In the South Equatorial Current subregion, the seasonal variability in Ωar is also driven by greater changes in TCO2 relative to TA. Seasonal shifts
in net biological production and vertical mixing did not appear to drive the Ωar seasonality for the SEC. Net evaporation changes did alter TCO2 and TA, but the changes in both parameters were similar with little influence on Ωar. Here, changes in the transport of waters higher in TCO2 relative to TA from the Eastern Pacific may provide a means to drive the seasonal variability in Ωar. This study shows the seasonal variability in aragonite saturation state is small through most of the Pacific study region. The results do imply that many reefs in the region do not strongly influence the seasonality in Ωar of the open ocean, but large variability at reef scales does occur (Yates and Halley, 2006, selleck chemicals Hofmann et al., 2011, Shaw et al., 2012 and Kelly and Hofmann, 2013). Therefore, coastal and island scale studies are necessary to understand and quantify the impact of ocean acidification on the reef
ecosystems of the region. The research discussed in this paper was conducted with funding from the Pacific Climate Change Science Program to B. T. and the Pacific Climate Change Science and Adaptation Program to A. L. These programs were supported by AusAID, in collaboration with the Department of Climate Change and Energy Efficiency, and delivered High Content Screening by the Bureau of Meteorology and the Commonwealth Scientific and Industrial Research Organisation. Ceramide glucosyltransferase We are grateful to Richard Matear and Bénédicte Pasquer for providing comments on earlier drafts. “
“Ikaite (CaCO3·6H2O) is a metastable phase of calcium carbonate, which normally forms in a cold environment and/or under high pressure (Marland, 1975). It is usually found in environments characterized
by low temperatures (below 4 °C), high pH, high alkalinity, elevated concentrations of phosphate (PO4) and organic matter (Buchardt et al., 1997 and Rickaby et al., 2006). Although synthetic CaCO3·6H2O had already been known from laboratory studies in the nineteenth century (Pelouze, 1865), it was first found in nature at the bottom of the Ika Fjord in Greenland (Pauly, 1963) and later in deep-sea sediments (Suess et al., 1982). Recently, Dieckmann et al., 2008 and Dieckmann et al., 2010 discovered this mineral in sea ice, which at the same time, was the first direct evidence of CaCO3 precipitation in natural sea ice. The occurrence of CaCO3 is considered to play a significant role in the CO2 flux of the sea ice system (Geilfus et al., 2012 and Rysgaard et al., 2007). At present it is not clear whether ikaite is the only calcium carbonate phase formed in sea ice (Dieckmann et al., 2010 and Rysgaard et al., 2012).