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Conservative mixing of stable isotopes across estuarine salinity gradients: A conceptual framework for monitoring watershed influences on downstream fisheries production

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Abstract

Strong changes in stable isotope tracers commonly occur across estuarine salinity gradients from freshwater to the sea. The tracer gradients reflect the different geochemistries and mixing of freshwater and seawater, and these bottom-up geochemical influences are recorded in estuarine food webs in the isotopic compositions of animals. Conservative mixing calculations suggest that watershed-level inputs of freshwater and nutrients should exert strong influences on isotopic values of estuarine consumers, especially consumers such as bivalves that largely depend on phytoplankton production. Deviations from conservative isotope mixing also occur, and the magnitude of these deviations measures the strength of within-estuary organic matter cycling for estuarine food webs, especially inputs of non-phytoplankton foods such as macrophyte detritus and benthic algae. Measuring consumer isotopes across salinity gradients should be a relatively simple way to monitor effects of watershed nutrient loading and hydrologic flushing in supporting estuarine fisheries production.

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Literature Cited

  • Adams, J., G. Bate, andM. O’Callaghan. 1999. Primary producers, p. 91–118.In B. R. Allanson and D. Baird (eds.), Estuaries of South Africa. Cambridge University Press, Cambridge, UK.

    Google Scholar 

  • Baird, D. 1999. Estuaries as ecosystems: A functional and comparative analysis, p. 269–288.In B. R. Allanson and D. Baird (eds.), Estuaries of South Africa. Cambridge University Press, Cambridge, UK.

    Google Scholar 

  • Cabana, G., andJ. B. Rasmussen. 1996. Comparison of aquatic food chains using nitrogen isotopes.Proceedings of the National Academy of Science 93:10844–10847.

    Article  CAS  Google Scholar 

  • Canuel, E. A., J. E. Cloern, D. B. Ringelberg, J. B. Guckert, andG. H. Rau. 1995. Molecular and isotopic tracers used to examine sources of organic matter and its incorporation into the food webs of San Francisco Bay.Limnology and Oceanography 40:67–81.

    Article  CAS  Google Scholar 

  • Chanton, J. P. andF. G. Lewis. 1999. Plankton and dissolved inorganic carbon isotopic composition in a river-dominated estuary: Appalachicola Bay, Florida.Estuaries 22:575–583.

    Article  CAS  Google Scholar 

  • Cifuentes, L. A. andP. M. Eldridge. 1998. A mass- and isotopebalance model of DOC mixing in estuaries.Limnology and Oceanography 43:1872–1882.

    CAS  Google Scholar 

  • Cifuentes, L. A., M. L. Fogel, J. R. Pennock, andJ. H. Sharp. 1989. Biogeochemical factors that influence the stable nitrogen isotope ratio of dissolved ammonium in the Delaware Estuary.Geochimica et Cosmochimica Acta 53:2713–2721.

    Article  CAS  Google Scholar 

  • Cifuentes, L. A., L. E. Schemel, andJ. H. Sharp. 1990. Qualitative and numerical analyses of the effects of river inflow variations on mixing diagrams in estuaries.Estuarine, Coastal and Shelf Science 30:411–427.

    Article  CAS  Google Scholar 

  • Cloern, J. E. 1996. Phytoplankton bloom dynamics in coastal ecosystems: A review with some general lessons from sustained investigation of San Francisco Bay, California.Reviews of Geophysics 34:127–168.

    Article  CAS  Google Scholar 

  • Cloern, J. E., E. A. Canuel, and S. M. Wienke. 1993. Particulate organic matter in the San Francisco Bay estuary California: Chemical indicators of its origin and assimilation into the benthic food webs. U.S. Geological Survey Open-File Report 93-146. Menlo Park, California.

  • Coffin, R. B. andL. A. Cifuentes. 1999. Stable isotope analysis of carbon cycling in the Perdido estuary, Florida.Estuaries 22: 917–926.

    Article  CAS  Google Scholar 

  • Deegan, L. A. andR. H. Garritt. 1997. Evidence for spatial variability in estuarine food webs.Marine Ecology Progress Series 147:31–47.

    Article  Google Scholar 

  • DeNiro, M. J. andS. Epstein. 1981. Isotopic composition of cellulose from aquatic organisms.Geochimica et Cosmochimica Acta 45:1885–1894.

    Article  CAS  Google Scholar 

  • Estep, M. F. andH. Dabrowski. 1980. Tracing foods webs with stable hydrogen isotopes.Science 209:1537–1538.

    Article  CAS  Google Scholar 

  • Estep, M. F. andT. C. Hoering. 1980. Biogeochemistry of the stable hydrogen isotopes.Geochimica et Cosmochimica Acta 44:1197–1206.

    Article  CAS  Google Scholar 

  • Farquhar, G. D., B. K. Henery, andJ. M. Styles. 1997. A rapid on-line technique for determination of oxygen isotope composition of nitrogen-containing organic matter.Rapid Communications in Mass Spectrometry 11:1554–1560.

    Article  CAS  Google Scholar 

  • Fogel, M. L. andL. A. Cifuentes. 1993. Isotope fractionation during primary production, p. 73–100.In M. H. Engel and S. A. Macko (eds.) Organic Geochemistry, Principles and Applications. Plenum Press, New York.

    Google Scholar 

  • Fry, B. 1988. Food web structure on Georges Bank from stable C. N. and S isotopic compositions.Limnology and Oceanography 33:1182–1190.

    CAS  Google Scholar 

  • Fry, B. 1989. Sulfate fertilization and changes in stable sulfur isotopic compositions of lake sediments, p. 445–453.In P. W. Rundel, J. R. Ehleringer, and K. A. Nagy (eds.), Stable Isotopes in Ecological Research. Springer Verlag, New York.

    Google Scholar 

  • Fry, B. 1991. Stable isotope diagrams of freshwater food webs.Ecology 72:2293–2297.

    Article  Google Scholar 

  • Fry, B. 2000. Using state isotopes to monitor watershed influences on aquatic trophodynamics.Canadian Journal of Fisheries and Aquatic Sciences 56:2167–2171.

    Article  Google Scholar 

  • Fry, B. andE. B. Sherr. 1984. δ15C measurements as indicators of carbon flow in marine and freshwater ecosystems.Contributions in Marine Science 27:13–47.

    CAS  Google Scholar 

  • Goericke, R., J. P. Montoya, andB. Fry. 1994. Physiology of isotopic fractionation in algae and cyanobacteria, p. 187–221.In K. Lajtha and R. H. Michener, (eds.), Stable Isotopes in Ecology and Environmental Science. Blackwell Scientific Publications, Oxford.

    Google Scholar 

  • Hager, S. W. andL. E. Schemel. 1992. Sources of nitrogen and phosphorus to northern San Francisco Bay.Estuaries 15:40–52.

    Article  CAS  Google Scholar 

  • Hodell, D. A. andC. L. Schelske. 1998. Production, sedimentation and isotopic composition of organic matter in Lake Ontario.Limnology and Oceanography 43:200–214.

    Article  CAS  Google Scholar 

  • Horrigan, S. G., J. P. Montoya, J. L. Nevins, andJ. J. McCarthy. 1990. Natural isotopic composition of dissolved inorganic nitrogen in the Chesapeake Bay.Estuarine, Coastal and Shelf Science 30:393–410.

    Article  CAS  Google Scholar 

  • Incze, L. S., L. M. Mayer, E. B. Sherr, andS. A. Macko. 1982. Carbon inputs to bivalve mollusks: A comparison of two estuaries.Canadian Journal of Fisheries and Aquatic Science 39: 1348–1352.

    Google Scholar 

  • Iverson, S. J., K. J. Frost, andL. F. Lowry. 1997. Fatty acid signatures reveal fine scale structure of foraging distribution of harbor seals and their prey in Prince William Sound, Alaska.Marine Ecology Progress Series 151:255–271.

    Article  CAS  Google Scholar 

  • Jassby, A. D., W. J. Kimmerer, S. G. Monismith, C. Armor, J. E. Cloern, T. M. Powell, J. R. Schubel, andT. J. Vendlinski. 1995. Isohaline position as a habitat indicator for estuarine populations.Ecological Applications 5:272–289.

    Article  Google Scholar 

  • Kendall, C. andT. B. Coplen. 2001. Distribution of oxygen-18 and deuterium in river waters across the United States.Hydrological Processes 15:1363–1393.

    Article  Google Scholar 

  • Liss, P. S. 1976. Conservative and non-conservative behaviour of dissolved constituents during estuarine mixing, p. 93–130.In J. D. Burton and J. D. Liss (eds.), Estuarine Chemistry. Academic Press, London.

    Google Scholar 

  • Liu, K.-K. andI. R. Kaplan. 1989. The eastern tropical Pacific as a source of15N-enriched nitrate in seawater off southern California.Limnology and Oceanography 34:820–830.

    CAS  Google Scholar 

  • Livingston, R. J., X. Niu, G. F. Lewis, III andG. C. Woodsum. 1997. Freshwater input to a Gulf estuary: Long-term control of trophic organization.Ecological Applications 7:277–299.

    Article  Google Scholar 

  • Loder, T. C. andR. P. Reichard. 1981. The dynamics of conservative mixing in estuaries.Estuaries 4:64–69.

    Article  Google Scholar 

  • Loneragan, N. R. andS. E. Bunn. 1999. Rivers flows and estuarine ecosystems: Implications for coastal fisheries from a review and a case study of the Logan River, southeast Queensland.Australian Journal of Ecology 24:431–440.

    Article  Google Scholar 

  • Lotrich, V. A. 1975. Summer home range and movements ofFundulus heteroclitus (Pisces: Cyprinodontidae) in a tidal creek.Ecology 56:191–198.

    Article  Google Scholar 

  • Macko, S. A., M. L. F. Estep, andW. Y. Lee. 1983. Stable hydrogen isotope analysis of foodwebs on laboratory and field populations of marine amphipods.Journal of Experimental Marine Biology and Ecology 72:243–249.

    Article  CAS  Google Scholar 

  • Mariotti, A., C. Lancelot, andG. Billen. 1984. Natural isotopic composition of nitrogen as a tracer of origin for suspended organic matter in the Scheldt estuary.Geochimica et Cosmochimica Acta 48:549–555.

    Article  CAS  Google Scholar 

  • Matson, E. A. andM. M. Brinson. 1990. Stable carbon isotopes and the C∶N ratio in the estuaries of the Pamlico and Neuse Rivers, North Carolina.Limnology and Oceanography 35:1290–1300.

    CAS  Google Scholar 

  • Mayer, L. M., D. W. Townsend, N. R. Pettigrew, T. C. Loder, M. W. Wong, D. Kistner-Morris, A. K. Laursen, A. D. Schoudel, C. Conairis, J. Brown, and C. Newell. 1996. The Kennebec, Sheepscot and Damariscotta River estuaries: Seasonal oceanographic data. University of Maine, Department of Oceanography Technical Report No. 9601. Orono, Maine.

  • McClelland, J. W., I. Valiela, andR. H. Michener. 1997. Nitrogen-stable isotope signatures in estuarine food webs: A record of increasing urbanization in coastal watersheds.Limnology and Oceanography 42:930–937.

    Article  CAS  Google Scholar 

  • Michener, R. H. andD. M. Schell. 1994. Stable isotope ratios as tracers in marine aquatic food webs, p. 138–157.In K. Lajtha and R. H. Michener (eds.), Stable Isotopes in Ecology and Environmental Science. Blackwell Scientific Publications, Oxford.

    Google Scholar 

  • Minagawa, M. andE. Wada. 1984. Stepwise enrichment of15N along food chains: Further evidence and the relation between δ15N and age.Geochimica et Cosmochimica Acta 48:1135–1140.

    Article  CAS  Google Scholar 

  • Montoya, J. P., S. G. Horrigan, andJ. J. McCarthy. 1990. Natural abundance of15N in particulate nitrogen and zooplankton in the Chesapeake Bay.Marine Ecology Progress Series 65: 35–61.

    Article  CAS  Google Scholar 

  • Mook, W. G. 1970. Stable carbon and oxygen isotopes of natural waters in the Netherlands, p. 163–190.In Isotope Hydrology, 1970, Proceedings of International Atomic Energy Agency and United Nations Educational, Scientific, and Cultural Organization, Vienna, March 9–13, 1970. International Atomic Energy Agency STI/PUB/255, Vienna.

  • Nixon, S. W. 1997. Prehistoric nutrient inputs and productivity in Narragansett Bay.Estuaries 20:253–261.

    Article  CAS  Google Scholar 

  • Peters, K. E., R. E. Sweeney, andI. R. Kaplan. 1978. Correlation of carbon and nitrogen stable isotope ratios in sedimentary organic matter.Limnology and Oceanography 23:598–604.

    Article  CAS  Google Scholar 

  • Peterson, B. J. 1999. Stable isotopes as tracers of organic matter input and transfer in benthic food webs: A review.Oceanologia Acta 20:479–487.

    Article  Google Scholar 

  • Peterson, B. J., R. Howarth, andR. Garritt. 1985. Multiple stable isotopes used to trace the flow of organic matter in estuarine food webs.Science 227:1361–1363.

    Article  CAS  Google Scholar 

  • Rees, C. E., W. J. Jenkins, andJ. Monster. 1978. The sulphur isotopic composition of ocean water sulphate.Geochimica et Cosmochimica Acta 42:377–381.

    Article  CAS  Google Scholar 

  • Richard, P., P. Riera, andR. Galois. 1997. Temporal variations in the chemical and carbon isotope compositions of marine and terrestrial organic inputs in the Bay of Marennes-Oleron, France.Journal of Coastal Research 13:879–889.

    Google Scholar 

  • Riera, P. 1998. δ15N of organic matter sources and benthic invertebrates along an estuarine gradient in Marennes-Oleron Bay (France): Implications for the study of trophic structure.Marine Ecology Progress Series 166:143–150.

    Article  Google Scholar 

  • Riera, P. andP. Richard. 1996. Isotopic determination of food sources ofCrassostrea gigas along a trophic gradient in the estuarine bay of Marennes-Oleron.Estuarine, Coastal and Shelf Science 42:347–360.

    Article  Google Scholar 

  • Riera, P. andP. Richard. 1997. Temporal variation of δ13C in particulate organic matter and oysterCrassostrea gigas in Marennes-Oleron Bay (France): Effect of freshwater inflow.Marine Ecology Progress Series 147:105–115.

    Article  Google Scholar 

  • Sackett, W. M. andW. S. Moore. 1966. Isotopic variations of dissolved inorganic carbon.Chemical Geology 1:323–328.

    Article  CAS  Google Scholar 

  • Saurer, M., I. Robertson, R. Siegwolf, andM. Leuenberger. 1998. Oxygen isotope analysis of cellulose: An interlaboratory comparison.Analytical Chemistry 70:2074–2080.

    Article  CAS  Google Scholar 

  • Schemel, L. E. andS. W. Hager. 1986. Chemical variability in the Sacramento River and in Northern San Francisco Bay.Estuaries 9:270–283.

    Article  CAS  Google Scholar 

  • Sklar, F. H. andJ. A. Browder. 1998. Coastal environmental impacts brought about by alterations to freshwater flow in the Gulf of Mexico.Environmental Management 22:547–562.

    Article  Google Scholar 

  • Smith, B. N. andS. Epstein. 1970. Biogeochemistry of the stable isotopes of hydrogen and carbon in salt marsh biota.Plant Physiology 46:738–742.

    CAS  Google Scholar 

  • Spiker, E. C. 1980. The behavior of14C and13C in estuarine water: Effects of in situ CO2 production and atmospheric exchange.Radiocarbon 22:647–654.

    CAS  Google Scholar 

  • Spiker, E. C. andL. E. Schemel. 1979. Distribution and stableisotope composition of carbon in San Francisco Bay. p. 119–126.In T. J. Conomos (ed.) The Urbanized Estuary: San Francisco. American Association for the Advancement of Science, Washington, D.C.

    Google Scholar 

  • Taylor, Jr.,H. P. 1974. The application of oxygen and hydrogen isotope studies to problems of hydrothermal alterations and ore deposition.Economic Geology 69:843–882.

    Article  CAS  Google Scholar 

  • Thorrold, S. R., C. M. Jones, P. K. Swart, andT. E. Targett. 1998. Accurate classification of juvenile weakfishCynoscion regalis to estuarine nursery areas based on chemical signatures in otoliths.Marine Ecology Progress Series 173:253–265.

    Article  CAS  Google Scholar 

  • Trust, B. A. andB. Fry. 1992. Stable sulphur isotopes in plants: A review.Plant, Cell and Environment 15:1105–1110.

    Article  CAS  Google Scholar 

  • Turner, R. E., N. Qureshi, N. N. Rabalais, Q. Dortch, D. Justic, R. F. Shaw, andJ. Cope. 1998. Fluctuating silicate: nitrate ratios and coastal plankton foods webs.Proceedings of the National Academy of Sciences 95:13048–13051.

    Article  CAS  Google Scholar 

  • Voss, M. andU. Struck. 1997. Stable nitrogen and carbon isotopes as indicator of eutrophication of the Oder river (Baltic sea).Marine Chemistry 59:35–49.

    Article  CAS  Google Scholar 

  • Wassenaar, L. I. andK. A. Hobson. 2000. Improved method for determining the stable-hydrogen isotopic composition (δD) of complex organic materials of environmental interest.Environmental Science and Technology 34:2354–2360.

    Article  CAS  Google Scholar 

  • Whitfield, A. andH. Marais. 1999. The ichthyofauna, p. 209–234.In B. R. Allanson and D. Baird (eds.) Estuaries of South Africa. Cambridge University Press, Cambridge, UK.

    Google Scholar 

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  • Richard, P. personal communication. Centre de Recherche en Ecologie Marine et Aquaculture de LésHoumeau, UMRIO, CNRS-IFREMER, B.P. 5, 17137 L’Houmeau, France.

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Fry, B. Conservative mixing of stable isotopes across estuarine salinity gradients: A conceptual framework for monitoring watershed influences on downstream fisheries production. Estuaries 25, 264–271 (2002). https://doi.org/10.1007/BF02691313

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