Articles | Volume 21, issue 10
https://doi.org/10.5194/cp-21-1853-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-21-1853-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
27 Oct 2025
Research article |
| 27 Oct 2025
| 27 Oct 2025
Quantitative reconstruction of deglacial bottom-water nitrate in marginal Pacific seas using the pore density of denitrifying benthic foraminifera
Anjaly Govindankutty Menon
CORRESPONDING AUTHOR
Department of Earth System Sciences, Institute for Geology, Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
Aaron L. Bieler
Climate Geochemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
Department of Earth and Planetary Sciences, ETH Zürich, Sonneggstrasse 5, 8092 Zürich, Switzerland
Hanna Firrincieli
Department of Earth System Sciences, Institute for Geology, Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
Rachel Alcorn
Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, 2800 Faucette Dr, Raleigh, NC, 27607, USA
Niko Lahajnar
Department of Earth System Sciences, Institute for Geology, Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
Center for Earth System Research and Sustainability, Institute for Geology, Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
Catherine V. Davis
Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, 2800 Faucette Dr, Raleigh, NC, 27607, USA
Ralf Schiebel
Climate Geochemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
Dirk Nürnberg
GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, Geb. 8c, Raum 106, 24148 Kiel, Germany
Gerhard Schmiedl
Department of Earth System Sciences, Institute for Geology, Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
Center for Earth System Research and Sustainability, Institute for Geology, Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
Nicolaas Glock
Department of Earth System Sciences, Institute for Geology, Universität Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany
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Shichao Tian, Birgit Gaye, Jianhui Tang, Yongming Luo, Wenguo Li, Niko Lahajnar, Kirstin Dähnke, Tina Sanders, Tianqi Xiong, Weidong Zhai, and Kay-Christian Emeis
Biogeosciences, 19, 2397–2415, https://doi.org/10.5194/bg-19-2397-2022, https://doi.org/10.5194/bg-19-2397-2022, 2022
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We constrain the nitrogen budget and in particular the internal sources and sinks of nitrate in the Bohai Sea by using a mass-based and dual stable isotope approach based on δ15N and δ18O of nitrate. Based on available mass fluxes and isotope data an updated nitrogen budget is proposed. Compared to previous estimates, it is more complete and includes the impact of the interior cycle (nitrification) on the nitrate pool. The main external nitrogen sources are rivers contributing 19.2 %–25.6 %.
Birgit Gaye, Niko Lahajnar, Natalie Harms, Sophie Anna Luise Paul, Tim Rixen, and Kay-Christian Emeis
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Amino acids were analyzed in a large number of samples of particulate and dissolved organic matter from coastal regions and the open ocean. A statistical analysis produced two new biogeochemical indicators. An indicator of sinking particle and sediment degradation (SDI) traces the degradation of organic matter from the surface waters into the sediments. A second indicator shows the residence time of suspended matter in the ocean (RTI).
Gerd Krahmann, Damian L. Arévalo-Martínez, Andrew W. Dale, Marcus Dengler, Anja Engel, Nicolaas Glock, Patricia Grasse, Johannes Hahn, Helena Hauss, Mark Hopwood, Rainer Kiko, Alexandra Loginova, Carolin R. Löscher, Marie Maßmig, Alexandra-Sophie Roy, Renato Salvatteci, Stefan Sommer, Toste Tanhua, and Hela Mehrtens
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The project "Climate-Biogeochemistry Interactions in the Tropical Ocean" (SFB 754) was a multidisciplinary research project active from 2008 to 2019 aimed at a better understanding of the coupling between the tropical climate and ocean circulation and the ocean's oxygen and nutrient balance. On 34 research cruises, mainly in the Southeast Tropical Pacific and the Northeast Tropical Atlantic, 1071 physical, chemical and biological data sets were collected.
Catherine V. Davis, Karen Wishner, Willem Renema, and Pincelli M. Hull
Biogeosciences, 18, 977–992, https://doi.org/10.5194/bg-18-977-2021, https://doi.org/10.5194/bg-18-977-2021, 2021
André Bahr, Monika Doubrawa, Jürgen Titschack, Gregor Austermann, Andreas Koutsodendris, Dirk Nürnberg, Ana Luiza Albuquerque, Oliver Friedrich, and Jacek Raddatz
Biogeosciences, 17, 5883–5908, https://doi.org/10.5194/bg-17-5883-2020, https://doi.org/10.5194/bg-17-5883-2020, 2020
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Cited articles
Alcorn, R. C., Ontiveros-Cuadras, J. F., Menon, A. G., Glock, N., Tappa, E. J., Burke, J., Cartapanis, O., and Davis, C. V.: Nonlinear Expansion of the Eastern Tropical North Pacific Oxygen Minimum Zone During the Last Deglaciation, Authorea Preprints, https://doi.org/10.22541/essoar.173765742.20874664, 2025.
Altabet, M. A. and Francois, R.: Sedimentary nitrogen isotopic ratio as a recorder for surface ocean nitrate utilization, Global Biogeochemical Cycles, 8, 103–116, https://doi.org/10.1029/93GB03396, 1994.
Altabet, M. A., Pilskaln, C., Thunell, R., Pride, C., Sigman, D., Chavez, F., and Francois, R.: The nitrogen isotope biogeochemistry of sinking particles from the margin of the Eastern North Pacific, Deep Sea Research Part I: Oceanographic Research Papers, 46, 655–679, https://doi.org/10.1016/S0967-0637(98)00084-3, 1999.
Auderset, A., Moretti, S., Taphorn, B., Ebner, P. R., Kast, E., Wang, X. T., Schiebel, R., Sigman, D. M., Haug, G. H., and Martínez-García, A.: Enhanced Ocean oxygenation during Cenozoic warm periods, Nature, 609, 77–82, https://doi.org/10.1038/s41586-022-05017-0, 2022.
Benson, L., Lund, S., Negrini, R., Linsley, B., and Zic, M.: Response of north American Great basin lakes to Dansgaard–Oeschger oscillations, Quaternary Science Reviews, 22, 2239–2251, https://doi.org/10.1016/S0277-3791(03)00210-5, 2003.
Bernhard, J. M., Edgcomb, V. P., Casciotti, K. L., McIlvin, M. R., and Beaudoin, D. J.: Denitrification likely catalyzed by endobionts in an allogromiid foraminifer, The ISME Journal, 6, 951–960, https://doi.org/10.1038/ismej.2011.171, 2012a.
Bernhard, J. M., Casciotti, K. L., McIlvin, M. R., Beaudoin, D. J., Visscher, P. T., and Edgcomb, V. P.: Potential importance of physiologically diverse benthic foraminifera in sedimentary nitrate storage and respiration, J. Geophys. Res., 117, https://doi.org/10.1029/2012JG001949, 2012b.
Bohlen, L., Dale, A. W., and Wallmann, K.. Simple transfer functions for calculating benthic fixed nitrogen losses and C: N: P regeneration ratios in global biogeochemical models, Global Biogeochemical Cycles, 26, https://doi.org/10.1029/2011GB004198, 2012.
Broecker, W. S., Peteet, D. M., and Rind, D.: Does the ocean–atmosphere system have more than one stable mode of operation?, Nature, 315, 21–26, https://doi.org/10.1038/315021a0, 1985.
Bubenshchikova, N., Nürnberg, D., and Tiedemann, R. Variations of Okhotsk Sea oxygen minimum zone: Comparison of foraminiferal and sedimentological records for latest MIS 12–11c and latest MIS 2–1, Marine Micropaleontology, 121, 52–69, https://doi.org/10.1016/j.marmicro.2015.09.004, 2015.
Burke, A. and Robinson, L. F.: The Southern Ocean's role in carbon exchange during the last deglaciation, Science, 335, 557–561, https://doi.org/10.1126/science.1208163, 2012.
Cartapanis, O., Tachikawa, K., and Bard, E.: Northeastern Pacific oxygen minimum zone variability over the past 70 kyr: Impact of biological production and oceanic ventilation, Paleoceanography, 26, https://doi.org/10.1029/2011PA002126, 2011.
Casciotti, K. L.: Nitrite isotopes as tracers of marine N cycle processes, Phil. Trans. R. Soc. A., 374, 20150295, https://doi.org/10.1098/rsta.2015.0295, 2016.
Chang, A. S., Pedersen, T. F., and Hendy, I. L.: Effects of productivity, glaciation, and ventilation on late Quaternary sedimentary redox and trace element accumulation on the Vancouver Island margin, western Canada, Paleoceanography, 29, 730–746, https://doi.org/10.1002/2013PA002581, 2014.
Chang, A. S., Pichevin, L., Pedersen, T. F., Gray, V., and Ganeshram, R.: New insights into productivity and redox-controlled trace element (Ag, Cd, Re, and Mo) accumulation in a 55 kyr long sediment record from Guaymas Basin, Gulf of California, Paleoceanography, 30, 77–94, https://doi.org/10.1002/2014PA002681, 2015.
Cheshire, H. and Thurow, J.: High-resolution migration history of the Subtropical High/Trade Wind system of the northeastern Pacific during the last ∼55 years: Implications for glacial atmospheric reorganization, Paleoceanography, 28, 319–333, https://doi.org/10.1002/palo.20031, 2013.
Choquel, C., Geslin, E., Metzger, E., Filipsson, H. L., Risgaard-Petersen, N., Launeau, P., Giraud, M., Jauffrais, T., Jesus, B., and Mouret, A.: Denitrification by benthic foraminifera and their contribution to N-loss from a fjord environment, Biogeosciences, 18, 327–341, https://doi.org/10.5194/bg-18-327-2021, 2021.
Clark, P., Pisias, N., Stocker, T., and Weaver, A. J.: The role of the thermohaline circulation in abrupt climate change, Nature, 415, 863–869, https://doi.org/10.1038/415863a, 2002.
Clark, P. U. and Mix, A. C.: Ice sheets and sea level of the Last Glacial Maximum, Quaternary Science Reviews, 21, 1–7, https://doi.org/10.1016/S0277-3791(01)00118-4, 2002.
Codispoti, L. A., Brandes, J. A., Christensen, J. P., Devol, A. H., Naqvi, S. W. A., Paerl, H. W., and Yoshinari, T.: The oceanic fixed nitrogen and nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci. Mar., 65, 85–105, https://doi.org/10.17615/ksfx-e447, 2001.
Dale, A. W., Sommer, S., Lomnitz, U., Bourbonnais, A., and Wallmann, K.: Biological nitrate transport in sediments on the Peruvian margin mitigates benthic sulfide emissions and drives pelagic N loss during stagnation events, Deep Res. I Oceanogr. Res. Pap., 112, 123–136, https://doi.org/10.1016/j.dsr.2016.02.013, 2016.
Devol, A. H., Uhlenhopp, A. G., Naqvi, S. W. A., Brandes, J. A., Jayakumar, D. A., Naik, H., Gaurin, S., Codispoti, L. A., and Yoshinari, T.: Denitrification rates and excess nitrogen gas concentrations in the Arabian Sea oxygen deficient zone, Deep Sea Research Part I: Oceanographic Research Papers, 53, 1533–1547, https://doi.org/10.1016/j.dsr.2006.07.005, 2006.
Dubois, N., Kienast, M., Kienast, S., Normandeau, C., Calvert, S. E., Herbert, T. D., and Mix, A.: Millennial-scale variations in hydrography and biogeochemistry in the Eastern Equatorial Pacific over the last 100 kyr, Quaternary Science Reviews, 30, 210–223, https://doi.org/10.1016/j.quascirev.2010.10.012, 2011.
Dubois, N., Kienast, M., Kienast, S. S., and Timmermann, A.: Millennial-scale Atlantic/East Pacific Sea surface temperature linkages during the last 100,000 years, Earth and Planetary Science Letters, 396, 134–142, https://doi.org/10.1016/j.epsl.2014.04.008, 2014.
Duplessy, J. C., Shackleton, N. J., Fairbanks, R. G., Labeyrie, L., Oppo, D., and Kallel, N.: Deepwater source variations during the last climatic cycle and their impact on the global deepwater circulation, Paleoceanography, 3, 343–360, https://doi.org/10.1029/PA003i003p00343, 1988.
Emmer, E. and Thunell, R. C.: Nitrogen isotope variations in Santa Barbara Basin sediments: Implications for denitrification in the eastern tropical North Pacific during the last 50,000 years, Paleoceanography, 15, 377–387, https://doi.org/10.1029/1999PA000417, 2000.
Erdem, Z., Schönfeld, J., Rathburn, A. E., Pérez, M.-E., Cardich, J., and Glock, N.: Bottom-water deoxygenation at the Peruvian margin during the last deglaciation recorded by benthic foraminifera, Biogeosciences, 17, 3165–3182, https://doi.org/10.5194/bg-17-3165-2020, 2020.
Evans, N., Tichota, J., Ruef, W., Moffett, J., and Devol, A.: Rapid Expansion of Fixed Nitrogen Deficit in the Eastern Pacific Ocean Revealed by 50-Year Time Series, Global Biogeochemical Cycles, 37, e2022GB007575, https://doi.org/10.1029/2022GB007575, 2023.
Fontanier, C., Duros, P., Toyofuku, T., Oguri, K., Koho, K. A., Buscail, R., Grémare, A., Radakovitch, O., Deflandre, B., De Nooijer, L. J., Bichon, S., Goubet, S., Ivanovsky, A., Chabaud, G., Menniti, C., Reichart, G.-J., and Kitazato, H.: Living (stained) deep-sea foraminifera off hachinohe (NE Japan, western Pacific): environmental interplay in oxygen-depleted ecosystems, J. Foraminifer. Res., 44, 281–299, https://doi.org/10.2113/gsjfr.44.3.281, 2014.
Frölicher, T. L., Aschwanden, M. T., Gruber, N., Jaccard, S. L., Dunne, J. P., and Paynter, D.: Contrasting upper and deep ocean oxygen response to protracted global warming, Global Biogeochemical Cycles, 34, e2020GB006601, https://doi.org/10.1029/2020GB006601, 2020.
Fu, W., Primeau, F., Keith Moore, J., Lindsay, K., and Randerson, J. T.: Reversal of increasing tropical ocean hypoxia trends with sustained climate warming, Global Biogeochemical Cycles, 32, 551–564, https://doi.org/10.1002/2017GB005788, 2018.
Galbraith, E. D., Kienast, M., Pedersen, T. F., and Calvert, S. E.: Glacial-interglacial modulation of the marine nitrogen cycle by high-latitude O2 supply to the global thermocline, Paleoceanography, 19, https://doi.org/10.1029/2003PA001000, 2004.
Ganeshram, R. S. and Pedersen, T. F.: Glacial-interglacial variability in upwelling and bioproductivity off NW Mexico: Implications for quaternary paleoclimate, Paleoceanography, 13, 634–645, https://doi.org/10.1029/98PA02508, 1998.
Ganeshram, R. S., Pedersen, T. F., Calvert, S. E., and Murray, J. W.: Large changes in oceanic nutrient inventories from glacial to interglacial periods, Nature, 376, 755–758, https://doi.org/10.1038/376755a0, 1995.
Ganeshram, R. S., Pedersen, T. F., Calvert, S. E., McNeill, G. W., and Fontugne, M. R.: Glacial-interglacial variability in denitrification in the world's oceans: Causes and consequences, Paleoceanography, 15, 361–376, https://doi.org/10.1029/1999PA000422, 2000.
Garcia, H. E., Boyer, T. P., Baranova, O. K., Locarnini, R. A., Mishonov, A. V., Grodsky, A., Paver, C. R., Weathers, K. W., Smolyar, I. V., Reagan, J. R., Seidov, D., and Zweng, M. M.: World Ocean Atlas 2018: product documentation, A. Mishonov, Technical Editor, NOAA Atlas NESDIS, https://doi.org/10.25923/tzyw-rp36, 2019.
Glock, N., Eisenhauer, A., Milker, Y., Liebetrau, V., Schönfeld, J., Mallon, J., Sommer, S., and Hensen, C.: Environmental influences on the pore density of Bolivina spissa (Cushman), J. Foraminifer. Res., 41, 22–32, https://doi.org/10.2113/gsjfr.41.1.22, 2011.
Glock, N., Schönfeld, J., Eisenhauer, A., Hensen, C., Mallon, J., and Sommer, S.: The role of benthic foraminifera in the benthic nitrogen cycle of the Peruvian oxygen minimum zone, Biogeosciences, 10, 4767–4783, https://doi.org/10.5194/bg-10-4767-2013, 2013.
Glock, N., Erdem, Z., Wallmann, K., Somes, C. J., Liebetrau, V., Schönfeld, J., Gorb, S., and Eisenhauer, A.: Coupling of oceanic carbon and nitrogen facilitates spatially resolved quantitative reconstruction of nitrate inventories, Nat. Commun., 9, 1217, https://doi.org/10.1038/s41467-018-03647-5, 2018.
Glock, N., Roy, A., Romero, D., Wein, T., Weissenbach, J., Revsbech, N. P., Høgslund, S., Clemens, D., Sommer, S., and Dagan, T.: Metabolic preference of nitrate over oxygen as an electron acceptor in foraminifera from the Peruvian oxygen minimum zone, Proc. Natl. Acad. Sci. USA, 116, 2860–2865, https://doi.org/10.1073/pnas.1813887116, 2019.
Glock, N., Erdem, Z., and Schönfeld, J.: The Peruvian oxygen minimum zone was similar in extent but weaker during the Last Glacial Maximum than Late Holocene, Communications Earth & Environment, 3, 307, https://doi.org/10.1038/s43247-022-00635-y, 2022.
Gomaa, F., Utter, D. R., Powers, C., Beaudoin, D. J., Edgcomb, V. P., Filipsson, H. L., Hansel, C. M., Wankel, S. D., Zhang, Y., and Bernhard, J. M.: Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments, Science Advances, 7, eabf1586, https://doi.org/10.1126/sciadv.abf1586, 2021.
Gorbarenko, S. A., Artemova, A. V., Goldberg, E. L., and Vasilenko, Y. P.: The response of the Okhotsk Sea environment to the orbital-millennium global climate changes during the Last Glacial Maximum, deglaciation and Holocene, Global and Planetary Change, 116, 76–90, https://doi.org/10.1016/j.gloplacha.2014.02.002, 2014.
Govindankutty Menon, A., Davis, C.V., Nürnberg, D., Nomaki, H., Salonen, I., Schmiedl, G., and Glock, N.: A deep-learning automated image recognition method for measuring pore patterns in closely related bolivinids and calibration for quantitative nitrate paleo-reconstructions, Sci. Rep., 13, 19628, https://doi.org/10.1038/s41598-023-46605-y, 2023.
Gray, W. R., Wills, R. C., Rae, J. W., Burke, A., Ivanovic, R. F., Roberts, W. H., Ferreira, D., and Valdes, P. J.: Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation, Geophysical Research Letters, 47, e2019GL086328, https://doi.org/10.1029/2019GL086328, 2020.
Gruber, N.: The marine nitrogen cycle: overview and challenges, in: Nitrogen in the marine environment, edited by: Capone, D. G., Bronk, D. A., Mulholland, M. R., and Carpenter, E. J., 2nd edn., 1–50, Elsevier, https://doi.org/10.1016/B978-0-12-372522-6.00001-3, 2008.
Hendy, I. L., Pedersen, T. F., Kennett, J. P., and Tada, R.: Intermittent existence of a southern Californian upwelling cell during submillennial climate change of the last 60 kyr, Paleoceanography, 19, https://doi.org/10.1029/2003PA000965, 2004.
Herguera, J. C., Herbert, T., Kashgarian, M., and Charles, C.: Intermediate and deep-water mass distribution in the Pacific during the Last Glacial Maximum inferred from oxygen and carbon stable isotopes, Quaternary Sci. Rev., 29, 1228–1245, https://doi.org/10.1016/j.quascirev.2010.02.009, 2010.
Hess, A. V., Auderset, A., Rosenthal, Y., Miller, K. G., Zhou, X., Sigman, D. M., and Martínez-García, A.: A well-oxygenated eastern tropical Pacific during the warm Miocene, Nature, 619, 521–525, https://doi.org/10.1038/s41586-023-06104-6, 2023.
Holbourn, A., Kiefer, T., Pflaumann, U., and Rothe, S.: WEPAMA Cruise MD 122/IMAGES VII, Rapp. Campagnes Mer OCE/2002/01, Inst. Polaire Fr. Paul Emile Victor (IPEV), Plouzane, France, 2002.
Jaccard, S. and Galbraith, E.: Large climate-driven changes of oceanic oxygen concentrations during the last deglaciation, Nature Geosci., 5, 151–156, https://doi.org/10.1038/ngeo1352, 2012.
Kamp, A., Høgslund, S., Risgaard-Petersen, N., and Stief, P.: Nitrate storage and dissimilatory nitrate reduction by eukaryotic microbes, Front. Microbiol., 6, 1492, https://doi.org/10.3389/fmicb.2015.01492, 2015.
Karstensen, J. and Quadfasel, D.: Formation of Southern Hemisphere thermocline waters: water mass conversion and subduction, J. Phys. Oceanogr., 32, 3020–3038, https://doi.org/10.1175/1520-0485(2002)032<3020:FOSHTW>2.0.CO;2, 2002.
Keeling, R. F., Kortzinger, A., and Gruber, N.: Ocean deoxygenation in a warming world, Ann. Rev.Mar. Sci., 2, 199–229, https://doi.org/10.1146/annurev.marine.010908.163855, 2010.
Keigwin, L. D.: Glacial-age hydrography of the far northwest Pacific Ocean, Paleoceanography, 13, 323–339, https://doi.org/10.1029/98PA00874, 1998.
Keigwin, L. D. and Jones, G. A.: Deglacial climatic oscillations in the Gulf of California, Paleoceanography, 5, 1009–1023, https://doi.org/10.1029/PA005i006p01009, 1990.
Kienast, M., Higginson, M. J., Mollenhauer, G., Eglinton, T. I., Chen, M. T., and Calvert, S. E.: On the sedimentological origin of down-core variations of bulk sedimentary nitrogen isotope ratios, Paleoceanography, 20, https://doi.org/10.1029/2004PA001081, 2005.
Kienast, S. S., Calvert, S. E., and Pedersen, T. F.: Nitrogen isotope and productivity variations along the northeast Pacific margin over the last 120 kyr: Surface and subsurface paleoceanography, Paleoceanography, 17, 7–1, https://doi.org/10.1029/2001PA000650, 2002.
Koutavas, A., Demenocal, P. B., Olive, G. C., and Lynch-Stieglitz, J.: Mid-Holocene El Niño-Southern Oscillation (ENSO) attenuation revealed by individual foraminifera in eastern tropical Pacific sediments, Geology, 34, 993–996, https://doi.org/10.1130/G22810A.1, 2006.
Kuhlmann, H., Freudenthal, T., Helmke, P., and Meggers, H.: Reconstruction of paleoceanography off NW Africa during the last 40,000 years: influence of local and regional factors on sediment accumulation, Marine Geology, 207, 209–224, https://doi.org/10.1016/j.margeo.2004.03.017, 2004.
Kutzbach, J. E. and Wright Jr., H. E.: Simulation of the climate of 18,000 years BP: Results for the North American/North Atlantic/European sector and comparison with the geologic record of North America, Quaternary Science Reviews, 4, 147–187, https://doi.org/10.1016/0277-3791(85)90024-1, 1985.
Lam, P. and Kuypers, M. M. M.: Microbial nitrogen cycling processes in oxygen minimum zones, Ann. Rev. Mar. Sci., 3, 317–345, https://doi.org/10.1146/annurev-marine-120709-142814, 2011.
Leclaire, J. and Kerry, K.: Calcium carbonate and organic carbon stratigraphy of late Quaternary laminated and homogeneous diatom oozes from the Guaymas Slope, HPC Site 480, Gulf of California, in: Initial Reports of the Deep Sea Drilling Project, Vol. 64, edited by: Curray, J. R., Moore, D. G., and the Leg 64 Science Party, U.S. Government Printing Office, Washington, DC, 1263–1275, https://doi.org/10.2973/dsdp.proc.64.168.1982, 1982.
Lembke-Jene, L., Tiedemann, R., Nürnberg, D., Gong, X., and Lohmann, G.: Rapid shift and millennial-scale variations in Holocene North Pacific Intermediate Water ventilation, Proceedings of the National Academy of Sciences, 115, 5365–5370, https://doi.org/10.1073/pnas.1714754115, 2018.
Levin, L. A.: Oxygen minimum zone benthos: Adaptation and community response to hypoxia, in: Oceanography and Marine Biology: An Annual Review, Vol. 41, edited by: Gibson, R. N. and Atkinson, J. A., CRC Press, Boca Raton, FL, 1–45, https://doi.org/10.1201/9780203180570-3, 2003.
Levin, L. A.: Manifestation, drivers, and emergence of open ocean deoxygenation, Annual Review of Marine Science, 10, 229–260, https://doi.org/10.1146/annurev-marine-121916-063359, 2018.
Li, N., Somes, C. J., Landolfi, A., Chien, C.-T., Pahlow, M., and Oschlies, A.: Global impact of benthic denitrification on marine N2 fixation and primary production simulated by a variable-stoichiometry Earth system model, Biogeosciences, 21, 4361–4380, https://doi.org/10.5194/bg-21-4361-2024, 2024.
Liu, K. K. and Kaplan, I. R.: The eastern tropical Pacific as a source of 15N-enriched nitrate in seawater off southern California, Limnology and Oceanography, 34, 820–830, https://doi.org/10.4319/lo.1989.34.5.0820, 1989.
Lourey, M. J., Trull, T. W., and Sigman, D. M.: Sensitivity of δ15N of nitrate, surface suspended and deep sinking particulate nitrogen to seasonal nitrate depletion in the Southern Ocean, Global Biogeochemical Cycles, 17, https://doi.org/10.1029/2002GB001973, 2003.
Martinez, P. and Robinson, R. S.: Increase in water column denitrification during the last deglaciation: the influence of oxygen demand in the eastern equatorial Pacific, Biogeosciences, 7, 1–9, https://doi.org/10.5194/bg-7-1-2010, 2010.
Meckler, A. N., Ren, H., Sigman, D. M., Gruber, N., Plessen, B., Schubert, C. J., and Haug, G. H.: Deglacial nitrogen isotope changes in the Gulf of Mexico: Evidence from bulk sedimentary and foraminifera-bound nitrogen in Orca Basin sediments, Paleoceanography, 26, https://doi.org/10.1029/2011PA002156, 2011.
Meissner, K. J., Galbraith, E. D., and Völker, C.: Denitrification under glacial and interglacial conditions: A physical approach, Paleoceanography, 20, https://doi.org/10.1029/2004PA001083, 2005.
Mollenhauer, G., Schneider, R. R., Müller, P. J., Spieß, V., and Wefer, G.: Glacial/interglacial variablity in the Benguela upwelling system: Spatial distribution and budgets of organic carbon accumulation, Global Biogeochemical Cycles, 16, 81-1, https://doi.org/10.1029/2001GB001488, 2002.
Mollier-Vogel, E., Leduc, G., Böschen, T., Martinez, P., and Schneider, R. R.: Rainfall response to orbital and millennial forcing in northern Peru over the last 18 ka, Quaternary Science Reviews, 76, 29–38, https://doi.org/10.1016/j.quascirev.2013.06.021, 2013.
Mollier-Vogel, E., Martinez, P., Blanz, T., Robinson, R., Desprat, S., Etourneau, J., Charlier, K., and Schneider, R. R.: Mid-holocene deepening of the Southeast Pacific oxycline, Glob. Planet. Change, 172, 365–373, https://doi.org/10.1016/j.gloplacha.2018.10.020, 2019.
Montoya, J. P., Horrigan, S. G., and McCarthy, J. J.: Natural abundance of 15N in particulate nitrogen and zooplankton in the Chesapeake Bay, Marine Ecology Progress Series, 35–61, https://www.jstor.org/stable/24844633, 1990.
Moore, C. M., Mills, M. M., Arrigo, K. R., Berman-Frank, I., Bopp, L., Boyd, P. W., Galbraith, E. D., Geider, R. J., Guieu, C., Jaccard, S. L., and Jickells, T. D.: Processes and patterns of oceanic nutrient limitation, Nat. Geosci., 6, 701–710, https://doi.org/10.1038/ngeo1765, 2013.
Moretti, S., Auderset, A., Deutsch, C., Schmitz, R., Gerber, L., Thomas, E., Luciani, V., Petrizzo, M. R., Schiebel, R., Tripati, A., Sexton, P., Norris, R., D'Onofrio, R., Zachos, J., Sigman, D. M., Haug, G. H., and Martínez-García, A.: Oxygen rise in the tropical upper ocean during the Paleocene-Eocene Thermal Maximum. Science, 383, 727–731, https://doi.org/10.1126/science.adh4893, 2024.
Muratli, J. M., Chase, Z., Mix, A. C., and McManus, J.: Increased glacial-age ventilation of the Chilean margin by Antarctic Intermediate Water, Nature Geoscience, 3, 23–26, https://doi.org/10.1038/ngeo715, 2010.
Naafs, B. D. A., Monteiro, F. M., Pearson, A., Higgins, M. B., Pancost, R. D., and Ridgwell, A.: Fundamentally different global marine nitrogen cycling in response to severe ocean deoxygenation, Proceedings of the National Academy of Sciences, 116, 24979–24984, https://doi.org/10.1073/pnas.1905553116, 2019.
Narita, H., Sato, M., Tsunogai, S., Murayama, M., Ikehara, M., Nakatsuka, T., Wakatsuchi, M., Harada, N., and Ujiié, Y.: Biogenic opal indicating less productive northwestern North Pacific during the glacial ages, Geophysical Research Letters, 29, 22–1, https://doi.org/10.1029/2001GL014320, 2002.
Nürnberg, D., Böschen, T., Doering, K., Mollier-Vogel, E., Raddatz, J., and Schneider, R.: Sea surface and subsurface circulation dynamics off equatorial Peru during the last ∼17 kyr, Paleoceanography, 30, 984–999, https://doi.org/10.1002/2014PA002706, 2015.
Nürnberg, D. and Tiedemann, R.: Environmental change in the Sea of Okhotsk during the last 1.1 million years, Paleoceanography 19, 1–23, https://doi.org/10.1029/2004PA001023, 2004.
Ohkushi, K., Kennett, J. P., Zeleski, C. M., Moffitt, S. E., Hill, T. M., Robert, C., Beaufort, L., and Behl, R. J.: Quantified intermediate water oxygenation history of the NE Pacific: A new benthic foraminiferal record from Santa Barbara basin, Paleoceanography, 28, 453–467, https://doi.org/10.1002/palo.20043, 2013.
Okazaki, Y., Timmermann, A., Menviel, L., Harada, N., Abe-Ouchi, A., Chikamoto, M. O., Mouchet, A., and Asahi, H.: Deepwater formation in the North Pacific during the last glacial termination, Science, 329, 200–204, https://doi.org/10.1126/science.1190612, 2010.
Orsi, W. D., Morard, R., Vuillemin, A., Eitel, M., Wörheide, G., Milucka, J., and Kucera, M.: Anaerobic metabolism of Foraminifera thriving below the seafloor, The ISME Journal, 14, 2580–2594, https://doi.org/10.1038/s41396-020-0708-1, 2020.
Oschlies, A.: A committed fourfold increase in ocean oxygen loss, Nat. Commun., 12, 2307, https://doi.org/10.1038/s41467-021-22584-4, 2021.
Pennington, J. T., Mahoney, K. L., Kuwahara, V. S., Kolber, D. D., Calienes, R., and Chavez, F. P.: Primary production in the eastern tropical Pacific: A review, Progress in oceanography, 69, 285–317, https://doi.org/10.1016/j.pocean.2006.03.012, 2006.
Piña-Ochoa, E., Høgslund, S., Geslin, E., Cedhagen, T., Revsbech, N. P., Nielsen, L. P., Schweizer, M., Jorissen, F., Rysgaard, S., and Risgaard-Petersen, N.: Widespread occurrence of nitrate storage and denitrification among Foraminifera and Gromiida, Proc. Natl. Acad. Sci. USA, 107, 1148–1153, https://doi.org/10.1073/pnas.0908440107, 2010a.
Piña-Ochoa, E., Koho, K. A., Geslin, E., and Risgaard-Petersen, N.: Survival and life strategy of the foraminiferan Globobulimina turgida through nitrate storage and denitrification, Mar. Ecol. Prog. Ser., 417, 39–49, https://doi.org/10.3354/meps, 2010b.
Pospelova, V., Price, A. M., and Pedersen, T. F.: Palynological evidence for late Quaternary climate and marine primary productivity changes along the California margin, Paleoceanography, 30, 877–894, https://doi.org/10.1002/2014PA002728, 2015.
Pride, C., Thunell, R., Sigman, D., Keigwin, L., Altabet, M., and Tappa, E.: Nitrogen isotopic variations in the Gulf of California since the last deglaciation: Response to global climate change, Paleoceanography, 14, 397–409, https://doi.org/10.1029/1999PA900004, 1999.
Pride, C. J.: An evaluation and application of paleoceanographic proxies in the Gulf of California, PhD dissertation, University of South Carolina, 1997.
Rae, J. W., Gray, W. R., Wills, R. C. J., Eisenman, I., Fitzhugh, B., Fotheringham, M., Shevenell, A. E., Taylor, B., and Burke, A.: Overturning circulation, nutrient limitation, and warming in the Glacial North Pacific, Sci. Adv., 6, eabd1654, https://doi.org/10.1126/sciadv.abd1654, 2020.
Rae, J. W. B., Burke, A., Robinson, L. F., Foster, G. L., and Elliott, T.: CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales, Nature, 562, 569–573, https://doi.org/10.1038/s41586-018-0614-0, 2018.
Rafter, P. A., Gray, W. R., Hines, S. K. V., Burke, A., Costa, K. M., Gottschalk, J., Hain, M. P., Rae, J. W. B., Southon, J. R., Walczak, M. H., Yu, J., Adkins, J. F., and DeVries, T.: Global reorganization of deep-sea circulation and carbon storage after the last ice age, Science Advances, 8, eabq5434, https://doi.org/10.1126/sciadv.abq5434, 2022.
Rakshit, S., Glock, N., Dale, A. W., Armstrong, M. M., Scholz, F., Mutzberg, A., and Algar, C. K.: Foraminiferal denitrification and deep bioirrigation influence benthic biogeochemical cycling in a seasonally hypoxic fjord. Geochim. Cosmochim. Acta, 388, 268–282, https://doi.org/10.1016/j.gca.2024.10.010, 2025.
Ren, H., Sigman, D. M., Chen, M. T., and Kao, S. J.: Elevated foraminifera-bound nitrogen isotopic composition during the last ice age in the South China Sea and its global and regional implications, Global Biogeochem. Cycles, 26, GB1020, https://doi.org/10.1029/2010GB004020, 2012.
Riechelson, H., Rosenthal, Y., Bova, S., and Robinson, R. S.: Southern Ocean biological pump role in driving Holocene atmospheric CO2: Reappraisal, Geophysical Research Letters, 51, e2023GL105569, https://doi.org/10.1029/2023GL105569, 2024.
Risgaard-Petersen, N., Langezaal, A. M., Ingvardsen, S., Schmid, M. C., Jetten, M. S. M., Op den Camp, H. J. M., Derksen, J. W. M., Piña-Ochoa, E., Eriksson, S. P., Nielsen, L. P., Revsbech, N. P., Cedhagen, T., and van der Zwaan, G. J.: Evidence for complete denitrification in a benthic foraminifer, Nature, 443, 93–96, https://doi.org/10.1038/nature05070, 2006.
Robinson, R. S., Sigman, D. M., DiFiore, P. J., Rohde, M. M., Mashiotta, T. A., and Lea, D. W.: Diatom-bound 15N/14N: New support for enhanced nutrient consumption in the ice age subantarctic, Paleoceanography, 20, https://doi.org/10.1029/2004PA001114, 2005.
Robinson, R. S., Mix, A., and Martinez, P.: Southern Ocean control on the extent of denitrification in the southeast Pacific over the last 70 ka, Quaternary Science Reviews, 26, 201–212, https://doi.org/10.1016/j.quascirev.2006.08.005, 2007.
Robinson, R. S., Martinez, P., Pena, L. D., and Cacho, I.: Nitrogen isotopic evidence for deglacial changes in nutrient supply in the eastern equatorial Pacific, Paleoceanography, 24, https://doi.org/10.1029/2008PA001702, 2009.
Romanova, V., Lohmann, G., Grosfeld, K., and Butzin, M.: The relative role of oceanic heat transport and orography on glacial climate, Quaternary Science reviews, 25, 832–845, https://doi.org/10.1016/j.quascirev.2005.07.007, 2006.
Russell, J. L. and Dickson, A. G.: Variability in oxygen and nutrients in South Pacific Antarctic intermediate water, Global Biogeochemical Cycles, 17, https://doi.org/10.1029/2000GB001317, 2003.
Salvatteci, R., Gutiérrez, D., Field, D., Sifeddine, A., Ortlieb, L., Bouloubassi, I., Boussafir, M., Boucher, H., and Cetin, F.: The response of the Peruvian Upwelling Ecosystem to centennial-scale global change during the last two millennia, Clim. Past, 10, 715–731, https://doi.org/10.5194/cp-10-715-2014, 2014.
Salvatteci, R., Gutiérrez, D., Sifeddine, A., Ortlieb, L., Druffel, E., Boussafir, M., and Schneider, R.: Centennial to millennial-scale changes in oxygenation and productivity in the Eastern Tropical South Pacific during the last 25,000 years, Quaternary Science Reviews, 131, 102–117, https://doi.org/10.1016/j.quascirev.2015.10.044, 2016.
Salvatteci, R., Schneider, R. R., Blanz, T., and Mollier-Vogel, E.: Deglacial to Holocene ocean temperatures in the Humboldt Current System as indicated by alkenone paleothermometry, Geophysical Research Letters, 46, 281–292, https://doi.org/10.1029/2018GL080634, 2019.
Schlitzer, R.: Ocean Data View, https://odv.awi.de (last access: 25 October 2023), 2023.
Schmidtko, S., Stramma, L., and Visbeck, M.: Decline in global oceanic oxygen content during the past five decades, Nature, 542, 335–339, https://doi.org/10.1038/nature21399, 2017.
Scholz, F., McManus, J., Mix, A. C., Hensen, C., and Schneider, R. R.: The impact of ocean deoxygenation on iron release from continental margin sediments, Nature Geoscience, 7, 433–437, https://doi.org/10.1038/ngeo2162, 2014.
Scholz, F., Schmidt, M., Hensen, C., Eroglu, S., Geilert, S., Gutjahr, M., and Liebetrau, V.: Shelf-to-basin iron shuttle in the Guaymas Basin, Gulf of California, Geochimica et Cosmochimica Acta, 261, 76–92, https://doi.org/10.1016/j.gca.2019.07.006, 2019.
Schubert, C. J. and Calvert, S. E.: Nitrogen and carbon isotopic composition of marine and terrestrial organic matter in Arctic Ocean sediments: implications for nutrient utilization and organic matter composition, Deep Sea Research Part I: Oceanographic Research Papers, 48, 789–810, https://doi.org/10.1016/S0967-0637(00)00069-8, 2001.
Seki, O., Ikehara, M., Kawamura, K., Nakatsuka, T., Ohnishi, K., Wakatsuchi, M., Narita, T., and Sakamoto, T.: Reconstruction of paleoproductivity in the Sea of Okhotsk over the last 30 kyr, Paleoceanography, 19, https://doi.org/10.1029/2002PA000808, 2004.
Sigman, D. M., Altabet, M. A., Michener, R., McCorkle, D. C., Fry, B., and Holmes, R. M.: Natural abundance-level measurement of the nitrogen isotopic composition of oceanic nitrate: an adaptation of the ammonia diffusion method, Marine Chemistry, 57, 227–242, https://doi.org/10.1016/S0304-4203(97)00009-1, 1997.
Skinner, L. C., Fallon, S., Waelbroeck, C., Michel, E., and Barker, S.: Ventilation of the deep Southern Ocean and deglacial CO2 rise, Science, 328, 1147–1151, https://doi.org/10.1126/science.1183627, 2010.
Somes, C. J., Schmittner, A., Muglia, J., and Oschlies, A.: A three-dimensional model of the marine nitrogen cycle during the last glacial maximum constrained by sedimentary isotopes, Frontiers in Marine Science, 4, 108, https://doi.org/10.3389/fmars.2017.00108, 2017.
Stramma, L., Johnson, G. C., Sprintall, J., and Mohrholz, V.: Expanding oxygen-minimum zones in the tropical oceans, Science, 320, 655–658, https://doi.org/10.1126/science.1153847, 2008.
Stramma, L., Schmidtko, S., Levin, L. A., and Johnson, G. C.: Ocean oxygen minima expansions and their biological impacts, Deep-Sea Res. I Ocean. Res. Pap., 57, 587–595, https://doi.org/10.1016/j.dsr.2010.01.005, 2010.
Studer, A. S., Mekik, F., Ren, H., Hain, M. P., Oleynik, S., Martínez-García, A., Jaccard, S. L., and Sigman, D. M.: Ice age-Holocene similarity of foraminifera-bound nitrogen isotope ratios in the eastern equatorial Pacific, Paleoceanography and Paleoclimatology, 36, e2020PA004063, https://doi.org/10.1029/2020PA004063, 2021.
Takano, Y., Ito, T., and Deutsch, C.: Projected centennial oxygen trends and their attribution to distinct ocean climate forcings, Global Biogeochemical Cycles, 32, 1329–1349, https://doi.org/10.1029/2018GB005939, 2018.
Taylor, M. A., Hendy, I. L., and Chappaz, A.: Assessing oxygen depletion in the Northeastern Pacific Ocean during the last deglaciation using I/Ca ratios from multiple benthic foraminiferal species, Paleoceanography, 32, 746–762, https://doi.org/10.1002/2016PA003062, 2017.
Ternois, Y., Kawamura, K., Keigwin, L., Ohkouchi, N., and Nakatsuka, T.: A biomarker approach for assessing marine and terrigenous inputs to the sediments of Sea of Okhotsk for the last 27,000 years, Geochimica et Cosmochimica Acta, 65, 791–802, https://doi.org/10.1016/S0016-7037(00)00598-6, 2001.
Tesdal, J.-E., Galbraith, E. D., and Kienast, M.: Nitrogen isotopes in bulk marine sediment: linking seafloor observations with subseafloor records, Biogeosciences, 10, 101–118, https://doi.org/10.5194/bg-10-101-2013, 2013.
Thunell, R. C., Sigman, D. M., Muller-Karger, F., Astor, Y., and Varela, R.: Nitrogen isotope dynamics of the Cariaco Basin, Venezuela, Global Biogeochemical Cycles, 18, https://doi.org/10.1029/2003GB002185, 2004.
Ujiié, H. and Ujiié, Y.: Late Quaternary course changes of the Kuroshio Current in the Ryukyu Arc region, northwestern Pacific Ocean, Marine Micropaleontology, 37, 23–40, https://doi.org/10.1016/S0377-8398(99)00010-9, 1999.
Van Geen, A., Fairbanks, R. G., Dartnell, P., McGann, M., Gardner, J. V., and Kashgarian, M.: Ventilation changes in the northeast Pacific during the last deglaciation, Paleoceanography, 11, 519–528, https://doi.org/10.1029/96PA01860, 1996.
Voss, M., Bange, H. W., Dippner, J. W., Middelburg, J. J., Montoya, J. P., and Ward, B.: The marine nitrogen cycle: recent discoveries, uncertainties and the potential relevance of climate change, Philos. Trans. R. Soc. B, 368, 293–296, https://doi.org/10.1098/rstb.2013.0121, 2013.
Wada, E. and Hattori, A.: Nitrogen isotope effects in the assimilation of inorganic nitrogenous compounds by marine diatoms, Geomicrobiol. J., 1, 85–101, https://doi.org/10.1080/01490457809377725, 1978.
Waelbroeck, C., Frank, N., Jouzel, J., Parrenin, F., Masson-Delmotte, V., and Genty, D.: Transferring radiometric dating of the last interglacial sea level high stand to marine and ice core records, Earth Planet. Sci. Lett., 265, 183–194, https://doi.org/10.1016/j.epsl.2007.10.006, 2008.
Wallmann, K., Schneider, B., and Sarnthein, M.: Effects of eustatic sea-level change, ocean dynamics, and nutrient utilization on atmospheric pCO2 and seawater composition over the last 130 000 years: a model study, Clim. Past, 12, 339–375, https://doi.org/10.5194/cp-12-339-2016, 2016.
Wallmann, K., José, Y. S., Hopwood, M. J., Somes, C. J., Dale, A. W., Scholz, F., Grasse, P., and Oschlies, A.: Biogeochemical feedbacks may amplify ongoing and future ocean deoxygenation: a case study from the Peruvian oxygen minimum zone, Biogeochemistry, 159, 45–67, https://doi.org/10.1007/s10533-022-00908-w, 2022.
Wang, Y., Hendy, I. L., and Thunell, R.: Local and remote forcing of denitrification in the northeast Pacific for the last 2,000 years, Paleoceanogr. Paleoclimatol., 34, 1517–1533, https://doi.org/10.1029/2019PA003577, 2019.
Wang, Y., Hendy, I. L., and Zhu, J.: Expansion of the Southern California oxygen minimum zone during the early-to mid-Holocene due to reduced ventilation of the Northeast Pacific, Quaternary Sci. Rev., 238, 106326, https://doi.org/10.1016/j.quascirev.2020.106326, 2020.
White, A. E., Foster, R. A., Benitez-Nelson, C. R., Masqué, P., Verdeny, E., Popp, B. N., Arthur, K. E., and Prahl, F. G.: Nitrogen fixation in the Gulf of California and the eastern tropical North Pacific, Prog. Oceanogr., 109, 1–17, https://doi.org/10.1016/j.pocean.2012.09.002, 2013.
Woehle, C., Roy, A.-S., Glock, N., Wein, T., Weissenbach, J., Rosenstiel, P., Hiebenthal, C., Michels, J., Schönfeld, J., and Dagan, T.: A Novel Eukaryotic Denitrification Pathway in Foraminifera, Curr. Biol., 28, 2536–2543, https://doi.org/10.1016/j.cub.2018.06.027, 2018.
Woehle, C., Roy, A., Glock, N., Michels, J., Wein, T., Weissenbach, J., Romero, D., Hiebenthal, C., Gorb, S. N., Schönfeld, J., and Dagan, T.: Denitrification in foraminifera has an ancient origin and is complemented by associated bacteria, Proc. Natl. Acad. Sci. USA, 119, e2200198119, https://doi.org/10.1073/pnas.2200198119, 2022.
Yamamoto, A., Abe-Ouchi, A., Shigemitsu, M., Oka, A., Takahashi, K., Ohgaito, R., and Yamanaka, Y.: Global deep ocean oxygenation by enhanced ventilation in the Southern Ocean under long-term global warming, Global Biogeochemical Cycles, 29, 1801–1815, https://doi.org/10.1002/2015GB005181, 2015.
Short summary
The pore density (number of pores per unit area) of unicellular eukaryotes is used to reconstruct past bottom-water nitrate at the Sea of Okhotsk, the Gulf of California, the Mexican Margin and the Gulf of Guayaquil. The reconstructed bottom-water nitrate at the Sea of Okhotsk, the Gulf of California and the Gulf of Guayaquil are influenced by the intermediate water masses, while the nitrate at the Mexican Margin is related to the deglacial NO3− variability in the Pacific Deep Water.
The pore density (number of pores per unit area) of unicellular eukaryotes is used to...
