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Prerequisites for the development of mass balance models of the biogeochemical cycle of mercury in the Mediterranean Sea
1008
C. Chemical Oceanography
showed that trace element distribution is controlled by depth and volcanism-related sedimentary facies and by authigenic precipitation related to chemical or biochemical processes. Migration and concentration patterns for individual elements are described. Second Inst. of Oceanogr., Natl. Bur. of Oceanogr., Hangzhou, People's Republic of China. (gsb) 86:6881 Li, Pengcheng, Wuying Han and Xineng Huang, 1985. Distribution of iron in the seawater of the northeastern South China Sea. Tropic Oceanol., 4(4):77-82. (In Chinese, English abstract.) South China Sea Inst. of Oceanol., Acad. Sin., People's Republic of China. 86:6882 Liebezeit, Gerd, 1986. Pelagic and benthic sources of sedimentary carbohydrates in a shallow-water environment, Kiel Bight, Baltic. Mar. Geol., 71(3-4):201-213.
The carbohydrate fraction of two cores taken at 25 and 28 m water depth and spanning approximately the last 200 years was analyzed for its constituent monomers. Grain-size fractionation of the 25 m core indicated a close association of carbohydrates with the ( 6 3 /~m fraction. From the carbohydrate composition, the presence of macroalgal sugars is evident. Calculation of contributions from benthic sources results in a value of 73%. Geol.-Palaontol. Inst., Bundesstrasse 55, D-2000, Hamburg 13, FRG. 86:6883 Osman, M.M., 1985. Prerequisites for the development of mass balance models of the biogeochemical cycle of mercury in the Mediterranean Sea. CENTRO, 1(2):21-34. Oceanogr. Dept., Alexandria Univ., Moharam Bey, Alexandria, Egypt. 8@6884 Patching, J.W., R.C.T. Raine, P.R.O. Barnett and J. Watson, 1986. Abyssal benthic oxygen consumption in the northeastern Atlantic: measurements using the suspended core technique. Oceanologica Acta, 9(1): 1-7.
A multiple corer method was used for measurement of in-situ sediment community oxygen uptake at depths of 4980 m in the Porcupine Abyssal Plain (mean uptake 67 #moles 02 m -2 hr -~ and 2880 m in the Rockall Trough (mean uptake 149 pmoles 02 m 2 hr-I). Experimental values were higher than those predicted from previous data. Dept. of Microbiol., Sch. of Mar. Sci., Univ. Coll., Galway, Ireland. (gsb)
OLR (1986) 33 (12)
86:6885 Prasada Rao, C., 1986. Geochemistry of temperatewater carhonates, Tasmania, Australia. Mar. Geol., 71(3-4):363-370.
Temperate shelf sediments off Tasmania are characterized by high CaCO 3 contents. Low concentrations of Mg ((2.7%) indicate ambient water temperatures ( 1 1 °C. Temperate shallow-water carbonates are low in Sr (due to the preponderance of calcitic fauna and calcite cement) and high in Na, Mn and Fe. High Na is mainly due to biochemical fractionation and some aragonite content. High concentrations of Mn and Fe are also due to the dominantly calcitic mineralogy of skeletal components and marine cements. Dept. of Geol., Univ. of Tasmania, Hobart, Tas. 7001, Australia. 86:6886 Sundby, Bjorn, L.G. Anderson, P.O.J. Hall, Ake Iverfeldt, M.M. Rutgers van der Loeff and S.F.G. Westerlund, 1986. The effect of oxygen on release and uptake of cobalt, manganese, iron and phosphate at the sediment-water interface. Geochim. cosmochim. Acta, 50(6): 1281-1288.
Porewater of a sediment core taken at 6 m depth was enriched in Fe, Mn, Co, and phosphate compared to the overlying bottom water. Yet, in-situ measurements with a benthic flux-chamber, in which dissolved oxygen and pH were maintained near ambient values (regulated flux-chamber), showed that the sediment did not release any of these ions but instead removed Co, Mn, and Fe from the overlying water. In a parallel experiment, where dissolved oxygen and pH were not maintained but allowed to decrease as a result of benthic respiration, Co, Mn, Fe, and e o 4 w e r e released from the sediment. An accidental interruption of the stirring in the regulated chamber caused a pulse of dissolved Co, Mn, Fe, and e o 4 to be released from the sediment. When the stirring was resumed, all four ions were again removed. The critical variable which controls the reactions at the sediment-water interface is the flux of oxygen from the water column into the sediment. Netherlands Inst. for Sea Res., P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands. 8@6887 Westerlund, S.F.G., L.G. Anderson, P.O.J. Hall, Ake Iverfeldt, M.M. Rutgers van der Loeff and Bjorn Sundby, 1986. Benthic fluxes of cadmium, copper, nickel, zinc and lead in the coastal environment. Geochim. cosmochim. Acta, 50(6): 12891296.
Fluxes of trace metals across the sediment-water interface were measured in-situ at 6 m depth in
C. Chemical Oceanography
showed that trace element distribution is controlled by depth and volcanism-related sedimentary facies and by authigenic precipitation related to chemical or biochemical processes. Migration and concentration patterns for individual elements are described. Second Inst. of Oceanogr., Natl. Bur. of Oceanogr., Hangzhou, People's Republic of China. (gsb) 86:6881 Li, Pengcheng, Wuying Han and Xineng Huang, 1985. Distribution of iron in the seawater of the northeastern South China Sea. Tropic Oceanol., 4(4):77-82. (In Chinese, English abstract.) South China Sea Inst. of Oceanol., Acad. Sin., People's Republic of China. 86:6882 Liebezeit, Gerd, 1986. Pelagic and benthic sources of sedimentary carbohydrates in a shallow-water environment, Kiel Bight, Baltic. Mar. Geol., 71(3-4):201-213.
The carbohydrate fraction of two cores taken at 25 and 28 m water depth and spanning approximately the last 200 years was analyzed for its constituent monomers. Grain-size fractionation of the 25 m core indicated a close association of carbohydrates with the ( 6 3 /~m fraction. From the carbohydrate composition, the presence of macroalgal sugars is evident. Calculation of contributions from benthic sources results in a value of 73%. Geol.-Palaontol. Inst., Bundesstrasse 55, D-2000, Hamburg 13, FRG. 86:6883 Osman, M.M., 1985. Prerequisites for the development of mass balance models of the biogeochemical cycle of mercury in the Mediterranean Sea. CENTRO, 1(2):21-34. Oceanogr. Dept., Alexandria Univ., Moharam Bey, Alexandria, Egypt. 8@6884 Patching, J.W., R.C.T. Raine, P.R.O. Barnett and J. Watson, 1986. Abyssal benthic oxygen consumption in the northeastern Atlantic: measurements using the suspended core technique. Oceanologica Acta, 9(1): 1-7.
A multiple corer method was used for measurement of in-situ sediment community oxygen uptake at depths of 4980 m in the Porcupine Abyssal Plain (mean uptake 67 #moles 02 m -2 hr -~ and 2880 m in the Rockall Trough (mean uptake 149 pmoles 02 m 2 hr-I). Experimental values were higher than those predicted from previous data. Dept. of Microbiol., Sch. of Mar. Sci., Univ. Coll., Galway, Ireland. (gsb)
OLR (1986) 33 (12)
86:6885 Prasada Rao, C., 1986. Geochemistry of temperatewater carhonates, Tasmania, Australia. Mar. Geol., 71(3-4):363-370.
Temperate shelf sediments off Tasmania are characterized by high CaCO 3 contents. Low concentrations of Mg ((2.7%) indicate ambient water temperatures ( 1 1 °C. Temperate shallow-water carbonates are low in Sr (due to the preponderance of calcitic fauna and calcite cement) and high in Na, Mn and Fe. High Na is mainly due to biochemical fractionation and some aragonite content. High concentrations of Mn and Fe are also due to the dominantly calcitic mineralogy of skeletal components and marine cements. Dept. of Geol., Univ. of Tasmania, Hobart, Tas. 7001, Australia. 86:6886 Sundby, Bjorn, L.G. Anderson, P.O.J. Hall, Ake Iverfeldt, M.M. Rutgers van der Loeff and S.F.G. Westerlund, 1986. The effect of oxygen on release and uptake of cobalt, manganese, iron and phosphate at the sediment-water interface. Geochim. cosmochim. Acta, 50(6): 1281-1288.
Porewater of a sediment core taken at 6 m depth was enriched in Fe, Mn, Co, and phosphate compared to the overlying bottom water. Yet, in-situ measurements with a benthic flux-chamber, in which dissolved oxygen and pH were maintained near ambient values (regulated flux-chamber), showed that the sediment did not release any of these ions but instead removed Co, Mn, and Fe from the overlying water. In a parallel experiment, where dissolved oxygen and pH were not maintained but allowed to decrease as a result of benthic respiration, Co, Mn, Fe, and e o 4 w e r e released from the sediment. An accidental interruption of the stirring in the regulated chamber caused a pulse of dissolved Co, Mn, Fe, and e o 4 to be released from the sediment. When the stirring was resumed, all four ions were again removed. The critical variable which controls the reactions at the sediment-water interface is the flux of oxygen from the water column into the sediment. Netherlands Inst. for Sea Res., P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands. 8@6887 Westerlund, S.F.G., L.G. Anderson, P.O.J. Hall, Ake Iverfeldt, M.M. Rutgers van der Loeff and Bjorn Sundby, 1986. Benthic fluxes of cadmium, copper, nickel, zinc and lead in the coastal environment. Geochim. cosmochim. Acta, 50(6): 12891296.
Fluxes of trace metals across the sediment-water interface were measured in-situ at 6 m depth in