Richard L. Wetzel

Research Interests

Current Projects

Selected Publications

Students

Courses

Professional Memberships

Collaborative Efforts

Ecosystem Modeling Website

Research Interests

My research interests focus on carbon – nitrogen cycling in estuaries, top – down vs botttom –up controls on ecosystem processes, and ecosystem modeling and simulation analysis. In particular, we have given particular attention to investigating physical and chemical controls on aquatic primary production (seagrasses, marsh macrophytes and phytoplankton) and the interactive effects of light, nutrients and grazing on these important estuarine communities.  For most investigations, we have developed ecosystem simulation models as an integrative tool for the synthesis of data over various temporal and spatial scales, guiding the research effort by identifying information or data gaps, and exploring controls on ecosystem dynamics through simulation studies.  More recently, we have expanded our modeling efforts to the watershed level through the development of BasinSim 1.0, a Windows - based watershed modeling package that simulates the loading of carbon, nitrogen, phosphorus and sediments to aquatic systems in small to medium sized basins.

Current Projects

• Development of a Multi – Species Tropho – Dynamic Model in Support of Sustainable Fisheries Management in Chesapeake Bay, Virginia Environmental Endowment.

 
• Intensive Water Quality Mapping of Nearshore and Mid – channel Regions of the James River Relative to SAV Growth and Survival Using the DATAFLOW Surface Water Quality Mapping System, CBP, US EPA.

 
• Assessment of Pulse Amplitude Modulated (PAM) Fluorescence Technology for Rapid Determination of Stress in Natural and Transplanted Seagrass Beds at CBNERRVA. Cooperative Institute for Coastal and Estuarine Environmental Technologies (CICEET) and NOAA.

 
• Application of a Watershed Model to Evaluate Non-Point Nutrient and Sediment Loadings in Small Virginia Watersheds, Commonwealth of Virginia, DCR.

 
• Development and Distribution of a Generalized, Desktop Simulation Package for Watershed Management, Commonwealth of Virginia, CBLAD.

Selected Publications

Ragone Calvo, L. M., R.L. Wetzel and E. M. Burreson. 2001. Development and verification of a model for the population dynamics of the protistan parasite Perkinsus marinus within its host, the eastern oyster, Crassostrea virginica in Chesapeake Bay. J. Shellfish Res. 20(1): (in press).

Sin, Yongsik, R.L. Wetzel and I. C. Anderson. 2000. Seasonal variations of size-fractionated phytoplankton along the salinity gradient in the York River estuary, Virginia (USA). J. Plankton Res., 22(10): 1945-1960.

Moore, K. A. and R.L. Wetzel. 2000. Seasonal variations in eelgrass (Zostera marina L.) responses to nutrient enrichment and reduced light availability in experimental systems. J. Exp. Mar. Biol. Ecology 244:1 – 28.

Dai, T., R.L. Wetzel, Tyler R. L. Christensen and E. A. Lewis. 2000. BasinSim 1.0 A Windows-Based Watershed Modeling Package User’s Guide. SRAMSOE #362, Virginia Institute of Marine Science, School of Marine Science, College of William & Mary, Gloucester Point, VA. 137 pp.

Buzzelli, C. P., R.L. Wetzel, and M. B. Meyers. 1999. A linked physical and biological framework to assess biogeochemical dynamics in a shallow estuarine system. Estuarine, Coastal and Shelf Science 49(6): 829-851.

Sin, Y., R.L. Wetzel, and I. C. Anderson. 1999. Spatial and temporal characteristics of phytoplankton and nutrients in the York River estuary: Analysis of long term data. Estuaries 22:260-275.

Wetzel, R.L. and Yongsik Sin. 1998. Ecosystem process models: applications to coastal marine systems. Ocean Research 20(2): 189 - 197.

Buzzelli, C.P., R.L. Wetzel and M.B. Meyers. 1998.  Dynamic simulation of littoral zone habitats in lower Chesapeake Bay. II. Seagrass habitat primary production and water quality relationships. Estuaries 21(4B) 673 - 689.

Dai, Ting and R.L. Wetzel. 1998. Ecological models, ActiveX technology and the Internet. Bull. Ecol. Soc. Amer. 79(1): 98-99.

Anderson, I.C., C.R. Tobias, B.B. Neikirk, and R.L. Wetzel. 1997. Development of a process-based nitrogen mass balance model for a Virginia Spartina alterniflora salt marsh: implications for net DIN flux. Mar.Ecol. Prog. Series, 159:13-27.

Moore, K.A. , R.L. Wetzel and R.J. Orth. 1997. Seasonal pulses of turbidity and their relations to eelgrass (Zostera marina L) survival in an estuary. J.Exp.Mar.Biol & Ecology. 215:115-134.

Rizzo, W.M, S.K. Dailey, G.J. Lackey, R.R. Christian, B.E. Berry, and R.L. Wetzel. 1996. A metabolism-based trophic index for comparing the ecological values of shallow water sediment habitats.  Estuaries 19(2A): 247-256.

Wetzel, R.L. 1994. Modeling the microbial loop: an estuarine modeler's perspective.  Microbial Ecology 28:331-334.

Past Students

• Tyler Christensen, M.S. Student
• Amy Lewis, M.S. Student
• Christian Hager, Ph.D. Student
• W. J. Seufzer, Ph.D. awarded 2001, Environmental adaptations of seagrass: A computational approach 
• Scott Neubauer, Ph.D. awarded 2000, Carbon dynamics in a tidal freshwater marsh (co-chair I.C. Anderson)
• Yongsik Sin, Ph.D. awarded 1998, Ecosystem analysis of water column processes in the York River estuary, Virginia: Historical records, field studies and modeling analysis 
• C. P. Buzzelli, Ph.D. awarded 1996, Integrative analysis of ecosystem processes in the littoral zone of Lower Chesapeake Bay: A modeling study of the Goodwin Islands National Estuarine Research Reserve
• B. E. Berry, M.A. awarded 1996, Exchanges of dissolved inorganic nitrogen and dissolved organic carbon between salt marsh sediments and overlying tidal water
• D. Fugate, M.A. awarded 1996, Fractal nature of tidal channel networks
• W. J. Seufzer, M.A. awarded 1994, Measurement of in situ eelgrass community metabolism in standing and flowing waters: Methods and models
• S. Hartenstein, M.A. awarded 1991, Nutrient standing stocks and partitioning in a forested coastal plain watershed: Groundwater, stream and marsh creek
• C. P. Buzzelli, M.A. awarded 1991, Sediment inorganic nitrogen stocks and root-rhizome ammonium uptake by eelgrass (Zostera marina L.) in the lower Chesapeake Bay
• L. J. Morris, M.A. awarded 1990, Nitrogen processing in the York River estuary, VA: Spatial and temporal patterns of nitrification
• H. A. Neckles, Ph.D. awarded 1990, Relative effects of nutrient enrichment and grazing on epiphyton-macrophyte (Zostera marina L.) dynamics (co-chair R.J. Orth)
• F. A. Hoffman, M.A. awarded 1989, Riverine sources of organic carbon and nutrients to coastal  waters
• E. T. Koepfler, Ph.D. awarded 1989, An examination of biological and physical-chemical factors affecting bacterial production in an estuarine environment (co-chair H. I. Kator)
• C. H. Ryer, Ph.D. awarded 1987, Studies of pipefish foraging in simulated seagrass habitats (co-chair R.J. Orth)
• R. F. van Tine, Ph.D. awarded 1987, Aspects of the ecology of estuarine light with special reference to seagrasses of the Chesapeake Bay: Measurements and models
• R. W. Middleton, Ph.D. awarded 1987, The seasonal and diel use by juvenile and adult finfishes of a mesohaline intertidal creek on the York River, Virginia (co-chair J. A. Musick)
• W. M. Rizzo, Ph.D. awarded 1986, Community metabolism and nutrient dynamics of a shoal sediment in a temperate estuary with special emphasis on scales of temporal variability
• H. A. Brooks, Ph.D. awarded 1985, Energy transformation and feeding chronology of postlarval and juvenile Bairdiella chrysoura
• L. Murray, Ph.D. awarded 1983, Metabolic and structural studies of several temperate seagrass communities with emphasis on microalgal components
• D. F. Ludwig, M.A. awarded 1983, Effects of disruptive grazing by the mud snail Ilyanassa obsoleta on a mud flat nematode population
• M. S. Kowalski, M.A. awarded 1979, Angiosperm growth, distribution and tissue nitrogen concentration in a sewage-impacted marsh: Yorktown Creek, Virginia

Courses Taught

• MS 651:  Ecosystem Modeling and Simulation Analysis
• MS 698:  Advanced Problems in Marine Science

Professional Memberships

• American Society of Limnologists and Oceanographers (ASLO)
• American Geophysical Union (AGU)
• Estuarine Research Federation (ERF)
• Atlantic Estuarine Research Society (AERS)
• Institute of Ecology, University of Georgia

Collaborative/Interdisciplinary Efforts

• Currently engaged in joint grants with the departments of Physical Sciences (Watershed Modeling) and Fisheries Sciences (Multi – species, trophic dynamic modeling).