Ecosystems

, Volume 18, Issue 5, pp 792–812 | Cite as

Seasonal Water Column NH4 + Cycling Along a Semi-arid Sub-tropical River–Estuary Continuum: Responses to Episodic Events and Drought Conditions

  • Denise A. Bruesewitz
  • Wayne S. Gardner
  • Rae F. Mooney
  • Edward J. Buskey
Article

Abstract

River–estuary continuums represent a dynamic range of environmental conditions in aquatic ecosystems, providing an ideal gradient for understanding changes in nitrogen (N) cycling. We measured rates of ammonium (NH4 +) cycling, including uptake and regeneration, in the water column of upper river, lower river, and estuary sites. This 1-year study encompassed periods of flood and drought, in a coastal catchment of south Texas. Low NH4 + concentrations and frequently balanced net NH4 + fluxes suggest minimal N cycling, but these measurements alone did not reveal the patterns of water column NH4 + uptake and regeneration in the river and estuarine systems. Rapid turnover of NH4 + supported productive estuaries, particularly during periods of droughts when riverine sources of NH4 + were minimal. However, NH4 + demand declined during storms across the river–estuary continuum, and regeneration rates were high, especially in the rivers. Most research in rivers has focused on benthic or whole-system dynamics, but our data demonstrate that active NH4 + cycling also occurs in isolated river water columns. Lower river sites were hotspots of NH4 + cycling on the landscape. Continued studies across river–estuary continuums are needed to enhance our understanding of aquatic systems and improve our ability to manage nutrients in the face of increased anthropogenic pressures and a changing climate.

Keywords

freshwater-marine isotope dilution nitrogen uptake regeneration ammonium demand National Estuarine Research Reserve 

Notes

Acknowledgments

We thank Britt Dean, Cammie Hyatt, Lindsey Pollard, and Katie Swanson for assistance in the field and laboratory, Mark McCarthy, Xiao Lin, and Kaijun Lu for technical assistance with N transformation calculations, and Wayne Shaffer for information about the Beeville, TX Moore Street WWTP. This research was conducted in part under an award from the Estuarine Reserves Division, Office of Ocean and Coastal Resource Management, National Ocean Service, National Oceanic and Atmospheric Administration, and by the United States Environmental Protection Agency, Gulf of Mexico Program, under award number MX954554810-0 to E. J. B. Three anonymous reviewers and subject-matter editor Karen McGlathery provided thoughtful reviews of an earlier version of this manuscript.

Supplementary material

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Supplementary material 1 (DOCX 18 kb)

References

  1. Abell JM, Ozkundakci D, Hamilton DP. 2010. Nitrogen and phosphorus limitation of phytoplankton growth in New Zealand lakes: implications for eutrophication control. Ecosystems 13:966–77.CrossRefGoogle Scholar
  2. Aguilera R, Marce R, Sabater S. 2012. Linking in-stream nutrient flux to land use and inter-annual hydrological variability at the watershed scale. Science of the Total Environment 440:72–81.PubMedCrossRefGoogle Scholar
  3. Alexander RB, Smith RA, Schwarz GE. 2000. Effect of stream channel size on the delivery of nitrogen to the Gulf of Mexico. Nature 403(6771):758–61.PubMedCrossRefGoogle Scholar
  4. Arango CP, Tank JL. 2008. Land use influences the spatiotemporal controls on nitrification and denitrification in headwater streams. Journal of the North American Benthological Society 27:90–107.CrossRefGoogle Scholar
  5. Armstrong N. 1982. Responses of Texas estuaries to freshwater inflows. In: Kennedy VS, Ed. Estuarine comparisons. New York: Academic Press. p 103–20.CrossRefGoogle Scholar
  6. Beaver JR, Jensen DE, Casamatta DA, Tausz CE, Scotese KC, Buccier KM, Teacher CE, Rosati TC, Minerovic AD, Renicker TR. 2013. Response of phytoplankton and zooplankton communities in six reservoirs of the middle Missouri River (USA) to drought conditions and a major flood event. Hydrobiologia 705:173–89.CrossRefGoogle Scholar
  7. Bernal S, von Schiller D, Sabater F, Marti E. 2012a. Hydrological extremes modulate nutrient dynamics in Mediterranean climate streams across different spatial scales. Hydrobiologia 719(1):31–42.CrossRefGoogle Scholar
  8. Bernal S, von Schiller D, Marti E, Sabater F. 2012b. In-stream net uptake regulates inorganic nitrogen export from catchments under base flow conditions. Journal of Geophysical Research 117(3):G00N05.Google Scholar
  9. Bernhardt ES, Likens GE, Buso DC, Driscoll CT. 2003. In-stream uptake dampens effects of major forest disturbance on watershed nitrogen export. Proceedings of the National Academy of Sciences of the United States of America 100:10304–8.PubMedCentralPubMedCrossRefGoogle Scholar
  10. Blackburn T. 1979. Method for measuring rates of NH4 + turnover in anoxic marine sediments using a N-15-NH4 + dilution technique. Applied and Environmental Microbiology 37:760–5.PubMedCentralPubMedGoogle Scholar
  11. Bowen JL, Valiela I. 2001. The ecological effects of urbanization of coastal watersheds: historical increases in nitrogen loads and eutrophication of Waquoit Bay estuaries. Canadian Journal of Fisheries and Aquatic Sciences 58:1489–500.CrossRefGoogle Scholar
  12. Boyer JN, Stanley DW, Christian RR. 1994. Dynamics of NH4 + and NO3 uptake in the water column of the Neuse River Estuary, North Carolina. Estuaries 17(2):361–71.CrossRefGoogle Scholar
  13. Bricker SB, Longstaff B, Dennison W, Jones A, Boicourt K, Wicks C, Woerner J. 2008. Effects of nutrient enrichment in the nation’s estuaries: a decade of change. Harmful Algae 8:21–32.CrossRefGoogle Scholar
  14. Brookshire ENJ, Valett HM, Gerber S. 2009. Maintenance of terrestrial nutrient loss signatures during in-stream transport. Ecology 90:293–9.PubMedCrossRefGoogle Scholar
  15. Bruesewitz DA, Gardner WS, Mooney RF, Pollard L, Buskey EJ. 2013. Estuarine ecosystem function response to flood and drought in a shallow, semiarid estuary: nitrogen cycling and ecosystem metabolism. Limnology and Oceanography 58(6):2293–309.CrossRefGoogle Scholar
  16. Bukaveckas PA, Barry LE, Beckwith MJ, David V, Lederer B. 2011. Factors determining the location of the chlorophyll maximum and the fate of algal production within the tidal freshwater James River. Estuaries and Coasts 34:569–82.CrossRefGoogle Scholar
  17. Bunch ND, Bernot MJ. 2012. Nitrate and ammonium uptake by natural stream sediment microbial communities in response to nutrient enrichment. Research in Microbiology 163:137–41.PubMedCrossRefGoogle Scholar
  18. Burford MA, Webster IT, Revill AT, Kenyon RA, Whittle M, Curwen G. 2012. Controls on phytoplankton productivity in a wet-dry tropical estuary. Estuarine, Coastal and Shelf Science 113:141–51.CrossRefGoogle Scholar
  19. Carini SA, McCarthy MJ, Gardner WS. 2010. An isotope dilution method to measure nitrification rates in the northern Gulf of Mexico and other eutrophic waters. Continental Shelf Research 30:1795–801.CrossRefGoogle Scholar
  20. Chen N, Wu J, Hong H. 2012. Effect of storm events on riverine nitrogen dynamics in a subtropical watershed, southeastern China. Science of the Total Environment 431:357–65.PubMedCrossRefGoogle Scholar
  21. Caperon J, Schell D, Hirota J, Laws E. 1979. Ammonium excretion rates in Kaneohe Bay, Hawaii, measured by a 15 N isotope dilution technique. Marine Biology 54:33–40.CrossRefGoogle Scholar
  22. Diaz RJ, Rosenberg R. 2008. Spreading dead zones and consequences for marine ecosystems. Science 321:926–9.PubMedCrossRefGoogle Scholar
  23. Dodds WK. 1993. What controls levels of dissolved phosphate and ammonium in surface waters? Aquatic Sciences 55(2):132–42.CrossRefGoogle Scholar
  24. Dodds WK. 2003. Misuse of inorganic N and soluble reactive P concentrations to indicate nutrient status of surface waters. Journal of the North American Benthological Society 22(2):171–81.CrossRefGoogle Scholar
  25. Dodds WK, Beaulieu JJ, Eichmiller JJ, Fisher JR, Franssen NR, Gudder DA, Makinster AS, McCarthy MJ, Murdock JN, O’Brien JM, Tank JL, Sheibley RW. 2008. Nitrogen cycling and metabolism in the thalweg of a prairie river. Journal of Geophysical Research 113:G04029. doi: 10.1029/2008JG000696.CrossRefGoogle Scholar
  26. Droop MR. 1983. 25 years of algal growth kinetics: a personal view. Botanica Marina 26:99–112.CrossRefGoogle Scholar
  27. Dunton K, Hardegree B, Whitledge T. 2001. Response of estuarine marsh vegetation to interannual variations in precipitation. Estuaries 24:851–61.CrossRefGoogle Scholar
  28. Ensign SH, Doyle MW, Piehler MF. 2012. Tidal geomorphology affects phytoplankton at the transition from forested streams to tidal rivers. Freshwater Biology 57:2141–55.CrossRefGoogle Scholar
  29. Ensign SH, McMillan SK, Thompson SP, Piehler MF. 2006. Nitrogen and phosphorus attenuation within the stream network of a coastal, agricultural watershed. Journal of Environmental Quality 35:1237–47.PubMedCrossRefGoogle Scholar
  30. Eyre BD, Ferguson AJP. 2006. Impact of a flood event on benthic and pelagic coupling in a sub-tropical east Australian estuary (Brunswick). Estuarine, Coastal and Shelf Science 66:111–22.CrossRefGoogle Scholar
  31. Eyre BD. 2000. Regional evaluation of nutrient transformation and phytoplankton growth in nine river-dominated subtropical east Australian estuaries. Marine Ecology Progress Series 205:61–83.CrossRefGoogle Scholar
  32. Fulweiler RW, Nixon SW, Buckley BA. 2010. Spatial and temporal variability of benthic oxygen demand and nutrient regeneration in an anthropogenically impacted New England estuary. Estuaries and Coasts 33(6):1377–90.CrossRefGoogle Scholar
  33. Fulweiler RW, Rabalais NN, Heiskanen AS. 2012. The eutrophication commandments. Marine Pollution Bulletin 64:1997–9.PubMedCrossRefGoogle Scholar
  34. Gardner W, Bootsman H, Evans C, John P. 1995a. Improved chromatographic analysis of 15N:14N ratios in ammonium or nitrate for isotope addition experiments. Marine Chemistry 48:271–82.CrossRefGoogle Scholar
  35. Gardner WS, Cavaletto JF, Johengen TH, Johnson JR, Heath RT, Cotner JB Jr. 1995b. Effects of the zebra mussel, Dreissena polymorpha, on community nitrogen dynamics in Saginaw Bay, Lake Huron. Journal of Great Lakes Research 21:529–44.CrossRefGoogle Scholar
  36. Gardner W, Cavaletto JF, Bootsma HA, Lavrentyev PJ, Troncone F. 1998. Nitrogen cycling rates and light effects in tropical Lake Maracaibo, Venezuela. Limnology and Oceanography 43(8):1814–25.Google Scholar
  37. Gardner W, McCarthy M, An S, Sobolev D, Sell K, Brock D. 2006. Nitrogen fixation and dissimilatory nitrate reduction to ammonium (DNRA) support nitrogen dynamics in Texas estuaries. Limnology and Oceanography 51:558–68.CrossRefGoogle Scholar
  38. Gardner W, McCarthy M. 2009. Nitrogen dynamics at the sediment-water interface in shallow, sub-tropical Florida Bay: why denitrification efficiency may decrease with increased eutrophication. Biogeochemistry 95:185–98.CrossRefGoogle Scholar
  39. Gardner WS, Cavaletto JF, Cotner JB, Johnson JR. 1997. Effects of natural light on nitrogen cycling rates in the Mississippi River plume. Limnology and Oceanography 42(2):273–81.CrossRefGoogle Scholar
  40. Glibert PM, Lipschultz F, McCarthy JJ, Altabet MA. 1982. Isotope dilution models of uptake and remineralization of ammonium uptake by marine plankton. Limnology and Oceanography 27(4):639–50.CrossRefGoogle Scholar
  41. Glibert PM. 1993. The interdependence of uptake and release of NH4 + and organic nitrogen. Marine Microbial Food Webs 7(1):53–67.Google Scholar
  42. Gilbert M, Needoba J, Koch C, Barnard A, Baptista A. 2013. Nutrient loading and transformations in the Columbia River Estuary determined by high-resolution in situ sensors. Estuaries and Coasts 36:708–27.CrossRefGoogle Scholar
  43. Hall RO Jr, Bernhardt ES, Likens GE. 2002. Relating nutrient uptake with transient storage in forested mountain streams. Limnology and Oceanography 47:255–65.CrossRefGoogle Scholar
  44. Hall RO Jr, Tank JL. 2003. Ecosystem metabolism controls nitrogen uptake in streams in Grand Teton National Park, Wyoming. Limnology and Oceanography 48(3):1120–8.CrossRefGoogle Scholar
  45. Hall RO Jr, Tank JL, Sobota DJ, Mulholland PJ, O’Brien JM, Dodds WK, Webster JR, Valett HM, Poole GC, Peterson BJ, Meyer JL, McDowell WH, Johnson SL, Hamilton SK, Grimm NB, Gregory SV, Dahm CN, Cooper LW, Ashkenas LR, Thomas SM, Sheibley RW, Potter JD, Niederlehner BR, Johnson LT, Helton AM, Crenshaw CM, Burgin AJ, Bernot MJ, Beaulieu JJ, Arango CP. 2009. Nitrate removal in stream ecosystems measured by 15N addition experiments: total uptake. Limnology and Oceanography 54(3):653–65.CrossRefGoogle Scholar
  46. Hamilton SK, Tank JL, Raikow DF, Wollheim WM, Peterson BJ, Webster JR. 2001. Nitrogen uptake and transformation in a midwestern U.S. stream: a stable isotope enrichment study. Biogeochemistry 54:297–340.CrossRefGoogle Scholar
  47. Higueras M, Kerhervé P, Sanchez-Vidal A, Calafat A, Ludwig W, Verdoit-Jarraya M, Heussner S, Canals M. 2014. Biogeochemical characterization of the riverine particulate organic matter transferred to the NW Mediterranean Sea. Biogeosciences 11(1):157–72.CrossRefGoogle Scholar
  48. Hoellein TJ, Tank JL, Rosi-Marshall EJ, Entrekin SA. 2009. Temporal variation in substratum-specific rates of N uptake and metabolism and their contribution at the stream-reach scale. Journal of the North American Benthological Society 28:305–18.CrossRefGoogle Scholar
  49. Howarth R, Marino R. 2006. Nitrogen as the limiting nutrient for eutrophication in coastal marine ecosystems: evolving views over three decades. Limnology and Oceanography 51:364–76.CrossRefGoogle Scholar
  50. Intergovernmental Panel on Climate Change (IPCC). 2007. The physical science basis. Contribution of Working Group I. In: Solomon S, Ed. The Fourth Assessment Report of the IPCC. pp 849–92. http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_wg1_report_the_physical_science_basis.htm.
  51. James RT, Gardner WS, McCarthy MJ, Carini SA. 2011. Nitrogen dynamics in Lake Okeechobee: forms, functions, and changes. Hydrobiologia 669:199–212.CrossRefGoogle Scholar
  52. Jochem FJ, McCarthy MJ, Gardner WS. 2004. Microbial ammonium cycling in the Mississippi River plume during the drought spring of 2000. Journal of Plankton Research 26:1265–75.CrossRefGoogle Scholar
  53. Johnson LT, Tank JL, Dodds WK. 2009. The influence of land use on stream biofilm nutrient limitation across eight North American ecoregions. Canadian Journal of Fisheries and Aquatic Sciences 66(7):1081–94.CrossRefGoogle Scholar
  54. Kaiser D, Unger D, Qiu G, Zhou H, Gan H. 2013. Natural and human influences on nutrient transport through a small subtropical Chinese estuary. Science of the Total Environment 450–451:92–107.PubMedCrossRefGoogle Scholar
  55. Kaiser D, Unger D, Qui G. 2014. Particulate organic matter dynamics in coastal systems of the northern Beibu Gulf. Continental Shelf Research 82:99–118.CrossRefGoogle Scholar
  56. Kennish MJ. 2002. Environmental threats and environmental future of estuaries. Environmental Conservation 29:78–107.CrossRefGoogle Scholar
  57. Larson JH, Richardson WB, Vallazza JM, Nelson JC. 2012. An exploratory investigation of the landscape-lake interface: land cover controls over consumer N and C isotopic composition in Lake Michigan river mouths. Journal of Great Lakes Research 38(4):610–19.CrossRefGoogle Scholar
  58. Lin X, McCarthy M, Carini S, Gardner W. 2011. Net, actual, and potential sediment-water interface NH4 fluxes in the northern Gulf of Mexico (NGOMEX): evidence for NH4 limitation of microbial dynamics. Continental Shelf Research 31:120–8.CrossRefGoogle Scholar
  59. Lopez CB, Cloern JE, Schraga TS, Little AJ, Lucas LV, Thompson JK, Burau JR. 2006. Ecological values of shallow-water habitats: implications for the restoration of disturbed ecosystems. Ecosystems 9(3):422–40.CrossRefGoogle Scholar
  60. Martí E, Grimm NB, Fisher SG. 1997. Pre- and post-flood retention efficiency of nitrogen in a Sonoran Desert stream. Journal of the North American Benthological Society 16:805–19.CrossRefGoogle Scholar
  61. Matheson FE, Quinn JM, Martin ML. 2012. Effects of irradiance on diel and seasonal patterns of nutrient uptake by stream periphyton. Freshwater Biology 57(8):1617–30.CrossRefGoogle Scholar
  62. McCarthy JJ, Taylor WR, Taft JL. 1977. Nitrogenous nutrition of the plankton in the Chesapeake Bay. Nutrient availability and phytoplankton preferences. Limnology and Oceanography 22:996–1011.CrossRefGoogle Scholar
  63. McCarthy MJ, Gardner WS, Lavrentyev PJ, Moats KM, Jochem FJ, Klarer DM. 2007. Effects of hydrological flow regime on sediment-water interface and water column nitrogen dynamics in a Great Lakes coastal wetland (Old Woman Creek, Lake Erie). Journal of Great Lakes Research 33:219–31.CrossRefGoogle Scholar
  64. McCarthy MJ, Gardner WS, Lehmann MF, Bird DF. 2013. Implications of water column ammonium uptake and regeneration for the nitrogen budget in temperate, eutrophic Missisquoi Bay, Lake Champlain (Canada/USA). Hydrobiologia 718(1):173–88.CrossRefGoogle Scholar
  65. Middelburg JJ, Nieuwenhuize J. 2000. Uptake of dissolved inorganic nitrogen in turbid, tidal estuaries. Marine Ecology Progress Series 192:79–88.CrossRefGoogle Scholar
  66. Milliman J, Farnsworth K, Jones P, Xu K, Smith L. 2008. Climatic and anthropogenic factors affecting river discharge to the global ocean, 1951-2000. Global and Planetary Change 62:187–94.CrossRefGoogle Scholar
  67. Montagna P, Kalke R. 1992. The effect of freshwater inflow on meiofaunal and macrofaunal populations in the Guadalupe and Nueces estuaries, Texas. Estuaries 15:307–26.CrossRefGoogle Scholar
  68. Mooney R, McClelland J. 2012. Watershed export events and ecosystem responses in the Mission-Aransas National Estuarine Research Reserve, south Texas. Estuaries and Coasts 35:1468–85.CrossRefGoogle Scholar
  69. Mulholland PJ, Hall RO Jr, Sobota DJ, Dodds WK, Findlay SEG, Grimm NB, Hamilton SK, McDowell WH, O’Brien JM, Tank JL, Ashkenas LR, Cooper LW, Dahm CN, Gregory SV, Johnson SL, Meyer JL, Peterson BJ, Poole GC, Valett HM, Webster JR, Arango CP, Beaulieu JJ, Bernot MJ, Burgin AG, Crenshaw CL, Helton AM, Johnson LT, Niederlehner BR, Potter JD, Sheibley RW, Thomas SM. 2009. Nitrate removal in stream ecosystems measured by 15 N addition experiments: denitrification. Limnology and Oceanography 54(3):666–80.CrossRefGoogle Scholar
  70. Newbold JD, O’Neill RV, Elwood JW, van Winkle W. 1982. Nutrient spiralling in streams: implications for nutrient limitation and invertebrate activity. The American Naturalist 120:628–52.CrossRefGoogle Scholar
  71. Newbold JD, Elwood JW, Schulze MS, Stark RW, Barmeier JC. 1983. Continuous ammonium enrichment of a woodland stream: uptake kinetics, leaf decomposition, and nitrification. Freshwater Biology 13(2):193–204.CrossRefGoogle Scholar
  72. Orlando S, Rozas L, Ward G, Klein C. 1993. Salinity characteristics of Gulf of Mexico estuaries. Conservation and Assessment: National Oceanic and Atmospheric Administration Office of Ocean Resources.Google Scholar
  73. Paerl HW, Rossignol K, Hall S, Peierls B, Wetz M. 2010. Phytoplankton community indicators of short- and long-term ecological change in the anthropogenically and climatically impacted Neuse River Estuary, North Carolina, USA. Estuaries and Coasts 33:485–97.CrossRefGoogle Scholar
  74. Paerl HW, Xu H, McCarthy MJ, Zhu G, Qin B, Li Y, Gardner WS. 2011. Controlling harmful cyanobacterial blooms in a hyper-eutrophic lake (Lake Taihu, China): the need for a dual nutrient (N & P) management strategy. Water Research 45(5):1973–83.PubMedCrossRefGoogle Scholar
  75. Paerl HW. 2009. Controlling eutrophication along the freshwater-marine continuum: dual nutrient (N and P) reductions are essential. Estuaries and Coasts 32:593–601.CrossRefGoogle Scholar
  76. Pennock JR. 1987. Temporal and spatial variability in phytoplankton ammonium and nitrate uptake in the Delaware Estuary. Estuarine, Coastal and Shelf Science 24:841–57.CrossRefGoogle Scholar
  77. Peterson BJ, Wollheim WM, Mulholland PJ, Webster JR, Meyer JL, Tank JL, Marti E, Bowden WB, Valett HM, Hershey AE, McDowell WH, Dodds WK, Hamilton SK, Gregory S, Morrall DD. 2001. Control of nitrogen export from watersheds by headwater streams. Science 292:86–90.PubMedCrossRefGoogle Scholar
  78. Porter ET, Mason RP, Sanford LP. 2010. Effect of tidal resuspension on benthic-pelagic coupling in an experimental ecosystem study. Marine Ecology Progress Series 413:33–53.CrossRefGoogle Scholar
  79. Probyn TA. 1985. Nitrogen uptake by size-fractionated phytoplankton populations in the southern Bunguela upwelling system. Marine Ecology Progress Series 22:249–58.CrossRefGoogle Scholar
  80. Rabalais N, Turner R, Diaz F, Justic D. 2009. Global change and eutrophication of coastal waters. ICES Journal of Marine Science 66:1528–37.CrossRefGoogle Scholar
  81. Reaugh ML, Roman MR, Stoecker DK. 2007. Changes in plankton community structure and function in response to variable freshwater flow in two tributaries of the Chesapeake Bay. Estuaries and Coasts 30:403–17.CrossRefGoogle Scholar
  82. Saeck EA, Hadwen WL, Rissik D, O’Brien KR, Burford MA. 2013. Flow events drive patterns of phytoplankton distribution along a river-estuary-bay continuum. Marine and Freshwater Research 64(7):655–70.CrossRefGoogle Scholar
  83. Scavia D, Field J, Boesch D, Buddemeier R, Burkett V, Cayan D, Fogarty M, Harwell M, Howarth R, Mason C, Reed D, Royer T, Sallenger A, Titus J. 2002. Climate change impacts on US coastal and marine ecosystems. Estuaries 25:149–64.CrossRefGoogle Scholar
  84. Scavia D, Bricker SB. 2006. Coastal eutrophication assessment in the United States. Biogeochemistry 79:187–208.CrossRefGoogle Scholar
  85. Sin Y, Hyun B, Jeong B, Soh HY. 2013. Impacts of eutrophic freshwater inputs on water quality and phytoplankton size structure in a temperate estuary altered by a sea dike. Marine Environmental Research 85:54–63.PubMedCrossRefGoogle Scholar
  86. Solis R, Powell G. 1999. Hydrography, mixing characteristics, and residence times of Gulf of Mexico estuaries. In: Bianchi TS, Pennock JR, Twilley RR, Eds. Biogeochemistry of Gulf of Mexico estuaries. New York: Wiley. p 29–61.Google Scholar
  87. Stream Solute Workshop. 1990. Solute dynamics in streams. Journal of the North American Benthological Society 9:95–119.CrossRefGoogle Scholar
  88. Tank JL, Rosi-Marshall EJ, Baker MA, Hall RO Jr. 2008. Are rivers just big streams? A pulse method to quantify nitrogen demand in a large river. Ecology 89:2935–45.PubMedCrossRefGoogle Scholar
  89. Trenberth K, Dai A, Rasmussen R, Parsons D. 2003. The changing character of precipitation. Bulletin of the American Meterological Society 84:1205–17.CrossRefGoogle Scholar
  90. Twomey LJ, Piehler MF, Paerl HW. 2005. Phytoplankton uptake of ammonium, nitrate and urea in the Nuese River Estuary, NC, USA. Hydrobiologia 533(1):123–34.CrossRefGoogle Scholar
  91. Underwood GJC and Kromkamp J. 1999. Primary production by phytoplantkon and microphytobenthos in estuaries. In: Nedwell DB, Raffaelli DG, Eds. Advances in Ecological Research: Estuaries, vol. 29. New York: Academic Press. pp. 93–153.Google Scholar
  92. United States Environmental Protection Agency (EPA). 2008. Water discharge permits (PCS). http://www.epa.gov/enviro/html/pcs/adhoc.html. Accessed 14 August 2014.
  93. Vincent WF. 1981. Rapid physiological assays for nutrient demand by the plankton 1. Nitrogen. Journal of Plankton Research 3(4):685–97.CrossRefGoogle Scholar
  94. Webster JR, Patten BC. 1979. Effects of watershed perturbation on stream potassium and calcium dynamics. Ecological Monographs 48:51–72.CrossRefGoogle Scholar
  95. Webster JR, Mulholland PJ, Tank JL, Valett HM, Dodds WK, Peterson BJ, Bowden WB, Dahm CN, Findlay S, Gergory SV, Grimm NB, Hamilton SK, Johnson SL, Martí E, McDowell WH, Meyer JL, Morrall DD, Thomas SA, Wollheim WM. 2003. Factors affecting ammonium uptake in streams—an inter-biome perspective. Freshwater Biology 48(8):1329–52.CrossRefGoogle Scholar
  96. Welter JR, Fisher SG, Grimm NB. 2005. Nitrogen transport and retention in an arid land watershed: influence of storm characteristics on terrestrial-aquatic linkages. Biogeochemistry 76(3):421–40.CrossRefGoogle Scholar
  97. Weston N, Giblin A, Banta G, Hopkinson C, Tucker J. 2010. The effects of varying salinity on ammonium exchange in estuarine sediments of the Parker River, Massachusetts. Estuaries and Coasts 33:985–1003.CrossRefGoogle Scholar
  98. Ye S, Covino TP, Sivapalan M, Basu NB, Li HY, Wang SW. 2012. Dissolved nutrient retention dynamics in river networks: a modeling investigation of transient flows and scale effects. Water Resources Research 48:W00J17.CrossRefGoogle Scholar
  99. York JK, Tomasky G, Valiela I, Repeta DJ. 2007. Stable isotopic detection of ammonium and nitrate assimilation by phytoplankton in the Waquoit Bay estuarine system. Limnology and Oceanography 52(1):144–55.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Denise A. Bruesewitz
    • 1
    • 2
  • Wayne S. Gardner
    • 2
  • Rae F. Mooney
    • 2
  • Edward J. Buskey
    • 2
  1. 1.Environmental Studies ProgramColby CollegeWatervilleUSA
  2. 2.University of Texas Marine Science InstitutePort AransasUSA

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