Royal Netherlands Institute for Sea Research
Phone number
+31 (0)222 36 9338
Senior Scientist
  • Organic Geochemistry
  • Biogeochemistry
  • Lipid biomarkers - bacteriohopanepolyols
  • Aerobic methanotrophy
  • Anaerobic ammonium oxidation (anammox)

Dr. Darci Rush

Senior Scientist

Searching for fossils of bacteria 

Geochemist Darci Rush searches the sea and ocean floors for traces of bacteria from the distant past. ‘Microorganisms, such as bacteria and unicellular algae formed the foundations of life on earth and are still vital for all life, both above and below the surface. For example, they play a crucial role in the carbon and nitrogen cycles and, consequently, the regulation of the climate.’

Bacteria consume methane

‘One of the specific substances I examine is the strong greenhouse gas methane. Methane (CH4) is produced by microorganisms under anoxic conditions in the seafloor. When it is released from the floor, it could escape into the atmosphere via the water column. In the atmosphere, each methane molecule retains twenty times as much heat as a CO2 molecule. On its way to the surface, part of that methane is consumed by bacteria, which use it as a source of carbon. I try to understand exactly where the equilibria lie: under which conditions was more or less methane released from the ocean floor in the past, and subsequently, how much was reabsorbed into the food chains of the ocean?’

Anoxic seas

‘Another molecule I’m interested in is nitrogen. In areas with little to no oxygen, deep in the ocean, I examine how nitrogen is removed from the food chain by bacteria both now and in the past. By removing nitrogen, the bacteria ensure that it is no longer available for the growth of algae higher in the water. Consequently, those algae can no longer contribute to the capture of CO2 from the atmosphere. As such deep, anoxic areas, like in the Gulf of Mexico, are increasing in size, there will be a growing number of locations where nitrogen will be removed from the nutrient cycle.’

Practical starting points

‘My interest in the chemistry of the oceans is mainly academic: I want to understand how things work. Yet at the same time, this work clearly has a practical side too. The pollution of the Gulf of Mexico with waste from American agriculture has a large influence on the development of anoxic zones and consequently on the climate too. My work therefore provides starting points for tackling ocean pollutions and the disruption of the climate system.’

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Research Interest

I am an organic geochemist with a particular interest in the power of microbial biogeochemistry.  Microscopic organisms have been shaping their environment since the beginning of life on Earth. Lipids are incredibly resistant molecules, and are preserved over long periods of time in the geologic record, acting as chemical fossils to these microbes. Using lipids to extract information about the environmental conditions in which these organisms once lived, I aim to develop biomarkers for specific microbial processes within biogeochemical cycles. Currently, my research projects focus on aerobic methanotrophy and anearobic ammonium oxidation. I also use a combination of genetic, isotopic, and lipid work to understand modern microbial processes. Ultimately, biomarkers can trace back the influence of microbes during extreme climatic events.

Current Projects

Past Projects

Jan 2017 - Sept 2021

Newcastle University · School of Natural and Environmental Sciences


Mar 2016 - Mar 2018

  • PostDoc Position NIOZ Royal Netherlands Institute for Sea Research

Towards reconstructing past atmospheric methane concentrations using organic biomarkers. NESSC project


Aug 2012 – Feb 2016

ERC AMOProx Project: investigate the the processes and environmental feedback of Aerobic Methane Oxidation (AMO).

Newcastle University · School of Civil Engineering and Geosciences


Aug 2008 – Jul 2012

  • PhD Thesis: "Ladderanes as tracers for present and past anaerobic ammonium oxidation"

NIOZ Royal Netherlands Institute for Sea Research · Department of Marine Organic Biogeochemistry (BGC)

Linked news

Monday 25 March 2024
Additional nutrients intensify dead zones in oceans
As more and more nutrients from land and air enter the world’s oceans, the dead zones without oxygen in the water will increase in size and intensity. That is the warning that PhD student Zoë van Kemenade, an organic geochemist at NIOZ, draws from…
Thursday 30 June 2022
NWO-Vidi grant to develop organic geochemical tools
NIOZ scientist Darci Rush received a NWO-Vidi grant for her research on Nu-BHPs (Nucleoside-BHPs as new proxies for paleo-temperature and paleo-pH). She intends to develop organic geochemical tools to reconstruct past temperature as well as soil pH,…
Wednesday 16 December 2020
‘PaleoNiMUR' project receives NWO Science-KLEIN Open Competition award
NIOZ scientist Darci Rush receives one of the 16 Open Competition Science-KLEIN grants awarded by NWO. Her research ‘PaleoNiMUR: Paleo-perspectives on the nitrogen cycle in marine upwelling regions’ will help predict how the nitrogen cycle will react…

Linked blogs

Tuesday 26 February 2019
NIOZ@SEA | 64PE450
Along the southwestern African continental margin off Namibia and Angola coral mound provinces were found during the Meteor (ANNA) cruise in 2016. While the corals in the south along the Namibian margin were mostly fossil frame structures, the corals…
Tuesday 26 February 2019
NIOZ@SEA | FUNAMOX expedition in the southeast Atlantic
Off the coast of southwest Africa, currents force cold deep waters full of essential elements required for ocean life to the surface. This so-called upwelling has enormous impacts on the chemistry and biology of the water and sediment. We are sailing…
Thursday 29 June 2017
Expedition Hotchpotch
During the last week the central theme in our work was sea level change, but this week has come to an end and it is time for a change of subject. And a change of people too. At 7 o’clock this morning Pelagia arrived at Texel. All the non-Pelagia crew…
Wednesday 29 March 2017
NIOZ@Sea: Black Sea cruise
This edition of NIOZ@Sea is a series of blogs from the Black Sea cruise of our scientists on board research vessel Pelagia. The Black Sea is the largest permanently stratified sea in the world. This is ideal to study the structure of microbial…

NIOZ publications

  • 2023
    Richter, N.; Hopmans, E.C.; Mitrovic, D.; Miguel Raposeiro, P.; Gonçalves, V.; Costa, A.C.; Amaral-Zettler, L.; Villanueva, L.; Rush, D. (2023). Distributions of bacteriohopanepolyols in lakes and coastal lagoons of the Azores Archipelago. Biogeosciences 20(11): 2065-2098.
    Schwartz-Narbonne, R.; Schaeffer, P.; Lengger, S.K.; Blewett, J.; Martin Jones, D.; Motsch, E.; Crombie, A.; Jetten, M.S.M.; Mikkelsen, D.; Normand, P.; Nuijten, G.H.L.; Pancost, R.D.; Rush, D. (2023). Bacterial physiology highlighted by the δ13C fractionation of bacteriohopanetetrol isomers. Org. Geochem. 181: 104617.
    van Kemenade, Z.R.; Cutmore, A.; Hennekam, R.; Hopmans, E.C.; van der Meer, M.T.J.; Mojtahid, M.; Jorissen, F.; Bale, N.; Reichart, G.-J.; Sinninghe Damsté, J.S; Rush, D. (2023). Marine nitrogen cycling dynamics under altering redox conditions: Insights from deposition of sapropels S1 and the ambiguous S2 in the Eastern Mediterranean Sea. Geochim. Cosmochim. Acta 354: 197-210.
  • 2022
    Kusch, S.; Rush, D. (2022). Revisiting the precursors of the most abundant natural products on Earth: a look back at 30+ years of bacteriohopanepolyol (BHP) research and ahead to new frontiers. Org. Geochem. 172: 104469.
    van Kemenade, Z.R.; Villanueva, L.; Hopmans, E.C.; Kraal, P.; Witte, H.J.; Sinninghe Damsté, J.S.; Rush, D. (2022). Bacteriohopanetetrol-x: constraining its application as a lipid biomarker for marine anammox using the water column oxygen gradient of the Benguela upwelling system. Biogeosciences 19(1): 201-221.
  • 2021
    Hopmans, E.C.; Smit, N.T.; Schwartz-Narbonne, R.; Sinninghe Damsté, J.S.; Rush, D. (2021). Analysis of non-derivatized bacteriohopanepolyols using UHPLC-HRMS reveals great structural diversity in environmental lipid assemblages. Org. Geochem. 160: 104285.
    Smit, N.T.; Villanueva, L.; Rush, D.; Grassa, F.; Witkowski, C.R.; Holzheimer, M.; Minnaard, A.J.; Sinninghe Damsté, J.S.; Schouten, S. (2021). Novel hydrocarbon-utilizing soil mycobacteria synthesize unique mycocerosic acids at a Sicilian everlasting fire. Biogeosciences 18(4): 1463-1479.
  • 2020
    de Bar, M.W.; Weiss, G.M.; Yildiz, C.; Rampen, S.W.; Lattaud, J.; Bale, N.J.; Mienis, F.; Brummer, G.-J. A.; Schulz, H.; Rush, D.; Kim, J.-H.; Donner, B.; Knies, J.; Lückge, A.; Stuut, J.-B.W.; Sinninghe Damsté, J.S; Schouten, S. (2020). Global temperature calibration of the Long chain Diol Index in marine surface sediments. Org. Geochem. 142: 103983.
    Schwartz-Narbonne, R.; Schaeffer, P.; Hopmans, E.C.; Schenesse, M.; Alex Charlton, E.; Martin Jones, D.; Sinninghe Damsté, J.S.; Farhan Ul Haque, M.; Jetten, M.S.M.; Lengger, S.K. (2020). A unique bacteriohopanetetrol stereoisomer of marine anammox. Org. Geochem. 143: 103994.
    Steen, A.D.; Kusch, S.; Abdulla, H.A.; Cakic, N.; Coffinet, S.; Dittmar, T.; Fulton, J.M.; Galy, V.; Hinrichs, K.-U.; Ingalls, A.E.; Koch, B.P.; Kujawinski, E.B.; Liu, Z.; Osterholz, H.; Rush, D.; Seidel, M.; Sepúlveda, J.; Wakeham, S.G. (2020). Analytical and Computational Advances, Opportunities, and Challenges in Marine Organic Biogeochemistry in an Era of “Omics”. Front. Mar. Sci. 7: article 718.
    Zindorf, M.; Rush, D.; Jaeger, J.; Mix, A.C.; Penkrot, M.L.; Schnetger, B.; Sidgwick, F.R.; Talbot, H.M.; van der Land, C.; Wagner, T.; Walczak, M.H.; März, C. (2020). Reconstructing oxygen deficiency in the glacial Gulf of Alaska: Combining biomarkers and trace metals as paleo-redox proxies. Chem. Geol. 558: 119864.
  • 2019
    Lattaud, J.; Erdem, Z.; Weiss, G.M.; Rush, D.; Balzano, S.; Chivall, D.; van der Meer, M.T.J.; Hopmans, E.C.; Sinninghe Damsté, J.S; Schouten, S. (2019). Hydrogen isotopic ratios of long-chain diols reflect salinity. Org. Geochem. 137: 103904.
    Lengger, S.K.; Rush, D.; Mayser, J.P.; Blewett, J.; Schwartz-Narbonne, R.; Talbot, H.M.; Middelburg, J.J.; Jetten, M.S.M.; Schouten, S.; Sinninghe Damsté, J.S. (2019). Dark carbon fixation in the Arabian Sea oxygen minimum zone contributes to sedimentary organic carbon (SOM). Global Biogeochem. Cycles 33(12): 1715-1732.
    Rush, D.; Talbot, H.M.; Van der Meer, M.T.J.; Hopmans, E.C.; Douglas, B.; Sinninghe Damsté, J.S (2019). Biomarker evidence for the occurrence of anaerobic ammonium oxidation in the eastern Mediterranean Sea during Quaternary and Pliocene sapropel formation. Biogeosciences 16(12): 2467-2479.
    Smit, N.T.; Rush, D.; Sahonero Canavesi, D.X.; Verweij, M.; Rasigraf, O.; Guerrero-Cruz, S.; Jetten, M.S.M.; Sinninghe Damsté, J.S; Schouten, S. (2019). Demethylated hopanoids in ‘Ca. Methylomirabilis oxyfera’ as biomarkers for environmental nitrite-dependent methane oxidation. Org. Geochem. 137: 103899.
  • 2018
    Rush, D.; Erdem, Z. (2018). Cruise 64PE434: NICO Leg 7 GoMex: R/V Pelagia, 11-03-2018 to 04-04-2018, Philipsburg, Sint Maarten – Nassau, Bahamas. NIOZ: Texel. 63 pp.
  • 2017
    Osborne, K.A.; Gray, N.D.; Sherry, A.; Leary, P.; Mejeha, O.; Bischoff, J.; Rush, D.; Sidgwick, F.R.; Birgel, D.; Kalyuzhnaya, M.; Talbot, H.M. (2017). Methanotroph-derived bacteriohopanepolyol signatures as a function of temperature related growth, survival, cell death and preservation in the geological record. Environmental Microbiology Reports 9(5): 492-500.
    Rush, D.; Sinninghe Damsté, J.S. (2017). Lipids as paleomarkers to constrain the marine nitrogen cycle. Environ. Microbiol. 19(6): 2119–2132,.
  • 2014
    Rush, D.; Jaeschke, A.; Geenevasen, J.A.J.; Tegelaar, E.; Pureveen, J.; Lewan, M.D.; Schouten, S.; Sinninghe Damsté, J.S. (2014). Generation of unusual branched long chain alkanes from hydrous pyrolysis of anammox bacterial biomass. Org. Geochem. 76: 136–145.
    Rush, D.; Sinninghe Damsté, J.S.; Poulton, S.W.; Thamdrup, B.; Leigh Garside, A.; Acuña-Gonzalez, J.; Schouten, S.; Jetten, M.S.M.; Talbot, H.M. (2014). Anaerobic ammonium-oxidising bacteria: A biological source of the bacteriohopanetetrol stereoisomer in marine sediments. Geochim. Cosmochim. Acta 140: 50-63.
  • 2012
    Rush, D.; Hopmans, E.C.; Wakeham, S.G.; Schouten, S.; Sinninghe Damsté, J.S. (2012). Occurrence and distribution of ladderane oxidation products in different oceanic regimes. Biogeosciences 9(7): 2407-2418.
    Rush, D.; Wakeham, S.G.; Hopmans, E.C.; Schouten, S.; Sinninghe Damsté, J.S. (2012). Biomarker evidence for anammox in the oxygen minimum zone of the Eastern Tropical North Pacific. Org. Geochem. 53: 80-87.
    Rush, D.J. (2012). Ladderanes as tracers for present and past anaerobic ammonium oxidation. PhD Thesis. Universiteit Utrecht: [s.l.]. ISBN 978-94-6203-168-5. 133 pp.
    Wakeham, S.G.; Turich, C.; Schubotz, F.; Podlaska, A.; Li, X.N.; Varela, R.; Astor, Y.; Sáenz, J.P.; Rush, D.; Sinninghe Damsté, J.S.; Summons, R.E.; Taylor, G.T.; Scranton, M.I.; Hinrichs, K.U. (2012). Biomarkers, chemistry and microbiology show chemoautotrophy in a multilayer chemocline in the Cariaco Basin. Deep-Sea Res., Part 1, Oceanogr. Res. Pap. 63: 133-156.
    Yan, J.; Haaijer, S.C.M.; Op den Camp, H.J.M.; van Niftrik, L.; Stahl, D.A.; Könneke, M.; Rush, D.; Sinninghe Damsté, J.S.; Hu, Y.Y.; Jetten, M.S.M. (2012). Mimicking the oxygen minimum zones: stimulating interaction of aerobic archaeal and anaerobic bacterial ammonia oxidizers in a laboratory-scale model system. Environ. Microbiol. 14(12): 3146-3158.
  • 2011
    Hu, B.L.; Rush, D.; van der Biezen, E.; Zheng, P.; van Mullekom, M.; Schouten, S.; Sinninghe Damsté, J.S.; Smolders, A.J.P.; Jetten, M.S.M.; Kartal, B. (2011). New Anaerobic, Ammonium-Oxidizing Community Enriched from Peat Soil. Appl. Environ. Microbiol. 77(3): 966-971.
    Rush, D.; Jaeschke, A.; Hopmans, E.C.; Geenevasen, J.A.J.; Schouten, S.; Sinninghe Damsté, J.S. (2011). Short chain ladderanes: Oxic biodegradation products of anammox lipids. Geochim. Cosmochim. Acta 75(6): 1662-1671.