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National Estuarine Eutrophication Assessment: Update

This project began in June 2004 and was completed in June 2007

Eutrophication is the overabundance of nutrients in a body of water that results in harmful algal blooms, fish kills, and in some cases ecosystem collapse. We used the Assessment of Estuarine Trophic Status (ASSETS) model to determine the causes and status of eutrophication and expected future conditions in 141 U.S. estuaries and coastal water bodies in the early 2000s.

Why We Care
Eutrophication is among the most serious threats to the function and services supported by coastal ecosystems. Attempts to reverse coastal eutrophication have centered on reducing land-based sources of nutrients, such as fertilizer applications and wastewater treatment plant discharges. Periodic updates of eutrophication status are important in order to determine whether management measures are working to reduce water quality problems.

What We Are Doing
This national assessment used the Assessment of Estuarine Trophic Status (ASSETS) model to determine the causes and status of eutrophication and expected future conditions in 141 U.S. estuaries and coastal water bodies in the early 2000s. Results show that the majority of U.S. estuaries (65 percent) are moderately to highly eutrophic due to high nitrogen loads. Systems that have high residence times are more likely to become eutrophic. Comparison to assessment results from the early 1990s shows little change in conditions. Several waterbodies outside the U.S. were also evaluated and show a similar gradient of problems.

Benefits of Our Work
The assessment showed that conditions in the U.S. are similar to conditions in waterbodies across the globe, suggesting that management measures that work elsewhere could also work in U.S. systems. We also showed that there is still work to be done to reduce eutrophication. Management measures are working to hold the line against worsening conditions, but conditions continue to be moderate to highly impacted by nutrients in the majority of U.S. estuaries. These results will help guide future management measures.

Next Steps
We are hoping that we will be able to make another update of conditions in U.S. estuaries to show the status and changes that have occurred from the early 2000s to the early 2010s. However, such an update is dependent on funding, which to date has not been available.

Additional Resources

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Products, Datasets & Reports

Peer-Reviewed Publications

  • Bettencourt, A. S.B. Bricker, J.G. Ferreira, A. Franco, J.C. Marques, J.J. Melo, A. Nobre, L. Ramos, C.S. Reis, F. Salas, M.C. Silva, T. Simas, W. Wolff. 2004. Typology and Reference Conditions for Portuguese Transitional and Coastal Waters Development of guidelines for the application of the European Union Water Framework Directive. INAG-IMAR, Lisbon, Portugal.
  • Borja, A., S.B. Bricker, D.M. Dauer, N.T. Demetriades, João G. Ferreira, A.T. Forbes, P. Hutchings, X. Jia i, R. Kenchington, J.C. Marques, C. Zhu. 2008. Overview of integrative tools and methods in assessing ecological integrity in estuarine and coastal systems worldwide. Marine Pollution Bulletin 56:1519–1537.
  • Borja, A., A. Basset, S. Bricker, J-C. Dauvin, M. Elliott, T. Harrison, J.C. Marques, S. Weisberg, R. West, 2012. Classifying Ecological Quality and Integrity of Estuaries. Chapter 1.9 within the ‘Treatise on Estuarine and Coastal Science’ (Editors-in-Chief, Eric Wolanski & Donald McLusky), Elsevier. DoI: 00109 is 10.1016/B978-0-12-374711-2.00109-1.
  • Bricker, S.B., J.G. Ferreira, T. Simas, 2003. An Integrated Methodology for Assessment of Estuarine Trophic Status. Ecological Modelling, 169(1), 39–60.
  • Bricker, S., D. Lipton, A. Mason, M. Dionne, D. Keeley, C. Krahforst, J. Latimer, and J. Pennock. 2006. Improving methods and indicators for evaluating coastal water eutrophication: A pilot study in the Gulf of Maine. NOAA Technical Memorandum NOS NCCOS 20. Silver Spring, MD. 81 pp.
  • Bricker, S.B., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, C. Wicks and J. Woerner. 2008. Effects of Nutrient Enrichment in the Nation’s Estuaries: A Decade of Change. Special issue of Harmful Algae 8: 21–32.
  • Bricker, S.B., W.C. Dennison, K.H. Dunton, J.G. Ferreira, M.R. Hall, J.A. Herrera-Silveira, B.J. Longstaff, S. Morales-Ojeda, C.P. Onuf, R. Pastres, J.E.Thomas and C.E. Wazniak. 2009. Chapter 11. The Coastal Bays in Context in: W.E. Dennison, J.E. Thomas, C.J. Cain, T.J.B. Carruthers, M.R. Hall, R.V. Jesien, C.E. Wazniak and D.E. Wilson (Eds) Shifting Sands: Environmental and cultural change in Maryland’s coastal bays. IAN Press, Cambridge, Maryland. 396 pp.
  • Bricker, S. 2011. Chapter 8: Eutrophication Assessment in Chesapeake Bay and Tributaries. pg. 59–66 in Mason, A.L., D. Apeti, and D. Whitall (eds). 2011. National Centers for Coastal Ocean Science (NCCOS) Research Highlights in the Chesapeake Bay. NOAA Technical Memorandum NOS NCCOS 128. National Ocean Service. National Centers for Coastal Ocean Science, Silver Spring, MD.
  • Bricker, S. and M. Devlin. 2011. Guest editors: Eutrophication – International Comparisons of Water Quality Challenges. Special issue of Biogeochemistry 105(2) 135–302.
  • Bricker, S. and M. Devlin. 2011. Preface: Eutrophication Issue. Biogeochemistry 106(2): 175–205. Article DOI: 10.1007/s10533-011-9577-z.
  • Dalton, C.C., F. Dillon, S. Bricker, M. Dionne. 2006. Synthesis of SWMP Data for ASSETS Eutrophication Assessment of the North Atlantic Region NERR Systems: A Final Report Submitted to The NOAA/UNH Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET). 92 pp.
  • Devlin, M., S. Bricker, S.J. Painting. 2011. Comparison of five methods for assessing impacts of nutrient enrichment using estuarine case studies. Biogeochemistry 106(2): 135–136. Article DOI: 10.1007/s10533-011-9588-9.
  • Ferreira, J. G., A. M. Nobre, T. C. Simas, M. C. Silva, A. Newton, S.B. Bricker, W. J. Wolff, P.E. Stacey, A. Sequeira. 2006. A methodology for defining homogeneous water bodies in estuaries – Application to the transitional systems of the EU Water Framework Directive. Estuarine Coastal and Shelf Science 66: 468–482.
  • Ferreira, J.G. , S.B. Bricker, T.C. Simas, 2007. Application and sensitivity testing of an eutrophication assessment method on coastal systems in the United States and European Union. J. Environmental Management, 82, 433–445.
  • Ferreira, J.G.F., A.J.D.S. Hawkins, S.B. Bricker. 2007. Farm-scale assessment of shellfish aquaculture in coastal systems – the Farm Aquaculture Resource Management (FARM) model. Aquaculture 264: 160–174.
  • Ferreira, C. Vale, C.V. Soares, F.Salas, P.E. Stacey, S. B. Bricker, M.C. Silva, J.C. Marques, 2007. Monitoring of coastal and transitional waters under the EU Water Framework Directive. Environmental Monitoring and Assessment, 135 (1–3), 195–216.
  • Ferreira, J.G. , H.C. Andersson, R.A. Corner, X. Desmit, Q. Fang, E.D. de Goede, S.B. Groom, H. Gu, B.G. Gustafsson, A.J.S. Hawkins, R. Hutson, H. Jiao, D. Lan, J. Lencart-Silva, R. Li, X. Liu, Q. Luo, J.K. Musango, A.M. Nobre, J.P. Nunes, P.L. Pascoe, J.G.C. Smits, A. Stigebrandt, T.C. Telfer, M.P de Wit, X. Yan, X.L. Zhang, Z. Zhang, M.Y.Zhu, C.B. Zhu, S.B. Bricker, Y. Xiao, S. Xu, C.E. Nauen, M. Scalet. 2008. Sustainable Options for People, Catchment and Aquatic Resources: The SPEAR Project, an International Collaboration on Integrated Coastal Zone Management. Institute of Marine Research. IMAR http://www.biaoqiang.org
  • Ferreira, J.G., A. Sequeira, A.J.S. Hawkins, A. Newton, T.D. Nickell, R. Pastres, J. Forte, A. Bodoy, S.B. Bricker. 2009. Analysis of coastal and offshore aquaculture: Application of the FARM model to multiple systems and shellfish species. Aquaculture 292:129–138.
  • Ferreira, J.G., J.H. Andersen, A. Borja, S.B. Bricker, J. Camp, M. Cardosa da Silva, E. Garces, A.S. Heiskanen, C. Humborg, L. Ignatiades, C. Lancelot, A. Menesguen, P. Tett, N. Hoepffner and U. Claussen. 2010. Marine Strategy Framework Directive: Task Group 5 Report Eutrophication. April 2010. Joint Report Prepared under the Administrative Arrangement between JRC and DG ENV (No. 31210-2009/2010), the Memorandum of Understanding between the European Commission and ICES managed by DG MARE and JRC’s own institutional funding. Editor: N. Zampoukas. European Commission and ICES.
  • Ferreira, J. G. , J. H. Andersen, A. Borja, S. B. Bricker, J. Camp, M. Cardoso da Silva, E. Garcés, A.-S. Heiskanen, Christoph Humborg, L. Ignatiades, C. Lancelot, A. Menesguen, P. Tett, N. Hoepffner, U. Claussen. 2011. Indicators of human-induced eutrophication to assess the environmental status within the European Marine Strategy Framework Directive. Estuarine Coastal Shelf Science. (Accepted March 29, 2011).
  • Ferreira, J.G., A.J.S., Hawkins, S.B. Bricker. 2011. Chapter 1 - The role of shellfish farms in provision of ecosystem goods and services. In: S. Shumway, Editor, Shellfish Aquaculture and the Environment. Wiley – Blackwell. 424pp.
  • Garmendia, M., S. Bricker, M. Revilla, Á. Borja, J. Franco, J. Bald and V. Valencia. 2012. Eutrophication assessment in Basque estuaries: comparison of a North American and a European method. Estuaries and Coasts 35(4): 991–1006.
  • Jewett E.B., Kidwell D.M., Lopez C.B., Bricker S.B., Burke M.K., Walbridge M.R., Eldridge P.M., Greene R.M., Hagy J.D., Buxton H.T., Diaz R.J. 2010. Scientific Assessment of Hypoxia in US Coastal Waters. Interagency Working Group on Harmful Algal Blooms, Hypoxia, and Human Health of the Joint Subcommittee on Ocean Science and Technology. Washington, DC. (cited as: Committee on Environment and Natural Resources. 2010. Scientific Assessment of Hypoxia in U.S. Coastal Waters. Interagency Working Group on Harmful Algal Blooms, Hypoxia, and Human Health of the Joint Subcommittee on Ocean Science and Technology. Washington, DC. )
  • Moorman, M.C., Hoos, A.B., Bricker, S.B., Moore, R.B., García, A.M., and Ator, S.W., 2014, Nutrient load summaries for major lakes and estuaries of the Eastern United States, 2002: U.S. Geological Survey Data Series 820, 94 p., http://dx.doi.org/10.3133/ds820. This publication is published in an 'electronic only' medium.
  • Nobre, A.M., J.G.Ferreira, A.Newton, T.Simas, J.D.Icely, R.Neves, 2005. Management of coastal eutrophication: Integration of field data, ecosystem-scale simulations and screening models. Journal of Marine Systems, 56 (3/4), 375–390.
  • Ana M. Nobre, Joa˜o G. Ferreira , Joa˜o P. Nunes , Xiaojun Yan , Suzanne Bricker, Richard Corner,Steve Groom, Haifeng Gu , Anthony J.S. Hawkins, Rory Hutson, Dongzhao Lan, Joa˜o D. Lencart e Silva, Philip Pascoe, Trevor Telfer, Xuelei Zhang , Mingyuan Zhu. 2010. Assessment of coastal management options by means of multilayered ecosystem models. Estuarine Coastal and Shelf Science 87(1): 43–62.
  • Nunes, J.P., J.G. Ferreira, S.B. Bricker, B. O’Loan, T. Dabrowski, B. Dallaghan, A.J S. Hawkins, B. O’Connor; T. O’Carroll, 2011. Towards an ecosystem approach to aquaculture: assessment of sustainable shellfish cultivation at different scales of space, time and complexity. Aquaculture 315: 369–383. 
  • Scavia, D. and S. B. Bricker. 2006. Coastal Eutrophication Assessment in the United States. Biogeochemistry 79: 187–208.
  • Silva, C., J.G. Ferreira and S.B. Bricker. 2011. An integrated approach of principal component analysis, the FARM model and GIS tools for sustainable management of bivalve shellfish farms. Aquaculture 318 (2011) 444–457.
  • Verity, P.G. , M.L. Alber, and S.B. Bricker. 2006. Development of Hypoxia in Well- Mixed Subtropical Estuaries in the Southeastern USA Estuaries and Coasts Vol. 29(4): 665–673.
  • Xiao, Y., Ferreira, J.G., Bricker, S.B., Nunes, J.P., Zhu, M., Zhang X., 2007. Trophic Assessment in Chinese Coastal Systems - Review of methodologies and application to the Changjiang (Yangtze) Estuary and Jiaozhou Bay. Estuaries and Coasts, 30(6), 1–18.

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