T. M.,
Ellis, W., Galloway, J. N., Hansen, L., Jickells, T. D., Knap, A. H.,
Reinhardt, K. H., Schneider, B., Soudine, A., Tokos, J. J., Tsunogai, S.,
Wollast, R., and Zhou, M.: The atmospheric input of trace species to the
world ocean, Global Biogeochem. Cy., 5, 193–259, https://doi.org/10.1029/91gb01778, 1991.
Dutkiewicz, S., Ward, B. A., Scott, J. R., and Follows, M. J.: Understanding predicted shifts in diazotroph biogeography using resource competition theory, Biogeosciences, 11, 5445–5461, https://doi.org/10.5194/bg-11-5445-2014, 2014.
Farnelid, H., Turk-Kubo, K., Muñoz-Marín, M. C., and Zehr, J. P.:
New insights into the ecology of the globally significant uncultured
nitrogen-fixing symbiont UCYN-A, Aquat. Microb. Ecol., 77, 125–138,
https://doi.org/10.3354/ame01794, 2016.
Göran, E. and Cooper, S. D.: Scale effects and extrapolation in
ecological experiments, Adv. Ecol. Res., 33, 161–213,
https://doi.org/10.1016/S0065-2504(03)33011-9, 2003.
Grabowski, M. N. W., Church, M. J., and Karl, D. M.: Nitrogen fixation rates
and controls at Stn ALOHA, Aquat. Microb. Ecol., 52, 175–183,
https://doi.org/10.3354/ame01209, 2008.
Gruber, N.: Warming up, turning sour, losing breath: ocean biogeochemistry
under global change, Philos. T. R. Soc. A, 369, 1980–1996,
https://doi.org/10.1098/rsta.2011.0003, 2011.
Gruber, N. and Galloway, J. N.: An Earth-system perspective of the global
nitrogen cycle, Nature, 451, 293–296, https://doi.org/10.1038/nature06592, 2008.
Guo, L., Xiu, P., Chai, F., Xue, H. J., Wang, D. X., and Sun, J.: Enhanced
chlorophyll concentrations induced by Kuroshio intrusion fronts in the
northern South China Sea, Geophys. Res. Lett., 44, 11565–11572,
https://doi.org/10.1002/2017GL075336, 2017.
Hama, T., Miyazaki, T., Ogawa, Y., Iwakuma, T., Takahashi, M., Otsuki, A.,
and Ichimura, S.: Measurement of photosynthetic production of a marine
phytoplankton population using a stable 13C isotope, Mar. Biol., 73,
31–36, https://doi.org/10.1007/BF00396282, 1983.
Hashihama, F., Furuya, K., Kitajima, S., Takeda, S., Takemura, T., and
Kanda, J.: Macro-scale exhaustion of surface phosphate by dinitrogen
fixation in the western North Pacific, Geophys. Res. Lett., 36, L03610,
https://doi.org/10.1029/2008gl036866, 2009.
Huang, Y., Laws, E. A., Chen, B., and Huang, B.: Stimulation of
heterotrophic and autotrophic metabolism in the mixing zone of the Kuroshio
Current and northern South China Sea: Implications for export production, J.
Geophys. Res.-Biogeo., 124, 2645–2661, https://doi.org/10.1029/2018jg004833, 2019.
Hudson, R. J. M. and Morel, F. M. M.: Iron transport in marine-phytoplankton
– kinetics of cellular and medium coordination reactions, Limnol. Oceanogr.,
35, 1002–1020, https://doi.org/10.4319/lo.1990.35.5.1002, 1990.
Hutchins, D. A. and Fu, F.: Microorganisms and ocean global change, Nat.
Microbiol., 2, 17058, https://doi.org/10.1038/nmicrobiol.2017.58, 2017.
Jacq, V., Ridame, C., L'Helguen, S., Kaczmar, F., and Saliot, A.: Response
of the unicellular diazotrophic cyanobacterium Crocosphaera watsonii to iron limitation, PLoS One,
9, e86749, https://doi.org/10.1371/journal.pone.0086749, 2014.
Jickells, T. D., An, Z. S., Andersen, K. K., Baker, A. R., Bergametti, G.,
Brooks, N., Cao, J. J., Boyd, P. W., Duce, R. A., Hunter, K. A., Kawahata,
H., Kubilay, N., laRoche, J., Liss, P. S., Mahowald, N., Prospero, J. M.,
Ridgwell, A. J., Tegen, I., and Torres, R.: Global iron connections between
desert dust, ocean biogeochemistry, and climate, Science, 308, 67–71,
https://doi.org/10.1126/science.1105959, 2005.
Karlusich, J. J. P., Pelletier, E., Lombard, F., Carsique, M., Dvorak, E.,
Colin, S., Picheral, M., Cornejo-Castillo, F. M., Acinas, S. G., Pepperkok,
R., Karsenti, E., de Vargas, C., Wincker, P., Bowler, C., Foster, R. A.:
Global distribution patterns of marine nitrogen-fixers by imaging and
molecular methods, Nat. Commun., 12, 4160, https://doi.org/10.1038/s41467-021-24299-y, 2021.
Krupke, A., Mohr, W., LaRoche, J., Fuchs, B. M., Amann, R. I., and Kuypers,
M. M.: The effect of nutrients on carbon and nitrogen fixation by the
UCYN-A-haptophyte symbiosis, ISME J., 9, 1635–1647, https://doi.org/10.1038/ismej.2014.253,
2015.
Kustka, A., Sañudo-Wilhelmy, S., Carpenter, E. J., Capone, D. G., and
Raven, J. A.: A revised estimate of the iron use efficiency of nitrogen
fixation, with special reference to the marine cyanobacterium
Trichodesmium spp. (cyanophyta), J. Phycol., 39, 12–25, https://doi.org/10.1046/j.1529-8817.2003.01156.x,
2003.
Kupper, H., Setlik, I., Seibert, S., Prasil, O., Setlikova, E.,
Strittmatter, M., Levitan, O., Lohscheider, J., Adamska, I., and
Berman-Frank, I.: Iron limitation in the marine cyanobacterium
Trichodesmium reveals new insights into regulation of photosynthesis and nitrogen
fixation, New Phytol., 179, 784–798, https://doi.org/10.1111/j.1469-8137.2008.02497.x, 2008.
Landolfi, A., Prowe, A. E. F., Pahlow, M., Somes, C. J., Chien, C. T.,
Schartau, M., Koeve, W., and Oschlies, A.: Can top-down controls expand the
ecological niche of marine N2 fixers?, Front. Microbiol., 12, 690200,
https://doi.org/10.3389/fmicb.2021.690200, 2021.
Langlois, R. J., Hummer, D., and LaRoche, J.: Abundances and distributions
of the dominant nifH phylotypes in the Northern Atlantic Ocean, Appl. Environ.
Microb., 74, 1922–1931, https://doi.org/10.1128/AEM.01720-07, 2008.
Langlois, R. J., Mills, M. M., Ridame, C., Croot, P., and LaRoche, J.:
Diazotrophic bacteria respond to Saharan dust additions, Mar. Ecol.-Prog.
Ser., 470, 1–14, https://doi.org/10.3354/meps10109, 2012.
Le Borgne, R., Barber, R. T., Delcroix, T., Inoue, H. Y., Mackey, D. J., and
Rodier, M.: Pacific warm pool and divergence: Temporal and zonal variations
on the equator and their effects on the biological pump, Deep-Sea Res.
Pt. II, 49, 2471–2512, https://doi.org/10.1016/S0967-0645(02)00045-0, 2002.
Li, W., Sunda, W. G., Lin, W., Hong, H., and Shi, D.: The effect of cell
size on cellular Zn and Cd and Zn-Cd-CO2 colimitation of growth rate
in marine diatoms, Limnol. Oceanogr., 65, 2896–2911, https://doi.org/10.1002/lno.11561,
2020.
Li, X., Wu, K., Gu, S., Jiang, P., Li, H., Liu, Z., and Dai, M.: Enhanced
biodegradation of dissolved organic carbon in the western boundary Kuroshio
Current when intruded to the marginal South China Sea, J. Geophys. Res.-Oceans,
126, e2021JC017585, https://doi.org/10.1029/2021jc017585, 2021.
Lu, Y., Wen, Z., Shi, D., Lin, W., Bonnet, S., Dai, M., and Kao, S. J.:
Biogeography of N2 fixation influenced by the western boundary current
intrusion in the South China Sea, J. Geophys. Res.-Oceans, 124, 6983–6996,
https://doi.org/10.1029/2018jc014781, 2019.
Ma, J., Yuan, D. X., Liang, Y., and Dai, M. H.: A modified analytical method
for the shipboard determination of nanomolar concentrations of
orthophosphate in seawater, J. Oceanogr., 64, 443–449, 2008.
Mills, M., Ridame, C., Davey, M., Roche, J. L., and Geider, R. J.: Iron and phosphorus co-limit nitrogen fixation in the eastern tropical North Atlantic, Nature, 429, 292–294, https://doi.org/10.1038/nature02550, 2004.
Mohr, W., Großkopf, T., Wallace, D. W., and LaRoche, J.: Methodological
underestimation of oceanic nitrogen fixation rates, PLoS One, 5, e12583,
https://doi.org/10.1371/journal.pone.0012583.g001, 2010.
Moisander, P. H., Beinart, R. A., Voss, M., and Zehr, J. P.: Diversity and
abundance of diazotrophic microorganisms in the South China Sea during
intermonsoon, ISME J., 2, 954–967, https://doi.org/10.1038/ismej.2008.51, 2008.
Moisander, P. H., Zhang, R., Boyle, E. A., Hewson, I., Montoya, J. P., and
Zehr, J. P.: Analogous nutrient limitations in unicellular diazotrophs and
Prochlorococcus in the South Pacific Ocean, ISME J., 6, 733–744, https://doi.org/10.1038/ismej.2011.152,
2012.
Montoya, J. P., Voss, M., Kähler, P., and Capone, D. G.: A simple,
high-precision, high-sensitivity tracer assay for N2 fixation, Appl.
Environ. Microb., 62, 986–993, https://doi.org/10.1128/AEM.62.3.986-993.1996, 1996.
Needoba, J. A., Foster, R. A., Sakamoto, C., Zehr, J. P., and Johnson, K.
S.: Nitrogen fixation by unicellular diazotrophic cyanobacteria in the
temperate oligotrophic North Pacific Ocean, Limnol. Oceanogr., 54,
1317–1327, https://doi.org/10.4319/lo.2007.52.4.1317, 2007.
Rodriguez, F., Lillington, J., Johnson, S., Timmel, C. R., Lea, S. M., and
Berks, B. C.: Crystal structure of the bacillus subtilis phosphodiesterase
PhoD reveals an iron and calcium-containing active site, J. Biol. Chem.,
289, 30889–30899, https://doi.org/10.1074/jbc.M114.604892, 2014.
Rubin, M., Berman-Frank, I., and Shaked, Y.: Dust- and mineral-iron
utilization by the marine dinitrogen-fixer Trichodesmium, Nat. Geosci., 4, 529–534,
https://doi.org/10.1038/ngeo1181, 2011.
Saito, M. A., Goepfert, T. J., and Ritt, J. T.: Some thoughts on the concept
of colimitation: Three definitions and the importance of bioavailability,
Limnol. Oceanogr., 53, 276–290, https://doi.org/10.4319/lo.2008.53.1.0276, 2008.
Saito, M. A., Bertrand, E. M., Dutkiewicz, S., Bulygin, V. V., Moran, D. M.,
Monteiro, F. M., Follows, M. J., Valois, F. W., and Waterbury, J. B.: Iron
conservation by reduction of metalloenzyme inventories in the marine
diazotroph Crocosphaera watsonii, P. Natl. Acad. Sci. USA, 108, 2184–2189,
https://doi.org/10.1073/pnas.1006943108, 2011.
Sañudo-Wilhelmy, S. A., Kustka, A. B., Gobler, C. J., Hutchins, D. A.,
Yang, M., Lwiza, K., Burns, J. A., Capone, D. G., Ravenk, J. A., and
Carpenter, E. J.: Phosphorus limitation of nitrogen fixation by
Trichodesmiun in the central Atlantic Ocean, Nature, 411, 66–69, https://doi.org/10.1038/35075041, 2001.
Sargent, E. C., Hitchcock, A., Johansson, S. A., Langlois, R., Moore, C. M.,
LaRoche, J., Poulton, A. J., and Bibby, T. S.: Evidence for polyploidy in
the globally important diazotroph Trichodesmium, FEMS Microbiol. Lett., 363,
https://doi.org/10.1093/femsle/fnw244, 2016.
Schlosser, C., Klar, J. K., Wake, B. D., Snow, J. T., Honey, D. J.,
Woodward, E. M. S., Lohan, M. C., Achterberg, E. P., and Moore, C. M.:
Seasonal ITCZ migration dynamically controls the location of the
(sub)tropical Atlantic biogeochemical divide, P. Natl. Acad. Sci. USA,
111, 1438–1442, https://doi.org/10.1073/pnas.1318670111, 2014.
Shiozaki, T., Furuya, K., Kodama, T., Kitajima, S., Takeda, S., Takemura,
T., and Kanda, J.: New estimation of N2 fixation in the western and
central Pacific Ocean and its marginal seas, Global Biogeochem. Cy., 24,
GB1015, https://doi.org/10.1029/2009gb003620, 2010.
Shiozaki, T., Kodama, T., and Furuya, K.: Large-scale impact of the island
mass effect through nitrogen fixation in the western South Pacific Ocean,
Geophys. Res. Lett., 41, 2907–2913, https://doi.org/10.1002/2014GL059835, 2014a.
Shiozaki, T., Chen, Y. L. L., Lin, Y. H., Taniuchi, Y., Sheu, D. S., Furuya,
K., and Chen, H. Y.: Seasonal variations of unicellular diazotroph groups A
and B, and Trichodesmium in the northern South China Sea and neighboring upstream Kuroshio
Current, Cont. Shelf Res., 80, 20–31, https://doi.org/10.1016/j.csr.2014.02.015, 2014b.
Shiozaki, T., Nagata, T., Ijichi, M., and Furuya, K.: Nitrogen fixation and the diazotroph community in the temperate coastal region of the northwestern North Pacific, Biogeosciences, 12, 4751–4764, https://doi.org/10.5194/bg-12-4751-2015, 2015a.
Shiozaki, T., Takeda, S., Itoh, S., Kodama, T., Liu, X., Hashihama, F., and Furuya, K.: Why is Trichodesmium abundant in the Kuroshio?, Biogeosciences, 12, 6931–6943, https://doi.org/10.5194/bg-12-6931-2015, 2015b.
Shiozaki, T., Bombar, D., Riemann, L., Hashihama, F., Takeda, S., Yamaguchi,
T., Ehama, M., Hamasaki, K., and Furuya, K.: Basin scale variability of
active diazotrophs and nitrogen fixation in the North Pacific, from the
tropics to the subarctic Bering Sea, Global Biogeochem. Cy., 31, 996–1009,
https://doi.org/10.1002/2017gb005681, 2017.
Snow, J. T., Schlosser, C., Woodward, E. M., Mills, M., Achterberg, E. P.,
Mahaffey, C., Bibby, T. S., and Moore, C. M.: Environmental controls on the
biogeography of diazotrophy and Trichodesmium in the Atlantic Ocean, Global Biogeochem.
Cy., 29, 865–884, https://doi.org/10.1002/2015GB005090, 2015.
Sohm, J. A., Webb, E. A., and Capone, D. G.: Emerging patterns of marine
nitrogen fixation, Nature reviews, Microbiology, 9, 499–508,
https://doi.org/10.1038/nrmicro2594, 2011.
Sperfeld, E., Raubenheimer, D., and Wacker, A.: Bridging factorial and
gradient concepts of resource co-limitation: Towards a general framework
applied to consumers, Ecol. Lett., 19, 201–215, https://doi.org/10.1111/ele.12554, 2016.
Stenegren, M., Caputo, A., Berg, C., Bonnet, S., and Foster, R. A.: Distribution and drivers of symbiotic and free-living diazotrophic cyanobacteria in the western tropical South Pacific, Biogeosciences, 15, 1559–1578, https://doi.org/10.5194/bg-15-1559-2018, 2018.
Tanita, I., Shiozaki, T., Kodama, T., Hashihama, F., Sato, M., Takahashi,
K., and Furuya, K.: Regionally variable responses of nitrogen fixation to
iron and phosphorus enrichment in the Pacific Ocean, J. Geophys.
Res.-Biogeo., 126, e2021JG006542, https://doi.org/10.1029/2021jg006542, 2021.
Thompson, A. W., Carter, B. J., Turk-Kubo, K. A., Malfatti, F., Azam, F.,
and Zehr, J. P.: Genetic diversity of the unicellular nitrogen-fixing
cyanobacteria UCYN-A and its prymnesiophyte host, Environ. Microbiol., 16,
3238–3249, https://doi.org/10.1111/1462-2920.12490, 2014.
Turk-Kubo, K. A., Achilles, K. M., Serros, T. R., Ochiai, M., Montoya, J.
P., and Zehr, J. P.: Nitrogenase (nifH) gene expression in diazotrophic
cyanobacteria in the Tropical North Atlantic in response to nutrient
amendments, Front Microbiol., 3, 386, https://doi.org/10.3389/fmicb.2012.00386, 2012.
Wang, W. L., Moore, J. K., Martiny, A. C., and Primeau, F. W.: Convergent
estimates of marine nitrogen fixation, Nature, 566, 205–211,
https://doi.org/10.1038/s41586-019-0911-2, 2019.
Ward, B. A., Dutkiewicz, S., Moore, C. M., and Follows, M. J.: Iron,
phosphorus, and nitrogen supply ratios define the biogeography of nitrogen
fixation, Limnol. Oceanogr., 58, 2059–2075, https://doi.org/10.4319/lo.2013.58.6.2059, 2013.
Watkins-Brandt, K. S., Letelier, R. M., Spitz, Y. H., Church, M. J.,
Böttjer, D., and White, A. E.: Addition of inorganic or organic
phosphorus enhances nitrogen and carbon fixation in the oligotrophic North
Pacific, Mar. Ecol.-Prog. Ser., 432, 17–29, https://doi.org/10.3354/meps09147, 2011.
Welschmeyer, N. A.: Fluorometric analysis of chlorophyll-a in the presence
of chlorophyll-B and pheopigments, Limnol. Oceanogr., 39, 1985–1992, 1994.
Wen, Z., Browning, T. J., Cai, Y., Dai, R., Zhang, R., Du, C., Jiang, R.,
Lin, W., Liu, X., Cao, Z., Hong, H., Dai, M., and Shi, D.: Nutrient
regulation of biological nitrogen fixation across the tropical western North
Pacific, Sci. Adv., 8, eabl7564, https://doi.org/10.1126/sciadv.abl7564, 2022.
White, A. E., Watkins-Brandt, K. S., and Church, M. J.: Temporal variability
of Trichodesmium spp. and diatom-diazotroph assemblages in the North Pacific Subtropical
Gyre, Front. Mar. Sci., 5, 27, https://doi.org/10.3389/fmars.2018.00027, 2018.
Wu, C., Fu, F. X., Sun, J., Thangaraj, S., and Pujari, L.: Nitrogen fixation
by Trichodesmium and unicellular diazotrophs in the northern South China Sea and the
Kuroshio in summer, Sci. Rep.-UK, 8, 2415, https://doi.org/10.1038/s41598-018-20743-0, 2018.
Wu, J., Chung, S. W., Wen, L. S., Liu, K. K., Chen, Y. L. L., Chen, H. Y.,
and Karl, D. M.: Dissolved inorganic phosphorus, dissolved iron, and
Trichodesmium in the oligotrophic South China Sea, Global Biogeochem. Cy., 17, 1008,
https://doi.org/10.1029/2002gb001924, 2003.
Xu, M. N., Zhang, W., Zhu, Y., Liu, L., Zheng, Z., Wan, X. H. S., Qian, W.,
Dai, M., Gan, J., Hutchins, D. A., and Kao, S. J.: Enhanced ammonia
oxidation caused by lateral Kuroshio intrusion in the boundary zone of the
northern South China Sea, Geophys. Res. Lett., 45, 6585–6593,
https://doi.org/10.1029/2018gl077896, 2018.
Yong, S. C., Roversi, P., Lillington, J., Rodriguez, F., Krehenbrink, M.,
Zeldin, O. B., Garman, E. F., Lea, S. M., and Berks, B. C.: A complex
iron-calcium cofactor catalyzing phosphotransfer chemistry, Science, 345,
1170–1173, https://doi.org/10.1126/science.1254237, 2014.
Zehr, J. P. and Capone, D. G.: Changing perspectives in marine nitrogen
fixation, Science, 368, eaay9514, https://doi.org/10.1126/science.aay9514, 2020.
Zhang, J. Z.: Shipboard automated determination of trace concentrations of
nitrite and nitrate in oligotrophic water by gas-segmented continuous flow
analysis with a liquid waveguide capillary flow cell, Deep-Sea Res. Pt.
I, 47, 1157–1171, https://doi.org/10.1016/S0967-0637(99)00085-0, 2000.
Zhang, R., Zhu, X., Yang, C., Ye, L., Zhang, G., Ren, J. L., Wu, Y., Liu, S.
M., Zhang, J., and Zhou, M.: Distribution of dissolved iron in the Pearl
River (Zhujiang) Estuary and the northern continental slope of the South
China Sea, Deep-Sea Res. Pt. II, 167, 14–24,
https://doi.org/10.1016/j.dsr2.2018.12.006, 2019.
Short summary
Fe and P are key factors controlling the biogeography and activity of marine N2-fixing microorganisms. We found lower abundance and activity of N2 fixers in the northern South China Sea than around the western boundary of the North Pacific, and N2 fixation rates switched from Fe–P co-limitation to P limitation. We hypothesize the Fe supply rates and Fe utilization strategies of each N2 fixer are important in regulating spatial variability in community structure across the study area.
Fe and P are key factors controlling the biogeography and activity of marine N2-fixing...
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