You have already added 0 works in your ORCID record related to the merged Research product.
Hypoxia causes preservation of labile organic matter and changes seafloor microbial community composition (Black Sea)
Copyright policy )Bottom-water oxygen supply is a key factor governing the biogeochemistry and community composition of marine sediments. Whether it also determines carbon burial rates remains controversial. We investigated the effect of varying oxygen concentrations (170 to 0 μM O2) on microbial remineralization of organic matter in seafloor sediments and on community diversity of the northwestern Crimean shelf break. This study shows that 50% more organic matter is preserved in surface sediments exposed to hypoxia compared to oxic bottom waters. Hypoxic conditions inhibit bioturbation and decreased remineralization rates even within short periods of a few days. These conditions led to the accumulation of threefold more phytodetritus pigments within 40 years compared to the oxic zone. Bacterial community structure also differed between oxic, hypoxic, and anoxic zones. Functional groups relevant in the degradation of particulate organic matter, such as Flavobacteriia, Gammaproteobacteria, and Deltaproteobacteria, changed with decreasing oxygenation, and the microbial community of the hypoxic zone took longer to degrade similar amounts of deposited reactive matter. We conclude that hypoxic bottom-water conditions—even on short time scales—substantially increase the preservation potential of organic matter because of the negative effects on benthic fauna and particle mixing and by favoring anaerobic processes, including sulfurization of matter.
Hypoxia enhances organic matter preservation in marine sediments by changing benthic communities, bioturbation, and burial rates.
Medical Subject Headings: fungi sense organs skin and connective tissue diseases geographic locations
Microsoft Academic Graph classification: Hypoxia (environmental) Chemistry Bioturbation Ecology Anoxic waters Benthic zone Organic matter chemistry.chemical_classification Remineralisation Dissolved organic carbon Phytodetritus
Research Article, Research Articles, SciAdv r-articles, Marine Ecology, Benthic microbial communities, organic matter quality, dissolved organic matter, hypoxia, Black Sea, sediments, sulfurization, 570 Life sciences; biology, 610 Medicine & health, 360 Social problems & social services, Multidisciplinary
Research Article, Research Articles, SciAdv r-articles, Marine Ecology, Benthic microbial communities, organic matter quality, dissolved organic matter, hypoxia, Black Sea, sediments, sulfurization, 570 Life sciences; biology, 610 Medicine & health, 360 Social problems & social services, Multidisciplinary
Medical Subject Headings: fungi sense organs skin and connective tissue diseases geographic locations
Microsoft Academic Graph classification: Hypoxia (environmental) Chemistry Bioturbation Ecology Anoxic waters Benthic zone Organic matter chemistry.chemical_classification Remineralisation Dissolved organic carbon Phytodetritus
- Alfred Wegener Institute for Polar and Marine Research Germany
- Leibniz Association Germany
- University of Southampton United Kingdom
- Helmholtz Association of German Research Centres Germany
- Carl von Ossietzky University of Oldenburg Germany
107111
1 Burdige D. J., Preservation of organic matter in marine sediments: Controls, mechanisms, and an imbalance in sediment organic carbon budgets?Chem. Rev.107, 467–485 (2007).17249736 [PubMed]
2 Emerson S., Hedges J. I., Processes controlling the organic carbon content of open ocean sediments. Paleoceanography 3, 621–634 (1988). [OpenAIRE]
3 Canfield D. E., Factors influencing organic carbon preservation in marine sediments. Chem. Geol.114, 315–329 (1994).11539298 [PubMed]
4 Arndt S., Jørgensen B. B., LaRowe D. E., Middelburg J. J., Pancost R. D., Regnier P., Quantifying the degradation of organic matter in marine sediments: A review and synthesis. Earth-Sci. Rev.123, 53–86 (2013). [OpenAIRE]
5 Sun M.-Y., Aller R. C., Lee C., Wakeham S. G., Effects of oxygen and redox oscillation on degradation of cell-associated lipids in surficial marine sediments. Geochim. Cosmochim. Acta 66, 2003–2012 (2002).
6 Lee C., Controls on organic carbon preservation: The use of stratified water bodies to compare intrinsic rates of decomposition in oxic and anoxic systems. Geochim. Cosmochim. Acta 56, 3323–3335 (1992).
7 Aller R. C., Bioturbation and remineralization of sedimentary organic matter: Effects of redox oscillation. Chem. Geol.114, 331–345 (1994).
8 Cowie G. L., Mowbray S., Lewis M., Matheson H., McKenzie R., Carbon and nitrogen elemental and stable isotopic compositions of surficial sediments from the Pakistan margin of the Arabian Sea. Deep Sea Res. Part II 56, 271–282 (2009).
9 Koho K. A., Nierop K. G. J., Moodley L., Middleburg J. J., Pozzato L., Soetaert K., van der Plicht J., Reichart G.-J., Microbial bioavailability regulates organic matter preservation in marine sediments. Biogeosciences 10, 1131–1141 (2013). [OpenAIRE]
10 Middelburg J. J., Levin L. A., Coastal hypoxia and sediment biogeochemistry. Biogeosciences 6, 1273–1293 (2009). [OpenAIRE]
- Alfred Wegener Institute for Polar and Marine Research Germany
- Leibniz Association Germany
- University of Southampton United Kingdom
- Helmholtz Association of German Research Centres Germany
- Carl von Ossietzky University of Oldenburg Germany
- Max Planck Institute for Terrestrial Microbiology Germany
- Helmholtz Centre Potsdam Germany
- Max Planck Institute for Marine Microbiology Germany
- University of Concepción Chile
- Natural Environment Research Council United Kingdom
- Museum für Naturkunde Germany
- Swiss Federal Institute of Aquatic Science and Technology Switzerland
- University of Bern Switzerland
- Max Planck Society Germany
- Museum für Naturkunde - Leibniz-Institut für Evolutions- und Biodiversitätsforschung MfN) Germany
Bottom-water oxygen supply is a key factor governing the biogeochemistry and community composition of marine sediments. Whether it also determines carbon burial rates remains controversial. We investigated the effect of varying oxygen concentrations (170 to 0 μM O2) on microbial remineralization of organic matter in seafloor sediments and on community diversity of the northwestern Crimean shelf break. This study shows that 50% more organic matter is preserved in surface sediments exposed to hypoxia compared to oxic bottom waters. Hypoxic conditions inhibit bioturbation and decreased remineralization rates even within short periods of a few days. These conditions led to the accumulation of threefold more phytodetritus pigments within 40 years compared to the oxic zone. Bacterial community structure also differed between oxic, hypoxic, and anoxic zones. Functional groups relevant in the degradation of particulate organic matter, such as Flavobacteriia, Gammaproteobacteria, and Deltaproteobacteria, changed with decreasing oxygenation, and the microbial community of the hypoxic zone took longer to degrade similar amounts of deposited reactive matter. We conclude that hypoxic bottom-water conditions—even on short time scales—substantially increase the preservation potential of organic matter because of the negative effects on benthic fauna and particle mixing and by favoring anaerobic processes, including sulfurization of matter.
Hypoxia enhances organic matter preservation in marine sediments by changing benthic communities, bioturbation, and burial rates.