, Volume 35, Issue 2, pp 323–334 | Cite as

Changes in Nitrogen Cycling Processes Along a Salinity Gradient in Tidal Wetlands of the Hudson River, New York, USA

  • Robert I. Osborne
  • Melody J. Bernot
  • Stuart E. G. Findlay
Original Research


Rising sea levels and stronger storm surges may expose tidal freshwater wetlands to saline waters, possibly leading to increased sulfate reduction and higher sulfide (H2S) concentrations. To better understand the effects of salinity on nitrogen cycling, porewater chemistry and sediment profiles of H2S and dissolved oxygen (O2) were measured along a salinity gradient in the Hudson River (New York, USA). Additionally, laboratory experiments exposed freshwater sediments to varying salinities after which sediment O2 and H2S dynamics along with nitrification and denitrification were measured. Overall, sites with higher salinities had lower oxygen availability (both as concentration and oxic sediment depth) and higher sulfide concentrations. Both nitrification and denitrification were depressed at higher salinities suggesting that exposure to saline water may alter nitrogen cycling of tidally influenced wetlands in the brackish region of the Hudson River estuary which may result in reduced retention of nitrogen.


Climate change Microelectrodes Nitrogen Oxygen Sulfide 



We thank Randy Bernot, Kem Badger and the Bernot lab members for helpful discussion, Lindy Caffo for laboratory support and three anonymous reviewers for comments on previous versions of the manuscript. This work was supported by a New York Sea Grant R/CMC-11 and the National Science Foundation IDBR (EAGER) – 1011787.


  1. Aminot A, Kirkwood DS, Kerouel R (1997) Determination of ammonium in seawater by the indophenol-blue method: evaluation of the ICES NUTS I/C 5 questionnaire. Marine Chemistry 56:59–75CrossRefGoogle Scholar
  2. An S, Gardner WS (2002) Dissimilatory nitrate reduction to ammonium (DNRA) as a nitrogen link, versus denitrification as a sink in a shallow estuary (Laguna Madre/Baffin Bay, Texas). Marine Ecology Progress Series 237:41–50CrossRefGoogle Scholar
  3. Ardón M, Morse JL, Colman BP, Bernhardt ES (2013) Drought-induced saltwater incursion leads to increased wetland nitrogen export. Global Change Biology 19:2976–2985CrossRefPubMedGoogle Scholar
  4. Arrigoni A, Findlay S, Fischer D, Tockner K (2008) Predicting carbon and nutrient transformations in tidal freshwater wetlands of the Hudson River. Ecosystems 11:790–802CrossRefGoogle Scholar
  5. Baldwin AH, Mendelssohn IA (1998) Effects of salinity and water level on coastal marshes: an experimental test of disturbance as a catalyst for vegetation change. Aquatic Botany 61:255–268CrossRefGoogle Scholar
  6. Barbier EB, Koch EW, Silliman BR, Hacker SD, Wolanski E, Primavera J, Granek EF, Polasky S, Aswani S, Cramer LA, Stoms DM, Kennedy CJ, Bael D, Kappel CV, Perillo GME, Reed DJ (2008) Coastal ecosystem-based management with nonlinear ecological functions and values. Science 319:321–323CrossRefPubMedGoogle Scholar
  7. Barbier EB, Hacker SD, Kennedy C, Koch EW, Stier AC, Silliman BR (2011) The value of estuarine and coastal ecosystem services. Ecological Monographs 81:169–193CrossRefGoogle Scholar
  8. Bowden WB (1987) The biogeochemistry of nitrogen in freshwater wetlands. Biogeochemistry 4:313–348CrossRefGoogle Scholar
  9. Brunet RC, Garcia-Gil LJ (1996) Sulfide-induced dissimilatory nitrate reduction to ammonia in anaerobic freshwater sediments. FEMS Microbiology Ecology 21:131–138CrossRefGoogle Scholar
  10. Bunch ND, Bernot MJ (2012) Nitrate and ammonium uptake by natural stream sediment microbial communities in response to nutrient enrichment. Research in Microbiology 163:137–141CrossRefPubMedGoogle Scholar
  11. Bridgham SD, Megonigal JP, Keller JK, Bliss NB, Tretting C (2006) The carbon balance of North American wetlands. Wetlands 26:889–916Google Scholar
  12. Cai W, Wiebe WJ, Wang Y, Sheldon JE (2000) Intertidal marsh as a source of dissolved inorganic carbon and a sink of NO3 in the Satilla River-estuarine complex in southeastern U.S. Limnology and Oceanography 45:1743–1752CrossRefGoogle Scholar
  13. Capone DG, Kiene RP (1988) Comparison of microbial dynamics in marine and freshwater sediments – contrasts in anaerobic carbon catabolism. Limnology and Oceanography 33:725–749CrossRefGoogle Scholar
  14. Craft CB (2012) Tidal freshwater forest accretion does not keep pace with sea level rise. Global Change Biology 18:3615–3623CrossRefGoogle Scholar
  15. DeLaune RD, Smith CJ, Patrick WH (1982) Methane release from gulf coast wetlands. Tellus B 35B:8–15CrossRefGoogle Scholar
  16. Eaton AD, Clesceri LS, Rice WE, Greenberg AE (2005) Standard methods for the examination of water and wastewater, 21st edn. American Public Health Association, Washington Google Scholar
  17. Findlay SEG, Fischer DT (2013) Ecosystem attributes related to tidal wetland effects on water quality. Ecology 94:117–125Google Scholar
  18. Giblin AE, Weston NB, Banta GT, Tucker J, Hopkinson CS (2010) The effects of salinity on nitrogen losses from an oligohaline estuarine sediment. Estuaries and Coasts 33:1054–1068CrossRefGoogle Scholar
  19. Greene SE (2005) Nutrient removal by tidal fresh and oligohaline marshes in a Chesapeake Bay tributary. MS Thesis. University of Maryland, Solomons, MDGoogle Scholar
  20. Gribsholt B, Boschker HTS, Struyf E, Andersson M, Tramper A, De Brabandere L, van Damme S, Brion N, Meire P, Dehairs F, Middelburg JJ, Heip CHR (2005) Nitrogen processing in a tidal freshwater marsh: a whole-ecosystem 15N labeling study. Limnology and Oceanography 50:1945–1959CrossRefGoogle Scholar
  21. Hamilton P (1990) Modelling salinity and circulation for the Columbia River Estuary. Progress in Oceanography 25:113–156CrossRefGoogle Scholar
  22. Jeroschewski P, Steuckart C, Kahl M (1996) An amperometric microsensor for the determination of H2S in aquatic environments. Analytical Chemistry 68:4351–4357CrossRefGoogle Scholar
  23. Joye SB, Hollibaugh JT (1995) Influence of sulfide inhibition of nitrification on nitrogen regeneration in sediments. Science 270:623–625CrossRefGoogle Scholar
  24. Kelley CA, Martens CS, Chanton JP (1990) Variations in sedimentary carbon remineralization rates in the White Oak River estuary, North Carolina. Limnology and Oceanography 35:372–383CrossRefGoogle Scholar
  25. Kemp MJ, Dodds WK (2001) Centimeter-scale patterns in dissolved oxygen and nitrification rates in a prairie stream. Journal of the North American Benthological Society 20:347–357CrossRefGoogle Scholar
  26. Kemp MJ, Dodds WK (2002) The influence of ammonium, nitrate, and dissolved oxygen concentrations on uptake, nitrification, and denitrification rates associated with prairie stream substrata. Limnology and Oceanography 47:1380–1393CrossRefGoogle Scholar
  27. Knowles N (2002) Natural and management influences on freshwater inflows and salinity in the San Francisco Estuary at monthly to interannual scales. Water Resources Research 38:1289–1299CrossRefGoogle Scholar
  28. Krauss KW, Duberstein JA, Doyle TW, Conner WH, Day RH, Inabinette LW, Whitbeck JL (2009) Site condition, structure, and growth of baldcypress along tidal/non-tidal salinity gradients. Wetlands 29:505–519CrossRefGoogle Scholar
  29. Larsen L, Moseman S, Santoro AE, Hopfensperger K, Burgin A (2008) A complex-systems approach to predicting effects of sea level rise and nitrogen loading on nitrogen cycling in coastal wetland ecosystems. In Proceedings of the Eco-DAS Symposium, Honolulu, Hawaii EcoDASVIII 5:67–92Google Scholar
  30. Magalhães CM, Joye SB, Moreira RM, Wiebe WJ, Bordalo AA (1980) Effect of salinity and inorganic nitrogen concentrations on nitrification and denitrification rates in intertidal sediments and rocky biofilms of the Douro River estuary, Portugal. Water Research 39:1783–1794CrossRefGoogle Scholar
  31. Megonigal JP, Neubauer SC (2009) Biogeochemistry of tidal freshwater wetlands. In: Perillo GME, Wolanski E, Cahoon DR, Brinson MM (eds) Coastal Wetlands: An Integrated Ecosystem Approach. Elsevier, p. 535Google Scholar
  32. Milly PCD, Dunne KA, Vecchia AV (2005) Global pattern of trends in streamflow and water availability in a changing climate. Nature 438:347–350CrossRefPubMedGoogle Scholar
  33. Mitsch WJ, Gosselink JG (1993) Wetlands, 2nd edn. Wiley, New York, p 722Google Scholar
  34. Neubauer SC, Givier K, Valentive SK, Megonigal JP (2005a) Seasonal patterns and plant-mediated controls of subsurface wetland biogeochemistry. Ecology 86:3334–3344CrossRefGoogle Scholar
  35. Neubauer SC, Givier K, Valentine SK, Megonigal JP (2005b) Seasonal patterns and plant-mediated controls of subsurface wetland biogeochemistry. Ecology 86:3334–3344CrossRefGoogle Scholar
  36. Odum WE (1988) Comparative ecology of tidal freshwater and salt marshes. Annual Review of Ecological Systems 19:147–176CrossRefGoogle Scholar
  37. Powell SJ, Prosser JI (1985) The effect of nitrapyrin and chloropicolinic acid on ammonium oxidation by Nitrosomonas europaea. FEMS Microbiology Letters 28:51–54CrossRefGoogle Scholar
  38. Reeburgh WS, Heggie DT (1977) Microbial methane consumption reactions and their effect on methane distributions in freshwater and marine environments. Limnology and Oceanography 22:1–9CrossRefGoogle Scholar
  39. Revsbech NP, Jørgensen B (1986) Microelectrodes: their use in microbial ecology. Advances in Microbial Ecology 9:293–352CrossRefGoogle Scholar
  40. Seitzinger SP (1988) Denitrification in freshwater and coastal marine ecosystems: ecological and geochemical significance. Limnology and Oceanography 33:702–724CrossRefGoogle Scholar
  41. Seitzinger SP, Gardner WS, Spratt AK (1991) The effect of salinity on ammonium sorption in aquatic sediments: implications for benthic nutrient recycling. Estuaries 14:167–174CrossRefGoogle Scholar
  42. Smith TM, Peterson TC, Lawrimore JH, Reynolds RW (2005) New surface temperature analyses for climate monitoring. Geophysical Research Letters 32:L14712Google Scholar
  43. Solórzano L (1969) Determination of ammonia in natural waters by the phenol hypochlorite method. Limnology and Oceanography 14:799–801CrossRefGoogle Scholar
  44. Strauss EA, Lamberti G (2000) Regulation of nitrification in aquatic sediments by organic carbon. Limnology and Oceanography 45:1854–1859CrossRefGoogle Scholar
  45. van der Nat FWA, Middelburg JJ (1998) Effects of two common macrophytes on methane dynamics in freshwater sediments. Biogeochemistry 43:79–104CrossRefGoogle Scholar
  46. Weston NB, Dixon RE, Joye SB (2006) Ramifications of increased salinity in tidal freshwater sediments: geochemistry and microbial pathways of organic matter mineralization. Journal of Geophysical Research – Biogeosciences 111:2005–2012CrossRefGoogle Scholar
  47. Weston NB, Vile MA, Neubauer SC, Velinsky DJ (2011) Accelerated \microbial organic matter mineralization following salt-water intrusion into tidal freshwater marsh soils. Biogeochemistry 102:135–151Google Scholar
  48. Weston NB, Neubauer SC, Velinsky DJ, Vile MA (2014) Net ecosystem carbon exchange and the greenhouse gas balance of tidal marshes along an estuarine salinity gradient. Biogeochemistry 120:163–189CrossRefGoogle Scholar
  49. Yoshinari T, Knowles R (1976) Acetylene inhibition of nitrous oxide reduction by denitrifying bacteria. Biochemical and Biophysical Research Communications 69:705–710CrossRefPubMedGoogle Scholar

Copyright information

© Society of Wetland Scientists 2015

Authors and Affiliations

  • Robert I. Osborne
    • 1
  • Melody J. Bernot
    • 1
  • Stuart E. G. Findlay
    • 2
  1. 1.Department of BiologyBall State UniversityMuncieUSA
  2. 2.Cary Institute of Ecosystem StudiesMilbrookUSA

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