Abstract
The aim of this study was to elucidate the relative importance of physical versus biological loss processes for the removal of microphytobenthic (MPB) bound nitrogen in a coastal environment at different times of the year via a dual isotope labeling technique. We used 51Cr, binding to inorganic sediment particles but not participating in any biological processes, and 15N–NO3 −, taken up by the MPB and turned over as part of the MPB nitrogen pool. Retention, down-mixing, and export of 15N were due to both biological and physical processes, so that by comparing retention of the two isotopes, we were able to discern the relative importance of physical and biological processes. The isotope marking was supplemented with measurements of sediment chlorophyll biomass and oxygen fluxes, allowing us to evaluate MPB biomass as well as primary production vs. respiration in the sediment. In spring/early summer, the system was characterized by tight N cycling and high N retention: any remineralized N was immediately taken up and retained in the MPB biomass. In late summer and autumn, the system was still physically stable, but high biological mediated N losses were observed. In early winter, the system was physically dominated due to low MPB biomasses and activity combined with a significant storm event. Our data support the hypothesis that the relative balance between physical and biological processes in determining retention and removal of MPB-bound nitrogen changes seasonally.
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An, S., and S.B. Joye. 2001. Enhancement of coupled nitrification-denitrification by benthic photosynthesis in shallow estuarine sediments. Limnology and Oceanography 46: 62–74.
Barranguet, C., J. Kromkamp, and J. Peene. 1998. Factors controlling primary production and photosynthetic characteristics of intertidal microphytobenthos. Marine Ecology Progress Series 173: 117–126.
Bryan, J.R., J.P. Riley, and P.J.L. Williams. 1976. Winkler procedure for making precise measurements of oxygen concentration for productivity and related studies. Journal of Experimental Marine Biology and Ecology 21: 191–197.
Cahoon, L.B., and J.E. Cooke. 1992. Benthic microalgal production in Onslow Bay, North Carolina, USA. Marine Ecology Progress Series 84: 185–196.
Calow, P., and C.R. Fletcher. 1972. A new radiotracer technique involving 14C and 51Cr, for estimating the assimilation efficiencies of aquatic, primary consumers. Oecologia 9: 155–170.
Cappelen, J. 2015. Denmark—DMI historical climate data collection 1768–2014. In Technical Report 15–02. Copenhagen, Denmark: Danish Meteorological Institute.
Dalsgaard, T. 2003. Benthic primary production and nutrient cycling in sediments with benthic microalgae and transient accumulation of macroalgae. Limnology and Oceanography 48: 2138–2150.
Dodds, W.K. 2003. The role of periphyton in phosphorus retention in shallow freshwater aquatic systems. Journal of Phycology 39: 840–849.
Floder, S., A. Combuchen, A. Pasternak, and H. Hillebrand. 2006. Competition between pelagic and benthic microalgae for phosphorus and light. Aquatic Sciences 68: 425–433.
Hill, W.R., M.G. Ryon, and E.M. Schilling. 1995. Light limitation in a stream ecosystem: responses by primary producers and consumers. Ecology 76: 1297–1309.
Kendrick, G.A., S. Langtry, J. Fitzpatrick, R. Griffiths, and C.A. Jacoby. 1998. Benthic microalgae and nutrient dynamics in wave-distributed environments in Marmion lagoon, Western Australia, compared with less disturbed mesocosms. Journal of Experimental Marine Biology and Ecology 228: 83–105.
Kristensen, E., G. Penha-Lopes, M. Delefosse, T. Valdemarsen, C.O. Quintana, and G.T. Banta. 2012. What is bioturbation? The need for a precise definition for fauna in aquatic sciences. Marine Ecology Progress Series 446: 285–302.
MacIntyre, H.L., R.J. Geider, and D.C. Miller. 1996. Microphytobenthos: the ecological role of the "secret garden" of unvegetated, shallow-water marine habitats. I. Distribution, abundance and primary production. Estuaries 19: 186–201.
Maire, O., P. Lecroart, F. Meysman, R. Rosenberg, J.C. Duchene, and A. Gremare. 2008. Quantification of sediment reworking rates in bioturbation research: a review. Aquatic Biology 2: 219–238.
Miles, A., and K. Sundbäck. 2000. Diel variation in microphytobenthic productivity in areas of different tidal amplitude. Marine Ecology Progress Series 205: 11–22.
Miller, D.C., R.J. Geider, and H.L. MacIntyre. 1996. Microphytobenthos: the ecological role of the "secret garden" of unvegetated, shallow water marine habitats. II. Role in sediment stability and shallow-water food webs. Estuaries 19: 202–212.
Risgaard-Petersen, N. 2003. Coupled nitrification-denitrification in autotrophic and heterotrophic estuarine sediments: on the influence of benthic microalgae. Limnology and Oceanography 48: 93–105.
Risgaard-Petersen, N., S. Rysgaard, L.P. Nielsen, and N.P. Revsbech. 1994. Diurnal variation of denitrification and nitrification in sediments colonized by benthic microphytes. Limnology and Oceanography 39: 573–579.
Rysgaard, S., P.B. Christensen, and L.P. Nielsen. 1995. Seasonal variation in nitrification and denitrification in estuarine sediment colonized by benthic microalgae and bioturbating infauna. Marine Ecology Progress Series 126: 111–121.
Sagan, G., and G. Thouzeau. 1998. Microphytobenthic biomass in the Bay of Brest and the western English Channel. Oceanologica Acta 21: 677–694.
Sandnes, J., T. Forbes, R. Hansen, and B. Sandnes. 2000. Influence of particle type and faunal activity on mixing of di(2-ethylhexyl)phthalate (DEHP) in natural sediments. Marine Ecology Progress Series 197: 151–167.
Sundbäck, K., and W. Granéli. 1988. Influence of microphytobenthos on the nutrient flux between sediment and water: a laboratory study. Marine Ecology Progress Series 43: 63–69.
Sundbäck, K., F. Linares, F. Larson, and A. Wulff. 2004. Benthic nitrogen fluxes along a depth gradient in a microtidal fjord: the role of denitrification and microphytobenthos. Limnology and Oceanography 49: 1095–1107.
Sundbäck, K., and A. Miles. 2000. Balance between denitrification and microalgal incorporation of nitrogen in microtidal sediments, NE Kattegat. Aquatic Microbial Ecology 22: 291–300.
Sundbäck, K., and A. Miles. 2002. Role of microphytobenthos and denitrification for nutrient turnover in embayments with floating macroalgal mats: a spring situation. Aquatic Microbial Ecology 30: 91–101.
Sundbäck, K., A. Miles, and E. Göransson. 2000. Nitrogen fluxes, denitrification and the role of microphytobenthos in microtidal shallow-water sediments: an annual study. Marine Ecology Progress Series 200: 59–76.
Tobias, C., A. Giblin, J. McClelland, J. Tucker, and B. Peterson. 2003. Sediment DIN fluxes and preferential recycling of benthic microalgal nitrogen in a shallow macrotidal estuary. Marine Ecology Progress Series 257: 25–36.
Underwood, G.J.C., and J. Kromkamp. 1999. Primary production by phytoplankton and microphytobenthos in estuaries. In Estuaries, ed. D.B. Nedwell and D. Raffaelli, 93–153. San Diego: Academic Press.
Widdows, J., A. Blauw, C.H.R. Heip, P.M.J. Herman, C.H. Lucas, J.J. Middelburg, S. Schmidt, M.D. Brinsley, F. Twisk, and H. Verbeek. 2004. Role of physical and biological processes in sediment dynamics of a tidal flat in Westerschelde estuary, SW Netherlands. Marine Ecology Progress Series 274: 41–56.
Widdows, J., and M.D. Brinsley. 2002. Impact of biotic and abiotic processes on sediment dynamics and the consequences to the structure and functioning of the intertidal zone. Journal of Sea Research 48: 143–156.
Ysebaert, T., M. Fettweis, P. Meire, and M. Sas. 2005. Benthic variability in intertidal soft-sediments in the mesohaline part of the Schelde estuary. Hydrobiologia 540: 197–216.
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Communicated by David Reide Corbett
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Nielsen, S.L., Risgaard-Petersen, N. & Banta, G.T. Nitrogen Retention in Coastal Marine Sediments—a Field Study of the Relative Importance of Biological and Physical Removal in a Danish Estuary. Estuaries and Coasts 40, 1276–1287 (2017). https://doi.org/10.1007/s12237-017-0216-3
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DOI: https://doi.org/10.1007/s12237-017-0216-3