Articles | Volume 45, issue 1
https://doi.org/10.5194/jm-45-275-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/jm-45-275-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
14 Apr 2026
Research article |
| 14 Apr 2026
| 14 Apr 2026
Dinoflagellate cysts as indicators of primary productivity along a Baltic Sea–North Sea–Atlantic transect
Department of Earth Sciences, Utrecht University, 3584 CB Utrecht, the Netherlands
Rick Hennekam
Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, 1790 AB, Den Burg, the Netherlands
Marcel T. J. van der Meer
Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1790 AB, Den Burg, the Netherlands
Timme H. Donders
Department of Physical Geography, Utrecht University, 3584 CB Utrecht, the Netherlands
Gert-Jan Reichart
Department of Earth Sciences, Utrecht University, 3584 CB Utrecht, the Netherlands
Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, 1790 AB, Den Burg, the Netherlands
Francesca Sangiorgi
Department of Earth Sciences, Utrecht University, 3584 CB Utrecht, the Netherlands
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Yord W. Yedema, Timme Donders, Francien Peterse, and Francesca Sangiorgi
J. Micropalaeontol., 42, 257–276, https://doi.org/10.5194/jm-42-257-2023, https://doi.org/10.5194/jm-42-257-2023, 2023
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The pollen and dinoflagellate cyst content of 21 surface sediments from the northern Gulf of Mexico is used to test the applicability of three palynological ratios (heterotroph/autotroph, pollen/dinocyst, and pollen/bisaccate ratio) as proxies for marine productivity and distance to the coast/river. Redundancy analysis confirms the suitability of these three ratios, where the H/A ratio can be used as an indicator of primary production, and the P/B ratio best tracks the distance to the coast.
Joost Frieling, Linda van Roij, Iris Kleij, Gert-Jan Reichart, and Appy Sluijs
Biogeosciences, 20, 4651–4668, https://doi.org/10.5194/bg-20-4651-2023, https://doi.org/10.5194/bg-20-4651-2023, 2023
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Alison J. Smith, Emi Ito, Natalie Burls, Leon Clarke, Timme Donders, Robert Hatfield, Stephen Kuehn, Andreas Koutsodendris, Tim Lowenstein, David McGee, Peter Molnar, Alexander Prokopenko, Katie Snell, Blas Valero Garcés, Josef Werne, Christian Zeeden, and the PlioWest Working Consortium
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Frida S. Hoem, Adrián López-Quirós, Suzanna van de Lagemaat, Johan Etourneau, Marie-Alexandrine Sicre, Carlota Escutia, Henk Brinkhuis, Francien Peterse, Francesca Sangiorgi, and Peter K. Bijl
Clim. Past, 19, 1931–1949, https://doi.org/10.5194/cp-19-1931-2023, https://doi.org/10.5194/cp-19-1931-2023, 2023
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We present two new sea surface temperature (SST) records in comparison with available SST records to reconstruct South Atlantic paleoceanographic evolution. Our results show a low SST gradient in the Eocene–early Oligocene due to the persistent gyral circulation. A higher SST gradient in the Middle–Late Miocene infers a stronger circumpolar current. The southern South Atlantic was the coldest region in the Southern Ocean and likely the main deep-water formation location in the Middle Miocene.
Katrin Hättig, Devika Varma, Stefan Schouten, and Marcel T. J. van der Meer
Clim. Past, 19, 1919–1930, https://doi.org/10.5194/cp-19-1919-2023, https://doi.org/10.5194/cp-19-1919-2023, 2023
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Laura Pacho, Lennart de Nooijer, and Gert-Jan Reichart
Biogeosciences, 20, 4043–4056, https://doi.org/10.5194/bg-20-4043-2023, https://doi.org/10.5194/bg-20-4043-2023, 2023
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Niels J. de Winter, Daniel Killam, Lukas Fröhlich, Lennart de Nooijer, Wim Boer, Bernd R. Schöne, Julien Thébault, and Gert-Jan Reichart
Biogeosciences, 20, 3027–3052, https://doi.org/10.5194/bg-20-3027-2023, https://doi.org/10.5194/bg-20-3027-2023, 2023
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Lena Mareike Thöle, Peter Dirk Nooteboom, Suning Hou, Rujian Wang, Senyan Nie, Elisabeth Michel, Isabel Sauermilch, Fabienne Marret, Francesca Sangiorgi, and Peter Kristian Bijl
J. Micropalaeontol., 42, 35–56, https://doi.org/10.5194/jm-42-35-2023, https://doi.org/10.5194/jm-42-35-2023, 2023
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Dinoflagellate cysts can be used to infer past oceanographic conditions in the Southern Ocean. This requires knowledge of their present-day ecologic affinities. We add 66 Antarctic-proximal surface sediment samples to the Southern Ocean data and derive oceanographic conditions at those stations. Dinoflagellate cysts are clearly biogeographically separated along latitudinal gradients of temperature, sea ice, nutrients, and salinity, which allows us to reconstruct these parameters for the past.
Suning Hou, Foteini Lamprou, Frida S. Hoem, Mohammad Rizky Nanda Hadju, Francesca Sangiorgi, Francien Peterse, and Peter K. Bijl
Clim. Past, 19, 787–802, https://doi.org/10.5194/cp-19-787-2023, https://doi.org/10.5194/cp-19-787-2023, 2023
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Neogene climate cooling is thought to be accompanied by increased Equator-to-pole temperature gradients, but mid-latitudes are poorly represented. We use biomarkers to reconstruct a 23 Myr continuous sea surface temperature record of the mid-latitude Southern Ocean. We note a profound mid-latitude cooling which narrowed the latitudinal temperature gradient with the northward expansion of subpolar conditions. We surmise that this reflects the strengthening of the ACC and the expansion of sea ice.
Yord W. Yedema, Francesca Sangiorgi, Appy Sluijs, Jaap S. Sinninghe Damsté, and Francien Peterse
Biogeosciences, 20, 663–686, https://doi.org/10.5194/bg-20-663-2023, https://doi.org/10.5194/bg-20-663-2023, 2023
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Terrestrial organic matter (TerrOM) is transported to the ocean by rivers, where its burial can potentially form a long-term carbon sink. This burial is dependent on the type and characteristics of the TerrOM. We used bulk sediment properties, biomarkers, and palynology to identify the dispersal patterns of plant-derived, soil–microbial, and marine OM in the northern Gulf of Mexico and show that plant-derived OM is transported further into the coastal zone than soil and marine-produced TerrOM.
Rick Hennekam, Katharine M. Grant, Eelco J. Rohling, Rik Tjallingii, David Heslop, Andrew P. Roberts, Lucas J. Lourens, and Gert-Jan Reichart
Clim. Past, 18, 2509–2521, https://doi.org/10.5194/cp-18-2509-2022, https://doi.org/10.5194/cp-18-2509-2022, 2022
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The ratio of titanium to aluminum (Ti/Al) is an established way to reconstruct North African climate in eastern Mediterranean Sea sediments. We demonstrate here how to obtain reliable Ti/Al data using an efficient scanning method that allows rapid acquisition of long climate records at low expense. Using this method, we reconstruct a 3-million-year North African climate record. African environmental variability was paced predominantly by low-latitude insolation from 3–1.2 million years ago.
Frédérique M. S. A. Kirkels, Hugo J. de Boer, Paulina Concha Hernández, Chris R. T. Martes, Marcel T. J. van der Meer, Sayak Basu, Muhammed O. Usman, and Francien Peterse
Biogeosciences, 19, 4107–4127, https://doi.org/10.5194/bg-19-4107-2022, https://doi.org/10.5194/bg-19-4107-2022, 2022
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The distinct carbon isotopic values of C3 and C4 plants are widely used to reconstruct past hydroclimate, where more C3 plants reflect wetter and C4 plants drier conditions. Here we examine the impact of regional hydroclimatic conditions on plant isotopic values in the Godavari River basin, India. We find that it is crucial to identify regional plant isotopic values and consider drought stress, which introduces a bias in C3 / C4 plant estimates and associated hydroclimate reconstructions.
Carolien M. H. van der Weijst, Koen J. van der Laan, Francien Peterse, Gert-Jan Reichart, Francesca Sangiorgi, Stefan Schouten, Tjerk J. T. Veenstra, and Appy Sluijs
Clim. Past, 18, 1947–1962, https://doi.org/10.5194/cp-18-1947-2022, https://doi.org/10.5194/cp-18-1947-2022, 2022
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The TEX86 proxy is often used by paleoceanographers to reconstruct past sea-surface temperatures. However, the origin of the TEX86 signal in marine sediments has been debated since the proxy was first proposed. In our paper, we show that TEX86 carries a mixed sea-surface and subsurface temperature signal and should be calibrated accordingly. Using our 15-million-year record, we subsequently show how a TEX86 subsurface temperature record can be used to inform us on past sea-surface temperatures.
Carolien M. H. van der Weijst, Josse Winkelhorst, Wesley de Nooijer, Anna von der Heydt, Gert-Jan Reichart, Francesca Sangiorgi, and Appy Sluijs
Clim. Past, 18, 961–973, https://doi.org/10.5194/cp-18-961-2022, https://doi.org/10.5194/cp-18-961-2022, 2022
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Gabriella M. Weiss, Julie Lattaud, Marcel T. J. van der Meer, and Timothy I. Eglinton
Clim. Past, 18, 233–248, https://doi.org/10.5194/cp-18-233-2022, https://doi.org/10.5194/cp-18-233-2022, 2022
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Here we study the elemental signatures of plant wax compounds as well as molecules from algae and bacteria to understand how water sources changed over the last 11 000 years in the northeastern part of Europe surrounding the Baltic Sea. Our results show diversity in plant and aquatic microorganisms following the melting of the large ice sheet that covered northern Europe as the regional climate continued to warm. A shift in water source from ice melt to rain also occurred around the same time.
Alice E. Webb, Didier M. de Bakker, Karline Soetaert, Tamara da Costa, Steven M. A. C. van Heuven, Fleur C. van Duyl, Gert-Jan Reichart, and Lennart J. de Nooijer
Biogeosciences, 18, 6501–6516, https://doi.org/10.5194/bg-18-6501-2021, https://doi.org/10.5194/bg-18-6501-2021, 2021
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The biogeochemical behaviour of shallow reef communities is quantified to better understand the impact of habitat degradation and species composition shifts on reef functioning. The reef communities investigated barely support reef functions that are usually ascribed to conventional coral reefs, and the overall biogeochemical behaviour is found to be similar regardless of substrate type. This suggests a decrease in functional diversity which may therefore limit services provided by this reef.
Frida S. Hoem, Isabel Sauermilch, Suning Hou, Henk Brinkhuis, Francesca Sangiorgi, and Peter K. Bijl
J. Micropalaeontol., 40, 175–193, https://doi.org/10.5194/jm-40-175-2021, https://doi.org/10.5194/jm-40-175-2021, 2021
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We use marine microfossil (dinocyst) assemblage data as well as seismic and tectonic investigations to reconstruct the oceanographic history south of Australia 37–20 Ma as the Tasmanian Gateway widens and deepens. Our results show stable conditions with typically warmer dinocysts south of Australia, which contrasts with the colder dinocysts closer to Antarctica, indicating the establishment of modern oceanographic conditions with a strong Southern Ocean temperature gradient and frontal systems.
Cited articles
Bauer, J. E., Cai, W. J., Raymond, P. A., Bianchi, T. S., Hopkinson, C. S., and Regnier, P. A.: The changing carbon cycle of the coastal ocean, Nature, 504, 61–70, https://doi.org/10.1038/nature12857, 2013.
Behrenfeld, M. J. and Falkowski, P. G.: Photosynthetic rates derived from satellite-based chlorophyll concentration, Limnology and Oceanography, 42, 1–20, https://doi.org/10.4319/lo.1997.42.1.0001, 1997.
Benninghoff, W. S.: Calculation of pollen and spore density in sediments by addition of exotic pollen in known quantities, Pollen et Spores, 4, 332–333, 1962.
Bergman Sjöstrand, D., Hansson, M., and Kronsell, J.: Cruise report from R/V Svea week 10–11, 2025, Swedish Meteorological and Hydrological Institute, https://www.smhi.se/en/publications-from-smhi/publications/2025-06-24-cruise-report-from-r-v-svea-week-10-11-2025 (last access: 25 July 2025), 2025.
Bozec, Y., Thomas, H., Elkalay, K., and de Baar, H. J.: The continental shelf pump for CO2 in the North Sea – evidence from summer observation, Marine Chemistry, 93, 131–147, https://doi.org/10.1016/j.marchem.2004.07.006, 2005.
Bringué, M., Pospelova, V., and Pak, D.: Seasonal production of organic-walled dinoflagellate cysts in an upwelling system: a sediment trap study from the Santa Barbara Basin, California, Marine Micropaleontology, 100, 34–51, https://doi.org/10.1016/j.marmicro.2013.03.007, 2013.
Carpenter, R., Peterson, M. L., and Bennett, J. T.: 210Pb-derived sediment accumulation and mixing rates for the Washington continental slope, Marine Geology, 48, 135–164, https://doi.org/10.1016/0025-3227(82)90183-0, 1982.
Carstensen, J., Andersen, J. H., Gustafsson, B. G., and Conley, D. J.: Deoxygenation of the Baltic Sea during the last century, Proceedings of the National Academy of Sciences, 111, 5628–5633, https://doi.org/10.1073/pnas.1323156111, 2014.
Christensen, K. H., Sperrevik, A. K., and Broström, G.: On the variability in the onset of the Norwegian Coastal Current, Journal of Physical Oceanography, 48, 723–738, https://doi.org/10.1175/JPO-D-17-0117.1, 2018.
Cochran, J. K. and Masqué, P.: Short-lived U/Th series radionuclides in the ocean: tracers for scavenging rates, export fluxes and particle dynamics, Reviews in Mineralogy and geochemistry, 52, 461–492, https://doi.org/10.2113/0520461, 2003.
Dadey, K. A., Janecek, T., and Klaus, A.: Dry-bulk density: its use and determination, Proceedings of the Ocean Drilling Program, Scientific Results, 126, 37, https://doi.org/10.2973/odp.proc.sr.126.157.1992, 1992.
Dale, B.: Cyst formation, sedimentation, and preservation: factors affecting dinoflagellate assemblages in recent sediments from Trondheimsfjord, Norway, Review of Palaeobotany and Palynology, 22, 39–60, https://doi.org/10.1016/0034-6667(76)90010-5, 1976.
Dale, B.: Eutrophication signals in the sedimentary record of dinoflagellate cysts in coastal waters, Journal of Sea Research, 61, 103–113, https://doi.org/10.1016/j.seares.2008.06.007, 2009.
Dale, B., Thorsen, T. A., and Fjellsa, A.: Dinoflagellate cysts as indicators of cultural eutrophication in the Oslofjord, Norway, Estuarine, Coastal and Shelf Science, 48, 371–382, https://doi.org/10.1006/ecss.1999.0427, 1999.
de Vernal, A. and Marret, F.: Organic-walled dinoflagellate cysts: tracers of sea-surface conditions, in: Proxies in Late Cenozoic Paleoceanography, Developments in Marine Geology, vol. 1, edited by: Hillaire-Marcel, C. and de Vernal, A., Elsevier, Amsterdam, 371–408, https://doi.org/10.1016/S1572-5480(07)01014-7, 2007.
de Vernal, A., Radi, T., Zaragosi, S., Van Nieuwenhove, N., Rochon, A., Allan, E., De Schepper, S., Eynaud, F., Head, M. J., Limoges, A., Londeix, L., Marret, F., Matthiessen, J., Penaud, A., Pospelova, V., Price, A., and Richerol, T.: Distribution of common modern dinoflagellate cyst taxa in surface sediments of the Northern Hemisphere in relation to environmental parameters: the new n = 1968 database, Marine Micropaleontology, 159, 101796, https://doi.org/10.1016/j.marmicro.2019.101796, 2020.
Devillers, R. and de Vernal, A.: Distribution of dinoflagellate cysts in surface sediments of the northern North Atlantic in relation to nutrient content and productivity in surface waters, Marine Geology, 166, 103–124, https://doi.org/10.1016/S0025-3227(00)00007-4, 2000.
Ellegaard, M., Dale, B., Mertens, K. N., Pospelova, V., and Ribeiro, S.: Dinoflagellate cysts as proxies for Holocene environmental change in estuaries: diversity, abundance and morphology, Applications of Paleoenvironmental Techniques in Estuarine Studies, 295–312, https://doi.org/10.1007/978-94-024-0990-1_12, 2017.
E.U. Copernicus Marine Service: Global Ocean Physics Analysis and Forecast, Marine Data Store (MDS) [data set], https://doi.org/10.48670/moi-00016, last access: 28 May 2025.
Faegri, K., Kaland, P. E., and Krzywinski, K.: Textbook of pollen analysis, John Wiley and Sons Ltd., ISBN 0-471-92178-5, 1989.
Frigstad, H., Kaste, Ø., Deininger, A., Kvalsund, K., Christensen, G., Bellerby, R. G. J., Sørensen, K., Norli, M., and King, A. L.: Influence of riverine input on Norwegian coastal systems, Frontiers in Marine Science, 7, 332, https://doi.org/10.3389/fmars.2020.00332, 2020.
Furnes, G. K., Hackett, B., and Sætre, R.: Retroflection of Atlantic water in the Norwegian Trench, Deep Sea Research Part A. Oceanographic Research Papers, 33, 247–265, https://doi.org/10.1016/0198-0149(86)90121-4, 1986.
García-Moreiras, I., Amorim, A., Pospelova, V., Zonneveld, K., Anderson, D. M., Beedessee, G., Dale, A., Dale, B., David, O., de Vernal, A., Fatourou, E., Folie-Boivin, E., Helenes, J., García-Portela, M., Gu, F., Gu, H., Iratçabal, V., Janouškovec, J., Limoges, A., Marret, F., Meyvisch, P., Nkouefuth Nfongmo, Y., Pochic, V., Reguera, B., Sangiorgi, F., Roza, S. E. V., Van Nieuwenhove, N., Williams, R. W., Winifred, V., and Mertens, K. N.: Progress, challenges and future directions in marine organic-walled dinoflagellate cyst research: new insights from an international workshop, Mar. Micropaleontol., 201, 102502, htps://doi.org/10.1016/j.marmicro.2025.102502, 2025.
Goldberg, E. D.: Marine geochemistry 1. Chemical scavengers of the sea, The Journal of Geology, 62, 249–265, https://doi.org/10.1086/626161, 1954.
Gurdebeke, P. R., Mertens, K. N., Takano, Y., Yamaguchi, A., Bogus, K., Dunthorn, M., Matsuoka, K., Vrielink, H., and Louwye, S.: The affiliation of Hexasterias problematica and Halodinium verrucatum sp. nov. to ciliate cysts based on molecular phylogeny and cyst wall composition, European Journal of Protistology, 66, 115–135, https://doi.org/10.1016/j.ejop.2018.09.002, 2018.
Gurdebeke, P., Mertens, K. N., Lubomir, R., Meyvisch, P., Potvin, E., Yang, E. J., André, C., Pospelova, V., and Louwye, S.: Alphonse Meunier's enigmatic Radiosperma belongs to the ciliates, in: VLIZ Marine Science Day 2023, 90, 63–63, https://doi.org/10.48470/41, 2023.
Gray, D. D., Zonneveld, K. A., and Versteegh, G. J.: Species-specific sensitivity of dinoflagellate cysts to aerobic degradation: a five-year natural exposure experiment, Review of Palaeobotany and Palynology, 247, 175–187, https://doi.org/10.1016/j.revpalbo.2017.09.002, 2017.
Grøsfjeld, K. and Harland, R.: Distribution of modern dinoflagellate cysts from inshore areas along the coast of southern Norway, Journal of Quaternary Science: Published for the Quaternary Research Association, 16, 651–659, https://doi.org/10.1002/jqs.653, 2001.
Gu, H., Liu, T., and Mertens, K. N.: Cyst–theca relationship and phylogenetic positions of Protoperidinium (Peridiniales, Dinophyceae) species of the sections Conica and Tabulata , with description of Protoperidinium shanghaiense sp. nov., Phycologia, 54, 49–66, https://doi.org/10.2216/14-047.1, 2015.
Head, M. J. and Mantilla-Duran, F.: Atlanticodinium striaticonulum n. gen., n. sp., a widespread extant dinoflagellate cyst from the late Cenozoic, and its comparison with Atlanticodinium janduchenei (Head et al., 1989) n. comb., Marine Micropaleontology, 159, 101774, https://doi.org/10.1016/j.marmicro.2019.101774, 2020.
Hedges, J. I. and Keil, R. G.: Sedimentary organic matter preservation: an assessment and speculative synthesis, Marine Chemistry, 49, 81–115, https://doi.org/10.1016/0304-4203(95)00008-F, 1995.
Heusser, L.: Spores and pollen in the marine realm, Introduction to Marine Micropaleontology, 327–339, https://doi.org/10.1016/B978-044482672-5/50014-3, 1998.
Hickel, W., Mangelsdorf, P., and Berg, J.: The human impact in the German Bight: eutrophication during three decades (1962–1991), Helgoländer Meeresuntersuchungen, 47, 243–263, https://doi.org/10.1007/BF02367167, 1993.
Hilgen, C. S., Hennekam, R., van der Meer, M. T. J., Donders, T. H., Reichart, G. J., and Sangiorgi, F.: Palynomorph and dinocyst assemblages, water column and sediment properties, and dinocyst-based proxies along the Baltic Sea-North Sea-Atlantic transect, Zenodo [data set], https://doi.org/10.5281/zenodo.15837224, 2026.
Jacobson, D. M. and Anderson, D. M.: Thecate heterophic dinoflagellates: feeding behavior and mechanisms, Journal of Phycology, 22, 249–258, https://doi.org/10.1111/j.1529-8817.1986.tb00021.x, 1986.
Jeong, H. J., Du Yoo, Y., Park, J. Y., Song, J. Y., Kim, S. T., Lee, S. H., Kim, K. Y., and Yih, W. H.: Feeding by phototrophic red-tide dinoflagellates: five species newly revealed and six species previously known to be mixotrophic, Aquatic Microbial. Ecology, 40, 133–150, https://doi.org/10.3354/ame040133, 2005.
Jeong, H. J., Seong, K. A., Yoo, Y. D., Kim, T. H., Kang, N. S., Kim, S., Park, J. Y., Kim, J. S., Kim, G. H., and Song, J. Y.: Feeding and grazing impact by small marine heterotrophic dinoflagellates on heterotrophic bacteria, Journal of Eukaryotic Microbiology, 55, 271–288, https://doi.org/10.1111/j.1550-7408.2008.00336.x, 2008.
Kim, S. Y., Lim, D. I., and Cho, H. J.: Dinoflagellate cyst assemblages from the northern shelf sediments of the East China Sea: an indicator of marine productivity, Marine Micropaleontology, 96, 75–83, https://doi.org/10.1016/j.marmicro.2012.09.003, 2012.
Lambert, C., Penaud, A., Poirier, C., and Goubert, E.: Distribution of modern dinocysts in surface sediments of southern Brittany (NW France) in relation to environmental parameters: implications for paleoreconstructions, Review of Palaeobotany and Palynology, 297, 104578, https://doi.org/10.1016/j.revpalbo.2021.104578, 2022.
Legge, O., Johnson, M., Hicks, N., Jickells, T., Diesing, M., Aldridge, J., and Williamson, P.: Carbon on the northwest European shelf: contemporary budget and future influences, Frontiers in Marine Science, 7, 143, https://doi.org/10.3389/fmars.2020.00143, 2020.
Leppäranta, M. and Myrberg, K.: Topography and hydrography of the Baltic Sea, Physical oceanography of the Baltic Sea, Springer, Berlin, Heidelberg, https://doi.org/10.1007/978-3-540-79703-6_5, 2009.
Marret, F., Bradley, L., de Vernal, A., Hardy, W., Kim, S. Y., Mudie, P., Penaud, A., Pospelova, V., Price, A. M., Radi, T., and Rochon, A.: From bi-polar to regional distribution of modern dinoflagellate cysts: an overview of their biogeography, Marine Micropaleontology, 159, 101753, https://doi.org/10.1016/j.marmicro.2019.101753, 2020.
Mertens, K. N., Verhoeven, K., Verleye, T., Louwye, S., Amorim, A., Ribeiro, S., Deaf, A. S., Harding, I. C., De Schepper, S., González, C., Kodrans-Nsiah, M., De Vernal, A., Henry, M., Radi, T., Dybkjaer, K., Poulsen, N. E., Feist-Burkhardt, S., Chitolie, J., Heilmann-Clausen, C., Londeix, L., Torun, J.-L., Marret, F., Matthiessen, J., McCarthy, F. M. G., Prasad, V., Pospelova, V., Hughes, J. E. K., Riding, J. B., Rochon, A., Sangiorgi, F., Welters, N., Sinclair, N., Thun, C., Soliman, A., Van Nieuwenhove, N., Vink, A., and Young, M.: Determining the absolute abundance of dinoflagellate cysts in recent marine sediments: The Lycopodium marker-grain method put to the test, Review of Palaeobotany and Palynology, 157, 238–252, https://doi.org/10.1016/j.revpalbo.2009.05.004, 2009.
Mertens, K. N., Dale, B., Ellegaard, M., Jansson, I. M., Godhe, A., Kremp, A., and Louwye, S.: Process length variation in cysts of the dinoflagellate Protoceratium reticulatum, from surface sediments of the Baltic–Kattegat–Skagerrak estuarine system: a regional salinity proxy, Review of Palaeobotany and Palynology, 40, 242–255, https://doi.org/10.1111/j.1502-3885.2010.00191.x, 2011.
Meyers, P. A.: Preservation of elemental and isotopic source identification of sedimentary organic matter, Chemical Geology, 114, 289–302, https://doi.org/10.1016/0009-2541(94)90059-0, 1994.
Mork, M.: Circulation phenomena and frontal dynamics of the Norwegian Coastal Current, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 302, 635–647, https://doi.org/10.1098/rsta.1981.0188, 1981.
Mudie, P. J., Marret, F., Gurdebeke, P. R., Hartman, J. D., and Reid, P. C.: Marine dinocysts, acritarchs and less well-known NPP: tintinnids, ostracod and foraminiferal linings, copepod and worm remains, in: Applications of Non-Pollen Palynomorphs: from Palaeoenvironmental Reconstructions to Biostratigraphy, edited by: Marret, F., O'Keefe, J., Osterloff, P., Pound, M., and Shumilovskikh, L., Geological Society, London, Special Publications, 511, https://doi.org/10.1144/SP511-2020-55, 2021.
Nittrouer, C. A. and Wright, L. D.: Transport of particles across continental shelves, Reviews of Geophysics, 32, 85–113, https://doi.org/10.1029/93RG02603, 1994.
Oksanen, J., Simpson, G. L., Blanchet, F. G., Kindt, R., Legendre, P., Minchin, P. R., O'Hara, R. B., Solymos, P., Stevens, M. H. H., Szoecs, E., Wagner, H., Barbour, M., Bedward, M., Bolker, B., Borcard, D., Borman, T., Carvalho, G., Chirico, M., De Caceres, M., Durand, S., Evangelista, H. B. A., FitzJohn, R., Friendly, M., Furneaux, B., Hannigan, G., Hill, M. O., Lahti, L., Martino, C., McGlinn, D., Ouellette, M.-H., Cunha, E. R., Smith, T., Stier, A., Ter Braak, C. J. F., and Weedon, J.: Package “vegan”, Community Ecology Package, 2, 1–295, 2013.
Pearson, K.: VII. Note on regression and inheritance in the case of two parents, Proceedings of the Royal Society of London, 58, 240–242, https://doi.org/10.1098/rspl.1895.0041, 1895.
Penaud, A., Hardy, W., Lambert, C., Marret, F., Masure, E., Servais, T., Siano, R., Wary, M., and Mertens, K. N.: Dinoflagellate fossils: geological and biological applications, Revue de Micropaléontologie, 61, 235–254, https://doi.org/10.1016/j.revmic.2018.09.003, 2018.
Pospelova, V., de Vernal, A., and Pedersen, T. F.: Distribution of dinoflagellate cysts in surface sediments from the northeastern Pacific Ocean (43–25° N) in relation to sea-surface temperature, salinity, productivity and coastal upwelling, Marine Micropaleontology, 68, 21–48, https://doi.org/10.1016/j.marmicro.2008.01.008, 2008.
Price, A. M. and Pospelova, V.: High-resolution sediment trap study of organic-walled dinoflagellate cyst production and biogenic silica flux in Saanich Inlet (BC, Canada), Marine Micropaleontology, 80, 18–43, https://doi.org/10.1016/j.marmicro.2011.03.003, 2011.
Punt, W. and Clarke, G. C. S. (Eds.): The Northwest European Pollen Flora: Reprinted from Review of Palaeobotany and Palynology, Elsevier, Vol. 33, ISBN 0-444-41883-0, 2016.
Radi, T. and de Vernal, A.: Dinocysts as proxy of primary productivity in mid–high latitudes of the Northern Hemisphere, Marine Micropaleontology, 68, 84–114, https://doi.org/10.1016/j.marmicro.2008.01.012, 2008.
Radi, T., Pospelova, V., de Vernal, A., and Barrie, J. V.: Dinoflagellate cysts as indicators of water quality and productivity in British Columbia estuarine environments, Marine Micropaleontology, 62, 269–297, https://doi.org/10.1016/j.marmicro.2006.09.002, 2007.
Rahm, L., Conley, D., Sandén, P., Wulff, F., and Stålnacke, P.: Time series analysis of nutrient inputs to the Baltic Sea and changing DSi:DIN ratios, Mar. Ecol. Prog. Ser., 130, 221–228, https://doi.org/10.3354/meps130221, 1996.
Reagan, J. R., Boyer, T. P., García, H. E., Locarnini, R. A., Baranova, O. K., Bouchard, C., Cross, S. L., Mishonov, A. V., Paver, C. R., Seidov, D., Wang, Z., and Dukhovskoy, D.: World Ocean Atlas 2023, NOAA National Centers for Environmental Information [data set], 0270533, https://doi.org/10.25923/rb67-ns53, 2024.
Redfield, A. C.: On the proportions of organic derivations in sea water and their relation to the composition of plankton, in: James Johnstone Memorial Volume, edited by: Daniel, R. J., University Press of Liverpool, Liverpool, UK, 176–192, 1934.
Reichart, G. J. and Brinkhuis, H.: Late Quaternary Protoperidinium cysts as indicators of paleoproductivity in the northern Arabian Sea, Marine Micropaleontology, 49, 303–315, https://doi.org/10.1016/S0377-8398(03)00050-1, 2003.
Rochon, A., de Vernal, A., Turon, J. L., Matthiessen, J., and Head, M. J.: Distribution of recent dinoflagellate cysts in surface sediments from the North Atlantic Ocean and adjacent seas in relation to sea-surface parameters, American Association of Stratigraphic Palynologists Contribution Series, 35, 1–146, 1999.
Sangiorgi, F. and Donders, T. H.: Reconstructing 150 years of eutrophication in the north-western Adriatic Sea (Italy) using dinoflagellate cysts, pollen and spores, Estuarine, Coastal and Shelf Science, 60, 69–79, https://doi.org/10.1016/j.ecss.2003.12.001, 2004.
Schoepfer, S. D., Shen, J., Wei, H., Tyson, R. V., Ingall, E., and Algeo, T. J.: Total organic carbon, organic phosphorus, and biogenic barium fluxes as proxies for paleomarine productivity, Earth-Science Reviews, 149, 23–52, https://doi.org/10.1016/j.earscirev.2014.08.017, 2015.
Sildever, S., Andersen, T. J., Ribeiro, S., and Ellegaard, M.: Influence of surface salinity gradient on dinoflagellate cyst community structure, abundance and morphology in the Baltic Sea, Kattegat and Skagerrak, Estuarine, Coastal and Shelf Science, 155, 1–7, https://doi.org/10.1016/j.ecss.2015.01.003, 2015.
Simpson, G. L.: Analogue methods in palaeoecology: Using the analogue package, J. Stat. Softw., 22, https://doi.org/10.18637/jss.v022.i02, 2007.
Snoeijs-Leijonmalm, P., Schubert, H., and Radziejewska, T. (Eds.): Biological Oceanography of the Baltic Sea, Springer Science and Business Media, https://doi.org/10.1007/978-94-007-0668-2, 2017.
Stockmarr, J.: Tables with spores used in absolute pollen analysis, Pollen Spores, 13, 615–621, 1971.
Ter Braak, C. J.: Canonical correspondence analysis: a new eigenvector technique for multivariate direct gradient analysis, Ecology, 67, 1167–1179, https://doi.org/10.2307/1938672, 1986.
Thomas, H., Bozec, Y., Elkalay, K., and de Baar, H. J.: Enhanced open-ocean storage of CO2 from shelf-sea pumping, Science, 304, 1005–1008, https://doi.org/10.1126/science.1095491, 2004.
Thorsen, T. A. and Dale, B.: Climatically influenced distribution of Gymnodinium catenatum during the past 2000 years in coastal sediments of southern Norway, Palaeogeography, Palaeoclimatology, Palaeoecology, 143, 159–177, https://doi.org/10.1016/S0031-0182(98)00079-0, 1998.
Tyson, R. V. and Pearson, T. H.: Modern and ancient continental shelf anoxia: an overview, SP, 58, 1–24, https://doi.org/10.1144/GSL.SP.1991.058.01.01, 1991.
Versteegh, G. J. and Zonneveld, K. A.: Use of selective degradation to separate preservation from productivity, Geology, 30, 615–618, https://doi.org//10.1130/0091-7613(2002)030%3C0615:UOSDTS%3E2.0.CO;2TS38, 2002.
Wakelin, S. L., Holt, J. T., Blackford, J. C., Allen, J. I., Butenschön, M., and Artioli, Y.: Modeling the carbon fluxes of the northwest European continental shelf: validation and budgets, Journal of Geophysical Research: Oceans, 117, https://doi.org/10.1029/2011JC007402, 2012.
Wang, Z., Zhang, Y., Lei, M., Ji, S., Chen, J., Zheng, H., Tang, Y., and Hu, R.: Distribution of dinoflagellate cysts in surface sediments from the Qingdao Coast, Yellow Sea, China: the potential risk of harmful algal blooms, Frontiers in Marine Science, 9, 910327, https://doi.org/10.3389/fmars.2022.910327, 2022.
Williams, G., Fensome, R., and McRae, R.: The Lentin and Williams Index of Fossil Dinoflagellates, 2017 Edn., American Association of Stratigraphic Palynologists Foundation, Contribution Series, AASP Contributions Series Number 48, ISSN 0160-8843, 2017.
Willumsen, P. S., Filipsson, H. L., Reinholdsson, M., and Lenz, C.: Surface salinity and nutrient variations during the Littorina Stage in the Fårö Deep, Baltic Sea, Boreas, 42, 210–223, https://doi.org/10.1111/j.1502-3885.2012.00286.x, 2013.
Winther, N. G. and Johannessen, J. A.: North Sea circulation: Atlantic inflow and its destination, Journal of Geophysical Research: Oceans, 111, https://doi.org/10.1029/2005JC003310, 2006.
Wu, X., de Vernal, A., and Allan, E.: Migration of deep convection center in subpolar North Atlantic around 6 ka suggested by a dinocyst proxy of mixed layer depth, Paleoceanogr. Paleoclim., 40, https://doi.org/10.1029/2024PA004998, 2025.
Yedema, Y. W., Donders, T., Peterse, F., and Sangiorgi, F.: Dinoflagellate cyst and pollen assemblages as tracers for marine productivity and river input in the northern Gulf of Mexico, J. Micropalaeontol., 42, 257–276, https://doi.org/10.5194/jm-42-257-2023, 2023.
Zonneveld, K. A. and Pospelova, V.: A determination key for modern dinoflagellate cysts, Palynology, 39, 387–409, https://doi.org/10.1080/01916122.2014.990115, 2015.
Zonneveld, K. A., Bockelmann, F., and Holzwarth, U.: Selective preservation of organic-walled dinoflagellate cysts as a tool to quantify past net primary production and bottom-water oxygen concentrations, Marine Geology, 237, 109–126, https://doi.org/10.1016/j.margeo.2006.10.023, 2007.
Zonneveld, K. A., Versteegh, G., and Kodrans-Nsiah, M.: Preservation and organic chemistry of Late Cenozoic organic-walled dinoflagellate cysts: A review, Mar. Micropaleontol., 68, 179–197, https://doi.org/10.1016/j.marmicro.2008.01.015, 2008.
Zonneveld, K. A., Chen, L., Möbius, J., and Mahmoud, M. S.: Environmental significance of dinoflagellate cysts from the proximal part of the Po-river discharge plume (off southern Italy, Eastern Mediterranean), J. Sea Res., 62, 189–213, https://doi.org/10.1016/j.seares.2009.02.003, 2009.
Zonneveld, K. A. F., Marret, F., Versteegh, G. J. M., Bogus, K., Bonnet, S., Bouimetarhan, I., Crouch, E., de Vernal, A., Elshanawany, R., Edwards, L., Esper, O., Forke, S., Grøsfjeld, K., Henry, M., Holzwarth, U., Kielt, J.-F., Kim, S.Y., Ladouceur, S., Ledu, D., Chen, L., Limoges, A., Londeix, L., Lu, S.-H., Mahmoud, M. S., Marino, G., Matsouka, K., Matthiessen, J., Mildenhal, D. C., Mudie, P., Neil, H. L., Pospelova, V., Qi, Y., Radi, T., Richerol, T., Rochon, A., Sangiorgi, F., Solignac, S., Turon, J.-L., Verleye, T., Wang, Y., Wang, Z., and Young, M.: Atlas of modern dinoflagellate cyst distribution based on 2405 data points, Rev. Palaeobot. Palyno., 191, 1197, https://doi.org/10.1016/j.revpalbo.2012.08.003, 2013.
Zwiep, K., Hennekam R., Donders T., van Helmond N., de Lange G., and Sangiorgi F.: Marine productivity, water column dynamics and seafloor anoxia in relation to Nile discharge during sapropels S1 and S3, Quaternary Science Reviews, 200, 178–190, https://doi.org/10.1016/j.quascirev.2018.08.026, 2018.
Short summary
The Northwest European Shelf plays a key role in the global carbon cycle. To assess its past role, we want to reconstruct primary productivity using microfossils. By comparing surface sediment assemblages with sediment properties and modern environmental conditions, we found a good microfossil-based indicator for primary productivity. This indicator will be useful to reconstruct productivity in the past Northwest European Shelf.
The Northwest European Shelf plays a key role in the global carbon cycle. To assess its past...
