Estuaries and Coasts

, Volume 35, Issue 6, pp 1468–1485 | Cite as

Watershed Export Events and Ecosystem Responses in the Mission–Aransas National Estuarine Research Reserve, South Texas

  • Rae F. MooneyEmail author
  • James W. McClelland


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.


Nitrogen 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.

Supplementary material

12237_2012_9537_MOESM1_ESM.doc (64 kb)
ESM 1 (DOC 64 kb)
12237_2012_9537_Fig11_ESM.jpg (1000 kb)

SRP, nitrate, and ammonium concentrations versus salinity in Copano Bay, with a conservative mixing line. (JPEG 999 kb)

12237_2012_9537_Fig12_ESM.jpg (1.4 mb)

Dissolved organic carbon (DOC), dissolved organic nitrogen (DON), particulate organic carbon (POC), and particulate organic nitrogen (PON) concentrations versus salinity in Copano Bay, with a conservative mixing line. (JPEG 1388 kb)

12237_2012_9537_Fig13_ESM.jpg (739 kb)

Stable carbon and nitrogen isotope ratios (δ values) of particulate organic carbon (POC) and particulate organic nitrogen (PON) versus salinity. (JPEG 739 kb)


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Copyright information

© Coastal and Estuarine Research Federation 2012

Authors and Affiliations

  1. 1.The University of Texas at Austin Marine Science InstitutePort AransasUSA

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