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

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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.

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References

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  Google Scholar 

  • Armstrong N. 1982. Responses of Texas estuaries to freshwater inflows. In: Kennedy VS, Ed. Estuarine comparisons. New York: Academic Press. p 103–20.

    Chapter  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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 

  • 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.

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • 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.

    CAS  PubMed Central  PubMed  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • Brookshire ENJ, Valett HM, Gerber S. 2009. Maintenance of terrestrial nutrient loss signatures during in-stream transport. Ecology 90:293–9.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • Diaz RJ, Rosenberg R. 2008. Spreading dead zones and consequences for marine ecosystems. Science 321:926–9.

    Article  CAS  PubMed  Google Scholar 

  • Dodds WK. 1993. What controls levels of dissolved phosphate and ammonium in surface waters? Aquatic Sciences 55(2):132–42.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • Droop MR. 1983. 25 years of algal growth kinetics: a personal view. Botanica Marina 26:99–112.

    Article  Google Scholar 

  • Dunton K, Hardegree B, Whitledge T. 2001. Response of estuarine marsh vegetation to interannual variations in precipitation. Estuaries 24:851–61.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • Fulweiler RW, Rabalais NN, Heiskanen AS. 2012. The eutrophication commandments. Marine Pollution Bulletin 64:1997–9.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • Glibert PM. 1993. The interdependence of uptake and release of NH4 + and organic nitrogen. Marine Microbial Food Webs 7(1):53–67.

    Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • Hall RO Jr, Bernhardt ES, Likens GE. 2002. Relating nutrient uptake with transient storage in forested mountain streams. Limnology and Oceanography 47:255–65.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

  • James RT, Gardner WS, McCarthy MJ, Carini SA. 2011. Nitrogen dynamics in Lake Okeechobee: forms, functions, and changes. Hydrobiologia 669:199–212.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  PubMed  Google Scholar 

  • 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.

    Article  Google Scholar 

  • Kennish MJ. 2002. Environmental threats and environmental future of estuaries. Environmental Conservation 29:78–107.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • Middelburg JJ, Nieuwenhuize J. 2000. Uptake of dissolved inorganic nitrogen in turbid, tidal estuaries. Marine Ecology Progress Series 192:79–88.

    Article  CAS  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • Paerl HW. 2009. Controlling eutrophication along the freshwater-marine continuum: dual nutrient (N and P) reductions are essential. Estuaries and Coasts 32:593–601.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • Probyn TA. 1985. Nitrogen uptake by size-fractionated phytoplankton populations in the southern Bunguela upwelling system. Marine Ecology Progress Series 22:249–58.

    Article  CAS  Google Scholar 

  • Rabalais N, Turner R, Diaz F, Justic D. 2009. Global change and eutrophication of coastal waters. ICES Journal of Marine Science 66:1528–37.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • Scavia D, Bricker SB. 2006. Coastal eutrophication assessment in the United States. Biogeochemistry 79:187–208.

    Article  Google Scholar 

  • 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.

    Article  CAS  PubMed  Google Scholar 

  • 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 

  • Stream Solute Workshop. 1990. Solute dynamics in streams. Journal of the North American Benthological Society 9:95–119.

    Article  Google Scholar 

  • 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.

    Article  PubMed  Google Scholar 

  • Trenberth K, Dai A, Rasmussen R, Parsons D. 2003. The changing character of precipitation. Bulletin of the American Meterological Society 84:1205–17.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

  • United States Environmental Protection Agency (EPA). 2008. Water discharge permits (PCS). http://www.epa.gov/enviro/html/pcs/adhoc.html. Accessed 14 August 2014.

  • Vincent WF. 1981. Rapid physiological assays for nutrient demand by the plankton 1. Nitrogen. Journal of Plankton Research 3(4):685–97.

    Article  CAS  Google Scholar 

  • Webster JR, Patten BC. 1979. Effects of watershed perturbation on stream potassium and calcium dynamics. Ecological Monographs 48:51–72.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  CAS  Google Scholar 

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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.

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Correspondence to Denise A. Bruesewitz.

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DAB, WSG, and EJB designed the study, DAB and RFM performed research and analyzed data, WSG contributed to novel methods, and DAB wrote the paper.

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Bruesewitz, D.A., Gardner, W.S., Mooney, R.F. et al. Seasonal Water Column NH4 + Cycling Along a Semi-arid Sub-tropical River–Estuary Continuum: Responses to Episodic Events and Drought Conditions. Ecosystems 18, 792–812 (2015). https://doi.org/10.1007/s10021-015-9863-z

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