Estuaries and Coasts

, Volume 38, Issue 6, pp 1918–1936 | Cite as

Spatial and Temporal Patterns of Benthic Respiration and Net Nutrient Fluxes in the Atchafalaya River Delta Estuary



Benthic respiration and nutrient flux rates were quantified during four distinct periods (spring peak in river discharge, summer period of offshore hypoxia, autumn period after breakdown of offshore hypoxia, and the non-hypoxic winter period) over an annual cycle in the Atchafalaya River Delta Estuary (ARDE). The overall mean benthic respiration rate for the ARDE was 12.9 mmol O2 m−2 day−1 with the highest and lowest rates occurring in summer and winter (22.1 and 5.4 mmol O2 m−2 day−1), respectively, and surprisingly little variance in relation to distance offshore of the deltas. Bottom water temperature explained 94 % of the variance in the natural log of benthic respiration. The mean annual fluxes for ammonium, dissolved organic nitrogen (DON), phosphate, and silicate were from the sediments to the water column (0.91, 0.44, 0.03, and 1.04 mmol m−2 day−1, respectively), but nitrate had a mean annual flux (−0.90 mmol N m−2 day−1) from the water column into the sediments. Net nitrate fluxes were greatest in summer, were generally higher at delta than at offshore sites, and were most strongly correlated with benthic respiration. Net NH4 + fluxes from the sediments to the overlying water column were greater at offshore sites than at delta sites resulting in the delta and offshore sites behaving as net dissolved inorganic nitrogen (DIN) sinks and sources, respectively. The results from this study suggest that benthic processes in the ARDE greatly alter bottom water oxygen availability as well as the size and form of nutrient fluxes exported to the northern Gulf of Mexico.


Sediment oxygen demand Benthic nutrient fluxes Benthic-pelagic coupling Metabolic theory Climate change Atchafalaya Bay 



We would like to thank Carrie Semmler for help with sample collection and processing and completion of the incubation experiments, Nancy Rabalais for assistance in the original study design, and Melissa Baustian for help with the design of the core incubation setup. Sediment grain size analyses were performed in the laboratory of Alex Kolker. Carl Sevin and Max Wike served as captains of the R/V Whiskey Pass and helped with the collection of water samples and benthic cores. Comments from two anonymous reviewers greatly improved an earlier version of this manuscript. Funding for this project was provided by the Louisiana Board of Regents Support Fund (LEQSF(2008–11)-RD-A-22) and National Oceanographic and Atmospheric Administration, Center for Sponsored Coastal Ocean Research program, NGOMEX09.


  1. Allison, M.A., G.C. Kineke, E.S. Gordon, and M.A. Goni. 2000. Development and reworking of a seasonal flood deposit on the inner continental shelf off the Atchafalaya River. Continental Shelf Research 20: 2267–2294.CrossRefGoogle Scholar
  2. APHA (American Public Health Association). 1992. Standard Methods for the Examination of Water and Wastewater, 18th ed. Washington, DC: American Public Health Association.Google Scholar
  3. Benke, A.C., and C.E. Cushing (eds.). 2005. Rivers of North America. Burlington: Academic Press. 1144 p.Google Scholar
  4. Boynton, W.R., and W.M. Kemp. 1985. Nutrient regeneration and oxygen consumption by sediments along an estuarine salinity gradient. Marine Ecology Progress Series 23: 45–55.CrossRefGoogle Scholar
  5. Boynton, W.R., and W.M. Kemp. 2008. Chapter 18-Estuaries. In Nitrogen in the Marine Environment, 2nd ed, ed. D.G. Capone, D.A. Bronk, M.R. Mulholland, and E.J. Carpenter, 809–866. San Diego: Academic Press.CrossRefGoogle Scholar
  6. Bratkovich, A., S.P. Dinnel, and D.A. Goolsby. 1994. Variability and prediction of freshwater and nitrate fluxes for the Louisiana-Texas shelf: Mississippi and Atchafalaya River source functions. Estuaries 17: 766–778.CrossRefGoogle Scholar
  7. Bronk, D.A., and D.K. Steinberg. 2008. Chapter 8-Nitrogen Regeneration. In Nitrogen in the Marine Environment, 2nd ed, ed. D.G. Capone, D.A. Bronk, M.R. Mulholland, and E.J. Carpenter, 385–467. San Diego: Academic Press.CrossRefGoogle Scholar
  8. Cotner, J.B., M.W. Suplee, N.W. Chen, and D.E. Shormann. 2004. Nutrient, sulfur and carbon dynamics in a hypersaline lagoon. Estuarine, Coastal and Shelf Science 59: 639–652.CrossRefGoogle Scholar
  9. Cowan, J.L.W., and W.R. Boynton. 1996. Sediment-water oxygen and nutrient exchanges along the longitudinal axis of Chesapeake Bay: Seasonal patterns, controlling factors and ecological significance. Estuaries 19: 562–580.CrossRefGoogle Scholar
  10. Cowan, J.L.W., J.R. Pennock, and W.R. Boynton. 1996. Seasonal and interannual patterns of sediment-water nutrient and oxygen fluxes in Mobile Bay, Alabama (USA): regulating factors and ecological significance. Marine Ecology Progress Series 141: 229–245.CrossRefGoogle Scholar
  11. Dalsgaard, T., L.P. Nielsen, V. Brotas, P. Viaroli, G. Underwood, D.B. Nedwell, et al. 2000. Protocol handbook for NICE – Nitrogen Cycling in Estuaries: a project under the EU research programme: Marine Science and Technology (Mast III), 62. Silkeborg, Denmark: National Research Institute.Google Scholar
  12. Dinnel, S.P., and W.J. Wiseman Jr. 1986. Fresh water on the Louisiana and Texas shelf. Continental Shelf Research 6: 765–784.CrossRefGoogle Scholar
  13. Dortch, Q., N.N. Rabalais, R.E. Turner, and G.T. Rowe. 1994. Respiration rates and hypoxia on the Louisiana shelf. Estuaries 17: 862–872.CrossRefGoogle Scholar
  14. Dunn, D.D. 1996. rends in Nutrient Inflows to the Gulf of Mexico from Streams Draining the Conterminous United States 1972–1993. U.S. Geological Survey, Water-Resources Investigations Report 96–4113. Prepared in cooperation with the U.S. Austin, Texas: Environmental Protection Agency, Gulf of Mexico Program, Nutrient Enrichment Issue Committee, U.S. Geological Survey.Google Scholar
  15. Eldridge, P.M., and J.W. Morse. 2008. Origins and temporal scales of hypoxia on the Louisiana shelf: importance of benthic and sub-pycnocline water metabolism. Marine Chemistry 108: 159–171.CrossRefGoogle Scholar
  16. Enquist, B.J., E.P. Economo, T.E. Huxman, A.P. Allen, D.D. Ignace, and J.F. Gillooly. 2003. Scaling metabolism from organisms to ecosystems. Nature 423: 639–642.CrossRefGoogle Scholar
  17. Eyre, B.D., and A.J.P. Ferguson. 2005. Benthic metabolism and nitrogen cycling in a subtropical east Australian estuary (Brunswick): Temporal variability and controlling factors. Limnology and Oceanography 50: 81–96.CrossRefGoogle Scholar
  18. Flint, R.W., and D. Kamykowski. 1984. Benthic nutrient regeneration in south Texas coastal waters. Estuarine, Coastal and Shelf Science 18: 221–230.CrossRefGoogle Scholar
  19. Fulweiler, R.W., S.W. Nixon, and B.A. Buckley. 2010. Spatial and temporal variability of benthic oxygen demand and nutrient regeneration in an anthropogenically impacted New England estuary. Estuaries and Coasts 33: 1377–1390.CrossRefGoogle Scholar
  20. Gardner, W.S., E.E. Briones, E.C. Kaegi, and G.T. Rowe. 1993. Ammonium excretion by benthic invertebrates and sediment-water nitrogen flux in the Gulf of Mexico near the Mississippi outflow. Estuaries 16: 799–808.CrossRefGoogle Scholar
  21. Giblin, A.E., C.S. Hopkinson, and J. Tucker. 1997. Benthic metabolism and nutrient cycling in Boston Harbor, Massachusetts. Estuaries 20: 346–364.CrossRefGoogle Scholar
  22. Gillooly, J.F., J.H. Brown, G.B. West, V.M. Savage, and E.L. Charnov. 2001. Effects of size and temperature on metabolic rate. Science 293: 2248–2251.CrossRefGoogle Scholar
  23. Hetland, R.D., and S.F. DiMarco. 2008. How does the character of oxygen demand control the structure of hypoxia on the Texas-Louisiana continental shelf? Journal of Marine Systems 70: 49–62.CrossRefGoogle Scholar
  24. Hopkinson, C.S., and E.M. Smith. 2005. Estuarine respiration: An overview of benthic, pelagic, and whole system respiration. In Respiration in aquatic systems, ed. P.A. del Giorgio and P.J. Williams, 122–146. Oxford: Oxford University Press. 328 pp.Google Scholar
  25. Hopkinson Jr., C.S., A.E. Giblin, and J. Tucker. 2001. Benthic metabolism and nutrient regeneration on the continental shelf of Eastern Massachusetts, USA. Marine Ecology Progress Series 224: 1–19.CrossRefGoogle Scholar
  26. Intergovernmental Panel on Climate Change. 2007. Climate change 2007: synthesis report.Google Scholar
  27. Jensen, M.H., E. Lomstein, and J. Sorensen. 1990. Benthic NH4 + and NO3 flux following sedimentation of a spring phytoplankton bloom in Aarhus Bight, Denmark. Marine Ecology Progress Series 61: 87–96.CrossRefGoogle Scholar
  28. Jensen, H.S., P.B. Mortensen, F.O. Andersen, E. Rasmussen, and A. Jensen. 1995. Phosphorus cycling in coastal marine sediment, Aarhus Bay, Denmark. Limnology and Oceanography 40: 908–917.CrossRefGoogle Scholar
  29. Justić, D., N.N. Rabalais, and R.E. Turner. 2005. Coupling between climate variability and coastal eutrophication: evidence and outlook for the northern Gulf of Mexico. Journal of Sea Research 54: 25–35.CrossRefGoogle Scholar
  30. Lane, R.R., J.W. Day, B. Marx, E. Reyes, and G.P. Kemp. 2002. Seasonal and spatial water quality changes in the outflow plume of the Atchafalaya River, Louisiana, USA. Estuaries 25: 30–42.CrossRefGoogle Scholar
  31. Lehrter, J.C., D.L. Beddick Jr., R. Devereux, D.F. Yates, and M.C. Murrell. 2012. Sediment-water fluxes of dissolved inorganic carbon, O2, nutrients, and N2 from the hypoxic region of the Louisiana continental shelf. Biogeochemistry 109: 233–252.CrossRefGoogle Scholar
  32. Lehrter, J.C., S.K. Dong, M.C. Murrell, J.D. Hagy, B.A. Schaeffer, R.M. Greene, R.W. Gould, and B. Penta. 2013. Nutrient distributions, transports, and budgets on the inner margin of a river-dominated continental shelf. Journal of Geophysical Research: Oceans 118: 4822–4838.Google Scholar
  33. López-Urrutia, A., and X.A.G. Moran. 2007. Resource limitation of bacterial production distorts the temperature dependence of oceanic carbon cycling. Ecology 88: 817–822.CrossRefGoogle Scholar
  34. López-Urrutia, A., E. San Martin, R.P. Harris, and X. Irigoien. 2006. Scaling the metabolic balance of the oceans. Proceedings of the National Academy of Sciences of the United States of America 103: 8739–8744.CrossRefGoogle Scholar
  35. McCarthy, M.J., S.A. Carini, Z. Liu, N.E. Ostrom, and W.S. Gardner. 2013. Oxygen consumption in the water column and sediments of the northern Gulf of Mexico hypoxic zone. Estuarine, Coastal and Shelf Science 123: 46–53.CrossRefGoogle Scholar
  36. Miller-Way, T., G.S. Boland, G.T. Rowe, and R.R. Twilley. 1994. Sediment oxygen consumption and benthic nutrient fluxes on the Louisiana continental shelf: a methodological comparison. Estuaries 17: 809–815.CrossRefGoogle Scholar
  37. Milliman, J.D., and R.H. Meade. 1983. World-wide delivery of river sediment to the oceans. Journal of Geology 91: 1–21.CrossRefGoogle Scholar
  38. Morse, J.W., and G.T. Rowe. 1999. Benthic biogeochemistry beneath the Mississippi River plume. Estuaries 22: 206–214.CrossRefGoogle Scholar
  39. Murrell, M.C., and J.C. Lehrter. 2011. Sediment and lower water column oxygen consumption in the seasonally hypoxic region of the Louisiana continental shelf. Estuaries and Coasts 34: 912–924.CrossRefGoogle Scholar
  40. Murrell, M.C., J.G. Campbell, J.D. Hagy III, and J.M. Caffrey. 2009. Effects of irradiance on benthic and water column processes in a Gulf of Mexico estuary: Pensacola Bay, Florida, USA. Estuarine, Coastal and Shelf Science 81: 501–512.CrossRefGoogle Scholar
  41. Nixon, S.W. 1981. Remineralization and nutrient cycling in coastal marine ecosystems. In Estuaries and nutrients, ed. B.J. Neilson and L.E. Cronin, 111–138. Clifton: Humana.CrossRefGoogle Scholar
  42. Nixon, S.W., J.W. Ammerman, L.P. Atkinson, V.M. Berounsky, G. Billen, W.C. Boicourt, et al. 1996. The fate of nitrogen and phosphorus at the land-sea margin of the North Atlantic Ocean. Biogeochemistry 35: 141–180.CrossRefGoogle Scholar
  43. Rabalais, N.N., R.E. Turner, and W.J. Wiseman Jr. 2002. Hypoxia in the Gulf of Mexico, a.k.a. “The Dead Zone”. Annual Review of Ecology and Systematics 33: 235–263.CrossRefGoogle Scholar
  44. Rabalais, N.N., R.E. Turner, B.K. Sen Gupta, D.F. Boesch, P. Chapman, and M.C. Murrell. 2007. Hypoxia in the northern Gulf of Mexico: does the science support the plan to reduce, mitigate and control hypoxia? Estuaries and Coasts 30: 753–772.CrossRefGoogle Scholar
  45. Roberts, B.J., and P.J. Mulholland. 2007. In-stream biotic control on nutrient biogeochemistry in a forested headwater stream, West Fork of Walker Branch. Journal of Geophysical Research, Biogeosciences 112: G04002. doi: 10.1029/2007JG000422.Google Scholar
  46. Roberts, B.J., P.J. Mulholland, and W.R. Hill. 2007. Multiple scales of temporal variability in ecosystem metabolism rates: Results from 2 years of continuous monitoring in a forested Headwater stream. Ecosystems 10: 588–606.CrossRefGoogle Scholar
  47. Rowe, G.T. 2001. Seasonal hypoxia in the bottom water off the Mississippi River Delta. Journal of Environmental Quality 30: 281–290.CrossRefGoogle Scholar
  48. Rowe, G.T., M.E. Cruz Kaegi, J.M. Morse, G.S. Boland, and E.G. Escobar Briones. 2002. Sediment community metabolism associated with continental shelf hypoxia, northern Gulf of Mexico. Estuaries 25: 1097–1106.CrossRefGoogle Scholar
  49. Ryther, J.H., and W.H. Dustan. 1971. Nitrogen, phosphorus, and eutrophication in the coastal marine environment. Science 171: 1008–1013.CrossRefGoogle Scholar
  50. Seitzinger, S.P. 1987. Nitrogen biogeochemistry in an unpolluted estuary: the importance of benthic denitrification. Marine Ecology Progress Series 41: 177–186.CrossRefGoogle Scholar
  51. Strickland, J.D.H., and T.R. Parsons. 1972. (2nd Edition) A practical handbook of sea-water analysis. Journal of the Fisheries Research Board of Canada 167: 311.Google Scholar
  52. Teague, K.G., C.J. Madden, and J.W. Day Jr. 1988. Sediment-water oxygen and nutrient fluxes in a river-dominated estuary. Estuaries 11: 1–9.CrossRefGoogle Scholar
  53. Turner, R.E., N.N. Rabalais, R.B. Alexander, G. McIsaac, and R.W. Howarth. 2007. Characterization of nutrient, organic carbon, and sediment loads and concentrations from the Mississippi River into the northern Gulf of Mexico. Estuaries and Coasts 30: 773–790.CrossRefGoogle Scholar
  54. Twilley, R.R., J. Cowen, T. Miller-Way, P.A. Montagna, and B. Mortazavi. 1999. Benthic nutrient fluxes in selected estuaries in the Gulf of Mexico. In: Biogeochemistry of Gulf of Mexico estuaries, ed. T.S. Bianchi, J.R. Pennock, and R.R. Twilley, 163–209. John Wiley and Sons, Inc.Google Scholar
  55. Yoon, W.B., and R. Benner. 1992. Denitrification and oxygen consumption in sediments of two south Texas estuaries. Marine Ecology Progress Series 90: 157–167.CrossRefGoogle Scholar
  56. Zimmerman, A.R., and R. Benner. 1994. Denitrification, nutrient regeneration and carbon mineralization in sediments of Galveston Bay, Texas, USA. Marine Ecology Progress Series 114: 275–288.CrossRefGoogle Scholar

Copyright information

© Coastal and Estuarine Research Federation 2015

Authors and Affiliations

  1. 1.Louisiana Universities Marine ConsortiumChauvinUSA
  2. 2.Department of Biological SciencesNicholls State UniversityThibodauxUSA

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