Freshwater inflow requirements for the Nueces Delta, Texas: Spartina alterniflora as an indicator of ecosystem condition
Vol. 4 No. 2 (2013). Cover photo: As Texas continues to face water challenges and drought, many communities are seeking to conserve water in various sectors, including lawn and landscape water use. ©Jose Manuel Gelpi Diaz, Crestock.


Spartina alterniflora
freshwater inflow
Nueces Delta

How to Cite

Stachelek, Jemma, and Kenneth H. Dunton. 2013. “Freshwater Inflow Requirements for the Nueces Delta, Texas: Spartina Alterniflora As an Indicator of Ecosystem Condition”. Texas Water Journal 4 (2). College Station, Texas:62-73.


Estuarine wetlands and salt marshes are fundamentally driven by variations in freshwater inflow. However, many estuaries have been subject to a heavily modified hydrology due to flood protection engineering and the construction of upstream dams for municipal water supply. Assessment of the impacts of these activities on the health of estuarine wetlands has traditionally focused on tracking the abundance of economically important shellfish and finfish species. In this study, we examine fluctuations in the abundance of selected salt marsh plants and use this information to develop estimates of freshwater inflow needs. The impact of freshwater inflow events on 3 common emergent plants in the Nueces River Delta (Spartina alterniflora, Borrichia frutescens, Salicornia virginica) was determined from long-term monitoring of permanent census plots. Of the 3 species examined, Spartina alterniflora was determined to be the best indicator species because its abundance most closely tracked variations in freshwater inflow. For example, under low salinity conditions S. alterniflora cover approached 66%. However, when salinities exceeded 25‰, S. alterniflora cover declined rapidly. Our results provide clear evidence that the presence or absence of key plant indicator species (in this case S. alterniflora) is reflective of overall estuarine hydrological condition over time scales exceeding 6 months.

Citation: Stachelek J, Dunton KH. 2013. Freshwater inflow requirements for the Nueces Delta, Texas: Spartina alterniflora as an indicator of ecosystem condition. Texas Water Journal. 4(2):62-73. Available from:


Adams DA. 1963. Factors influencing vascular plant zonation in North Carolina salt marshes. Ecology. 44:445-456.

Alexander HD, Dunton KH. 2002. Freshwater inundation effects on emergent vegetation of a hypersaline salt marsh. Estuaries. 25:1426-1435.

Barry D, Hartigan JA. 1993. A Bayesian analysis for change point problems. Journal of The American Statistical Association. 88:309-19.

[BBEST] Nueces River and Corpus Christi and Baffin Bays Basin and Bay Expert Science Team. 2011. Environmental Flows Recommendations Report. Final Submission to the Environmental Flows Advisory Group, Nueces River and Corpus Christi and Baffin Bays Basin and Bay Area Stake¬holders Committee, and Texas Commission on Environ-mental Quality [Internet]. Available from: http://www.

[BOR] Bureau of Reclamation. 1975. Final environmental impact statement, Nueces River project, Choke Canyon dam and reservoir site. Austin (Texas): U.S. Department of the Interior.

[BOR] Bureau of Reclamation. 2000. Concluding Report: Rincon Bayou Demonstration Project, Volume II: Findings. Austin (Texas): U.S. Department of the Interior, Bureau of Reclamation, Oklahoma-Texas Area Office.

Bertness MD. 1991. Zonation of Spartina patens and Spartina alterniflora in New England salt marsh. Ecology. 72:138- 148.

Bertness MD, Gough L, Shumway SW. 1992. Salt tolerances and the distribution of fugitive salt marsh plants. Ecology. 73:1842-1851.

Brock DA. 2001. Nitrogen budget for low and high freshwater inflows, Nueces Estuary, Texas. Estuaries. 24:509.

Buzan D, Lee W, Culbertson J, Kuhn N, Robinson L. 2009. Positive relationship between freshwater inflow and oyster abundance in Galveston Bay, Texas. Estuaries and Coasts. 32:206-212.

Dale VH, Beyeler SC. 2001. Challenges in the development and use of ecological indicators. Ecological Indicators. 1:3-10.

Doering PH, Chamberlain RH, Haunert DE. 2002. Using submerged aquatic vegetation to establish minimum and maximum freshwater inflows to the Caloosahatchee estuary, Florida. Estuaries 25:1343-1354.

Dunton KH, Hardegree B, Whitledge TE. 2001. Response of estuarine marsh vegetation to interannual variations in precipitation. Estuaries. 24:851-861.

Erdman C, Emerson JW. 2007. bcp: An R package for perform¬ing a Bayesian analysis of change point problems. Journal of Statistical Software. 23:1-13.

Forbes MG, Dunton KH. 2006. Response of a subtropical estuarine marsh to local climatic change in the southwest-ern Gulf of Mexico. Estuaries and Coasts. 29:1242-1254.

Forbes MG, Alexander HD, Dunton KH. 2008. Effects of pulsed riverine versus non-pulsed wastewater inputs of freshwater on plant community structure in a semi-arid salt marsh. Wetlands. 28:984-994.

Henley DE, Rauschuber DG. 1981. Freshwater needs of fish and wildlife resources in the Nueces-Corpus Christi Bay Area, Texas: a literature synthesis. Washington, D.C.: U.S. Fish and Wildlife Service, Office of Biological Services. FWS/OBS-80/10.

Kenkel N. 2006. On selecting an appropriate multivariate analysis. Canadian Journal of Plant Science. 2:663-676.

Kirwan ML, Guntenspergen G, Morris JT. 2009. Latitudi¬nal trends in Spartina alterniflora productivity and the response of coastal marshes to global change. Global Change Biology. 15(8):1982-1989.

Kneib RT. 2003. Bioenergetic and landscape considerations for scaling expectations of nekton production from intertidal marshes. Marine Ecology Progress Series. 264:279-296.

Longley WL. 1994. Freshwater inflows to Texas bays and estuaries: ecological relationships and methods for deter-mination of needs. Austin (Texas): Texas Water Develop¬ment Board and Texas Parks and Wildlife Department.

Mitsch WJ, Gosselink JG. 2007. Wetlands, 4th edition. New York (New York): John Wiley & Sons, Inc.

Montagna PA, Kalke RD, Ritter C. 2002. Effect of restored freshwater inflow on macrofauna and meiofauna in upper Rincon Bayou, Texas, USA. Estuaries. 25:1436-1447.

Montagna PA, Palmer T, Gil M, Dunton K, Hill E, Nicolau B. 2009. Response of the Nueces estuarine marsh system to freshwater inflow: an integrative data synthesis of baseline conditions for faunal communities [Internet]. Final Report to the Coastal Bend Bays & Estuaries Program. 27 p. Project Number 0821. Available from: http://www.

Okansen J, Kindt R, Legendre P, O’Hara RB. 2007. vegan: Community Ecology Package version 1.7-7.

Palmer MA, Ambrose, RF, Poff N. 1997. Ecological theory and community restoration ecology. Restoration Ecology. 5:291-300.

Parsons TR, Maita Y, Lalli CM. 1984. A manual of chemical and biological methods for seawater analysis. 1st edition. New York (New York): Pergammon Press. 173 p.

Penfound WT, Hathaway ES. 1938. Plant communities in the marshlands of southeastern Louisiana. Ecological Monographs. 8:1-56.

Powell GL, Matsumoto J, Brock D. 2002. Methods for deter¬mining minimum freshwater inflow needs of Texas bays and estuaries. Estuaries. 25:1262-1274.

Pulich WM Jr, Tolan JM, Lee WY, Alvis W. 2002. Freshwater inflow recommendation for the Nueces Estuary. Technical Report. Austin (Texas): Texas Parks and Wildlife Depart¬ment, Resource Protection Division, Coastal Studies Program. 99 p.

Rasser M. 2009. The role of biotic and abiotic processes in the zonation of salt marsh plants in the Nueces River Delta, Texas [dissertation]. [Austin (Texas)]: University of Texas at Austin.

Richter B, Mathews R, Harrison D. 2003. Ecologically sustain¬able water management: managing river flows for ecologi¬cal integrity. Ecological Applications. 13:206-224.

Ryan A. 2011. Modeling hydrodynamic fluxes in the Nueces River Delta [thesis]. [Austin (Texas]: University of Texas at Austin.

Shumway SW, Bertness MD. 1992. Salt stress limitation of seedling recruitment in a salt-marsh plant community. Oecologia. 92:490-497.

Solis RS, Powell GL. 1999. Hydrography, mixing character¬istics, and residence times of Gulf of Mexico estuaries. In: Bianchi TS, Pennock JR, Twilley RR, editors. Biogeo¬chemistry of Gulf of Mexico Estuaries. New York (New York): John Wiley and Sons, Inc. p. 29–61.

ter Braak CJF, Prentice IC. 1988. A theory of gradient analysis. Advances in Ecological Research. 18:271-313.

[TDWR] Texas Department of Water Resources. 1982. The influence of freshwater inflows upon the major bays and estuaries of the Texas Gulf Coast: Executive Summary. 2nd edition. Austin (Texas): Texas Department of Water Resources. 51p. LP-115.

Tolan JM. 2007. El Niño-Southern Oscillation impacts trans¬lated to the watershed scale: Estuarine salinity patterns along the Texas Gulf Coast, 1982 to 2004. Estuarine, Coastal and Shelf Science. 72:247-260.

[USGS] United States Geological Survey, Water Resources. 2011. Real-Time Water Data for Texas, Station 08211500 [Internet], [cited 2011 August ]. Available from: http://

Wallace SC. 2011. Spatial and temporal variation in trophic structure of the Nueces Marsh, TX [thesis]. [Austin (Texas)]: University of Texas at Austin.

Ward GH, Valdes JB. 1995. Water Resources, p. 68-87. In: North GR, Schmandt J, and Clarkson J, editors. The impact of global warming on Texas: A report of the task force on climate change in Texas. Austin (Texas): Univer¬sity of Texas Press.

Webb JW. 1983. Soil water salinity variations and their effects on Spartina alterniflora. Contributions in Marine Science. 26:1-13.

Whaley S, Minello T. 2002. The distribution of benthic infauna of a Texas salt marsh in relation to the marsh edge. Wetlands. 22:753-766.

White S, Alber M. 2009. Drought-associated shifts in Spartina alterniflora and S. cynosuroides in the Altamaha River Estuary. Wetlands. 29:215-224.

Zacharias M, Roff J. 2001. Use of focal species in marine conservation and management: a review and critique. Aquatic Conservation: Marine and Freshwater Ecosys¬tems. 76:59-76.

Zedler J. 1983. Freshwater impacts in normally hypersaline marshes. Estuaries and Coasts. 6:346-355.

Zedler JB, Kercher S. 2005. Wetland resources: status, trends, ecosystem services, and restorability. Annual Review of Environment and Resources. 30:39-74.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Copyright (c) 2013 Jemma Stachelek, Kenneth H. Dunton