Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Coastal eutrophication as a driver of salt marsh loss

Nature volume 490, pages 388–392 (2012)Cite this article

Subjects

Abstract

Salt marshes are highly productive coastal wetlands that provide important ecosystem services such as storm protection for coastal cities, nutrient removal and carbon sequestration. Despite protective measures, however, worldwide losses of these ecosystems have accelerated in recent decades1. Here we present data from a nine-year whole-ecosystem nutrient-enrichment experiment. Our study demonstrates that nutrient enrichment, a global problem for coastal ecosystems2,3,4, can be a driver of salt marsh loss. We show that nutrient levels commonly associated with coastal eutrophication increased above-ground leaf biomass, decreased the dense, below-ground biomass of bank-stabilizing roots, and increased microbial decomposition of organic matter. Alterations in these key ecosystem properties reduced geomorphic stability, resulting in creek-bank collapse with significant areas of creek-bank marsh converted to unvegetated mud. This pattern of marsh loss parallels observations for anthropogenically nutrient-enriched marshes worldwide, with creek-edge and bay-edge marsh evolving into mudflats and wider creeks5,6,7. Our work suggests that current nutrient loading rates to many coastal ecosystems have overwhelmed the capacity of marshes to remove nitrogen without deleterious effects. Projected increases in nitrogen flux to the coast, related to increased fertilizer use required to feed an expanding human population, may rapidly result in a coastal landscape with less marsh, which would reduce the capacity of coastal regions to provide important ecological and economic services.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Comparison photos of the marshes from the ecosystem nutrient-enrichment experiment.
Figure 2: Ecosystem attributes of reference and nutrient-enriched salt marshes after up to 7 years of nutrient enrichment.
Figure 3: The global relationship between nutrient loading and salt-marsh distribution and loss.

Similar content being viewed by others

References

  1. Millennium Ecosystem Assessment. Ecosystems and Human Well-Being—Synthesis Report (World Resources Institute, 2005)

  2. Galloway, J. et al. Transformation of the nitrogen cycle: recent trends, questions and potential solutions. Science 320, 889–892 (2008)

    Article  ADS  CAS  Google Scholar 

  3. Canfield, D. E., Glazer, A. N. & Falkowski, P. G. The evolution and future of Earth’s nitrogen cycle. Science 330, 192–196 (2010)

    Article  ADS  CAS  Google Scholar 

  4. Verhoeven, J. T. et al. Regional and global concerns over wetlands and water quality. Trends Ecol. Evol. 21, 96–103 (2006)

    Article  Google Scholar 

  5. MacGarvin, M. Out of Sight, Out of Mind: Marine Eutrophication in the United Kingdom (WWF-UK, 2001)

    Google Scholar 

  6. Hartig, E. K., Gornitz, V., Kolker, A., Mushacke, F. & Fallon, D. Anthropogenic and climate-change impacts on salt marshes of Jamaica Bay, New York City. Wetlands 22, 71–89 (2002)

    Article  Google Scholar 

  7. Tiner, R. W., Huber, I. J., Nuerminger, T. & Marshall, E. Salt Marsh Trends in Selected Estuaries of Southwestern Connecticut. NWI Cooperative Report (US Fish and Wildlife Service, Long Island Studies Program, Connecticut Department of Environmental Protection, 2006)

    Google Scholar 

  8. Diaz, R. J. & Rosenberg, R. Spreading dead zones and consequences for marine ecosystems. Science 321, 926–929 (2008)

    Article  ADS  CAS  Google Scholar 

  9. Valiela, I. & Cole, M. L. Comparative evidence that salt marshes and mangroves may protect seagrass meadows from land-derived nitrogen loads. Ecosystems 5, 92–102 (2002)

    Article  Google Scholar 

  10. Sousa, A., Lillebø, A. I., Caçador, I. & Pardal, M. Contribution of Spartina maritima to the reduction of eutrophication in estuarine systems. Environ. Pollut. 156, 628–635 (2008)

    Article  CAS  Google Scholar 

  11. Childer, D., Day, J. W., Jr & Mckeller, H. H., Jr in Concepts and Controversies in Tidal Marsh Ecology (eds Weinstein, M. & Kreeger, D. ) 391–424 (Kluwer Academic, 2000)

    Google Scholar 

  12. Drake, D. et al. Salt marsh ecosystem biogeochemical responses to nutrient enrichment: a paired 15N tracer study. Ecology 90, 2535–2546 (2009)

    Article  CAS  Google Scholar 

  13. Deegan, L. A. et al. Susceptibility of salt marshes to nutrient enrichment and predator removal. Ecol. Appl. 17, S42–S63 (2007)

    Article  Google Scholar 

  14. Bertness, M. D. & Pennings, S. in Concepts and Controversies in Tidal Marsh Ecology (eds Weinstein, M. & Kreeger, D. ) 39–58 (Kluwer Academic, 2000)

    Google Scholar 

  15. Pinthus, M. J. Lodging in wheat, barley and oats: the phenomenon, its causes and preventative measures. Adv. Agron. 25, 209–263 (1974)

    Article  Google Scholar 

  16. Darby, F. A. & Turner, R. E. Effects of eutrophication on salt marsh root and rhizome biomass accumulation. Mar. Ecol. Prog. Ser. 363, 63–70 (2008)

    Article  ADS  Google Scholar 

  17. Mozdzer, T. et al. Nitrogen uptake by the shoots of smooth cordgrass Spartina alterniflora. Mar. Ecol. Prog. Ser. 433, 43–52 (2011)

    Article  ADS  CAS  Google Scholar 

  18. Terzaghi, K., Peck, R. B. & Mesri, G. Soil Mechanics in Engineering Practice 3rd edn (Wiley-Interscience, 1996)

    Google Scholar 

  19. Rinaldi, M., Casagli, N., Dapporto, S. & Gargini, A. Monitoring and modelling of pore water pressure changes and riverbank stability during flow events. Earth Surf. Processes Landf. 29, 237–254 (2004)

    Article  ADS  Google Scholar 

  20. Fagherazzi, S. et al. Numerical models of salt marsh evolution: ecological, geomorphic, and climatic factors. Rev. Geophys. 50, RG1002 (2012)

    Article  ADS  Google Scholar 

  21. Valiela, I., Teal, J. M. & Persson, N. Y. Production and dynamics of experimentally enriched salt marsh vegetation: belowground biomass. Limnol. Oceanogr. 21, 245–252 (1976)

    Article  ADS  Google Scholar 

  22. Wigand, C., Brennan, P., Stolt, M., Holt, M. & Ryba, S. Soil respiration rates in coastal marshes subject to increased watershed nitrogen loads in southern New England, USA. Wetlands 29, 952–963 (2009)

    Article  Google Scholar 

  23. Turner, R. E. et al. Salt marshes and eutrophication: an unsustainable outcome. Limnol. Oceanogr. 54, 1634–1642 (2009)

    Article  ADS  CAS  Google Scholar 

  24. Davey, E. et al. Use of computed tomography imaging for quantifying coarse roots, rhizomes, peat, and particle densities in marsh soils. Ecol. Appl. 21, 2156–2171 (2011)

    Article  Google Scholar 

  25. Morris, J. T. & Bradley, P. M. Effects of nutrient loading on the carbon balance of coastal wetland sediments. Limnol. Oceanogr. 44, 699–702 (1999)

    Article  ADS  CAS  Google Scholar 

  26. Turner, R. E. Beneath the salt marsh canopy: loss of soil strength with increasing nutrient loads. Estuaries Coasts 34, 1084–1093 (2011)

    Article  CAS  Google Scholar 

  27. Selman, M., Greenhalgh, S., Diaz, R. & Sugg, Z. Eutrophication and hypoxia in coastal areas: a global assessment of the state of knowledge. http://www.wri.org/publication/eutrophication-and-hypoxia-in-coastal-areas (World Resources Institute, 2008)

  28. Schmidt, M. W. et al. Persistence of soil organic matter as an ecosystem property. Nature 478, 49–56 (2011)

    Article  ADS  CAS  Google Scholar 

  29. Piehler, M. F. & Smyth, A. R. Habitat-specific distinctions in estuarine denitrification affect both ecosystem function and services. Ecosphere 2, art12 (2011)

    Article  Google Scholar 

  30. Deegan, L. A. Lessons learned: the effects of nutrient enrichment on the support of nekton by seagrass and saltmarsh ecosystems. Estuaries 25, 727–742 (2002)

    Article  CAS  Google Scholar 

  31. Minello, T. J., Able, K. W., Weinstein, M. P. & Hays, C. G. Salt marshes as nurseries for nekton: testing hypotheses on density, growth and survival through meta-analysis. Mar. Ecol. Prog. Ser. 246, 39–59 (2003)

    Article  ADS  Google Scholar 

  32. Mariotti, G. et al. Influence of storm surges and sea level on shallow tidal basin erosive processes. J. Geophys. Res. 115, C11012 (2010)

    Article  ADS  Google Scholar 

  33. Johnson, D. S. & Fleeger, J. W. Weak response of saltmarsh infauna to ecosystem-wide nutrient enrichment and fish predator reduction: a four-year study. J. Exp. Mar. Biol. Ecol. 373, 35–44 (2009)

    Article  Google Scholar 

  34. Johnson, D. S. High marsh invertebrates are susceptible to eutrophication. Mar. Ecol. Prog. Ser. 438, 143–152 (2011)

    Article  ADS  Google Scholar 

  35. Redfield, A. C. Ontogeny of a salt marsh estuary. Science 147, 50–55 (1965)

    Article  ADS  CAS  Google Scholar 

  36. Niering, W. A. & Warren, R. S. Vegetation patterns and processes in New England salt marshes. Bioscience 30, 301–307 (1980)

    Article  Google Scholar 

  37. van Eerdt, M. M. The influence of vegetation on erosion and accretion in saltmarshes of the Oosterschelde, The Netherlands. Plant Ecology 62, 367–373 (1985)

    Article  Google Scholar 

  38. Osman, N. & Barakbah, S. S. Parameters to predict slope stability—soil water and root profiles. Ecol. Eng. 28, 90–95 (2006)

    Article  Google Scholar 

  39. Kirwan, M. L. & Murray, A. B. A coupled geomorphic and ecological model of tidal marsh evolution. Proc. Natl Acad. Sci. USA 104, 6118–6122 (2007)

    Article  ADS  CAS  Google Scholar 

  40. Craft, C., Reader, J., Sacco, J. N. & Broome, S. W. Twenty-five years of ecosystem development of constructed Spartina alterniflora (Loisel) marshes. Ecol. Appl. 9, 1405–1419 (1999)

    Article  Google Scholar 

  41. Mendelssohn, I. A. & Morris, J. T. in Concepts and Controversies in Tidal Marsh Ecology (eds Weinstein, M. P. & Kreeger, D. A. ) 59–80 (Kluwer Academic, 2000)

    Google Scholar 

  42. O’Shea, M. L. & Brosnan, T. M. Trends in indicators of eutrophication in western Long Island sound and the Hudson-Raritan Estuary. Estuaries 23, 877–901 (2000)

    Article  Google Scholar 

  43. Bricker, S. et al. Effects of Nutrient Enrichment In the Nation’s Estuaries: A Decade of Change (NOAA Coastal Ocean Program Decision Analysis Series No. 26, National Centers for Coastal Ocean Science, 2007)

    Google Scholar 

  44. US Environmental Protection Agency (USEPA). National Coastal Condition Report II. http://www.epa.gov/owow/oceans/nccr/2005/ (USEPA, 2005)

  45. Effland, M. J. Modified procedure to determine acid-insoluble lignin in wood and pulp. Tappi J. 60, 143–144 (1977)

    CAS  Google Scholar 

  46. Bowen, J. L., Crump, B., Deegan, L. A. & Hobbie, J. E. Increased supply of ambient nitrogen has minimal effect on salt marsh bacterial production. Limnol. Oceanogr. 54, 713–722 (2009)

    Article  ADS  CAS  Google Scholar 

  47. Koop-Jakobsen, K. & Giblin, A. E. The effect of increased nitrate loading on nitrate reduction via denitrification and DNRA in salt marsh sediments. Limnol. Oceanogr. 55, 789–802 (2010)

    Article  ADS  CAS  Google Scholar 

  48. Bernot, M. J. et al. Comparing denitrification estimates for a Texas estuary by using acetylene inhibition and membrane inlet mass spectrometry. Appl. Environ. Microbiol. 69, 5950–5956 (2003)

    Article  CAS  Google Scholar 

  49. Wollheim, W. M. et al. Global N removal by freshwater aquatic systems using a spatially distributed, within-basin approach. Glob. Biogeochem. Cycles 22, GB2026 (2008)

    Article  ADS  Google Scholar 

  50. Beaulieu, J. J. et al. Nitrous oxide emission from denitrification in stream and river networks. Proc. Natl Acad. Sci. USA 108, 214–219 (2011)

    Article  ADS  CAS  Google Scholar 

  51. Murray, B. C. et al. Green Payments for Blue Carbon. Economic Incentives for Protecting Threatened Coastal Habitats. Nicholas Institute Report NI R 11-04 (Nicholas Institute for Environmental Policy Solutions, 2011)

    Google Scholar 

  52. Hurlbert, S. H. Pseudoreplication and the design of ecological field experiments. Ecol. Monogr. 54, 187–211 (1984)

    Article  Google Scholar 

  53. Zar, J. H. Biostatistical Analysis 2nd edn (Prentice-Hall, 1984)

    Google Scholar 

  54. Carpenter, S. R., Chisholm, S. W., Krebs, C. J., Schindler, D. W. & Wright, R. F. Ecosystem experiments. Science 269, 324–327 (1995)

    Article  ADS  CAS  Google Scholar 

  55. Schindler, D. W. Replication versus realism: The need for ecosystem-scale experiments. Ecosystems 1, 323–334 (1998)

    Article  Google Scholar 

  56. Hobbs, N. T. & Hilborn, R. Alternatives to statistical hypothesis testing in ecology: A guide to self teaching. Ecol. Appl. 16, 5–19 (2006)

    Article  Google Scholar 

  57. Oksanen, L. Logic of experiments in ecology: is pseudoreplication a pseudoissue? Oikos 94, 27–38 (2001)

    Article  Google Scholar 

Download references

Acknowledgements

We thank our TIDE (Trophic cascades and Interacting control processes in a Detritus-based Ecosystem), LENS (Landscape Evolution in a Nutrient enriched Saltmarsh) and PIE-LTER (Plum Island Ecosystems Long-term Ecological Research) colleagues for field assistance and comments. We thank the many research assistants, graduate and undergraduate students who maintained the nutrient enrichment and analysed samples. This work is supported by grants from the NSF (DEB0816963, DEB0213767, OCE0923689, OCE 0423565, OCE0924287), the NOAA and The Mellon Foundation.

Author information

Authors and Affiliations

  1. The Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, Massachusetts 02543, USA,

    Linda A. Deegan, David Samuel Johnson & Bruce J. Peterson

  2. Department of Biology, Sewanee University of the South, 735 University Avenue, Sewanee, 37383, Tennessee, USA

    David Samuel Johnson

  3. Department of Botany, Connecticut College, 270 Mohegan Avenue, New London, Connecticut 06320, USA,

    R. Scott Warren

  4. Department of Biological Sciences, Louisiana State University, Baton Rouge, 70803, Louisiana, USA

    John W. Fleeger

  5. Department of Earth and Environment, Boston University, 675 Commonwealth Avenue, Boston, Massachusetts 02215, USA,

    Sergio Fagherazzi

  6. Department of Natural Resources and the Environment, University of New Hampshire, 8 College Road, Durham, 03824, New Hampshire, USA

    Wilfred M. Wollheim

Authors
  1. Linda A. Deegan
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. David Samuel Johnson
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. R. Scott Warren
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Bruce J. Peterson
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. John W. Fleeger
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Sergio Fagherazzi
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Wilfred M. Wollheim
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

L.A.D., D.S.J., R.S.W., B.J.P. & J.W.F. designed the experiment and participated in sampling and data analysis. S.F. participated in geomorphic and geotechnical evaluation. W.M.W. estimated global N loading to coastal saltmarshes. L.A.D. and D.S.J. wrote the initial manuscript. All authors contributed to and approved the manuscript.

Corresponding author

Correspondence to Linda A. Deegan.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

The data reported in this paper are archived in the Plum Island PIE-LTER database.

Supplementary information

Supplementary Information

This file contains Supplementary Text, Supplementary References and Supplementary Figure 1. (PDF 557 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Deegan, L., Johnson, D., Warren, R. et al. Coastal eutrophication as a driver of salt marsh loss. Nature 490, 388–392 (2012). https://doi.org/10.1038/nature11533

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature11533

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing