Articles | Volume 15, issue 13
Research article 05 Jul 2018
Research article | 05 Jul 2018
A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century
Sami A. Jokinen et al.
No articles found.
Karol Kuliński, Gregor Rehder, Eero Asmala, Alena Bartosova, Jacob Carstensen, Bo Gustafsson, Per O. J. Hall, Christoph Humborg, Tom Jilbert, Klaus Jürgens, Markus Meier, Bärbel Müller-Karulis, Michael Naumann, Jørgen E. Olesen, Oleg Savchuk, Andreas Schramm, Caroline P. Slomp, Mikhail Sofiev, Anna Sobek, Beata Szymczycha, and Emma Undeman
Earth Syst. Dynam. Discuss.,
Preprint under review for ESDShort summary
In its content, the paper covers the aspects related to changes in carbon, nitrogen and phosphorus (C, N, P) external loads, their transformations in the coastal zone, changes in organic matter production (eutrophication) and remineralization (oxygen availability), and the role of sediments in burial and turnover of C, N and P. Furthermore, this paper focuses also on changes in the marine CO2 system, structure of the microbial community and the role of contaminants for biogeochemical processes.
Joonas J. Virtasalo, Peter Österholm, Aarno T. Kotilainen, and Mats E. Åström
Biogeosciences, 17, 6097–6113,Short summary
Rivers draining the acid sulphate soils of western Finland deliver large amounts of metals (e.g. Cd, Co, Cu, La, Mn, Ni, and Zn) to the coastal sea. To better understand metal enrichment in the sea floor, we analysed metal contents and grain size distribution in nine sediment cores, which increased in the 1960s and 1970s and stayed at high levels afterwards. The enrichment is visible more than 25 km out from the river mouths. Organic aggregates are suggested as the key seaward metal carriers.
Jérôme Kaiser, Norbert Wasmund, Mati Kahru, Anna K. Wittenborn, Regina Hansen, Katharina Häusler, Matthias Moros, Detlef Schulz-Bull, and Helge W. Arz
Biogeosciences, 17, 2579–2591,Short summary
Cyanobacterial blooms represent a threat to the Baltic Sea ecosystem, causing deoxygenation of the bottom water. In order to understand the natural versus anthropogenic factors driving these blooms, it is necessary to study long-term trends beyond observations. We have produced a record of cyanobacterial blooms since 1860 using organic molecules (biomarkers) preserved in sediments. Cyanobacterial blooms in the Baltic Sea are likely mainly related to temperature variability.
Elizabeth Atar, Christian März, Andrew C. Aplin, Olaf Dellwig, Liam G. Herringshaw, Violaine Lamoureux-Var, Melanie J. Leng, Bernhard Schnetger, and Thomas Wagner
Clim. Past, 15, 1581–1601,Short summary
We present a geochemical and petrographic study of the Kimmeridge Clay Formation from the Cleveland Basin (Yorkshire, UK). Our results indicate that deposition during this interval was very dynamic and oscillated between three distinct modes of sedimentation. In line with recent modelling results, we propose that these highly dynamic conditions were driven by changes in climate, which affected continental weathering, enhanced primary productivity, and led to organic carbon enrichment.
Joonas J. Virtasalo, Jan F. Schröder, Samrit Luoma, Juha Majaniemi, Juha Mursu, and Jan Scholten
Solid Earth, 10, 405–423,Short summary
This study establishes the local stratigraphy and 3-D aquifer geometry of a submarine groundwater discharge site in the Hanko Peninsula, south Finland. The study is based on a rich dataset of marine seismic profiles, multibeam and side-scan sonar images of the seafloor, and onshore ground-penetrating radar and refraction seismic profiles. The groundwater discharge takes place through metre-scale pockmarks on the seafloor, confirmed by elevated radon concentrations in the overlying water.
Joonas J. Virtasalo, Jan F. Schröder, Samrit Luoma, Juha Majaniemi, Juha Mursu, and Jan Scholten
Hydrol. Earth Syst. Sci. Discuss.,
Preprint withdrawnShort summary
Submarine groundwater discharge (SGD) is a significant source of nutrients and other potentially harmful substances to coastal sea. We analyse a rich dataset of offshore seismic sub-bottom profiles, multibeam and sidescan sonar images of seafloor, and onshore ground-penetrating radar profiles to establish the geometry of an SGD site in south Finland. The SGD takes place through meter scale pits (pockmarks) on the seafloor, confirmed by elevated radon concentrations in the overlying water.
Claire Waelbroeck, Sylvain Pichat, Evelyn Böhm, Bryan C. Lougheed, Davide Faranda, Mathieu Vrac, Lise Missiaen, Natalia Vazquez Riveiros, Pierre Burckel, Jörg Lippold, Helge W. Arz, Trond Dokken, François Thil, and Arnaud Dapoigny
Clim. Past, 14, 1315–1330,Short summary
Recording the precise timing and sequence of events is essential for understanding rapid climate changes and improving climate model predictive skills. Here, we precisely assess the relative timing between ocean and atmospheric changes, both recorded in the same deep-sea core over the last 45 kyr. We show that decreased mid-depth water mass transport in the western equatorial Atlantic preceded increased rainfall over the adjacent continent by 120 to 980 yr, depending on the type of climate event.
Tom Jilbert, Eero Asmala, Christian Schröder, Rosa Tiihonen, Jukka-Pekka Myllykangas, Joonas J. Virtasalo, Aarno Kotilainen, Pasi Peltola, Päivi Ekholm, and Susanna Hietanen
Biogeosciences, 15, 1243–1271,Short summary
Iron is a common dissolved element in river water, recognizable by its orange-brown colour. Here we show that when rivers reach the ocean much of this iron settles to the sediments by a process known as flocculation. The iron is then used by microbes in coastal sediments, which are important hotspots in the global carbon cycle.
Björn Klaes, Rolf Kilian, Gerhard Wörner, Sören Thiele-Bruhn, and Helge W. Arz
E&G Quaternary Sci. J., 67, 1–6,
Jukka-Pekka Myllykangas, Tom Jilbert, Gunnar Jakobs, Gregor Rehder, Jan Werner, and Susanna Hietanen
Earth Syst. Dynam., 8, 817–826,Short summary
The deep waters of the Baltic Sea host an expanding
dead zone, where low-oxygen conditions favour the natural production of two strong greenhouse gases, methane and nitrous oxide. Oxygen is introduced into the deeps only during rare
salt pulses. We studied the effects of a recent salt pulse on Baltic greenhouse gas production. We found that where oxygen was introduced, methane was largely removed, while nitrous oxide production increased, indicating strong effects on greenhouse gas dynamics.
Matthias Egger, Peter Kraal, Tom Jilbert, Fatimah Sulu-Gambari, Célia J. Sapart, Thomas Röckmann, and Caroline P. Slomp
Biogeosciences, 13, 5333–5355,Short summary
By combining detailed geochemical analyses with diagenetic modeling, we provide new insights into how methane dynamics may strongly overprint burial records of iron, sulfur and phosphorus in marine systems subject to changes in organic matter loading or water column salinity. A better understanding of these processes will improve our ability to read ancient sediment records and thus to predict the potential consequences of global warming and human-enhanced inputs of nutrients to the ocean.
C. Lenz, T. Jilbert, D.J. Conley, M. Wolthers, and C.P. Slomp
Biogeosciences, 12, 4875–4894,
H. Kuehn, L. Lembke-Jene, R. Gersonde, O. Esper, F. Lamy, H. Arz, G. Kuhn, and R. Tiedemann
Clim. Past, 10, 2215–2236,Short summary
Annually laminated sediments from the NE Bering Sea reveal a decadal-scale correlation to Greenland ice core records during termination I, suggesting an atmospheric teleconnection. Lamination occurrence is tightly coupled to Bølling-Allerød and Preboreal warm phases. Increases in export production, closely coupled to SST and sea ice changes, are hypothesized to be a main cause of deglacial anoxia, rather than changes in overturning/ventilation rates of mid-depth waters entering the Bering Sea.
L. S. Shumilovskikh, D. Fleitmann, N. R. Nowaczyk, H. Behling, F. Marret, A. Wegwerth, and H. W. Arz
Clim. Past, 10, 939–954,
Related subject area
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(Panzano Bay, Gulf of Trieste)Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processesDinocyst assemblage constraints on oceanographic and atmospheric processes in the eastern equatorial Atlantic over the last 44 kyrSedimentary response to sea ice and atmospheric variability over the instrumental period off Adélie Land, East AntarcticaEquatorward phytoplankton migration during a cold spell within the Late Cretaceous super-greenhouseUpwellings mitigated Plio-Pleistocene heat stress for reef corals on the Florida platform (USA)Millennial changes in North Atlantic oxygen concentrationsVanishing coccolith vital effects with alleviated carbon limitationLate Pleistocene glacial–interglacial shell-size–isotope variability in planktonic foraminifera as a function of local hydrographyCoral records of reef-water pH across the central Great Barrier Reef, Australia: assessing the influence of river runoff on inshore 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Catherine V. Davis, Karen Wishner, Willem Renema, and Pincelli M. Hull
Biogeosciences, 18, 977–992,
Práxedes Muñoz, Lorena Rebolledo, Laurent Dezileau, Antonio Maldonado, Christoph Mayr, Paola Cárdenas, Carina B. Lange, Katherine Lalangui, Gloria Sanchez, Marco Salamanca, Karen Araya, Ignacio Jara, Gabriel Easton, and Marcel Ramos
Biogeosciences, 17, 5763–5785,Short summary
We analyze marine sedimentary records to study temporal changes in oxygen and productivity in marine waters of central Chile. We observed increasing oxygenation and decreasing productivity from 6000 kyr ago to the modern era that seem to respond to El Niño–Southern Oscillation activity. In the past centuries, deoxygenation and higher productivity are re-established, mainly in the northern zones of Chile and Peru. Meanwhile, in north-central Chile the deoxygenation trend is maintained.
Luka Šupraha and Jorijntje Henderiks
Biogeosciences, 17, 2955–2969,Short summary
The cell size, degree of calcification and growth rates of coccolithophores impact their role in the carbon cycle and may also influence their adaptation to environmental change. Combining insights from culture experiments and the fossil record, we show that the selection for smaller cells over the past 15 Myr has been a common adaptive trait among different lineages. However, heavily calcified species maintained a more stable biogeochemical output than the ancestral lineage of E. huxleyi.
Niels J. de Winter, Clemens V. Ullmann, Anne M. Sørensen, Nicolas Thibault, Steven Goderis, Stijn J. M. Van Malderen, Christophe Snoeck, Stijn Goolaerts, Frank Vanhaecke, and Philippe Claeys
Biogeosciences, 17, 2897–2922,Short summary
In this study, we present a detailed investigation of the chemical composition of 12 specimens of very well preserved, 78-million-year-old oyster shells from southern Sweden. The chemical data show how the oysters grew, the environment in which they lived and how old they became and also provide valuable information about which chemical measurements we can use to learn more about ancient climate and environment from such shells. In turn, this can help improve climate reconstructions and models.
Hannah M. Palmer, Tessa M. Hill, Peter D. Roopnarine, Sarah E. Myhre, Katherine R. Reyes, and Jonas T. Donnenfield
Biogeosciences, 17, 2923–2937,Short summary
Modern climate change is causing expansions of low-oxygen zones, with detrimental impacts to marine life. To better predict future ocean oxygen change, we study past expansions and contractions of low-oxygen zones using microfossils of seafloor organisms. We find that, along the San Diego margin, the low-oxygen zone expanded into more shallow water in the last 400 years, but the conditions within and below the low-oxygen zone did not change significantly in the last 1500 years.
Yuanyuan Hong, Moriaki Yasuhara, Hokuto Iwatani, and Briony Mamo
Biogeosciences, 16, 585–604,Short summary
This study analyzed microfaunal assemblages in surface sediments from 52 sites in Hong Kong marine waters. We selected 18 species for linear regression modeling to statistically reveal the relationship between species distribution and environmental factors. These results show environmental preferences of commonly distributed species on Asian coasts, providing a robust baseline for past environmental reconstruction of the broad Asian region using microfossils in sediment cores.
Jorge Domingo Carrillo-Briceño, Zoneibe Luz, Austin Hendy, László Kocsis, Orangel Aguilera, and Torsten Vennemann
Biogeosciences, 16, 33–56,Short summary
By combining taxonomy and geochemistry, we corroborated the described paleoenvironments from a Neogene fossiliferous deposit of South America. Shark teeth specimens were used for taxonomic identification and as proxies for geochemical analyses. With a multidisciplinary approach we refined the understanding about the paleoenvironmental setting and the paleoecological characteristics of the studied groups, in our case, for the bull shark and its incursions into brackish waters.
Anna Binczewska, Bjørg Risebrobakken, Irina Polovodova Asteman, Matthias Moros, Amandine Tisserand, Eystein Jansen, and Andrzej Witkowski
Biogeosciences, 15, 5909–5928,Short summary
Primary productivity is an important factor in the functioning and structuring of the coastal ecosystem. Thus, two sediment cores from the Skagerrak (North Sea) were investigated in order to obtain a comprehensive picture of primary productivity changes during the last millennium and identify associated forcing factors (e.g. anthropogenic, climate). The cores were dated and analysed for palaeoproductivity proxies and palaeothermometers.
Saúl González-Lemos, José Guitián, Miguel-Ángel Fuertes, José-Abel Flores, and Heather M. Stoll
Biogeosciences, 15, 1079–1091,Short summary
Changes in atmospheric carbon dioxide affect ocean chemistry and the ability of marine organisms to manufacture shells from calcium carbonate. We describe a technique to obtain more reproducible measurements of the thickness of calcium carbonate shells made by microscopic marine algae called coccolithophores, which will allow researchers to compare how the shell thickness responds to variations in ocean chemistry in the past and present.
Ulrich Kotthoff, Jeroen Groeneveld, Jeanine L. Ash, Anne-Sophie Fanget, Nadine Quintana Krupinski, Odile Peyron, Anna Stepanova, Jonathan Warnock, Niels A. G. M. Van Helmond, Benjamin H. Passey, Ole Rønø Clausen, Ole Bennike, Elinor Andrén, Wojciech Granoszewski, Thomas Andrén, Helena L. Filipsson, Marit-Solveig Seidenkrantz, Caroline P. Slomp, and Thorsten Bauersachs
Biogeosciences, 14, 5607–5632,Short summary
We present reconstructions of paleotemperature, paleosalinity, and paleoecology from the Little Belt (Site M0059) over the past ~ 8000 years and evaluate the applicability of numerous proxies. Conditions were lacustrine until ~ 7400 cal yr BP. A transition to brackish–marine conditions then occurred within ~ 200 years. Salinity proxies rarely allowed quantitative estimates but revealed congruent results, while quantitative temperature reconstructions differed depending on the proxies used.
Shuichang Zhang, Xiaomei Wang, Huajian Wang, Emma U. Hammarlund, Jin Su, Yu Wang, and Donald E. Canfield
Biogeosciences, 14, 2133–2149,
Liza M. Roger, Annette D. George, Jeremy Shaw, Robert D. Hart, Malcolm Roberts, Thomas Becker, Bradley J. McDonald, and Noreen J. Evans
Biogeosciences, 14, 1721–1737,Short summary
The shell compositions of bivalve species from south Western Australia are described here to better understand the factors involved in their formation. The shell composition can be used to reconstruct past environmental conditions, but certain species manifest an offset compared to the environmental parameters measured. As shown here, shells that experience the same conditions can present different compositions in relation to structure, organic composition and environmental conditions.
Johan Vellekoop, Lineke Woelders, Sanem Açikalin, Jan Smit, Bas van de Schootbrugge, Ismail Ö. Yilmaz, Henk Brinkhuis, and Robert P. Speijer
Biogeosciences, 14, 885–900,Short summary
The Cretaceous–Paleogene boundary, ~ 66 Ma, is characterized by a mass extinction. We studied groups of both surface-dwelling and bottom-dwelling organisms to unravel the oceanographic consequences of these extinctions. Our integrated records indicate that a reduction of the transport of organic matter to the sea floor resulted in enhanced recycling of nutrients in the upper water column and decreased food supply at the sea floor in the first tens of thousands of years after the extinctions.
Biogeosciences, 13, 6003–6014,Short summary
Marine planktonic diatoms are today both the main silica and carbon exporter to the deep sea. However, 50 million years ago, radiolarians were the main silica exporter and diatoms were a rare, geographically restricted group. Quantification of their rise to dominance suggest that diatom abundance is primarily controlled by the continental weathering and has a negative feedback, observable on a geological timescale, on the carbon cycle.
Jelena Vidović, Rafał Nawrot, Ivo Gallmetzer, Alexandra Haselmair, Adam Tomašových, Michael Stachowitsch, Vlasta Ćosović, and Martin Zuschin
Biogeosciences, 13, 5965–5981,Short summary
We studied the ecological history of the Gulf of Trieste. Before the 20th century, the only activity here was ore mining, releasing high amounts of mercury into its northern part, Panzano Bay. Mercury did not cause changes to microorganisms, as it is not bioavailable. In the 20th century, agriculture caused nutrient enrichment in the bay and increased diversity of microorganisms. Industrial activities increased the concentrations of pollutants, causing only minor changes to microorganisms.
Aurélie Penaud, Frédérique Eynaud, Antje Helga Luise Voelker, and Jean-Louis Turon
Biogeosciences, 13, 5357–5377,Short summary
This paper presents new analyses conducted at high resolution in the Gulf of Cadiz over the last 50 ky. Palaeohydrological changes in these subtropical latitudes are discussed through dinoflagellate cyst assemblages but also dinocyst transfer function results, implying sea surface temperature and salinity as well as annual productivity reconstructions. This study is thus important for our understanding of past and future productivity regimes, also implying consequences on the biological pump.
William Hardy, Aurélie Penaud, Fabienne Marret, Germain Bayon, Tania Marsset, and Laurence Droz
Biogeosciences, 13, 4823–4841,Short summary
Our approach is based on a multi-proxy study from a core collected off the Congo River and discusses surface oceanic conditions (upwelling cells, river-induced upwelling), land–sea interactions and terrestrial erosion and in particular enables us to spatially constrain the migration of atmospheric systems. This paper thus presents new data highlighting, with the highest resolution ever reached in this region, the great correlation between phytoplanktonic organisms and monsoonal mechanisms.
Philippine Campagne, Xavier Crosta, Sabine Schmidt, Marie Noëlle Houssais, Olivier Ther, and Guillaume Massé
Biogeosciences, 13, 4205–4218,Short summary
Diatoms and biomarkers have been recently used for palaeoclimate reconstructions in the Southern Ocean. Few sediment-based ecological studies have investigated their relationships with environmental conditions. Here, we compare high-resolution sedimentary records with meteorological data to study relationships between our proxies and recent atmospheric and sea surface changes. Our results indicate that coupled wind pattern and sea surface variability act as the proximal forcing at that scale.
Niels A. G. M. van Helmond, Appy Sluijs, Nina M. Papadomanolaki, A. Guy Plint, Darren R. Gröcke, Martin A. Pearce, James S. Eldrett, João Trabucho-Alexandre, Ireneusz Walaszczyk, Bas van de Schootbrugge, and Henk Brinkhuis
Biogeosciences, 13, 2859–2872,Short summary
Over the past decades large changes have been observed in the biogeographical dispersion of marine life resulting from climate change. To better understand present and future trends it is important to document and fully understand the biogeographical response of marine life during episodes of environmental change in the geological past. Here we investigate the response of phytoplankton, the base of the marine food web, to a rapid cold spell, interrupting greenhouse conditions during the Cretaceous.
Thomas C. Brachert, Markus Reuter, Stefan Krüger, Julia Kirkerowicz, and James S. Klaus
Biogeosciences, 13, 1469–1489,Short summary
We present stable isotope proxy data and calcification records from fossil reef corals. The corals investigated derive from the Florida carbonate platform and are of middle Pliocene to early Pleistocene age. From the data we infer an environment subject to intermittent upwelling on annual to decadal timescales. Calcification rates were enhanced during periods of upwelling. This is likely an effect of dampened SSTs during the upwelling.
B. A. A. Hoogakker, D. J. R. Thornalley, and S. Barker
Biogeosciences, 13, 211–221,Short summary
Models predict a decrease in future ocean O2, driven by surface water warming and freshening in the polar regions, causing a reduction in ocean circulation. Here we assess this effect in the past, focussing on the response of deep and intermediate waters from the North Atlantic during large-scale ice rafting and millennial-scale cooling events of the last glacial. Our assessment agrees with the models but also highlights the importance of biological processes driving ocean O2 change.
M. Hermoso, I. Z. X. Chan, H. L. O. McClelland, A. M. C. Heureux, and R. E. M. Rickaby
Biogeosciences, 13, 301–312,
B. Metcalfe, W. Feldmeijer, M. de Vringer-Picon, G.-J. A. Brummer, F. J. C. Peeters, and G. M. Ganssen
Biogeosciences, 12, 4781–4807,Short summary
Iron biogeochemical budgets during the natural ocean fertilisation experiment KEOPS-2 showed that complex circulation and transport pathways were responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. The exchange of iron between dissolved, biogenic and lithogenic pools was highly dynamic, resulting in a decoupling of iron supply and carbon export and controlling the efficiency of fertilisation.
J. P. D'Olivo, M. T. McCulloch, S. M. Eggins, and J. Trotter
Biogeosciences, 12, 1223–1236,Short summary
The boron isotope composition in the skeleton of massive Porites corals from the central Great Barrier Reef is used to reconstruct the seawater pH over the 1940-2009 period. The long-term decline in the coral-reconstructed seawater pH is in close agreement with estimates based on the CO2 uptake by surface waters due to rising atmospheric levels. We also observed a significant relationship between terrestrial runoff data and the inshore coral boron isotopes records.
J. Schönfeld, W. Kuhnt, Z. Erdem, S. Flögel, N. Glock, M. Aquit, M. Frank, and A. Holbourn
Biogeosciences, 12, 1169–1189,Short summary
Today’s oceans show distinct mid-depth oxygen minima while whole oceanic basins became transiently anoxic in the Mesozoic. To constrain past bottom-water oxygenation, we compared sediments from the Peruvian OMZ with the Cenomanian OAE 2 from Morocco. Corg accumulation rates in laminated OAE 2 sections match Holocene rates off Peru. Laminated deposits are found at oxygen levels of < 7µmol kg-1; crab burrows appear at 10µmol kg-1 today, both defining threshold values for palaeoreconstructions.
S. C. Löhr and M. J. Kennedy
Biogeosciences, 11, 4971–4983,
R. Hoffmann, J. A. Schultz, R. Schellhorn, E. Rybacki, H. Keupp, S. R. Gerden, R. Lemanis, and S. Zachow
Biogeosciences, 11, 2721–2739,
T. J. Algeo, P. A. Meyers, R. S. Robinson, H. Rowe, and G. Q. Jiang
Biogeosciences, 11, 1273–1295,
C. Berger, K. J. S. Meier, H. Kinkel, and K.-H. Baumann
Biogeosciences, 11, 929–944,
T. Caley, S. Zaragosi, J. Bourget, P. Martinez, B. Malaizé, F. Eynaud, L. Rossignol, T. Garlan, and N. Ellouz-Zimmermann
Biogeosciences, 10, 7347–7359,
N. Preto, C. Agnini, M. Rigo, M. Sprovieri, and H. Westphal
Biogeosciences, 10, 6053–6068,
I. Polovodova Asteman, K. Nordberg, and H. L. Filipsson
Biogeosciences, 10, 1275–1290,
J.-E. Tesdal, E. D. Galbraith, and M. Kienast
Biogeosciences, 10, 101–118,
L. Durantou, A. Rochon, D. Ledu, G. Massé, S. Schmidt, and M. Babin
Biogeosciences, 9, 5391–5406,
C. A. Grove, J. Zinke, T. Scheufen, J. Maina, E. Epping, W. Boer, B. Randriamanantsoa, and G.-J. A. Brummer
Biogeosciences, 9, 3063–3081,
D. Wall-Palmer, M. B. Hart, C. W. Smart, R. S. J. Sparks, A. Le Friant, G. Boudon, C. Deplus, and J. C. Komorowski
Biogeosciences, 9, 309–315,
S. F. Rella and M. Uchida
Biogeosciences, 8, 3545–3553,
M. C. Nash, U. Troitzsch, B. N. Opdyke, J. M. Trafford, B. D. Russell, and D. I. Kline
Biogeosciences, 8, 3331–3340,
A. Penaud, F. Eynaud, A. Voelker, M. Kageyama, F. Marret, J. L. Turon, D. Blamart, T. Mulder, and L. Rossignol
Biogeosciences, 8, 2295–2316,
D. Gallego-Torres, F. Martinez-Ruiz, P. A. Meyers, A. Paytan, F. J. Jimenez-Espejo, and M. Ortega-Huertas
Biogeosciences, 8, 415–431,
B. Williams, J. Halfar, R. S. Steneck, U. G. Wortmann, S. Hetzinger, W. Adey, P. Lebednik, and M. Joachimski
Biogeosciences, 8, 165–174,
B. van de Schootbrugge, D. Harazim, K. Sorichter, W. Oschmann, J. Fiebig, W. Püttmann, M. Peinl, F. Zanella, B. M. A. Teichert, J. Hoffmann, A. Stadnitskaia, and Y. Rosenthal
Biogeosciences, 7, 3123–3138,
L. Zillén and D. J. Conley
Biogeosciences, 7, 2567–2580,
D. Munsel, U. Kramar, D. Dissard, G. Nehrke, Z. Berner, J. Bijma, G.-J. Reichart, and T. Neumann
Biogeosciences, 7, 2339–2350,
C. J. Beer, R. Schiebel, and P. A. Wilson
Biogeosciences, 7, 2193–2198,
P. Martinez and R. S. Robinson
Biogeosciences, 7, 1–9,
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Oxygen deficiency is a major environmental problem deteriorating seafloor habitats especially in the coastal ocean with large human impact. Here we apply a wide set of chemical and physical analyses to a 1500-year long sediment record and show that, although long-term climate variability has modulated seafloor oxygenation in the coastal northern Baltic Sea, the oxygen loss over the 20th century is unprecedentedly severe, emphasizing the need to reduce anthropogenic nutrient input in the future.
Oxygen deficiency is a major environmental problem deteriorating seafloor habitats especially in...