Planktonic foraminiferas in bottom sediments and paleotemperatures in the areas of the Benguela and Canary upwellings

Distribution of planktonic foraminiferal tests was studied in four drill cores of Upper Quaternary sediments from the zone of influence of the Canary upwelling and in nine sediment cores from the zone of the Benguela upwelling. Paleotemperatures were reconstructed from these data. It was established that under conditions during stadials, interstadials, and interglacials of Quaternary time, the upwelling existed continuously, intensifying and expanding during colder epochs and weakening and contracting in the warmer intervals. During the last stadial (about 18000 yrs ago), relative cooling of sea waters as compared to central regions of the ocean in the zone of the Canary upwelling was not lower than 9°C (4.5°C higher than at present time), and in the zone of the Benguela upwelling it was not lower than 15°C (8.5°C higher than at present time).

Composition of organic matter in suspended matter and bottom sediments of the southeastern Baltic Sea

Data on contents and compositions of hydrocarbons (HCs)-aliphatic (AHCs) and polycyclic aromatic (PAHs) are provided in comparison with contents of total organic carbon (Corg), lipids in suspended matter, and Corg in bottom sediments. Particular attention is paid to distribution of HCs in the area of the Kravtsov oil field. It is established that concentrations of AHCs in water are governed by concentrations of suspended matter and elevated AHC concentrations are confined to coastal areas. In the area of D-6 platform sandy bottom sediments are notable for great variability of HC concentrations, both laterally and from year to year. In summer of 2010 average content of AHCs was 40 ppm (19% of Corg) and that of PAHs was 0.023 ppm. Natural seepage from sediment mass is considered to be a source of HCs along with oil contamination.

Calcium isotope fractionation in cultured, modern and fossil scleractinian coral skeleton

The present study investigates the influence of environmental (temperature, salinity) and biological (growth rate, inter-generic variations) parameters on calcium isotope fractionation (d44/40Ca) in scleractinian coral skeleton to better constrain this record. Previous studies focused on the d44/40Ca record in different marine organisms to reconstruct seawater composition or temperature, but only few studies investigated corals. This study presents measurements performed on modern corals from natural environments (from the Maldives for modern and from Tahiti for fossil corals) as well as from laboratory cultures (Centre Scientifique de Monaco). Measurements on Porites sp., Acropora sp., Montipora verrucosa and Stylophora pistillata allow constraining inter-generic variability. Our results show that the fractionation of d44/40Ca ranges from 0.6 to 0.1 per mil, independent of the genus or the environmental conditions. No significant relationship between the rate of calcification and d44/40Ca was found. The weak temperature dependence reported in earlier studies is most probably not the only parameter that is responsible for the fractionation. Indeed, sub-seasonal temperature variations reconstructed by d18O and Sr/Ca ratio using a multi-proxy approach, are not mirrored in the coral's d44/40Ca variations. The intergeneric variability and intrageneric variability among the studied samples are weak except for S. pistillata, which shows calcium isotopic values increasing with salinity. The variability between samples cultured at a salinity of 40 is higher than those cultured at a salinity of 36 for this species. The present study reveals a strong biological control of the skeletal calcium isotope composition by the polyp and a weak influence of environmental factors, specifically temperature and salinity (except for S. pistillata). Vital effects have to be investigated in situ to better constrain their influence on the calcium isotopic signal. If vital effects could be extracted from the isotopic signal, the calcium isotopic composition of coral skeletons could provide reliable information on the calcium composition and budget in ocean.

Major ion concentrations in rain water and atmospheric moisture above the Atlantic Ocean

Concentratios of Cl-, Mg2+, Ca2+, and HCO3- ions were studied in rain waters and condensed atmospheric moisture above the Atlantic Ocean. Maximal number of samples was collected in the eastern tropical North Atlantic. Concentration of chloride ions ranged from 1 to 28 mg/l in rain waters (average 4.3 mg/l) and ranged from 0.3 to 2 mg/l in condensed atmospheric moisture with the average about one order of magnitude less than that for rain waters. Chloride normalized concentrations of magnesium and calcium are greater in rain waters and condensed atmospheric moisture than in ocean water due to more intensive subtraction of these ions as compared to chloride ions. Chloride normalized HCO3- concentration is one order of magnitude greater in atmospheric moisture than in seawater, possibly because of volatile component CO2 taking part in exchange between the ocean and the atmosphere.

Sulfur in bottom sediments and intersitial waters of the Gulf of California

The book is devoted to study of diagenetic changes of organic matter and mineral part of sediments and interstitial waters of the Pacific Ocean due to physical-chemical and microbiological processes. Microbiological studies deal with different groups of bacteria. Regularities of quantitative distribution and the role of microorganisms in geochemical processes are under consideration. Geochemical studies highlight redox processes of the early stages of sediment diagenesis, alterations of interstitial waters, regularities of variations in chemical composition of iron-manganese nodules.

Suspended matter in waters of the Kem' River estuary (white Sea) and its composition in July-August 2003 and 2002

On the base of detailed studies in the Keret' and Kem' estuaries (Karelian coast of the White Sea) in 2000-2003 a comparative analysis has been carried out. It includes: salinity and freshening of the water column, variations of suspended matter concentration and its chemical composition, current velocity and zooplankton species composition during flood- and ebb tides.

(Table 1) Hepatic EROD activity and and retinoid concentrations in the liver, and plasma thyroid hormones of northern fulmars (Fulmarus glacialis) from Bjørnøya

We investigated whether the hepatic cytochrome P450 1A activity (measured as 7-ethoxyresorufin-O-deethylase (EROD)) and plasma thyroid hormone and liver retinoid concentrations were explained by liver and blood levels of halogenated organic contaminants (HOCs) in free-ranging breeding northern fulmars (Fulmarus glacialis) from Bjornoya in the Norwegian Arctic. Hepatic EROD activity and liver levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) were positively correlated, suggesting that hepatic EROD activity is a good indicator for dioxin and dioxin-like HOC exposure in breeding northern fulmars. There were not found other strong relationships between HOC concentrations and hepatic EROD activity, plasma thyroid or liver retinoid concentrations in the breeding northern fulmars. It is suggested that the HOC levels found in the breeding northern fulmars sampled on Bjornoya were too low to affect plasma concentrations of thyroid hormones and liver levels of retinol and retinyl palmitate, and that hepatic EROD activity is a poor indicator of polychlorinated biphenyl (PCB) and pesticide exposure.