Spring molybdenum enrichment in scallop shells: a potential tracer of diatom productivity in temperate coastal environments (Brittany, NW France)
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Published:2010-01-19
Issue:1
Volume:7
Page:233-245
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ISSN:1726-4189
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Container-title:Biogeosciences
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language:en
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Short-container-title:Biogeosciences
Author:
Barats A.,Amouroux D.,Pécheyran C.,Chauvaud L.,Thébault J.,Donard O. F. X.
Abstract
Abstract. Skeletal molybdenum/calcium ([Mo]/[Ca])shell ratios were examined in shells of the Great Scallop Pecten maximus collected in temperate coastal environments of Western Europe (42 to 49° N). These ratios were determined by quantitative LA-ICP-MS analyses of daily striae taken every third day (i.e. a temporal resolution of 3 days) in 36 flat valves (2-years old; 3 shells/year). Variations of ([Mo]/[Ca])shell ratios were significant and reproducible for scallops from the same population, from different years (1998–2004) and temperate coastal locations (NW France). The [Mo]/[Ca])shell ratios exhibit typical profiles characterized by a background content, below the detection limit for this method (<0.003 μmol/mol) for most of the shell growth period, which is punctuated by a significant transient enrichment (0.031–2.1 μmol/mol) mainly occurring from May to June. The Bay of Brest (France) was investigated in particular because of its long term observations on scallop communities, environmental variables, and high resolution analyses of dissolved Mo in bottom seawater in 2000. In 2000, dissolved Mo exhibited a significant increase in concentration just preceding the maximum ([Mo]/[Ca])shell ratio. Both the intense monitoring survey in 2000 and over the 7-year period indicates that the ([Mo]/[Ca])shell maximum is directly influenced by spring changes of environmental conditions at the sediment water interface (SWI), occurring subsequent to the intense and periodic spring bloom. Spring maxima of ([Mo]/[Ca])shell ratios are closely correlated to the extent of silicic acid and nitrate depletion in seawater between winter and late spring (r2=0.878 and 0.780, p<0.05, n=6) that reflects diatom uptake and productivity in the Bay of Brest. The Mo inputs in bottom waters and subsequent shell enrichment are thus suggested to be directly or indirectly influenced by such biogenic material input at the SWI. The [Mo]/[Ca])shell records thus reveal unexpected biogeochemical cycles of Mo influenced by coastal spring productivity, faithfully recorded in scallop shells.
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Ecology, Evolution, Behavior and Systematics
Reference61 articles.
1. Adelson, J. M., Heltz, G. R., and Miller, C. V.: Reconstructing the rise of recent coastal anoxia: molybdenum in Chesapeake Bay sediments, Geochim. Cosmochim. Acta, 65, 237–252, 2001. 2. Bally, G., Mesnage, V., Deloffre, J., Clarisse, O., Lafite, R., and Dupont, J.-P.: Chemical characterization of porewaters in an intertidal mudflat of the Seine estuary: relationship to erosion–deposition cycles, Mar. Pollut. Bull., 49, 163–173, 2004. 3. Barats, A.: Micro analyse quantitative des éléments traces dans la calcite de la coquille Saint Jacques Pecten maximus par Ablation Laser et Spectrométrie de Masse à Plasma Inductif Couplé (LA-ICP-MS): une archive journalière de la biogéochimie des environnements côtiers tempérés, Laboratoire de Chimie Analytique Bio Inorganique et Environnement, Université de Pau et des Pays de l'Adour, Pau, France, 301 pp., 2006. 4. Barats, A., Pécheyran, C., Amouroux, D., Dubascoux, S., Chauvaud, L., and Donard, O. F. X.: Matrix-matched quantitative trace element analysis in calcium carbonate shells by Laser Ablation ICP-MS: application to the determination of daily scale profiles in scallop shell (Pecten maximus), Anal. Bioanal. Chem., 387, 1131–1140, 2007. 5. Barats, A., Amouroux, D., Pécheyran, C., Chauvaud, L., and Donard, O. F. X.: High-frequency archives of manganese inputs to coastal waters (Bay of Seine, France) resolved by the LA-ICP-MS analysis of calcitic growth layers along scallop shells (Pecten maximus), Environ. Sci. Technol., 42, 86–92, 2008.
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