NOAA CSCOR Project Officer:
Libby Jewett

Project Rationale

Nutrient enrichment of estuaries has contributed to the degradation of benthic habitats by fueling algal production and associated depletion of oxygen (hypoxia) from bottom waters in coastal systems worldwide. A major impediment to developing successful restoration strategies is the complicating effect of climate variability. There is a clear need for improved numerical models and empirical analyses that are capable of producing dependable forecasts of hypoxia and related ecological responses to nutrient loading under variable climatic conditions. We propose to develop, test and apply such models in two contrasting coastal systems, Chesapeake Bay and Delaware Inland Bays, where rich time-series of water quality data exist and active collaborations between researchers and managers are ongoing. The proposed study will provide analysis and forecasting of climate and nutrient effects on hypoxia, water quality and living resources by developing an improved modeling system that is flexible and readily adapted for implementation in diverse coastal ecosystems.

Progress

We are pleased that this project continues to move forward in developing, implementing and analyzing linked simulation models and statistical analyses of estuarine circulation, biogeochemistry and habitats. These models are for use in guiding hypoxia remediation.

In Year 3 of this project, we have coupled ROMS hydrodynamic and RCA biogeochemical models and begun calibration of RCA. A simple O2 model, including planktonic and benthic O2 production and consumption, and air-sea gas exchange, has been linked to ROMS to simulate physical effects on O2 dynamics. This model has been used to analyze interannual variations in hypoxia distributions, suggesting that counteracting effects on vertical mixing and longitudinal advection tend to minimize effects of freshwater runoff on physical processes controlling hypoxia. For the shallow Delaware Inland Bays, ROMS has also been linked with a simple photosynthesis-respiration model that captures diel O2 change and nighttime hypoxia. In addition, a stand-alone version of the sediment flux model (SFM) portion of RCA has been developed for analysis of biogeochemical data and for conducting hypoxia scenario experiments. An extensive data set developed in retrospective analysis has been used to test and refine SFM, and data assimilation methods have been used for SFM parameter optimization using MERL data. This version of SFM will be available for use be other hypoxia simulation models in CHRP (e.g., GOMEX) and beyond.

Retrospective analysis of data on variations in O2 in relation to changes in nutrient levels and climatic variables has produce a range of multivariable statistical models that have contributed to increased understanding of controls on hypoxia. Data analysis has led to innovative and striking hypotheses on the role of long-term climate change and decadal scale climate cycles on variations in hypoxia. Collaborations with colleagues at Johns Hopkins University (Murphy, Ball) and Old Dominion University (M. Scully) have produced convincing empirical relationships and model simulation experiments that emphasize the roles of variable summer winds and relative sea level rise in controlling patterns of hypoxia in Chesapeake Bay. Other data analysis have demonstrated the importance of interannual and regional variations in timing of hypoxia onset, and the fact that it may have different controls from those associated with hypoxic volume.

Habitat-related data analysis and modeling studies have demonstrated the utility and power of this modeling approach using ROMS output to depict spatial-temporal zones of suitable temperature and salinity habitats for selected species. Information on habitat requirements (including O2) is being greatly expanded through an ongoing literature review on 7 fish and 4 invertebrate species in the Bay, including variations among age groups for key species. Information is ready for expanding this analysis to include O2 when the coupled ROMS-RCA model is ready for scenario simulations. The particle-tracking model has also been applied to examine anoxia effects on larval oyster transport.

Findings from this project were presented in 27 scientific conferences, 3 management meetings, and 11 scientific publications. Outreach efforts have been very effective in supporting the Chesapeake Bay and DIB management as well as K-12 teacher training.

back to top

Scientific Publications

Brady, D.C. and Targett, T.E. 2010. Movement of Juvenile Weakfish (Cynoscion regalis) and Spot (Leistomus xanthurus) in Relation to Diel-cycling Hypoxia in an Estuarine Tributary: Assessment Using Acoustic Telemetry. Marine Ecology Progress Series (In review).

Kemp, W.M., J. M. Testa, D. J. Conley, D. Gilbert, J. D. Hagy. 2009. Temporal responses of coastal hypoxia to nutrient loading and physical controls. Biogeosciences. 6: 2985–3008.

Kemp, W.M., and Testa, J.M., 2010. Metabolic balance between ecosystem production and consumption. In: Wolansky, E. and McLusky, D. (Eds.), Treatise on Estuarine and Coastal Science, Volume 7, Chapter 6. Elsevier Ltd., Oxford, pp. XX-XX (in press).

Li, M., L. Zhong and L. W. Harding. 2009. Sensitivity of plankton biomass and productivity to variations in physical forcing and biological parameters in Chesapeake Bay. Journal of Marine Research, 67, 667-700.

Li, M. and L. Zhong. 2009. Flood-ebb and spring-neap variations of stratification, mixing and circulation in Chesapeake Bay. Continental Shelf Research, 29, 4-14.

Najjar, R., C. Pyke, M.B. Adams, D. Breitburg, C. Hershner, M. Kemp, R. Howarth, M. Mulholland, M. Paolisso, D. Secor, K. Sellner, D.Wardrop, R.Wood. 2010. Potential climate-change impacts on the Chesapeake Bay. Estuar. Coastal Shelf Sci. 86: 1–20.

Secor, D.H., R. Fulford, J. Manderson, D.M. Nelson, E. North, H. Townsend, and R. Zajac. 2010. Habitat Suitability Models: State of the Art, Chesapeake Applications. Report to Chesapeake Bay Program Scientific and Technical Committee, 39 pp (In review) (http://www.chesapeake.org/stac/).

Smith, K.A., E. W. North, and D. H. Secor. 2009. Estimating habitat volume based on physical and biogeochemical models. International Council for the Exploration of the Sea (ICES) Conference Manuscript. ICES CM/K:09.

Testa, J. C. Gurbisz, L. Murray, W. Gray, J. Bosch, C. Burrell, M. Kemp. 2009. Investigating aquatic dead zones: A series of activities designed to explore the mysteries of the deep. The Science Teacher. 77 (2): 29-34.

Testa, J.M., and Kemp, W.M., 2010. Oxygen dynamics and biogeochemical consequences. In: Wolansky, E. and McLusky, D. (Eds.), Treatise on Estuarine and Coastal Science, Volume 5, Chapter 5. Elsevier Ltd., Oxford, pp. XX-XX (in press)

Zhang, J., D. Gilbert, A. Gooday, L. Levin, A. Naqvi, J. Middelburg, M. Scranton, W. Ekau, A. Pena, B. Dewitte, T. Oguz, P. Monteiro, E. Urban, N. Rabalais, V. Ittekkot, W. M. Kemp, O. Ulloa, R. Elmgren, E. Escobar-Briones, and A. Van der Plas. 2010. Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development. Biogeosciences. 7: 1443–1467.

back to top

Presentations

Presentations at Science Meetings

Bosch, J.A. and W.M. Kemp. 2009. Hypoxia, benthic macrofauna and nitrogen cycling in Chesapeake Bay. Coastal and Estuarine Research Federation Meeting, Portland, OR (November).

Brady D.C. and Targett, T.E. 2009 Movement of Juvenile Weakfish (Cynoscion regalis) and Spot (Leistomus xanthurus) in Relation to Diel-cycling Hypoxia in an Estuarine Tributary: Assessment Using Acoustic Telemetry. Coastal and Estuarine Research Federation, Portland, OR (November)

Brady, D.C. 2010 Invited Seminar to the University of Maine’s School of Marine Sciences. Laboratory, field, and modeling approaches to predict hypoxia exposure of estuarine fish

Brady, D.C., Testa, J., Di Toro, D.M., and Kemp, W.M. 2010 Sediment-Water Oxygen and Nutrient Exchanges in Chesapeake Bay. Chesapeake Modeling Symposium, Annapolis, MD (May)

Fennel, K (2010) Data-assimilative models for coastal ocean ecosystems: Challenges and opportunities (Invited) Eos Trans. AGU, 91(26), Ocean Sci. Meet. Suppl., Abstract PO24A-03

Fennel, K., Wilkin, J., Najjar, R. (2009) Nitrogen and carbon cycling on the North American east coast continental shelf, CMOS 43rd Annual Congress, Halifax, NS May 31 – June 4, Abstract 1C-203.2

Kemp, W.M., W. Boynton, D. Breitburg. 2009. Restoration of eutrophic coastal ecosystems: Theories, example observations, and synthesis of ideas: An introduction. Coastal and Estuarine Research Federation Meeting, Portland, OR (Nov).

Kemp, W.M., W. Boynton, D. Breitburg. 2009. Restoration of eutrophic coastal ecosystems: An integrative introduction. (Session co-Chairs). Coastal and Estuarine Research Federation Meeting, Portland, OR (Nov).

Kemp, W.M. 2009. Catchment science: Interactions of hydrology, biology and geochemistry. Invited speaker, Gordon Conference, Proctor Academy, Andover, NH (July).

Li, M., Y. Li and R. Najjar. 2010. Response of Chesapeake Bay estuary to climatic forcing. Invited Talk at Ocean Science Meeting, Portland, Oregon.

Li, M. 2009. Impact of climate change and extreme weather events on estuaries and coastal oceans - The Chesapeake Bay example. Invited Talk at Second NSF-NSFC US-China Exchange to Explore Research Cooperation on Climate Change, Baltimore.

Li, Y. and M. Li. 2010. Modeling hypoxia response to river flow and wind forcing in Chesapeake Bay. Oral presentation at Ocean Science Meeting, Portland.

Li, Y. and M. Li. 2010. Modeling hypoxia response to river flow and wind forcing in Chesapeake Bay. Oral presentation at Chesapeake Modeling Symposium, Annapolis.

Murray, L., M. Kemp, J. Testa, J. Bosch, C. Gurbisz, T. Carruthers. Expanding the word on hypoxia. Coastal and Estuarine Research Federation Meeting, Portland, OR (Nov).

North, E. W. What can science tell us the fishermen don’t already know? Plenary talk at the International Council for the Exploration of the Sea (ICES) Annual Science Conference. Berlin, Germany. September 24, 2009.

North, E. W. Biological-physical interactions: from processes to prediction. UMCES Chesapeake Biological Laboratory seminar series. December 2, 2009.

North, E. W. Biological-physical interactions: from processes to prediction. UMCES Appalachian Laboratory seminar series. December 3, 2009.

North, E. W. Biological-physical interactions: from processes to prediction. UMCES Horn Point Laboratory seminar series. January 27, 2010.

North, E. W., and Z. Schlag. The influence of anoxia on larval connectivity: a model-based hypothesis. 2009 Ocean Sciences Meeting. Portland, OR. February, 2010.

North, E. W., and Z. Schlag. The influence of anoxia on larval connectivity: a model-based hypothesis. ICES Working Group on Modelling Physical-Biological Interactions. March 25, 2010. Aberdeen, Scotland.

North, E. W., and Z. Schlag. The influence of anoxia on larval connectivity: a model-based hypothesis. Chesapeake Community Modeling Symposium. May 10, 2010. Annapolis, MD.

North, E. W. Inviting feedback to clarify uncertainty. Chesapeake Community Modeling Symposium. May 11, 2010. Annapolis, MD.

North, E. W., Z. Schlag, W. Long, A. Schlenger. Larval transport, habitat volume, and marine protected area optimization models: from development to operational use. Chesapeake Community Modeling Symposium. May 11, 2010. Annapolis, MD.

Smith, K.A., E. W. North, Z.R. Schlag, A.J. Schlenger, and D. H. Secor. Estimating habitat volume based on physical and biogeochemical models. International Council for the Exploration of the Sea (ICES) Annual Science Conference. Berlin, Germany. September 24, 2009.

Testa, J.M., R. Murphy, W.M. Kemp. 2009. Recalcitrance and Tipping Points in Recovery from Hypoxia in Chesapeake Bay. Coastal and Estuarine Research Federation Meeting, Portland, OR (Nov).

Wilson, R., Fennel, K. (2009) Parameter optimization of a two-layered diagenetic model through variational data assimilation, CMOS 43rd Annual Congress, Halifax, NS May 31 – June 4, Abstract 2D-100-I5.4

Wilson, R., Fennel, K., Brady, D., DiToro, D. (2010) Parameter Optimization of a Two-Layered Sediment Model Through Variational Assimilation Eos Trans. AGU, 91(26), Ocean Sci. Meet. Suppl., Abstract IT45C-06

Presentations at Regional Management Meetings

Brady, D.C., Targett, T.E., and Di Toro, D.M. 2010 Overexposure: Using laboratory, field, and modeling approaches to predict hypoxia exposure of estuarine fish. Center for the Inland Bays Science and Technical Advisory Committee (July)

North, E. W. What can science tell us the fishermen don’t already know? OneNOAA Science Seminar Series. Silver Spring, MD. October 26, 2009

Kemp, W.M., M. Li, W. Boynton, and D. DiToro. Modeling hypoxia in relation to nutrients, climate and ecological controls, Session co-chairs. Chesapeake Community Modeling Symposium. May 10, 2010. Annapolis, MD.

back to top

Outreach

See the Dead Zones web site for a unique education module which focuses on hypoxia

Outreach presentations and media coverage

July 2009: Presentation and Collaboration—Trends in Coastal Dead Zones. L. Murray, W.M. Kemp et al. COSEE Science Education Team. Cambridge, MD.

October 2009: Presentation and Participation—“Guidance for projects on Hypoxia in the Coastal Zone.” W.M. Kemp, Invited Speaker and Panelist. United Nations, UNEP GEF, “Expert Consultation, East China Normal University, Shanghai, China.

November 2009: Presentation—“Understanding trends in coastal ecosystems through science-education partnerships. Kemp, W.M., T. Carruthers, D. Gibson., C. Witherspoon, C. Gurbisz, L. Murray. Workshop Sponsored by NSF COSEE Program at the Coastal and Estuarine Research Federation Meeting, Portland, OR.

November 2009: Presentation—“Degradation and restoration of Chesapeake Bay water quality and living resources.” The Bay in Crisis: Saving the Chesapeake. W.M. Kemp, Invited Speaker and Panelist. University of Baltimore Law School, Baltimore, MD.

December 2009: Presentation—“Chesapeake Bay ecosystem: Decades of degradation and a road to recovery?” Ecology and Management of DoD Coastal and Estuarine Ecosystems. W.M. Kemp, Invited Speaker. Department of Defense, SERDP, Washington, DC.

May 1, 2010: Newspaper—“Westerly Breeze Takes the Wind out of Bay Cleanup’s Sails,” Bay Journal article by Karl Blankenship, http://www.bayjournal.com/article.cfm?article=3835

May 12, 2010: Radio (WYPR, Baltimore)—Blowin’ in the Wind, Radio interview of W.M. Kemp by Tom Pelton, host of “The Environment in Focus”, on Chesapeake Bay hypoxia responses to nutrient management and climate, http://www.wypr.org/EnvironmentFocus.html.

June 15, 2010: Website Like—NOAA-UMCES EcoCheck forecast by Dr. Younjoo Lee, (UMCES-CBL) for Chesapeake Bay hypoxia in summer 2010 (<http://www.eco-check.org/forecast/chesapeake/2010/indicators/hypoxia/#_Forecast>).

June 16-17, 2010: Presentation and Participation—“Guidance for projects on Hypoxia in the Coastal Zone-II.” W.M. Kemp, Invited Speaker and Panelist. United Nations, UNEP GEF, “Expert Consultation,” Heinz Center, Washington, DC.

back to top