Skip to main content

Advertisement

Springer Nature Link
Log in

Spatial Distribution of Dissolved Radon in the Choptank River and Its Tributaries: Implications for Groundwater Discharge and Nitrate Inputs

  • Published:
Estuaries and Coasts Aims and scope Submit manuscript

Abstract

The Choptank River, Chesapeake Bay’s largest eastern-shore tributary, is experiencing increasing nutrient loading and eutrophication. Productivity in the Choptank is predominantly nitrogen-limited, and most nitrogen inputs occur via discharge of high-nitrate groundwater into the river system’s surface waters. However, spatial patterns in the magnitude and quality of groundwater discharge are not well understood. In this study, we surveyed the activity of 222Rn, a natural groundwater tracer, in the Choptank’s main tidal channel, the large tidal tributary Tuckahoe Creek, smaller tidal and non-tidal tributaries around the basin, and groundwater discharging into those tributaries, measuring nitrate and salinity concurrently. 222Rn activities were <100 Bq m−3 in the main tidal channel and 100–700 Bq m−3 in the upper Choptank River and Tuckahoe Creek, while the median Rn activities of fresh tributaries and discharging groundwater were 1,000 and 7,000 Bq m−3, respectively. Nitrate-N concentrations were <0.01 mg L−1 throughout most of the tidal channel, 1.5–3 mg L−1 in the upper reaches, up to 13 mg L−1 in tributary samples, and up to 19.6 mg L−1 in groundwater. Nitrate concentrations in tributary surface water were correlated with Rn activity in three of five sub-watersheds, indicating a groundwater nitrate source. 222Rn and salinity mass balances indicated that Rn-enriched groundwater discharges directly into the Choptank’s tidal waters and suggested that it consists of a mixture of fresh groundwater and brackish re-circulated estuarine water. Further sampling is necessary to constrain the Rn activity and nitrate concentration of discharging groundwater and quantify direct discharge and associated nitrogen inputs.

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

Access this article

Log in via an institution

Subscribe and save

Springer+
from $39.99 /Month
  • Starting from 10 chapters or articles per month
  • Access and download chapters and articles from more than 300k books and 2,500 journals
  • Cancel anytime
View plans

Buy Now

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
Fig. 7
Fig. 8

Similar content being viewed by others

Explore related subjects

Discover the latest articles, books and news in related subjects, suggested using machine learning.

References

  • Benitez, J.A. 2002. Historical land cover changes (1665–2000) and impact on N and P export from the Choptank watershed. Ph.D. dissertation, University of Maryland College Park.

  • Böhlke, J.K., and J.M. Denver. 1995. Combined use of groundwater dating, chemical, and isotopic analyses to resolve the history and fate of nitrate contamination in two agricultural watersheds, Atlantic Coastal Plain, Maryland. Water Resources Research 31: 2319–2339.

    Article  Google Scholar 

  • Borges, A.V., B. Delille, L.-S. Schiettecatte, F. Gazeau, G. Abril, and M. Frankignoulle. 2004. Gas transfer velocities of CO2 in three European estuaries (Randers Fjord, Scheldt, and Thames). Limnology and Oceanography 49: 1630–1641.

    Article  CAS  Google Scholar 

  • Bouwman, A.F., G. Van Drecht, and K.W. van der Hoek. 2005. Surface N balances and reactive N loss to the environment from global intensive agricultural production systems for the period 1970–2030. Science in China. Series C, Life Sciences 48: 767–779.

    Article  CAS  Google Scholar 

  • Burnett, W.C., J.E. Cable, R.D. Corbett and J.P. Chanton. 1996. Tracing groundwater flow into surface waters using natural 222Rn. Groundwater Discharge in the Coastal Zone: Proceedings of an International Symposium 8:22–36. LOICZ Reports Studies.

  • Burnett, W.C., G. Kim, and D. Lane-Smith. 2001. A continuous radon monitor for assessment of radon in coastal ocean waters. Journal of Radioanalytical and Nuclear Chemistry 249: 167–172.

    Article  CAS  Google Scholar 

  • Burnett, W.C., and H. Dulaiova. 2003. Estimating the dynamics of groundwater input into the coastal zone via continuous 222Rn measurements. Journal of Environmental Radioactivity 1–2: 21–35.

    Article  Google Scholar 

  • Burnett, W.C., P.K. Aggarwal, A. Aureli, H. Bokuniewicz, J.E. Cable, M.A. Charette, E. Kontar, S. Krupa, K.M. Kulkarni, A. Loveless, W.S. Moore, J.A. Oberdorfer, J. Oliveira, N. Ozyurt, P. Povinec, A.M.G. Privitera, R. Rajar, R.T. Ramessur, J. Scholten, T. Stieglitz, M. Taniguchi, and J.V. Turner. 2006. Quantifying submarine groundwater discharge in the coastal zone via multiple methods. Science of the Total Environment 367(2–3): 498–543.

    Article  CAS  Google Scholar 

  • Burnett, W.C., R.N. Peterson, I.R. Santos, and R.W. Hicks. 2010. Use of automated radon measurements for rapid assessment of groundwater flow into Florida streams. Journal of Hydrology 380: 298–304.

    Article  CAS  Google Scholar 

  • Cable, J.E., G.C. Bugna, W.C. Burnett, and J.P. Chanton. 1996. Application of 222Rn and CH4 for assessment of groundwater discharge to the coastal ocean. Limnology and Oceanography 41(6): 1347–1353.

    Article  Google Scholar 

  • Cable, J.E., and J.B. Martin. 2008. In situ evaluation of nearshore marine and fresh pore water transport into Flamengo Bay, Brazil. Estuarine, Coastal and Shelf Science 76: 473–483.

    Article  Google Scholar 

  • Caraco, N.F., and J.J. Cole. 1999. Human impact on nitrate export: an analysis using major world rivers. Ambio 28: 167–170.

    Google Scholar 

  • Caraco, N.F., and J.J. Cole. 2001. Human influence on nitrogen export: a comparison of mesic and xeric catchments. Marine and Freshwater Research 52: 119–125.

    Article  CAS  Google Scholar 

  • Charette, M.A., and K.O. Buesseler. 2004. Submarine groundwater discharge of nutrients and copper to an urban subestuary of Chesapeake Bay (Elizabeth River). Limnology and Oceanography 49: 376–385.

    Article  CAS  Google Scholar 

  • Cooper, S.R., and G.S. Brush. 1993. A 2,500-year history of anoxia and eutrophication in Chesapeake Bay. Estuaries and Coasts 16: 617–626. doi:10.2307/1352799.

    Article  CAS  Google Scholar 

  • Corbett, D.R., W.C. Burnett, P.H. Cable, and S.B. Clark. 1997. Radon tracing of groundwater input into Par Pond, Savannah River Site. Journal of Hydrology 203: 209–227.

    Article  Google Scholar 

  • Corbett, D.R., W.C. Burnett, P.H. Cable, and S.B. Clark. 1998. A multiple approach to the determination of radon fluxes from sediments. Journal of Radioanalytical and Nuclear Chemistry 236: 247–253.

    Article  CAS  Google Scholar 

  • Dulaiova, H., R. Peterson, W.C. Burnett, and D. Lane-Smith. 2005. A multi-detector continuous monitor for assessment of 222Rn in the coastal ocean. Journal of Radioanalytical and Nuclear Chemistry 263: 361–363. doi:10.1007/s10967-005-0063-8.

    Article  CAS  Google Scholar 

  • Dulaiova, H., M.E. Gonneea, P.B. Henderson, and M.A. Charette. 2008. Geochemical and physical sources of radon variation in a subterranean estuary – implications for groundwater radon activities in submarine groundwater discharge studies. Marine Chemistry 110: 120–127.

    Article  CAS  Google Scholar 

  • Dulaiova, H., R. Camilli, P.B. Henderson, and M.A. Charette. 2010. Coupled radon, methane and nitrate sensors for large-scale assessment of groundwater discharge and non-point source pollution to coastal waters. Journal of Environmental Radioactivity 101(7): 553–563.

    Article  CAS  Google Scholar 

  • Fisher, T.R., K.-Y. Lee, H. Berndt, J.A. Benitez, and M.M. Norton. 1998. Hydrology and chemistry of the Choptank basin. Water, Air, and Soil Pollution 105: 387–397.

    Article  CAS  Google Scholar 

  • Fisher, T.R., J.D. Hagy III, W.R. Boynton, and M.R. Williams. 2006. Cultural eutrophication in the Choptank and Patuxent estuaries of Chesapeake Bay. Limnology and Oceanography 51: 435–447.

    Article  CAS  Google Scholar 

  • Fisher, T.R., A.B. Gustafson, A.I. Koskelo, R.J. Fox, T. Kana, K.A. Beckert, J.P. Stone, T.E. Jordan, K.W. Staver, A.J. Sutton, G. McCarty and M. Lang. 2010. The Choptank Basin in Transition: Intensifying Agriculture, Slow Urbanization, and Estuarine Eutrophication. Chapter 7 in Coastal Lagoons: Critical Habitats of Environmental Change. New York, Taylor and Francis, p. 137–168.

  • Freeze, R.A. and J.A. Cherry. Groundwater. Englewood Cliffs, NJ, USA. Prentice-Hall, 1979. 604 pp.

  • Garrison, G.H., C.R. Glenn, and G.M. McMurtry. 2003. Measurement of submarine groundwater discharge in Kahana Bay, O`ahu, Hawai`i. Limnology and Oceanography 48(2): 920–928.

    Article  Google Scholar 

  • Glibert, P.M., R. Magnien, M.W. Lomas, J. Alexander, C. Tan, E. Haramoto, M. Trice, and T.M. Kana. 2001. Harmful algal blooms in the Chesapeake and coastal bays of Maryland, USA: Comparison of 1997, 1998, and 1999 events. Estuaries and Coasts 24: 875–883. doi:10.2307/1353178.

    Article  CAS  Google Scholar 

  • Hammond, D.E., H.J. Simpson, and G. Mathieu. 1977. Radon 222 distribution and transport across the sediment-water interface in the Hudson River estuary. Journal of Geophysical Research 82: 3913–3920. doi:10.1029/JC082i027p03913.

    Article  CAS  Google Scholar 

  • Hussain, N., T.M. Church, and G. Kim. 1999. Use of 222Rn and 226Ra to trace groundwater discharge into the Chesapeake Bay. Marine Chemistry 65: 127–134.

    Article  CAS  Google Scholar 

  • Hwang, D.-W., G. Kim, W.-C. Lee, and H.-T. Oh. 2010. The role of submarine groundwater discharge (SGD) in nutrient budgets of Gamak Bay, a shellfish farming bay, in Korea. Journal of Sea Research 64: 224–230.

    Article  CAS  Google Scholar 

  • Jordan, T.E., D.L. Correll, and D.E. Weller. 1997. Effects of agriculture on discharges of nutrients from coastal plain watersheds of Chesapeake Bay. Journal of Environmental Quality 26(3): 836–848.

    Article  CAS  Google Scholar 

  • Kalbus, E., F. Reinstorf, and M. Schirmer. 2006. Measuring methods for groundwater-surface water interactions: A review. Hydrology and Earth System Sciences 10: 873–887.

    Article  CAS  Google Scholar 

  • Kettle, A.J., and M.O. Andreae. 2000. Flux of dimethylsulfide from the oceans: A comparison of updated data sets and flux models. Journal of Geophysical Research 105: 26,793–26,808.

    Article  CAS  Google Scholar 

  • Kim, G., K.-K. Lee, K.-S. Park, D.-W. Hwang, and H.-S. Yang. 2003. Large submarine groundwater discharge (SGD) from a volcanic island. Geophysical Research Letters 30: 2098–2101.

    Article  Google Scholar 

  • Knee, K.L., and A. Paytan. 2012. Submarine groundwater discharge: A source of nutrients, metals and pollutants to the coastal ocean. In: Wolanski, E. and D.S. McLusky, eds. Treatise on Estuarine and Coastal Science 4: 205–233.

    Google Scholar 

  • Kroeger, K.D., M.L. Cole, and I. Valiela. 2006. Groundwater-transported dissolved organic nitrogen exports from coastal watersheds. Limnology and Oceanography 51: 2248–2261.

    Article  CAS  Google Scholar 

  • Kroeger, K.D., P.W. Swarzenski, W.J. Greenwood, and C. Reich. 2007. Submarine groundwater discharge to Tampa Bay: Nutrient fluxes and biogeochemistry of the coastal aquifer. Marine Chemistry 104: 85–97.

    Article  CAS  Google Scholar 

  • Lambert, M.J., and W.C. Burnett. 2003. Submarine groundwater discharge estimates at a Florida coastal site based on continuous radon measurements. Biogeochemistry 66: 55–73. doi:10.1023/B:BIOG.0000006057.63478.fa.

    Article  CAS  Google Scholar 

  • Lee, K.-Y., T.R. Fisher, T.E. Jordan, D.L. Correll, and D.E. Weller. 2000. Modeling the hydrochemistry of the Choptank River Basin using GWLF and Arc/Info: 1. Model calibration and validation. Biogeochemistry 49: 143–173. doi:10.1023/A:1006375530844.

    Article  CAS  Google Scholar 

  • Lee, K.-Y., T.R. Fisher, and E. Rochelle-Newall. 2001. Modeling the hydrochemistry of the Choptank River basin using GWLF and Arc/Info: 2. Model validation and application. Biogeochemistry 56: 311–348. doi:10.1023/A:1013169027082.

    Article  CAS  Google Scholar 

  • Lorite-Herrera, M., K. Hiscock, and R. Jiménez-Espinosa. 2009. Distribution of dissolved inorganic and organic nitrogen in river water and groundwater in an agriculturally-dominated catchment, south-east Spain. Water, Air, and Soil Pollution 198: 335–346.

    Article  CAS  Google Scholar 

  • Marshall, H.G., and L. Burchardt. 2004. Monitoring phytoplankton populations and water quality parameters in estuarine rivers of Chesapeake Bay, USA. Oceanological and Hydrobiological Sciences 33: 55–64.

    Google Scholar 

  • McCarty, G.W., L.L. McConnell, C.J. Hapeman, A. Sadeghi, C. Graff, W.D. Hively, M.W. Lang, T.R. Fisher, T. Jordan, C.P. Rice, E.E. Codling, D. Whitall, A. Lynn, J. Keppler, and M.L. Fogel. 2008. Water quality and conservation practice effects in the Choptank River watershed. Journal of Soil and Water Conservation 63: 461–474.

    Article  Google Scholar 

  • Mulligan, A.E., and M.A. Charette. 2006. Intercomparison of submarine groundwater discharge estimates from an unconfined aquifer. Journal of Hydrology 327: 411–425.

    Article  Google Scholar 

  • Mullinger, N.J., A.M. Binley, J.M. Pates, and N.P. Crook. 2007. Radon in chalk streams: Spatial and temporal variation of groundwater sources in the Pang and Lambourn watersheds, UK. Journal of Hydrology 339: 172–182.

    Article  CAS  Google Scholar 

  • Paerl, H.W. 1999. Cultural eutrophication of shallow coastal waters: Coupling changing anthropogenic nutrient inputs to regional management approaches. Limnologica 29: 249–254.

    Article  CAS  Google Scholar 

  • Paerl, H.W. 2006. Assessing and managing nutrient-enhanced eutrophication in estuarine and coastal waters: Interactive effects of human and climatic perturbations. Ecological Engineering 26: 40–54.

    Article  Google Scholar 

  • Peterson, R.N., I.R. Santos, and W.C. Burnett. 2010. Evaluating groundwater discharge to tidal rivers based on a Rn-222 time-series approach. Estuarine, Coastal and Shelf Science 86: 165–178.

    Article  CAS  Google Scholar 

  • Phillips, P.J., J.M. Denver, R.J. Shedlock, and P.A. Hamilton. 1993. Effect of forested wetlands on nitrate concentrations in ground water and surface water on the Delmarva Peninsula. Wetlands 13: 75–83. doi:10.1007/BF03160867.

    Article  Google Scholar 

  • Rapaglia, J.P., and H.J. Bokuniewicz. 2009. The effect of groundwater advection on salinity in pore waters of permeable sediments. Limnology and Oceanography 54: 630–643.

    Article  CAS  Google Scholar 

  • Santos, I.R., W.C. Burnett, T. Dittmar, I.G.N.A. Suryaputra, and J. Chanton. 2009. Tidal pumping drives nutrient and dissolved organic matter dynamics in a Gulf of Mexico subterranean estuary. Geochimica et Cosmochimica Acta 73: 1325–1339.

    Article  CAS  Google Scholar 

  • Santos, I.R., R.N. Peterson, B.D. Eyre, and W.C. Burnett. 2010. Significant lateral inputs of fresh groundwater into a stratified tropical estuary: Evidence from radon and radium isotopes. Marine Chemistry 121: 37–48.

    Article  CAS  Google Scholar 

  • Santos, I.R., R.N. Glud, D. Maher, D. Erler, and B.D. Eyre. 2011. Diel coral reef acidification driven by porewater advection in permeable carbonate sands, Heron Island, Great Barrier Reef. Geophysical Research Letters 38: 1–5.

    Article  Google Scholar 

  • Schwartz, M.C. 2003. Significant groundwater input to a coastal plain estuary: Assessment from excess radon. Estuarine, Coastal and Shelf Science 56: 31–42.

    Article  Google Scholar 

  • Slomp, C.P., and P. Van Cappellen. 2004. Nutrient inputs to the coastal ocean through submarine groundwater discharge: controls and potential impact. Journal of Hydrology 295: 64–86.

    Article  CAS  Google Scholar 

  • Smith, V.H., and D.W. Schindler. 2009. Eutrophication science: where do we go from here? Trends in Ecology & Evolution 24: 201–207.

    Article  Google Scholar 

  • Staver, L.W., K.W. Staver, and J.C. Stevenson. 1996. Nutrient inputs to the Choptank River estuary: Implications for watershed management. Estuaries and coasts 19: 342–358. doi:10.2307/1352455.

    Article  CAS  Google Scholar 

  • Street, J.H., K.L. Knee, E.E. Grossman, and A. Paytan. 2008. Submarine groundwater discharge and nutrient addition to the coastal zone and coral reefs of leeward Hawai`i. Marine Chemistry 109: 355–376.

    Article  CAS  Google Scholar 

  • Tango, P., W. Butler and C. Wazniak. 2004. Assessment of harmful algae bloom species in the Maryland Coastal Bays. In: Wazniak C, Hall M, editors. Maryland’s Coastal Bays Ecosystem Health Assessment 2004. Annapolis, MD: Maryland Department of Natural Resources; http://www.dnr.state.md.us/coastalbays/sob_2004.html.

  • Taniguchi, M., W.C. Burnett, J.E. Cable, and J.V. Turner. 2002. Investigation of submarine groundwater discharge. Hydrological Processes 16: 2115–2129.

    Article  Google Scholar 

  • Weil, R.R., R.A. Weismuller, and R.S. Turner. 1990. Nitrate contamination of groundwater under irrigated coastal plain soils. Journal of Environmental Quality 19: 441–448.

    Article  CAS  Google Scholar 

  • Wilson, J., and C. Rocha. 2012. Regional scale assessment of Submarine Groundwater Discharge in Ireland combining medium resolution satellite imagery and geochemical tracing techniques. Remote Sensing of Environment 119: 21–34.

    Article  Google Scholar 

Download references

Acknowledgments

We thank Adina Paytan and Rick Peterson for the use of their RAD7 radon detectors and for advice about carrying out the study. Micah Ryder helped obtain and analyze geographic data, and David Culver generously provided access to GIS software. Dana Brenner, Nancy Goff, Christina Hill, Ryan Ihnacik, Alanna Lecher, Ginny Leviton, Joe Miklas, and Amelia Snyder assisted with sample collection and analysis. Rick Peterson, Thomas Fisher, and two anonymous reviewers provided comments that improved the quality of this manuscript. Financial support for this research came from a Smithsonian Institution Postdoctoral Fellowship (to K. Knee) and National Science Foundation grants (DEB-0919181 and DEB-0919141 to T. Jordan and T. Fisher).

Author information

Authors and Affiliations

  1. Department of Environmental Science, American University, 4400 Massachusetts Ave. NW, Washington, DC, 20016, USA

    Karen L. Knee

  2. Smithsonian Environmental Research Center, 647 Contees Wharf Rd, Edgewater, MD, 21037-0028, USA

    Karen L. Knee & Thomas E. Jordan

Authors
  1. Karen L. Knee
    View author publications

    Search author on:PubMed Google Scholar

  2. Thomas E. Jordan
    View author publications

    Search author on:PubMed Google Scholar

Corresponding author

Correspondence to Karen L. Knee.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Knee, K.L., Jordan, T.E. Spatial Distribution of Dissolved Radon in the Choptank River and Its Tributaries: Implications for Groundwater Discharge and Nitrate Inputs. Estuaries and Coasts 36, 1237–1252 (2013). https://doi.org/10.1007/s12237-013-9619-y

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12237-013-9619-y

Keywords