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Methane hydrate-bearing seeps as a source of aged dissolved organic carbon to the oceans

Nature Geoscience volume 4, pages 37–41 (2011)Cite this article

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Abstract

Marine sediments contain about 500–10,000 Gt of methane carbon1,2,3, primarily in gas hydrate. This reservoir is comparable in size to the amount of organic carbon in land biota, terrestrial soils, the atmosphere and sea water combined1,4, but it releases relatively little methane to the ocean and atmosphere5. Sedimentary microbes convert most of the dissolved methane to carbon dioxide6,7. Here we show that a significant additional product associated with microbial methane consumption is methane-derived dissolved organic carbon. We use Δ14C and δ13C measurements and isotopic mass-balance calculations to evaluate the contribution of methane-derived carbon to seawater dissolved organic carbon overlying gas hydrate-bearing seeps in the northeastern Pacific Ocean. We show that carbon derived from fossil methane accounts for up to 28% of the dissolved organic carbon. This methane-derived material is much older, and more depleted in 13C, than background dissolved organic carbon. We suggest that fossil methane-derived carbon may contribute significantly to the estimated 4,000–6,000 year age of dissolved organic carbon in the deep ocean8, and provide reduced organic matter and energy to deep-ocean microbial communities.

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Figure 1: Radiocarbon (14C) and 13C properties of DOC plotted versus DOC concentration from deep sea water overlying northern Cascadia margin seeps.
Figure 2: Sediment depth profiles from Barkley Canyon showing the AOM zone and associated production of DOC.
Figure 3: Carbon contributions to deep-seawater DOC at the Barkley Canyon seep, determined by three mass-balance calculations.

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References

  1. Kvenvolden, K. A. Methane hydrate—a major reservoir of carbon in the shallow geosphere? Chem. Geol. 71, 41–51 (1988).

    Article  Google Scholar 

  2. Milkov, A. V. Global estimates of hydrate-bound gas in marine sediments: How much is really out there? Earth Sci. Rev. 66, 183–197 (2004).

    Article  Google Scholar 

  3. Buffet, B. & Archer, D. Global inventory of methane clathrate: Sensitivity to changes in the deep ocean. Earth Planet. Sci. Lett. 227, 185–199 (2004).

    Article  Google Scholar 

  4. Hedges, J. I. Global biogeochemical cycles: Progress and problems. Mar. Chem. 39, 67–93 (1992).

    Article  Google Scholar 

  5. Reeburgh, W. S. Oceanic methane biogeochemistry. Chem. Rev. 107, 486–513 (2007).

    Article  Google Scholar 

  6. Hinrichs, K-U. & Boetius, A. in Ocean Margin Systems (eds Wefer, G. et al.) (Springer, 2002).

    Google Scholar 

  7. Hoehler, T. M., Alperin, M. J., Albert, D. B. & Martens, C. S. Field and laboratory studies of methane oxidation in an anoxic marine sediment—evidence for a methanogen–sulfate reducer consortium. Glob. Biogeochem. Cycles 8, 451–463 (1994).

    Article  Google Scholar 

  8. Williams, P. M. & Druffel, E. R. M. Dissolved organic matter in the ocean: Comments on a controversy. Oceanography 1, 14–17 (1988).

    Article  Google Scholar 

  9. Bauer, J. E. & Druffel, E. R. M. Ocean margins as a significant source of organic matter to the deep ocean. Nature 392, 482–485 (1998).

    Article  Google Scholar 

  10. Dittmar, T. & Koch, B. P. Thermogenic organic matter dissolved in the abyssal ocean. Mar. Chem. 102, 208–217 (2006).

    Article  Google Scholar 

  11. Wang, X-C., Chen, R. F., Whelan, J. & Eglinton, L. Contribution of ‘old’ carbon from natural marine hydrocarbon seeps to sedimentary and dissolved organic carbon pools in the Gulf of Mexico. Geophys. Res. Lett. 28, 3313–3316 (2001).

    Article  Google Scholar 

  12. Bauer, J. E., Druffel, E. R. M., Wolgast, D. M., Griffin, S. & Masiello, C. A. Distributions of dissolved organic and inorganic carbon and radiocarbon in the eastern North Pacific continental margin. Deep-Sea Res. II 45, 689–713 (1998).

    Article  Google Scholar 

  13. Pohlman, J. W. Sediment Biogeochemistry of Northern Cascadia Margin Shallow Gas Hydrate Systems (College of William and Mary, 2006).

    Google Scholar 

  14. Pohlman, J. W. et al. The origin of thermogenic gas hydrates on the northern Cascadia Margin as inferred from isotopic (13C/12C and D/H) and molecular composition of hydrate and vent gas. Org. Geochem. 36, 703–716 (2005).

    Article  Google Scholar 

  15. Pohlman, J. W. et al. Methane sources in gas hydrate bearing cold seeps: Evidence from radiocarbon and stable isotopes. Mar. Chem. 115, 102–109 (2009).

    Article  Google Scholar 

  16. Alperin, M. J., Reeburgh, W. S. & Whiticar, M. J. Carbon and hydrogen isotope fractionation resulting from anaerobic methane oxidation. Glob. Biogeochem. Cycles 2, 279–288 (1988).

    Article  Google Scholar 

  17. Valentine, D. L. et al. Biogeochemical investigations of marine methane seeps, Hydrate Ridge, Oregon. J. Geophys. Res. 110, G02005 (2005).

    Article  Google Scholar 

  18. Segers, R. Methane production and consumption: A review of processes underlying wetland methane fluxes. Biogeochemistry 41, 23–51 (1998).

    Article  Google Scholar 

  19. Miller, J. B. & Tans, P. P. Calculating isotopic fractionation from atmospheric measurements at various scales. Tellus 55, 207–214 (2003).

    Article  Google Scholar 

  20. Heuer, V. B., Pohlman, J. W., Torres, M. E., Elvert, M. & Hinrichs, K-U. The stable carbon isotope biogeochemistry of acetate and other dissolved carbon species in deep subseafloor sediments of the northern Cascadia Margin. Geochim. Cosmochim. Acta 73, 3323–3336 (2009).

    Article  Google Scholar 

  21. Mau, S. et al. Estimates of methane output from mud extrusions at the erosive convergent margin off Costa Rica. Mar. Geol. 225, 129–144 (2007).

    Article  Google Scholar 

  22. Sauter, E. J. et al. Methane discharge from a deep-sea submarine volcano into the upper water column by gas hydrate-coated methane bubbles. Earth Planet. Sci. Lett. 243, 354–365 (2004).

    Article  Google Scholar 

  23. Milkov, A. V. Worldwide distribution of submarine mud volcanoes and associated gas hydrates. Mar. Geol. 167, 29–42 (2000).

    Article  Google Scholar 

  24. Kvenvolden, K. A., Lorenson, T. D. & Reeburgh, W. S. Attention turns to naturally occurring methane seepage. Eos 82, 457 (2001).

    Article  Google Scholar 

  25. Frye, M. Preliminary Evaluation of in-Place Gas Hydrate Resources: Gulf of Mexico Outer Continental Shelf. MMS Report 2008–004 (US Department of Interior, Minerals Management Service, 2008).

    Google Scholar 

  26. Zachos, J. C. et al. Rapid acidification of the ocean during the Paleocene–Eocene thermal maximum. Science 308, 1611–1615 (2005).

    Article  Google Scholar 

  27. Pohlman, J. W., Ruppel, C., Hutchinson, D. R. & Coffin, R. B. Assessing sulfate reduction and methane cycling in a high salinity pore water system in the northern Gulf of Mexico. Mar. Petrol. Geol. 25, 942–951 (2008).

    Article  Google Scholar 

  28. Stuiver, M. & Polach, H. A. Discussion: Reporting of 14C data. Radiocarbon 19, 355–363 (1977).

    Article  Google Scholar 

  29. Osburn, C. L. & St-Jean, G. The use of wet chemical oxidation with high-amplification isotope ratio mass spectrometry (WCO-IRMS) to measure stable isotope values of dissolved organic carbon in seawater. Limnol. Oceanogr. Methods 5, 296–308 (2007).

    Article  Google Scholar 

  30. Ricker, W. E. Linear regressions in fishery research. J. Fish. Res. Board Can. 30, 409–434 (1973).

    Article  Google Scholar 

Download references

Acknowledgements

We thank the captain and crew of the CCGV J. P. Tully and ROV ROPOS, E. Kessee, B. Green and L. Lapham for assistance with sample collection and analysis, and the staffs of the University of Arizona and National Ocean Science AMS facilities for radiocarbon analyses. J. Seewald, V.B. Heuer and D.L. Valentine are thanked for constructive comments on previous versions of the manuscript. This research was supported by financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Chemical Oceanography and Integrated Carbon Cycle Research Programs of the National Science Foundation and the USGS Mendenhall Research Postdoctoral Fellowship Program. Any use of trade names is only for descriptive purposes and does not imply endorsement by the US Government.

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Authors and Affiliations

  1. U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts 02543, USA

    John W. Pohlman & William F. Waite

  2. Department of Evolution, Aquatic Ecology Laboratory, Ecology and Organismal Biology, The Ohio State University, Columbus, Ohio 43212, USA

    James E. Bauer

  3. Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA

    Christopher L. Osburn

  4. School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia V8W2Y2, Canada

    N. Ross Chapman

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  1. John W. Pohlman
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Contributions

J.W.P. led and coordinated the design and execution of the field study, collection and analyses of samples, and writing of the manuscript. J.E.B. and W.F.W. contributed to the study design, sample analyses, development of the mass-balance model and writing of the manuscript. All other authors made essential, substantive contributions to the original and revised versions of the manuscript. In addition, C.L.O. assisted with pore-water DOC δ13C analyses and N.R.C. was Chief Scientist and contributed to the study design and sampling at sea.

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Correspondence to John W. Pohlman.

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Pohlman, J., Bauer, J., Waite, W. et al. Methane hydrate-bearing seeps as a source of aged dissolved organic carbon to the oceans. Nature Geosci 4, 37–41 (2011). https://doi.org/10.1038/ngeo1016

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