Virginia Institute of Marine Science
Iris Anderson Home

Iris C. Anderson

Professor of Marine Science

Email : [[iris]]
Phone : (804) 684-7811
Interests : Nitrogen and carbon cycling
Office : Andews Hall 329
Department : Biological Sciences

  • B.S., Colby College
  • S.M., Massachusetts Institute of Technology
  • Ph.D., Medical College of Virginia, Virginia Commonwealth University
Research Interests

Coastal systems are increasingly stressed by inputs of nutrients from land, groundwater, the atmosphere, and ocean. My research is focused on the sources and fates of nutrients in riverine and estuarine systems and in shallow coastal embayments. Nutrient sources studied include external sources such as groundwater, land use, and atmosphere as well as internal sources such as nitrogen fixation and organic matter recycling. The fates of nutrients are influenced by chemical, biological and physical regulators including the chemical composition of the nutrients, microbial community composition, light quality and quantity, temperature, sediment type, dissolved oxygen, sediment resuspension, water column stratification, and water residence time. We study the interaction of these factors and their effects on nutrient cycling both in situ and under simulated conditions in mesocosms and environmental chambers. Microbial processes both in the water column and sediment play a critical role in transforming, removing, or immobilizing nutrients. We study both autotrophic and heterotrophic microbial processes responsible for the transformation of carbon and nitrogen using stable isotope techniques. For example, many of our recent studies have focused on the role of benthic microalgae, autotrophic organisms which live on bottom sediments in shallow systems, and which appear to mediate water quality and nutrient cycling provided they receive sufficient light. Unfortunately, in response to increasing nutrient enrichment of our coastal systems, eutrophication, the over-production of organic matter, has resulted in the appearance of blooms of phytoplankton or macroalgae (seaweeds), which reduce light availability to the bottom sediment, interfering with the ability of benthic microalgae to remove and transform nutrients. We are currently funded by NSF to study the fate of carbon and nitrogen as it is transferred from either the water column or sediment pore water through various biological and chemical pools, including macroalgae, benthic microalgae, sediment bacteria, sediment macrofauna, pore water dissolved inorganic and organic pools, and water column dissolved inorganic and organic pools. In another study funded by the NSF Long-Term Ecological Research Program, we study the effects of nutrient loading from various land uses on system metabolism within a series of embayments located in the Virginia Coast Reserve on Virginia's Eastern Shore. Finally, we are just starting a large Department of Defense-funded collaborative study with colleagues at the University of North Carolina and NOAA labs to determine the effects of land uses related to military activities on both nutrient enrichment and light quality and quantity and their regulation of benthic processes in the New River Estuary of North Carolina.

Current Projects
  • Defense Coastal/Estuarine Research Program (DCERP); AE-3: Developing Indicators of Ecosystem Function for Shallow Estuaries: Benthic Functional Responses in the New River Estuary
  • Benthic Microalgal Regulation of Carbon and Nitrogen Turnover in Land Margin Ecosystems: A Dual Stable Isotope Tracer Approach. Funded by NSF DEB Ecosystems Program.
  • The role of coastal lagoons in removing or retarding nutrients during transport to the coastal ocean. Funded by NSF LTER program under subcontract to the University of Virginia.
Selected Publications

Stanhope, J. W., Anderson, I. C., and Reay, W. G. In press. Base Flow Nutrient Discharges from Lower Delmarva Peninsula Watersheds of Virginia, USA. Journal of Environ. Quality.

Li, Y., Brush, M. J., Wang, H. V., Anderson, I. C., and Sisson, G. M.  In press.  Effects of benthic microalgae on eutrophication processes - a laboratory experiment and a model simulation.  Proceedings of the Tenth International Conference on Estuarine and Coastal Modeling.

Aranibar, J. N., Anderson, I. C., Epstein, H. E., Feral, C. J. W., Swap, R. J. Ramontso, J., and  Macko, S. A., 2008. Nitrogen isotope composition of soils, C3 and C4 plants alongland use gradients in southern Africa.  J. Arid Environ.  72:326-337.

Joye, S. B. and I. C. Anderson, 2008. Nitrogen cycling in Estuarine and Nearshore Sediments. In: Capone, D., Bronk, D., Carpenter, E. and Mulhollond, M. (Eds), Nitrogen in the Marine Environment, Springer Verlag, Chapter 19, pp 868-915.

McGlathery, K. J., Sundback, K, Anderson, I. C., 2007. Eutrophication in shallow coastal bays and lagoons: the role of plants in the coastal filter.  Mar. Ecol Prog. Ser. 348: 1 - 18.

Neubauer, S. C., Anderson, I. C., and Neikirk, B. B., 2005. Nitrogen cycling and ecosystem exchanges in a Virginia tidal freshwater marsh.  Estuaries. 28:909-922.

McGlathery, K., Sundbäck, K., Anderson, I. C., 2004. The importance of primary producers for the benthic nitrogen and phosphorus cycling. In The influence of Primary Producers on Estuarine Nutrient Cycling edited by Nielsen, S.L., G. T. Banta & M. F. Pedersen, Kluwer Academic Publishers. pp. 232-263.

Anderson, I. C., McGlathery, K. J., and Tyler, A. C., 2003. Microbial mediation of ‘reactive nitrogen' transformations in a temperate lagoon. Marine Ecology Progress Series. 246: 73-84.

Neubauer, S. C. and Anderson, I. C., 2003. Transport of dissolved inorganic carbon from a tidal freshwater marsh to the York River estuary. Limnology and Oceanography. 48(1): 299-307.

Aranibar, J. A., Anderson, I. C., Ringrose, S., and Macko, S. A., 2003. The importance of cyanobacterial crusts as a source of nitrogen to Southern Aftrican arid ecosystems - indicated by acetylene reduction and stable isotopes. J. Arid Environments. 54:345-358.

Aranibar, J.N., I. C. Anderson, A.L.F. Potgieter, S.A.Macko, H.H. Shugart and R. Sowry, 2003. Nutrient cycling response to fire frequency in the Kruger National Park (South Africa) indicated by stable isotopes. Isotopes in Environmental Health Studies. 39:141-158.

Tyler, A. C., K. J. McGlathery, and I. C. Anderson 2003.  Benthic algae control sediment-water column fluxes of organic and inorganic nitrogen compounds in a temperate lagoon.  Limnology and Oceanography, 48:2125-2137.

McGlathery, K. J., K. Sundback, and I. C. Anderson, 2003. The importance of primary producers for benthic N and P cycling.  In:  The Influence of Primary Producers on Estuarine Nutrient Cycling, Nielsen, S. L., G. M. Banta, and M. F. Pedersen, (Eds.), Kluwer Academic Publishers.

Neubauer, S. C., Anderson, I. C., Constantine, J. A., and Kuehl, S. A., 2002. Sediment deposition and accretion in a mid-Atlantic (U.S.A.) tidal freshwater marsh.  Estuarine Coastal and Shelf Science. 54: 713-727.

Kopacek, J., Stuchlik, E., Vesely, J., Schaumburg, J. Anderson, I.C., Fott, J., Hejzlar, J., and Vrba, J., 2002. Hysteresis in reversal of Central European mountain lakes from atmospheric acidification. Water, Air, and Soil Pollution: 2(2):91-114.

Tobias, C.R., Macko, S.A., Anderson, I.C., Canuel, E.A., and Harvey, J.W., 2001.  Tracking   the fate of a high concentration groundwater nitrate plume through a fringing marsh: A combined groundwater tracer and in situ isotope enrichment study. Limnology and Oceanography. 46(8): 1977-1989.

Miller, W. D., Neubauer, S. C., and Anderson, I. C., 2001. Effects of sea level induced disturbances on high salt marsh metabolism.  Estuaries.  24(3): 357-367.

Tobias, C. R., Harvey, J. W., and Anderson, I. C., 2001. Quantifying groundwater discharge through fringing wetlands to estuaries:  Seasonal variability, methods comparison, and implications for wetland-estuary exchange.  Limnol. Oceanogr. 46(3) 604-615.

Tobias, C. R., Anderson, I. C., Canuel E. A., and Macko, S. A., 2001. Nitrogen cycling through a fringing marsh - aquifer ecotone.  Marine Ecology Progress Series.  210: 25-39.

Tyler, A. C., McGlathery, K. J., and Anderson, I. C., 2001. Macroalgal mediation of dissolved organic nitrogen fluxes in a temperate coastal lagoon. Est. Coastal Shelf Sci. 53:155-168.

McGlathery, K. J., Anderson, I. C., and Tyler, A. C., 2001. Magnitude and variability of benthic and pelagic metabolism in a temperate coastal lagoon. Marine Ecology Progress Series. 216:1-15.

Anderson, I. C., Tobias, C. R., Macko, S. A., and Poth, M. A., 2000. Sources and sinks of nitrogen in acidified glacial lakes of the Bohemian Forest, Czech Republic.  Silva Gabreta. 4: 135-146.

Neubauer, S. C., Miller, W. D., and Anderson, I. C., 2000. Carbon cycling in a tidal freshwater marsh ecosystem: a gas flux study. Marine Ecology Progress Series.  199: 13-30.

Korontzi, S. K., Macko, S. A., Anderson, I. C. and Poth, M. A., 2000. Carbon and nitrogen biogeochemical processes in a disturbed southern Californian forest ecosystem. Global Biogeochemical Cycles.  14: 177-188.

Sin, Y., Wetzel, R. L., Anderson, I. C., 2000.  Seasonal variations of size fractionated phytoplankton along the salinity gradient in the York River Estuary, Virginia.  Journal of Plankton Research.  22: 1945-1960.

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

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

Current Students
  • 2010-present - Gar Sechrist (M.S. Candidate)
  • 2009-present - Meaghan Whitehead (M.S. Candidate)
  • 2008-present - Daniel Maxey (M.S. Candidate)
Past Students
  • 2009 Juliette Poleto Giordano (M.S.) co-advised with Mark Brush. Nutrient Loading and System Response in the Coastal Lagoons of the Delmarva Peninsula
  • 2003 Amber Kozak Hardison (Ph.D. Candidate) Co-advised with Liz Canuel. The Influence of Macroalgal Blooms on Biogeochemical Processes in a Shallow Coastal Lagoon: A Dual Isotope Tracer and Biomarker Approach
  • 2003 Jennifer Wu Stanhope (M.S.) co-advised with Jim Perry. Relationships between watershed characteristics and base flow nutrient discharges to Eastern Shore coastal lagoons, Virginia.2002
  • 2002 Tami Lunsford (M.S.) A Comparison of the fate of Dissolved Organic Matter in two coastal systems: Hog Island Bay, VA (USA) and Plum Island Sound, MA (USA).
  • 2000 Scott Neubauer, (Ph.D.) co-advised with Richard Wetzel. Carbon Dynamics in a Tidal Freshwater Marsh
  • 1999 Craig Tobias (Ph.D.) co-advised with Liz Canuel. Nitrogen Dynamics at the Groundwater- Saltmarsh Interface
  • 1998 David Miller (M.A.) The Effects of Increased Inundation and Wrack Deposition on Photosynthesis and Respiration in a Virginia Salt Marsh. (College of William and Mary)
  • 1998 Yongsik Sin (Ph.D.) co-advised with Richard Wetzel. Phytoplankton Dynamics in the York River Estuary: Field Studies, Experimental Investigations, and Simulation Analysis.
  • 1996 Betty Berry Neikirk (M.S.) co-advised with Richard Wetzel. Sediment-Water Interactions in a Coastal Spartina alterniflora Marsh.
  • 1991 Juli Homstead (M.S.) (Old Dominion University)

NSF Research Experience for Undergraduates Interns

  • Lisa Kurian, Slippery Rock University, 2003
  • Leandra Lockwood, Fairleigh Dickinson University, 2003
  • Adriana Veloza, East Stroudsburg University, 2001
  • Rachel Eichenlaub, Randolph Macon College, 1999 and 2000 (senior thesis)
  • Jose Constantine, College of William and Mary, 1998 and 1999 (W&M senior thesis)
  • Benani Sen, University of Virginia, 1997
  • Peter Paik, College of William and Mary, 1995
  • David Christian, University of Delaware, 1995
  • Steven Roberts, East Carolina University, 1995
  • Emily Saks, College of William and Mary, 1994

High School Student Interns

  • Jessica Burshell, Summer intern 2003
  • Melissa Diskein, Science Fair Project, Fall 2001, Fall 2002
  • Neena Saha, First Program, Summer 2000
  • Schuyler van Montfrans, York High School, Fall 2000
  • Jessica Burton, Grafton High School, Summer 1997 FIRST Program
  • Jessica Burton, Governor's School for Science and Technology (Fall/Winter, 1997)
    Courses Taught
    • MS 573: Environmental Microbiology, with Howard Kator
    • MS 575: Aquatic Microbial Ecology, with Howard Kator
    • MS 579: Wetlands Ecology (Lecturer)
    • MS 655: Isotope Geochemistry, with Debbie Bronk
    • MS 698: Aquatic Microbiology
    • MS 698: Biogeochemical and Physiological Processes in Intertidal and Subtidal Habitats, with Ken Moore
    • MS 698: Biogeochemical Processes in Wetlands
    • MS 698: Seminar in Biogeochemistry, with Liz Canuel, Jim Bauer, and Hugh Ducklow
    • PUBP 635 Principles of Marine Environmental Science and Policy, with Dennis Taylor and Hugh Ducklow
    Faculty-Student Awards
    • Dean's Prize for the Advancement of Women in Marine Science, awarded May 2003.
    • Distinguished Publication Award--USDA Forest Service for: Anderson, I. C., Poth, M. A., Homstead, J., and Burdige, D. J. 1993. A Comparison of NO and N2O Production by the autotrophic nitrifier Nitrosomonas europaea and the heterotrophic nitrifier Alcaligenes faecalis. Appl. Environ. Microbiol. 59: 3525-3533, February 1996.
    • Distinguished Publication Award--USDA Forest Service for: Enhanced biogenic emissions of nitric oxide and nitrous oxide following surface biomass burning. Journal of Geophysical Research, Vol. 93, pp. 3893-3898, April 20, 1988.
    • Postdoctoral Fellowship, National Research Council, Atmospheric Sciences Division, Langley Research Center, Hampton, VA. 1984-1986.
    • American Society of Engineering Education Fellowship, Atmospheric Sciences Division, Langley Research Center, Hampton, VA. 1982-1984.
    Professional Memberships
    • Estuarine Reearch Federation
    • American Society Limnology & Oceanograhy
    • American Geophysical Union
    • Atlantic Estuarine Research Society
    Collaborative Interdisciplinary Activities
    • 3D Dynamic Mapping using ACROBAT, Profiler and selected fixed stations. Collaborators include H. Kator and M. Brush (all at VIMS).
    • Effects of Military Activity on Benthic Processes in the New River Estuary, North Carolina. Collaborators include H. Paerl (UNC-CH), C. Currin (NOAA, Beaufort), M. Piehler (UNC-CH) M. Brush (VIMS), J. McNinch (VIMS).
    • The role of benthic microalgae in regulation of carbon and nitrogen turnover in Virginia and Maryland Coastal Bays. Collaborators include C. Tobias (UNC-W), J. Vallino (MBL), and E. Canuel (VIMS).
    • Improved Performance Capabilities for the Acrobat Towed Instrument Platform: Data Collection, Calibration and Interpolation/Graphic Visualization. Collaborators include L. Haas, H. Kator, J. Shen, M. Brush (all at VIMS).
    • An integrated approach to understand relationships between shallow water benthic community structure and ecosystem function. Collaborate with L. Schaffner (VIMS).