Plankton abundance and feeding characteristics of Thysanoessa raschii from Godthabsfjord, Greenland

Despite being a key zooplankton group, knowledge on krill biology from the Arctic is inadequate. The present study examine the functional biology and evaluate the trophic role of krill in the Godthabsfjord (64°N, 51°W) SW Greenland, through a combination of fieldwork and laboratory experiments. Krill biomass was highest in the middle fjord and inner fjord, whereas no krill was found offshore. The dominating species Thysanoessa raschii revealed a type III functional response when fed with the diatom Thalassiosira weissflogii. At food saturation, T. raschii exhibited a daily ration of 1% body C/d. Furthermore, T. raschii was capable of exploiting plankton cells from 5 to 400 µm, covering several trophic levels of the pelagic food web. The calculated grazing impact by T. raschii on the fjord plankton community was negligible. However, the schooling and migratory behaviour of krill will concentrate and elevate the grazing in specific areas of the euphotic zone.

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 rocks, minerals, water, and gases from uplift areas of the Central Atlantic

Original geological, geophysical, lithological, mineralogical data on uplifts of the Central Atlantic are given in the book based on materials of Cruise 1 of the R/V Akademik Nikolaj Strakhov. Geological and geophysical studies include description of the obtained material and analysis of structural and morphological elements of the ocean floor. Results of lithological, petrochemical and geochemical studies were extremely innovative and develop a conceptual model. The latter include studies of petrochemical evolution of tholeiitic alkaline plate volcanism, large-scale hydrothermal transformation of basement rocks - palygorskitization, phosphatization and ferromanganese mineralization. Showing imposition Superposition of hydrogenic alteration on hydrothermally altered rocks and its role in Cenozoic history of sedimentation is shown.

(Table) Specific activities of 137Cs, 90Sr and 239,240Pu in surface waters obtained during cruises BP06-BP09, Indian Ocean

One of the main sources of anthropogenic radionuclides in the ocean is the global fallout resulting from the nuclear tests that had been conducted by the United States, the former Soviet Union, and other countries between 1945 and 1990 mainly in the Northern Hemisphere. The most extensive fallout was observed in the middle latitudes of the Northern Hemisphere in 1963 immediately after the nuclear tests of 1961-1962 conducted by the United States and the Soviet Union. In 2006-2009, under the auspices of an agreement between the Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences and the National Center of Antarctic and Marine Research of the Ministry of Earth Sciences of India, cooperative geological and geochemical investigations were organized in several regions of the Indian Ocean. During these expeditions, the spatial distribution of anthropogenic radionuclides was investigated in the water of the Indian Ocean. The main results of these investigations are reported in this paper.

Hydrological and hydrochemical parameters in mouth areas of rivers entering the Kandalaksha Bay in June and September 2000

Distributions of dissolved oxygen concentration, pH, and concentrations of dissolved silica, phosphates, strontium, calcium, fluorine, and boron in mouth areas of small rivers (Niva, Kolvitsa, Knyazhaya, and Keret') entering Kandalaksha Bay of the White Sea were studied. Strontium, calcium, fluorine, and boron showed conservative, silica and phosphates showed non-conservative behavior caused by their biological consumption.

Species-specific consequences of ocean acidification for the calcareous tropical green algae Halimeda, 2011

Ocean acidification (OA), resulting from increasing dissolved carbon dioxide (CO2) in surface waters, is likely to affect many marine organisms, particularly those that calcify. Recent OA studies have demonstrated negative and/or differential effects of reduced pH on growth, development, calcification and physiology, but most of these have focused on taxa other than calcareous benthic macroalgae. Here we investigate the potential effects of OA on one of the most common coral reef macroalgal genera,Halimeda. Species of Halimeda produce a large proportion of the sand in the tropics and are a major contributor to framework development on reefs because of their rapid calcium carbonate production and high turnover rates. On Palmyra Atoll in the central Pacific, we conducted a manipulative bubbling experiment to investigate the potential effects of OA on growth, calcification and photophysiology of 2 species of Halimeda. Our results suggest that Halimeda is highly susceptible to reduced pH and aragonite saturation state but the magnitude of these effects is species specific. H. opuntiasuffered net dissolution and 15% reduction in photosynthetic capacity, while H. taenicola did not calcify but did not alter photophysiology in experimental treatments. The disparate responses of these species to elevated CO2 partial -pressure (pCO2) may be due to anatomical and physiological differences and could represent a shift in their relative dominance in the face of OA. The ability for a species to exert biological control over calcification and the species specific role of the carbonate skeleton may have important implications for the potential effects of OA on ecological function in the future.