Abstract
In sediments with oxidized surface layers, the percentage of mineralized nitrogen that is nitrified/denitrified, compared with that released directly as ammonium, appears to be affected by the presence of sea salts. In estuarine systems, a significant portion of the nitrogen is released as ammonium, whereas in freshwater systems, most of the mineralized nitrogen is often released from the sediments as nitrogen gas. We hypothesized that this discrepancy is caused by differential competition between physical diffusion and nitrification/denitrification in the two systems. The vertical migration (by Fickian diffusion) of ammonium out of the oxic layer may be hindered by cation exchange (or sorption) interactions with sediment particles to a greater extent in fresh water than in estuarine systems. The resulting relatively long residence time, and potentially high levels of particle-bound ammonium in the freshwater sediments, would favor nitrification as the major ammonium removal process. By contrast, ion pair formation of ammonium with seawater anions and blockage of sediment cation exchange sites with seawater cations may allow a sizable fraction of the ammonium to diffuse out of estuarine sediments before it is nitrified. A salt effect, consistent with this hypothesis, has been demonstrated in experimental systems by changing the ionic composition of water flowing above intact cores of freshwater and estuarine sediments. Steady-state ammonium release from Lake Michigan sediments was substantially enhanced in the presence of 30% seawater over that in the presence of lake water alone. Likewise, steady-state ammonium release, from Ochlockonee River and Bay sediments (Florida) and from Toms River and Barnegat Bay sediments (New Jersey), was usually higher in the presence of diluted synthetic seawater than it was in the presence of fresh water.
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Literature Cited
Berner, R. A. 1980. Early Diagenesis: A Theoretical Approach. Princeton University Press. Princeton, New Jersey, 250 p.
Boatman, C. D. andJ. W. Murray. 1982. Modeling exchangeable NH4+ adsorption in marine sediments: Process and controls of adsorption.Limnology and Oceanography 27:99–110.
Blackburn, T. andK. Henriksen. 1983. Nitrogen cycling in different types of sediments from Danish waters.Limnology and Oceanography 28:477–493.
Capone, D. G. andR. P. Kiene. 1988. Comparison of microbial dynamics in marine and freshwater sediments: Contrasts in anaerobic carbon metabolism.Limnology and Oceanography 33:725–749.
Cole, J. J., S. Finlay andM. L. Pace. 1988. Bacterial production in fresh and saltwater ecosystems: A cross-system overview.Marine Ecology Progress Series 43:1–10.
Fitzgerald, S. A. 1989. The biogeochemistry of amino acids in sediments from the Great Lakes. Ph.D. Dissertation, University of Wisconsin-Milwaukeee, Milwaukee.
Gardner, W. S. 1978. Microfluorometric method to measure ammonium in natural waters.Limnology and Oceanography 23: 1069–1072.
Gardner, W. S. andJ. M. Malczyk. 1983. Discrete injection segmented flow analysis of nutrients in small volume water samples.Analytical Chemistry 55:1645–1647.
Gardner, W. S., T. F. Nalepa, andJ. M. Malczyk. 1987. Nitrogen mineralization and denitrification in Lake Michigan sediments.Limnology and Oceanography 32:1226–1238.
Henriksen, K. andW. M. Kemp. 1988. Nitrification in estuarine and coastal marine sediments: Methods, patterns and regulating factors, p. 207–250.In J. Sorensen, T. H. Blackburn, and T. Rosswall (eds.), Nitrogen Cycling in Coastal Marine Environments. Proceedings SCOPE Symposium 33. Wiley-Interscience, New York.
Hobbie, J. E. 1988. A comparison of the ecology of planktonic bacteria in fresh and salt water.Limnology and Oceanography 33:750–764.
Jenkins, M. C. andW. M. Kemp. 1984. The coupling of nitrification and denitrification in two estuarine sediments.Limnology and Oceanography 29:609–619.
Lehman, J. T. 1980. Release and cycling of nutrients between planktonic algae and herbivores.Limnology and Oceanography 25:620–632.
Mantoura, R. F. C. andC. A. Llewellyn. 1983. The rapid determination of algal chlorophyll and carotenoid pigments and their breakdown products in natural waters by reversephase high-performance liquid chromatography.Analica Chimica Acta 151:297–314.
Nishio, T., I. Koike andA. Hattori. 1983. Estimates of denitrification and nitrification in coastal and estuarine sediments.Applied and Environmental Microbiology 45:444–450.
Nixon, S. W. 1981. Remineralization and nutrient cycling in coastal marine ecosystems, p. 111–138.In B. J. Neilson and L. E. Cronin (eds.), Estuaries and Nutrients. The Humana Press, Clifton, New Jersey.
Nowicki, B. L. andS. W. Nixon. 1985. Benthic nutrient remineralization in a coastal lagoon ecosystem. Estuaries 8:182–190.
Parsons, T. R., Y. Maita, andC. M. Lalli. 1984. A Manual of Chemical and Biological Methods for Seawater Analysis. Pergamon Press, New York. 173 p.
Pilson, M. E. Q. 1985. Annual cycles of nutrients and chlorophyll in Naragansett Bay, Rhode Island.Journal of Marine Research 43:849–873.
Riley, J. P. andG. Skirrow. 1965. Chemical Oceanography, Vol. 1. Academic Press, New York. 712 p.
Rosenfeld, J. K. 1979. Ammonium adsorption in nearshore anoxic sediments.Limnology and Oceanography 24:356–364.
Ryther, J. H. andW. M. Dunstan. 1971. Nitrogen, phosphorus and eutrophication in the coastal marine environment.Science 171:1008–1013.
Seitzinger, S. P. 1987. Nitrogen biogeochemistry in an unpolluted estuary: The importance of benthic denitrification.Marine Ecology Progress Series 41:177–186.
Seitzinger, S. P. 1988. Denitrification in freshwater and coastal marine ecosystems: Ecological and geochemical significance.Limnology and Oceanography 33:702–724.
Seitzinger, S. P., S. W. Nixon, andM. E. Q. Pilson. 1984. Denitrification and nitrous oxide production in a coastal marine ecosystem.Limnology and Oceanography 29:73–83.
Seitzinger, S. P., W. S. Gardner andA. K. Spratt. 1991. The effect of salinity on ammonium sorption in aquatic sediments: Implications for benthic nutrient recycling.Estuaries 14:167–174.
Synder, L. R. andJ. J. Kirkland. 1979. Introduction to Modern Liquid Chromatography. Second Edition, Wiley, New York. 863 p.
Ulman, W. J. andR. C. Aller. 1989. Nutrient release rates from the sediments of Saginaw Bay, Lake Huron.Hydrobiologia 171:127–140.
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Great Lakes Environmental Research Laboratory Contribution No. 684.
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Gardner, W.S., Seitzinger, S.P. & Malczyk, J.M. The effects of sea salts on the forms of nitrogen released from estuarine and freshwater sediments: Does ion pairing affect ammonium flux?. Estuaries 14, 157–166 (1991). https://doi.org/10.2307/1351689
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DOI: https://doi.org/10.2307/1351689