Watershed Export Events and Ecosystem Responses in the Mission–Aransas National Estuarine Research Reserve, South Texas
- 497 Downloads
While inputs from land are recognized as important resources supporting production in estuaries, the role that storm events play in resource delivery and the response of estuarine systems to pulsed inputs are less well appreciated. Temporal variations in (1) watershed export via the Mission and Aransas rivers and (2) nutrient and organic matter dynamics in Copano Bay were examined in the Mission–Aransas National Estuarine Research Reserve, south Texas. Inorganic nutrient, dissolved organic matter (DOM), and particulate organic matter (POM) concentrations in the rivers varied substantially with discharge, as did carbon and nitrogen stable isotope ratios of POM. Accounting for these variations was critical for calculating robust watershed export estimates. In Copano Bay, soluble reactive phosphorus, POM, and DOM remained elevated for several months following major runoff events, whereas inorganic nitrogen was rapidly depleted. Chlorophyll-a concentrations and POC-δ13C in Copano Bay showed that increased POM concentrations were linked to enhanced in situ production.
KeywordsNitrogen Nutrients Storm events River export Stable isotopes NERR
This work was supported by the National Oceanic and Atmospheric Administration’s National Estuarine Research Reserve Graduate Research Fellowship (NA07NOS4200020) and a grant from the National Aeronautics and Space Administration (NASA-NNX07AL79G). We would like to acknowledge K.H. Dunton, D.R. Maidment, and two anonymous reviewers for comments on this work. Special thanks to P. Garlough for help with isotope analyses, field work, and lab support. Thanks are also due to the Mission–Aransas NERR staff: E.J. Buskey, C. Hyatt, S. Morehead, K.M. Madden, and C. Cook. We also would like to thank K. Jackson, G.C. Shank, S. Hamman, S. Diaz, M. Barajas, K. Swanson, L. Upchurch, L. Hurley, A.D. Evans, A.N. Evans, B. Gemmell, R. Withall, C. Smith, G. Hensgen, R. Mills, S. Bulloch, N. Klein, J. Stachelek, and S. Johnson.
- Armstrong, N.E. 1982. Responses of Texas estuaries to freshwater inflows. In Estuarine comparisons, ed. Victor S. Kennedy, 103–120. New York: Academic.Google Scholar
- GESAMP (Group of Experts on Scientific Aspects of Marine Environmental Protection) and Advisory Committee on Protection of the Sea. 2001. Protecting the oceans from land-based activities: Land based sources and activities affecting the quality and uses of the marine, coastal and associated freshwater environment. GESAMP Reports and Studies: 71. United Nations Environment Programme.Google Scholar
- Helsel, D.R., and R.M. Hirsch. 2002. Statistical methods in water resources. In Techniques of water resources research, Book 4, Chapter A3, 295–322. Washington: US Geological Survey.Google Scholar
- IPCC (Intergovernmental Panel on Climate Change). 2001. Climate Change 2001: Impacts, adaptation, and vulnerability; contribution of Working Group II to the Third Assessment Report of the IPCC, ed. J.J. McCarthy et al. New York: Cambridge University Press.Google Scholar
- IPCC (Intergovernmental Panel on Climate Change). 2007. The physical science basis; contribution of Working Group I to the Fourth Assessment Report of the IPCC. ed. S.D. Solomon et al. New York: Cambridge University Press.Google Scholar
- Johnson, S.J. 2009. A general method for modeling coastal water pollutant loadings. Ph.D. Dissertation. The University of Texas at Austin.Google Scholar
- Jones, M.N. 1984. Nitrate reduction by shaking with cadmium. Water Resources 18: 643–646.Google Scholar
- Mooney, R.F., D.A. Bruesewitz, J.W. McClelland, W.S. Gardner, and E.J. Buskey. 2011. Nutrient and organic matter dynamics following storm events in the Mission–Aransas National Estuarine Research Reserve (NERR), Texas. Coastal and Estuarine Research Federation Biennial Conference, 9 November 2011.Google Scholar
- Nixon, S.W. 1995. Coastal marine eutrophication: a definition, social causes, and future concerns. Ophelia 41: 199–219.Google Scholar
- NOAA (National Oceanic and Atmospheric Administration). 1990. Estuaries of the United States: Vital statistics of a national resource base. A special NOAA 20th anniversary report. NOAA National Ocean Service, Office of Oceanography and Marine Assessment, Rockville.Google Scholar
- Orlando Jr., S.P., L.P. Rozas, G.H. Ward, and C.J. Klein. 1993. Salinity characteristics of Gulf of Mexico estuaries. Silver Spring: National Oceanic and Atmospheric Administration Office of Ocean Resources Conservation and Assessment.Google Scholar
- Paerl, H.W., K.L. Rossignol, S.N. Hall, B.L. Peierls, and M.S. Wetz. 2010. Phytoplankton community indicators of short- and long- term ecological change in the anthropogenically and climatically impacted Nuese River Estuary, North Carolina, USA. Estuaries and Coasts 33: 485–497.CrossRefGoogle Scholar
- Peterson, B.J., W.M. Wollheim, P.J. Mulholland, J.R. Webster, J.L. Meyer, J.L. Tank, E. Marti, W.B. Bowden, H.M. Valett, A.E. Hershey, W.H. McDowell, W.K. Dodds, S.K. Hamiliton, S. Gregory, and D.D. Morrall. 2001. Control of nitrogen export from watersheds by headwater streams. Science 292: 86–90.CrossRefGoogle Scholar
- Runkel, R.L., C.G. Crawford, and T.A. Cohn. 2004. Load estimator (LOADEST): a FORTRAN program for estimating constituent loads in streams and rivers. In Techniques and methods Book 4, Chapter A5, ed. U.S. Geological Survey, 1–69. Reston: US Geological Survey.Google Scholar
- Smith, E.H., and S.J. Dilworth. 1999. Mission/Aransas watershed wetland conservation plan. Austin: Texas General Land Office- Coastal Division.Google Scholar
- Strickland, J.D.R., and T.R. Parsons. 1972. A practical handbook of seawater analysis, 2nd edition (Bulletin 167). Ottawa: Fisheries Research Board of Canada.Google Scholar
- Teeri, J.A., and L.G. Stowe. 1976. Climatic patterns and the distribution of C4 grasses in North America. Oecologia 23: 1–12.Google Scholar
- US Environmental Protection Agency. 2008. Water discharge permits (PCS). http://www.epa.gov/enviro/html/pcs/adhoc.html. Accessed 18 Apr 2008.
- Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. Matson, D.W. Schindler, W.H. Schlesinger, and D.G. Tilman. 1997. Human alteration of the global nitrogen cycle—Sources and consequences. Ecological Applications 7: 737–750.Google Scholar