Bicarbonate marine

PBD Standard Atmospheric CO2 Marine Bicarbonate Marine Plants Marine Animals Aquatic Bicarbonate Aquatic Plants Aquatic Animals C3 Rants C4 Plants CAM Plants Terrestrial Animals... 

The products of chemical weathering, Ca, H4Si04, and 2HCOj, are transported by river runoff into the ocean, where they are then available to be returned to biogenic form by marine plankton. (Marine plankton have an enzyme, carbonic anhydrase, that converts bicarbonate to CO2.)... 

Carbonate sediments deposited in shallow marine environments are often exposed to the influence of meteoric waters during their diagenetic history. Meteoric diagenesis lowers 8 0- and 8 C-values, because meteoric waters have lower 8 0-values than sea water. For example. Hays and Grossman (1991) demonstrated that oxygen isotope compositions of carbonate cements depend on the magnitude of depletion of respective meteoric waters. 5 C-values are lowered because soil bicarbonate is C-depleted relative to ocean water bicarbonate. 

Jensen, H.S., and Thamdrup, B. (1993) Iron-bound phosphorus in marine sediments as measured by bicarbonate-dithionite extraction. Hydrobiologia 252, 47-59. 

Fractionation and Contamination. The ratio 14C/12C in certain materials may be affected by isotopic fractionation. For example, the uptake of carbon dioxide and its incorporation into plant tissue may be accompanied by substantial fractionation that depends on the plant species. With marine organisms, fractionation may also be important, especially when inorganic carbonate and bicarbonate are involved. Corrections for fractionation must be made for precise radiocarbon dating. 

The rate of C-bicarbonate incorporation into protein has also been used to estimate rates of phytoplankton N-assimilation (DiTuUio and Laws, 1983). This method, applicable to aU N-Umited marine ecosystems, builds on the observation that the C N ratio in protein is remarkably constant and that, under N limitation, a fairly constant percentage (85%) of phytoplankton N is incorporated into protein, with little or no N storage (DiTuUio and Laws, 1983). AppUcation of the method involves an incubation with " C-HCOa foUowed by extraction and isolation of the C-labeled protein fraction. From measurement of the ratio of the total... 

Wuchter, C., Schouten, S., Boschker, H. T., and Sinninghe Damste, J. S. (2003). Bicarbonate uptake by marine Crenarchaeota. FEMS Microbiol. Lett. 219, 203—207. 

Pahnska, K. A., Laloui, W., Bedu, S., Loiseaux-de Goer, S., Castets, A. M., Rippka, R., and Tandeau de Marsac, N. (2002). The signal transducer Pn and bicarbonate acquisition in Prochlorocoaus marinus PCC 9511, a marine cyanobacterium naturally deficient in nitrate and nitrite assimilation. Microbiology. 148, 2405-2412. 

Nimer N. A., Iglesias-Rodriguez M. D., and Merrett M. J. (1997) Bicarbonate utilization by marine phytoplankton species. J. Phycol. 33, 625—631. 

Crill P. M. and Martens C. S. (1986) Methane production from bicarbonate and acetate in an anoxic marine sediment. Geochim. Cosmochim. Acta 50, 2089-2097. 

Mechanisms of calcium carbonate deposition. The carbonate of shell has its origin in the bicarbonate of the medium (Hammen and Wilbur, 1959), metabolic CO2 (Campbell and Speeg, 1969), or in some cases from calcium carbonate spherules present in the tissues (Watabe et al., 1976). In marine bivalves, bicarbonate probably comes chiefly from the medium (Wheeler et al., 1975). The principal source of shell calcium is the medium with tissue spherules providing a secondary supply. The CaCOs of molluscs is thought to be deposited in isotopic equilibrium with the medium (Milliman, 1974). However, discrimination in favour of C and 0 has been observed (Keith et al., 1964 Tourtelot and Rye, 1969), and this discrimination may be different in aragonitic and calcitic layers. 

There is a bicarbonate imbalance between weathering and marine CaCOs precipitation of 3.4 - 2.4 x 10 = 1.0 x 10 eq (Note that eq and mol are interchangeable for HCO3 because it is singly charged.)... 

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