Skip to main content
SpringerLink
Log in

Variations of the nitrate isotopic composition in the St. Lawrence River caused by seasonal changes in atmospheric nitrogen inputs

  • Published:
Biogeochemistry Aims and scope Submit manuscript

Abstract

We present 42 dual-isotope nitrate analyses of fresh water samples collected in the St. Lawrence River between June 2006 and July 2008. Measured δ15N–NO3 − and δ18O–NO3 − values correlate negatively, while δ18O–NO3 − displays no negative correlation with nitrate concentration. This suggests that nitrate uptake and/or elimination by denitrification is not the main driver of observed variations in nitrate concentration and isotopic signature in the St. Lawrence River. In addition, δ18O–NO3 − is negatively correlated with the seasonally variable δ18O of ambient water, indicating that the variation in the isotopic signature of nitrate is barely modulated by in-stream nitrate regeneration (nitrification). It rather is constrained by along-river changes in the external sources of nitrate. Given the distinct nitrogen (N) and oxygen (O) isotopic signature of atmospheric nitrate, we argue that observed seasonal variations of δ15N–NO3 − and δ18O–NO3 − in the St. Lawrence River are due to variable contributions of snowmelt-derived water. Based on a N and O isotope mass balance, we show that total nitrate loading in the St. Lawrence River is dominated by a N input from the Great Lakes (47 ± 28 %) and from nitrate regeneration of both internal and external N (48 ± 22 %). While temporal nitrate N and O isotope dynamics in the St. Lawrence River are mainly influenced by the atmospheric N input fluctuations, with an increase in atmospheric loading during spring, atmospheric N plays overall a rather insignificant role with regards to the N budget (5 ± 4 %).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

References

  • Aleem MI, Hoch GE, Varner JE (1965) Water as source of oxidant and reductant in bacterial chemosynthesis. Proc Natl Acad Sci USA 54(3):869–873. doi:10.1073/pnas.54.3.869

    Article  Google Scholar 

  • Alkhatib M, Lehmann MF, del Giorgio PA (2012) The nitrogen isotope effect of benthic remineralization-nitrification-denitrification coupling in an estuarine environment. Biogeosciences 9(5):1633–1646. doi:10.5194/bg-9-1633-2012

    Article  Google Scholar 

  • Altabet MA, Pilskaln C, Thunell R, Pride C, Sigman D, Chavez F, Francois R (1999) The nitrogen isotope biogeochemistry of sinking particles from the margin of the eastern North Pacific. Deep Sea Res Part I 46(4):655–679

    Article  Google Scholar 

  • Amberger A, Schmidt HL (1987) The natural isotope content of nitrate as an indicator of its origin. Geochim Cosmochim Acta 51(10):2699–2705

    Article  Google Scholar 

  • Aravena R, Evans ML, Cherry JA (1993) Stable isotopes of oxygen and nitrogen in source identification of nitrate from septic systems. Ground Water 31(2):180–186

    Article  Google Scholar 

  • Bedard-Haughn A, van Groenigen JW, van Kessel C (2003) Tracing 15N through landscapes: potential uses and precautions. J Hydrol 272(1–4):175–190

    Article  Google Scholar 

  • Benoit P, Gratton Y, Mucci A (2006) Modeling of dissolved oxygen levels in the bottom waters of the Lower St. Lawrence Estuary: coupling of benthic and pelagic processes. Mar Chem 102:13–32

    Article  Google Scholar 

  • Bohlke JK, Mroczkowski SJ, Coplen TB (2003) Oxygen isotopes in nitrate: new reference materials for 18O:17O:16O measurements and observations on nitrate-water equilibration. Rapid Commun Mass Spectrom 17(16):1835–1846

    Article  Google Scholar 

  • Böttcher J, Strebel O, Voerkelius S, Schmidt HL (1990) Using isotope fractionation of nitrate-nitrogen and nitrate-oxygen for evaluation of microbial denitrification in a sandy aquifer. J Hydrol 114(3–4):413–424

    Article  Google Scholar 

  • Bourbonnais A, Lehmann MF, Waniek JJ, Schulz-Bull DE (2009) Nitrate isotope anomalies reflect N2 fixation in the Azores Front region (subtropical N-E Atlantic). J Geophys Res 114. doi:10.1029/2007JC004617

  • Burns DA, Kendall C (2002) Analysis of δ15N and δ18O to differentiate NO3 − sources in runoff at two watersheds in the Catskill Mountains of New York. Water Resour Res 38(5):91–912

    Article  Google Scholar 

  • Burns DA, Boyer EW, Elliott EM, Kendall C (2009) Sources and transformations of nitrate from streams draining varying land uses: evidence from dual isotope analysis. J Environ Qual 38(3):1149–1159

    Article  Google Scholar 

  • Casciotti KL, Sigman DM, Hastings MG, Böhlke JK, Hilkert A (2002) Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method. Anal Chem 74(19):4905–4912

    Article  Google Scholar 

  • Casciotti KL, Sigman DM, Ward BB (2003) Linking diversity and stable isotope fractionation in ammonia-oxidizing bacteria. Geomicrobiol J 20(4):335–353

    Article  Google Scholar 

  • Cey EE, Rudolph DL, Aravena R, Parkin G (1999) Role of the riparian zone in controlling the distribution and fate of agricultural nitrogen near a small stream in southern Ontario. J Contam Hydrol 37(1–2):45–67

    Article  Google Scholar 

  • Dansgaard W (1964) Stable isotopes in precipitation. Tell 16:436–468

    Article  Google Scholar 

  • Dijkstra P, Laviolette CM, Coyle JS, Doucett RR, Schwartz E, Hart SC, Hungate BA (2008) 15N enrichment as an integrator of the effects of C and N on microbial metabolism and ecosystem function. Ecol Lett 11(4):389–397

    Article  Google Scholar 

  • Finlay JC, Sterner RW, Kumar S (2007) Isotopic evidence for in-lake production of accumulating nitrate in lake superior. Ecol Appl 17(8):2323–2332. doi:10.1890/07-0245.1

    Article  Google Scholar 

  • Galloway JN, Dentener FJ, Capone DG, Boyer EW, Howarth RW, Seitzinger SP, Asner GP, Cleveland CC, Green PA, Holland EA, Karl DM, Michaels AF, Porter JH, Townsend AR, Vöosmarty CJ (2004) Nitrogen cycles: past, present, and future. Biogeochemistry 70(2):153–226

    Article  Google Scholar 

  • Gearing JN, Pocklington R (1990) Organic geochemical studies in the St. Lawrence Estuary. In: El-Sabh MI, Silverberg N (eds) Oceanography of a large-scale estuarine system, the St.-Lawrence Coastal and estuarine studies, vol 39. Springer, New York, pp 170–201

    Chapter  Google Scholar 

  • Gilbert D, Sundby B, Gobeil C, Mucci A, Tremblay GH (2005) A seventy-two-year record of diminishing deep-water oxygen in the St. Lawrence estuary: the northwest Atlantic connection. Limnol Oceanogr 50(5):1654–1666

    Article  Google Scholar 

  • Gonfiantini R, Stichler W, Rozanski K (1995) Standards and intercomparison materials distributed by the International Atomic Energy Agency for stable isotope measurements. In: Proceedings of a consultants meeting Vienna, Austria, 1–3 Dec 1995. International Atomic Energy Agency, pp 13–29

  • Granger J, Sigman DM, Lehmann MF, Tortell PD (2004a) Nitrogen and oxygen isotope effects associated with nitrate assimilation and denitrification by laboratory cultures of marine plankton. Eos Trans AGU 85 (47):Fall Meet Suppl, Abstract H51E–O52

  • Granger J, Sigman DM, Needoba JA, Harrison PJ (2004b) Coupled nitrogen and oxygen isotope fractionation of nitrate during assimilation by cultures of marine phytoplankton. Limnol Oceanogr 49(5):1763–1773

    Article  Google Scholar 

  • Hélie JF, Hillaire-Marcel C (2006) Sources of particulate and dissolved organic carbon in the St Lawrence River: isotopic approach. Hydrol Process 20(9):1945–1959

    Article  Google Scholar 

  • Hollocher TC (1984) Source of the oxygen atoms of nitrate in the oxidation of nitrite by Nitrobacter agilis and evidence against a PON anhydride mechanism in oxidative phosphorylation. Arch Biochem Biophys 233(2):721–727

    Article  Google Scholar 

  • Howarth RW (1998) An assessment of human influences on fluxes of nitrogen from the terrestrial landscape to the estuaries and continental shelves of the North Atlantic Ocean. Nutr Cycl Agroecosyst 52(2–3):213–223

    Article  Google Scholar 

  • Howarth RW, Billen G, Swaney D, Townsend A, Jaworski N, Lajtha K, Downing JA, Elmgren R, Caraco N, Jordan T, Berendse F, Freney J, Kudeyarov V, Murdoch P, Zhu ZL (1996) Regional nitrogen budgets and riverine N & P fluxes for the drainages to the North Atlantic Ocean: natural and human influences. Biogeochemistry 35(1):75–139

    Article  Google Scholar 

  • Howarth RW, Swaney DP, Boyer EW, Marino R, Jaworski N, Goodale C (2006) The influence of climate on average nitrogen export from large watersheds in the North-eastern United States. Biogeochemistry 79(1–2):163–186

    Article  Google Scholar 

  • Kellman L, Hillaire-Marcel C (1998) Nitrate cycling in streams: using natural abundances of NO3 −δ15N to measure in situ denitrification. Biogeochemistry 43(3):273–292

    Article  Google Scholar 

  • Kendall C, Elliott EM, Wankel SD (2007) Tracing anthropogenic inputs of nitrogen to ecosystems. In: Michener RH, Lajtha K (eds) Stable isotopes in ecology and environmental science. Blackwell, Oxford, p 592

    Google Scholar 

  • Knapp AN, DiFiore PJ, Deutsch C, Sigman DM, Lipschultz F (2008) Nitrate isotopic composition between Bermuda and Puerto Rico: implications for N2 fixation in the Atlantic Ocean. Global Biogeochem Cycles 22(3). doi:10.1029/2007GB003107

  • Korol M (2002) Canadian fertilizer consumption, shipments and trade 2001–2002. Agriculture and AgriFood Canada Strategic Policy Branch, Ottawa, Canada

  • Lehmann MF, Bernasconi SM, Barbieri A, McKenzie JA (2002) Preservation of organic matter and alteration of its carbon and nitrogen isotope composition during simulated and in situ early sedimentary diagenesis. Geochim Cosmochim Acta 66(20):3573–3584

    Article  Google Scholar 

  • Lehmann MF, Reichert P, Bernasconi SM, Barbieri A, McKenzie JA (2003) Modelling nitrogen and oxygen isotope fractionation during denitrification in a lacustrine redox-transition zone. Geochim Cosmochim Acta 67(14):2529–2542

    Article  Google Scholar 

  • Lehmann MF, Sigman DM, Berelson WM (2004) Coupling the 15N/14N and 18O/16O of nitrate as a constraint on benthic nitrogen cycling. Mar Chem 88(1–2):1–20

    Article  Google Scholar 

  • Lehmann MF, Sigman DM, McCorkle DC, Brunelle BG, Hoffmann S, Kienast M, Cane G, Clement J (2005) Origin of the deep Bering Sea nitrate deficit: constraints from the nitrogen and oxygen isotopic composition of water column nitrate and benthic nitrate fluxes. Global Biogeochem Cycles 19(4). doi:10.1029/2005GB002508

  • Lehmann MF, Sigman DM, McCorkle DC, Granger J, Hoffmann S, Cane G, Brunelle BG (2007) The distribution of nitrate 15N/14N in marine sediments and the impact of benthic nitrogen loss on the isotopic composition of oceanic nitrate. Geochim Cosmochim Acta 71(22):5384–5404

    Article  Google Scholar 

  • Lehmann MF, Barnett B, Gélinas Y, Gilbert D, Maranger RJ, Mucci A, Sundby B, Thibodeau B (2009) Aerobic respiration and hypoxia in the lower St. Lawrence Estuary: stable isotope ratios of dissolved oxygen constrain oxygen sink partitioning. Limnol Oceanogr 54(6):2157–2169

    Article  Google Scholar 

  • Mayer B, Boyer EW, Goodale C, Jaworski NA, Van Breemen N, Howarth RW, Seitzinger S, Billen G, Lajtha K, Nadelhoffer K, Van Dam D, Hetling LJ, Nosal M, Paustian K (2002) Sources of nitrate in rivers draining sixteen watersheds in the north-eastern US.: isotopic constraints. Biogeochemistry 57–58:171–197

    Article  Google Scholar 

  • McClelland JW, Valiela I (1998) Linking nitrogen in estuarine producers to land-derived sources. Limnol Oceanogr 43(4):577–585

    Article  Google Scholar 

  • Mengis M, Walther U, Bernasconi SM, Wehrli B (2001) Limitations of using δ18O for the source identification of nitrate in agricultural soils. Environ Sci Technol 35(9):1840–1844. doi:10.1021/es0001815

    Article  Google Scholar 

  • Miyajima T, Yoshimizu C, Tsuboi Y, Tanaka Y, Tayasu I, Nagata T, Koike I (2009) Longitudinal distribution of nitrate δ15N and δ18O in two contrasting tropical rivers: implications for instream nitrogen cycling. Biogeochemistry 95:1–18

    Google Scholar 

  • Myre A (2006) Isotopic monitoring (2H and 18O) of the St. Lawrence and Ottawa rivers from 1997 to 2003: linkages with seasonal and interannual hydroclimatic variability. Thesis Dissertation, Université du Québec à Montréal, Montreal

  • Nixon SW, Ammerman JW, Atkinson LP, Berounsky VM, Billen G, Boicourt WC, Boynton WR, Church TM, Ditoro DM, Elmgren R, Garber JH, Giblin AE, Jahnke RA, Owens NJP, Pilson MEQ, Seitzinger SP (1996) The fate of nitrogen and phosphorus at the land-sea margin of the North Atlantic Ocean. Biogeochemistry 35(1):141–180

    Article  Google Scholar 

  • Ohte N, Sebestyen SD, Shanley JB, Doctor DH, Kendall C, Wankel SD, Boyer EW (2004) Tracing sources of nitrate in snowelt runoff using a high-resolution isotopic technique. Geophys Res Lett 31. doi:10.1029/2004GL020908

  • Ostrom NE, Elsbury K, McLaughlin K, Kendall C, Paytan A (2006) Stable isotope signatures of nitrate and phosphate: potential tools for determining sources and cycling of nutrients in Lake Erie. Lake Erie millennium network conference, Windsor, ON, Canada, 28 Feb–2 Mar 2006

  • Panno SV, Hackley KC, Kelly WR, Hwang HH (2006) Isotopic evidence of nitrate sources and denitrification in the Mississippi River, Illinois. J Environ Qual 35(2):495–504

    Article  Google Scholar 

  • Phillips DL, Gregg JW (2001) Uncertainty in source partitioning using stable isotopes. Oecologia 127(2):171–179. doi:10.1007/s004420000578

    Article  Google Scholar 

  • Prospero JM, Barrett K, Church T, Dentener F, Duce RA, Galloway JN, Levy Ii H, Moody J, Quinn P (1996) Atmospheric deposition of nutrients to the North Atlantic Basin. Biogeochemistry 35(1):27–73

    Article  Google Scholar 

  • Sebilo M, Billen G, Grably M, Mariotti A (2003) Isotopic composition of nitrate-nitrogen as a marker of riparian and benthic denitrification at the scale of the whole Seine River system. Biogeochemistry 63(1):35–51

    Article  Google Scholar 

  • Sigman DM, Casciotti KL, Andreani M, Barford C, Galanter M, Böhlke JK (2001) A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater. Anal Chem 73(17):4145–4153

    Article  Google Scholar 

  • Sigman DM, Granger J, DiFiore PJ, Lehmann MM, Ho R, Cane G, van Geen A (2005) Coupled nitrogen and oxygen isotope measurements of nitrate along the eastern North Pacific margin. Global Biogeochem Cycles 19(4). doi:10.1029/2005gb002458

  • Spoelstra J, Schiff SL, Hazlett PW, Jeffries DS, Semkin RG (2007) The isotopic composition of nitrate produced from nitrification in a hardwood forest floor. Geochim Cosmochim Acta 71(15):3757–3771

    Article  Google Scholar 

  • Sterner RW, Anagnostou E, Brovold S, Bullerjahn GS, Finlay JC, Kumar S, McKay RML, Sherrell RM (2007) Increasing stoichiometric imbalance in North America’s largest lake: nitrification in Lake Superior. Geophys Res Lett 34(10):L10406. doi:10.1029/2006gl028861

    Google Scholar 

  • Strickland JDH, Parsons TR (1972) A practical handbook of seawater analysis. Bull Fish Res Board Can 167:207–211

    Google Scholar 

  • Thibodeau B, de Vernal A, Mucci A (2006) Recent eutrophication and consequent hypoxia in the bottom waters of the Lower St. Lawrence Estuary: micropaleontological and geochemical evidence. Mar Geol 231(1–4):37–50

    Article  Google Scholar 

  • Thibodeau B, de Vernal A, Hillaire-Marcel C, Mucci A (2010a) Twentieth century warming in deep waters of the Gulf of St. Lawrence: a unique feature of the last millennium. Geophys Res Lett 37. doi:10.1029/2010GL044771

  • Thibodeau B, Lehmann MF, Kowarzyk J, Mucci A, Gélinas Y, Gilbert D, Maranger R, Alkhatib M (2010b) Benthic nutrient fluxes along the Laurentian Channel: impacts on the N budget of the St. Lawrence marine system. Estuar Coast Shelf Sci 90(4):195–205. doi:10.1016/j.ecss.2010.08.015

    Google Scholar 

  • Wankel SD, Kendall C, Francis CA, Paytan A (2006) Nitrogen sources and cycling in the San Francisco Bay estuary: a nitrate dual isotopic composition approach. Limnol Oceanogr 51(4):1654–1664

    Article  Google Scholar 

  • Wankel SD, Kendall C, Pennington JT, Chavez FP, Paytan A (2007) Nitrification in the euphotic zone as evidenced by nitrate dual isotopic composition: observations from Monterey Bay, California. Global Biogeochem Cycles 21(2). doi:10.1029/2006GB002723

Download references

Acknowledgments

This work was funded by Natural Sciences and Engineering Research Council of Canada (NSERC) through Allocation and Discovery Grants to MFL and Discovery Grants to C. Hillaire-Marcel. BT acknowledges Fonds Québécois de Recherche Nature et Technologie (FQRNT), GEOTOP Research Center and the Japan Society for the Promotion of Science (JSPS) for financial support. We thank S. Xiu Phuong for technical assistance during laboratory measurements, E. Rosa for the sampling, B. Williams and T. Miyajima for their comments on a earlier version of the manuscript. We are grateful to two anonymous reviewers for their valuable comments.

Author information

Authors and Affiliations

  1. Atmosphere and Ocean Research Institute (AORI), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan

    Benoit Thibodeau

  2. Geochemistry and Geodynamics Research Center (GEOTOP), Université du Québec à Montréal, Montreal, QC, H3C 3P8, Canada

    Jean-François Hélie

  3. Institute for Environmental Geosciences, University of Basel, Bernoullistrasse 30, 4056, Basel, Switzerland

    Moritz F. Lehmann

Authors
  1. Benoit Thibodeau
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jean-François Hélie
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Moritz F. Lehmann
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Benoit Thibodeau.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Thibodeau, B., Hélie, JF. & Lehmann, M.F. Variations of the nitrate isotopic composition in the St. Lawrence River caused by seasonal changes in atmospheric nitrogen inputs. Biogeochemistry 115, 287–298 (2013). https://doi.org/10.1007/s10533-013-9834-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10533-013-9834-4

Keywords

Search

Navigation