Estuaries and Coasts

, Volume 37, Issue 5, pp 1092–1106 | Cite as

An Evaluation of Temporal Changes in Sediment Accumulation and Impacts on Carbon Burial in Mobile Bay, Alabama, USA

  • Christopher G. SmithEmail author
  • Lisa E. Osterman


The estuarine environment can serve as either a source or sink of carbon relative to the coastal ocean carbon budget. A variety of time-dependent processes such as sedimentation, carbon supply, and productivity dictate how estuarine systems operate, and Mobile Bay is a system that has experienced both natural and anthropogenic perturbations that influenced depositional processes and carbon cycling. Sediments from eight box cores provide a record of change in bulk sediment accumulation and carbon burial over the past 110 years. Accumulation rates in the central part of the basin (0.09 g cm−2) were 60–80 % less than those observed at the head (0.361 g cm−2) and mouth (0.564 g cm−2) of the bay. Sediment accumulation in the central bay decreased during the past 90 years in response to both anthropogenic (causeway construction) and natural (tropical cyclones) perturbations. Sediment accumulation inevitably increased the residence time of organic carbon in the oxic zone, as observed in modeled remineralization rates, and reduced the overall carbon burial. Such observations highlight the critical balance among sediment accumulation, carbon remineralization, and carbon burial in dynamic coastal environments. Time-series analysis based solely on short-term observation would not capture the long-term effects of changes in sedimentation on carbon cycling. Identifying these relationships over longer timescales (multi-annual to decadal) will provide a far better evaluation of coastal ocean carbon budgets.


Carbon remineralization Sediment accumulation Anthropogenic modifications Natural disturbances 2-G model Lead-210 



The US Geological Survey Coastal and Marine Geology Program provided funding for this research as part of the Northern Gulf of Mexico Ecosystem Change and Hazard Susceptibility Project. The authors would like to thank Caitlin Reynolds, Christopher Reich, Adis Muslic, Dan Umberger, Marci Marot, Scott Adams, and Kathryn Richwine of the USGS for their continued support in the lab and in the field. The manuscript benefited from as discussions with and suggestions made by Thomas J. Smith of the USGS and two anonymous reviewers. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US government.

Supplementary material

12237_2013_9731_MOESM1_ESM.xlsx (41 kb)
Supplementary Table 1 Summary of basic physical properties of surface sediment samples, marsh core sediments, and box-core sediments. Marsh core and box-core sediments represent down-core averages, while the surface sediments are an average of three separate sampling trips (XLSX 40 kb)
12237_2013_9731_MOESM2_ESM.xlsx (47 kb)
Supplementary Table 2 Summary of C and N isotopic signatures and C and N content of bulk organic matter of surface sediment samples, marsh core sediments, and box-core sediments. Marsh core and box-core sediments represent down-core averages, while the surface sediments are an average of three separate sampling trips (XLSX 47 kb)
12237_2013_9731_MOESM3_ESM.xlsx (12 kb)
Supplementary Table 3 Summary of excess 210Pb and total 137Cs depth-integrated inventories for box-core sediments. For comparison, inventories of excess 210Pb and total 137Cs collected from the various locations along the Gulf of Mexico are also presented (XLSX 12 kb)


  1. Aller, R.C. 1998. Mobile deltaic and continental shelf muds as suboxic, fluidized bed reactors. Marine Chemistry 61: 143–155.CrossRefGoogle Scholar
  2. Allison, M.A., T.S. Bianchi, B.A. McKee, and T.P. Sampere. 2007. Carbon burial on river-dominated continental shelves: Impact of historical changes in sediment loading adjacent to the Mississippi River. Geophysical Research Letters 34, L01606.CrossRefGoogle Scholar
  3. Appleby, P.G. 2001. Chronostratigraphic techniques in recent sediments. In Tracking Environmental Change using Lake Sediments, eds. W.M. Last and J.P. Smol. 171–203. Dordrecht: SpringerGoogle Scholar
  4. Appleby, P.G., and F. Oldfield. 1978. The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210Pb to the sediment. Catena 5: 1–8.CrossRefGoogle Scholar
  5. Austin, G.B. 1954. On the circulation and tidal flushing of Mobile Bay, Alabama. College Station: Department of Geography, Texas A&M University.Google Scholar
  6. Baskaran, M. 2011. Po-210 and Pb-210 as atmospheric tracers and global atmospheric Pb-210 fallout: A review. Journal of Environmental Radioactivity 102: 500–513.CrossRefGoogle Scholar
  7. Bentley, S.J., T.R. Keen, C.A. Blain, and W.C. Vaughan. 2002. The origin and preservation of a major hurricane event bed in the northern Gulf of Mexico: Hurricane Camille, 1969. Marine Geology 186: 423–446.CrossRefGoogle Scholar
  8. Berner, R.A. 1980. Early diagenesis: A theoretical approach. Princeton: Princeton University Press.Google Scholar
  9. Bianchi, T.S., and M.A. Allison. 2009. Large-river delta-front estuaries as natural ‚”recorders” of global environmental change. Proceedings of the National Academy of Sciences 106: 8085–8092.CrossRefGoogle Scholar
  10. Bianchi, T.S., S. Mitra, and B.A. McKee. 2002. Sources of terrestrially-derived organic carbon in lower Mississippi River and Louisiana shelf sediments: Implications for differential sedimentation and transport at the coastal margin. Marine Chemistry 77: 211–223.CrossRefGoogle Scholar
  11. Binford, M.W. 1990. Calculation and uncertainty analysis of 210Pb dates for PIRLA project lake sediment cores. Journal of Paleolimnology 3: 253–267.CrossRefGoogle Scholar
  12. Breithaupt, J.L., J.M. Smoak, T.J. Smith, C.J. Sanders, and A. Hoare. 2012. Organic carbon burial rates in mangrove sediments: Strengthening the global budget. Global Biogeochemical Cycles 26.Google Scholar
  13. Burdige, D.J. 2006. Geochemistry of marine sediments. Princeton: Princeton University Press.Google Scholar
  14. Cahoon, D.R., J.C. Lynch, P. Hensel, R. Boumans, B.C. Perez, B. Segura, and J.W. Day. 2002. High-precision measurements of wetland sediment elevation: I. Recent improvements to the sedimentation-erosion table. Journal of Sedimentary Research 72: 730–733.CrossRefGoogle Scholar
  15. Cloern, J.E., E.A. Canuel, and D. Harris. 2002. Stable carbon and nitrogen isotope composition of aquatic and terrestrial plants of the San Francisco Bay estuarine system. Limnology and Oceanography 47: 713–729.CrossRefGoogle Scholar
  16. Corbett, D.R., B. McKee, and M. Allison. 2006. Nature of decadal-scale sediment accumulation on the western shelf of the Mississippi River Delta. Continental Shelf Research 26: 2125–2140.CrossRefGoogle Scholar
  17. Corbett, D.R., D. Vance, E. Letrick, D. Mallinson, and S. Culver. 2007. Decadal-scale sediment dynamics and environmental change in the Albemarle Estuarine System, north carolina. Estuarine, Coastal and Shelf Science 71: 717–729.CrossRefGoogle Scholar
  18. Curtis, W.F., J.J. Culbertson and E.B. Chase, 1973. Fluvial-sediment discharge to the oceans from the conterminous United States. US Geological Survey, U.S.G.S. Circular 670, p. 17.Google Scholar
  19. Cutshall, N.H., and I.L. Larsen. 1986. Calibration of a portable intrinsic ge gamma-ray detector using point sources and testing for field applications. Health Physics 51: 53–59.Google Scholar
  20. Dalrymple, R.W., B.A. Zaitlin, and R. Boyd. 1992. Estuarine facies models—Conceptual basis and stratigraphic implications. Journal of Sedimentary Petrology 62: 1130–1146.CrossRefGoogle Scholar
  21. Danielson, J.J., J.C. Brock, D.M. Howard, D.B. Gesch, J.M. Bonisteel-Cormier, L.J. Travers. 2013. Topobathymetric model of Mobile Bay, Alabama. US Geological Survey, U.S.G.S Data Series 769.
  22. Doyle, L.J., and T.N. Sparks. 1980. Sediments of the Mississippi, Alabama, and Florida (MAFLA) continental shelf. Journal of Sedimentary Petrology 50: 905–916.Google Scholar
  23. Fearn, M.L. 2004. Changes in water conditions and sedimentation rates associated with construction of the Mobile Bay Causeway. In Geology and Hydrology of the Alabama Gulf Coast, ed. D. Haywick.
  24. Gruebel, K.A., and C.S. Martens. 1984. Radon-222 tracing of sediment–water chemical transport in an estuarine sediment. Limnology and Oceanography 29: 587–597.CrossRefGoogle Scholar
  25. Ha, H.K., and K. Park. 2012. High-resolution comparison of sediment dynamics under different forcing conditions in the bottom boundary layer of a shallow, micro-tidal estuary. Geophysical Research Letters 117, C06020.Google Scholar
  26. Harris, D., W.R. Horwath, and C. van Kessel. 2001. Acid fumigation of soils to remove carbonates prior to total organic carbon or carbon-13 isotopic analysis. Soil Science Society of America Journal 65: 1853–1856.CrossRefGoogle Scholar
  27. Hedges, J.I., and R.G. Keil. 1995. Sedimentary organic matter preservation: An assessment and speculative synthesis. Marine Chemistry 49: 81–115.CrossRefGoogle Scholar
  28. Henrichs, S.M. 1992. Early diagenesis of organic matter in marine sediments: Progress and perplexity. Marine Chemistry 39: 119–149.CrossRefGoogle Scholar
  29. Isphording, W.C. and G.M. Lamb. 1979. The sediments of Mobile Bay. Dauphin Island Sea Lab Report 80-002. 24 p.Google Scholar
  30. Isphording, W.C. and F.D. Imsand, 1991. Cyclonic events and sedimentation in the Gulf of Mexico. Coastal Sediments 1991, Seattle, pp. 1122–1136Google Scholar
  31. Isphording, W.C., F.D. Imsand, and R.B. Jackson. 1996. Fluvial sediment characteristics of the Mobile River Delta. Transactions Gulf Coast Association of Geological Societies 46: 185–191.Google Scholar
  32. Kendall, C., D.H. Doctor, D.H. Heinrich, and K.T. Karl. 2003. Stable isotope applications in hydrologic studies. Treatise on geochemistry, 319–364. Oxford: Pergamon.Google Scholar
  33. Kindinger, J.L., P.S. Balson and J.G. Flocks. 1994. Stratigraphy of the Mississippi–Alabama shelf and the Mobile River incised-valley system. In Incised-valley systems: Origin and sedimentary sequences, eds. R.W. Dalrymple, R. Boyd and B.A. Zaitlain, 83–95. Tulsa: SEPM (Society for Sedimentary Geology).Google Scholar
  34. Marot, M.E. and C.G. Smith. 2012. Radioisotopic data of sediment collected in Mobile and Bon Secour Bays, Alabama. US Geological Survey, USGS Open-File Report 2012-1172, 15 p.Google Scholar
  35. Mars, J.C., A.W. Shultz, and W.W. Schroeder. 1992. Stratigraphy and Holocene evolution of Mobile Bay in southwestern Alabama. Gulf Coast Association of Geological Societies 42: 529–542.Google Scholar
  36. May, E.B. 1976. Holocene sediments of Mobile Bay, Alabama. Alabama Marine Resources Bulletin No. 11. pp. 1–25. Alabama Department of Conservation and Natural Resources.Google Scholar
  37. Mobile Bay National Estuary Program (MBNEP). 2006. Implementation Reviews, Mobile Bay National Estuary Program,
  38. Nichols, M.M., and R.B. Biggs. 1985. Estuaries. In Coastal sedimentary enviroments, ed. R.A. Davis, 77–186. New York: Springer.CrossRefGoogle Scholar
  39. Noble, M.A., W.W. Schroeder, W.J. Wiseman Jr., H.F. Ryan, and G. Gelfenbaum. 1996. Subtidal circulation patterns in a shallow, highly stratified estuary: Mobile Bay. Alabama. Geophysical Research Letters 101: 25689–25703.CrossRefGoogle Scholar
  40. Osterman, L.E., and C.G. Smith. 2012. Over 100 years of environmental change recorded by foraminifers and sediments in Mobile Bay, Alabama, Gulf of Mexico, USA. Estuarine, Coastal and Shelf Science 115: 345–358.CrossRefGoogle Scholar
  41. Otvos, E.G. 2004. Holocene gulf levels: Recognition issues and an updated sea-level curve. Journal of Coastal Research 20: 680–699.CrossRefGoogle Scholar
  42. Park, K., J.F. Valentine, S. Sklenar, K.R. Weis, and M.R. Dardeau. 2007. The effects of Hurricane Ivan in the inner part of Mobile Bay, Alabama. Journal of Coastal Research 23: 1332–1336.CrossRefGoogle Scholar
  43. Regnier, P., P. Friedlingstein, P. Ciais, F.T. Mackenzie, N. Gruber, I.A. Janssens, G.G. Laruelle, R. Lauerwald, S. Luyssaert, A.J. Andersson, S. Arndt, C. Arnosti, A.V. Borges, A.W. Dale, A. Gallego-Sala, Y. Godderis, N. Goossens, J. Hartmann, C. Heinze, T. Ilyina, F. Joos, D.E. LaRowe, J. Leifeld, F.J.R. Meysman, G. Munhoven, P.A. Raymond, R. Spahni, P. Suntharalingam, and M. Thullner. 2013. Anthropogenic perturbation of the carbon fluxes from land to ocean. Nature Geoscience 6: 597–607.CrossRefGoogle Scholar
  44. Rice, D.L., and R.B. Hanson. 1984. A kinetic model for detritus nitrogen: Role of the associated bacteria in nitrogen accumulation. Bulletin of Marine Science 35: 326–340.Google Scholar
  45. Richwine, K.A. and L.E. Osterman. 2012. Benthic foraminiferal census data from Mobile Bay, Alabama—Counts of surface samples and box cores. US Geological Survey, USGS Data Series 704.
  46. Robbins, J.A., and D.N. Edgington. 1975. Determination of recent sedimentation rates in Lake Michigan using Pb-210 and Cs-137. Geochimica et Cosmochimica Acta 39: 285–304.CrossRefGoogle Scholar
  47. Rodriguez, A.B.., and C.T. Meyer. 2006. Sea-level variation during the Holocene deduced from the morphologic and stratigraphic evolution of Morgan Peninsula, Alabama, U.S.A. Journal of Sedimentary Research 76: 257–269.CrossRefGoogle Scholar
  48. Rodriguez, A.B.., D.L. Greene, J.B. Anderson, and A.R. Simms. 2008. Response of Mobile Bay and eastern Mississippi Sound, Alabama, to changes in sediment accommodation and accumulation. Geological Society of America Special Papers 443: 13–29.Google Scholar
  49. Rucker, J.B., R.P. Stumpf, and W.W. Schroeder. 1990. Temporal variability of remotely sensed suspended sediment and sea surface temperature patterns in Mobile Bay, Alabama. Estuaries 13: 155–160.CrossRefGoogle Scholar
  50. Ryan, J.J., and H.G. Goodell. 1972. Marine geology and estuarine history of Mobile Bay, Alabama part 1. Contemporary sediments. The Geological Society of America Memoirs 133: 517–556.CrossRefGoogle Scholar
  51. Sanders, C.J., J.M. Smoak, A.S. Naidu, L.M. Sanders, and S.R. Patchineelam. 2010. Organic carbon burial in a mangrove forest, margin and intertidal mud flat. Estuarine, Coastal and Shelf Science 90: 168–172.CrossRefGoogle Scholar
  52. Schroeder, W.W., J.L.W. Cowan, J.R. Pennock, S.A. Luker, and W.J. Wiseman. 1998. Response of resource excavations in Mobile Bay, Alabama, to extreme forcing. Estuaries 21: 652–657.CrossRefGoogle Scholar
  53. Smith, C.G., L.E. Osterman, and R.Z. Poore. 2013. An examination of historical inorganic sedimentation and organic matter accumulation in several marsh types within the Mobile Bay and Mobile–Tensaw River Delta region. Jounal of Coastal Research Special Issue 63: 68–83.CrossRefGoogle Scholar
  54. Stumpf, R.P., G. Gelfenbaum, and J.R. Pennock. 1993. Wind and tidal forcing of a buoyant plume, Mobile Bay, Alabama. Continental Shelf Research 13: 1281–1301.CrossRefGoogle Scholar
  55. Swarzenski, P., M. Baskaran, R. Rosenbauer, and W. Orem. 2006. Historical trace element distribution in sediments from the Mississippi River Delta. Estuaries and Coasts 29: 1094–1107.CrossRefGoogle Scholar
  56. Velardo, B.M., and S.J. Bentley. 2003. Impacts of tropical systems on the sedimentary fabric of the Mississippi Sound. Gulf Coast Association of Geological Societies Transactions 53: 815–823.Google Scholar
  57. Wright, L.D., and C.A. Nittrouer. 1995. Dispersal of river sediments in coastal seas—6 contrasting cases. Estuaries 18: 494–508.CrossRefGoogle Scholar

Copyright information

© Coastal and Estuarine Research Federation (outside the USA) 2013

Authors and Affiliations

  1. 1.US Geological SurveySt. Petersburg Coastal and Marine Science CenterSt. PetersburgUSA

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