Macrobenthos from the Novaya Zemlya Trough, Kara Sea

During Cruise 54 of R/V Akademik Mstislav Keldysh macrobenthos of the Novaya Zemlya Trough was studied with use of a Sigsby trawl along a submeridional transect near 75°30'N at depth range from 68 to 362 m. In total 140 species of bottom animals were found. Relative role of taxons was assessed using three parameters: abundance, biomass, and energy flow. Similarity of the parameters was used for comparison of samples. New material greatly contributes to data on composition of fauna and structure of communities of the studied region. It was revealed that small scyphozoid polyps and sipunculoids play an important role in the trough's community. Presence of a community dominated by Ophiocten sericeum (with important role of small bivalves) was revealed for the first time not only at the eastern by also at the western slope of the Novaya Zemlya Trough. The sharpest changes in composition and structure of the bottom community were confined to a zone of transition from the trough floor to the slope. These changes are determined by specificity of the macrorelief (of the floor and slope), composition of ground (soft brown silts abound in rhizopods and dense gray silts with admixture of pebbles), and possibly by hydrodynamic processes near the bottom.

Compilation of measurements from two interdisciplinary STAR-shaped surveys in the North Sea: The ZISCH - Dataset

The measurements were obtained during two North Sea wide STAR-shaped cruises during summer 1986 and winter 1987, which were performed to investigate the circulation induced transport and biologically induced pollutant transfer within the interdisciplinary research in the project "ZISCH - Zirkulation und Schadstoffumsatz in der Nordsee / Circulation and Contaminant Fluxes in the North Sea (1984-1989)". The inventory presents parameters measured on hydrodynamics, nutrient dynamics, ecosystem dynamics and pollutant dynamics in the pelagic and benthic realm. The research program had the objective of quantifying fluxes of major budgets, especially contaminants in the North Sea. In spring 1986, following the phytoplankton spring bloom, and in late winter 1987, at minimum primary production activity, the North Sea ecosystem was investigated on a station net covering the whole North Sea. The station net was shaped like a star. Sampling started in the centre, followed by the northwest section and moving counter clockwise around the North Sea following the residual currents. By this strategy, a time series was measured in the central North Sea and more synoptic data sets were obtained in the individual sections. Generally advection processes have to be considered when comparing the data from different stations. The entire sampling period lasted for more than six weeks in each cruise. Thus, a time-lag should be considered especially when comparing the data from the eastern and the western part of the central and northern North Sea, where samples were taken at the beginning and at the end of the campaign. The ZISCH investigations represented a qualitatively and quantitatively new approach to North Sea research in several respects. (1) The first simultaneous blanket coverage of all important biological, chemical and physical parameters in the entire North Sea ecosystem; (2) the first simultaneous measurements of major contaminants (metals and organohaline compounds) in the different ecosystem compartments; (3) simultaneous determinations of atmospheric inputs of momentum, energy and matter as important ecosystem boundary conditions; (4) performance of the complex measurement program during two seasons, namely the spring plankton bloom and the subsequent winter period of minimal biological activity; and (5) support of data analysis and interpretation by oceanographic and meteorological numerical models on the same scales.

Chemical composition of waters, suspended matter, bottom sediments, and benthic organisms along a section from the Ob River estuary (Obskaya Guba) to the central Kara Sea

Biogeochemical behavior of a group of heavy metals and metalloids in water (including their dissolved and suspended particulate forms), bottom sediments, and zoobenthos was studied in the Ob River estuary (Obskaya Guba) - Kara Sea section on the basis of data obtained during Cruise 54 of R/V Akademik Mstislav Keldysh in September-October 2007. Changes in ratios of dissolved and particulate forms of Fe, Mn, Zn, Cu, Pb, Cd, and As were shown, as well as growth of adsorbed fractions of the elements in near-bottom suspended matter under mixing of riverine and marine waters. Features of chemical element accumulation in typical benthic organisms of the Obskaya Guba and the Kara Sea were revealed, and their concentrating factors were calculated based on specific conditions of the environment. It was shown that shells of bivalves possessing higher biomass compared to other groups of organisms in the Obskaya Guba play an important role in deposition of heavy metals. In the Obskaya Guba mollusks accumulate Cd and Pb at the background level, whereas Cu and Zn contents appear to be higher than the background level.

Abundance and biomass of macrobenthic infauna of the offshore northern North Sea

Between 1980 and 1985 ninety-seven stations were sampled by Smith-Mclntyre grab from the offshore northern section of the North Sea. Four hundred and nine infaunal species were identified from the 76 selected macrofaunal stations. The number of species per station varied from 25 to 80 with a maximum abundance of 9,600 individuals m**2. The biomass ranged from 0.13 to 18.86 g dry weight m**2. At most stations, however, biomass varied between 1 and 4 g dry weight m**2. Diversity and abundance were highest in the 120-140 m zone, characterised by fine sand containing variable amounts of silt. The highest biomasses were recorded in two areas; firstly where stronger currents predominate and the sediments are coarser (east of Shetland and west of the Norwegian Trough), and secondly in the fine sandy deposits of the centrally located area. In the silty sediments (Fladen Ground and smaller depressions) there was a predominantly subsurface deposit-feeding community, whereas in the coarser area east of the Shetlands carnivores predominated. Over the remaining area surface deposit feeders were dominant.

Quartz content and mass accumulation rates at DSDP Hole 86-576A

The amount and the accumulation rate of quartz were measured in 33 samples from Hole 576A. The amount and source of mineral aerosol being deposited in the northwest Pacific during the Cenozoic are evaluated using these data. When Hole 576A is compared to a Cenozoic record in the central North Pacific, a strong uniformity in the composition of the mineral aerosol across the North Pacific is seen. The data suggest that Hole 576A entered the influence of the westerlies about 15 m.y. ago and that since that time the rates of sediment deposition have increased. Only the dramatic change in quartz accumulation 2.5 m.y. ago can be clearly related to a climatic event, but a gradual increase in quartz accumulation through the Miocene and early Pliocene is probably a result of increasing Northern Hemisphere aridity and intensified atmospheric activity associated with global cooling during the interval.

MARECHIARA-mesozooplankton long-term time-series at the fixed coastal station in the Gulf of Naples: abundance and biomass, data for the years 1984-2006

The MARECHIARA-mesozooplankton dataset contains mesozooplankton data collected in the ongoing time-series at Sation MC (40°48.5' N, 14°15' E) in the Gulf of Naples. This dataset spans over the period 1984-2006 and contains data of mesozooplankton abundance and species composition as well as biomass (as dry weight). Mesozooplankton was regularly sampled in 1984-1990 and 1995-2006, only a few samples were collected in 1991-1992 and no samples in 1993-1994. During the first period of the series sampling frequency was fortnightly, and weekly since 1995.

Sulfur and carbon in mIcrobial processes in waters and sediments of the Kara Sea in September 2007

Results of microbiological, biogeochemical and isotope geochemical studies in the Kara Sea are described. Samples for these studies were obtained during Cruise 54 of R/V Akademik Mstislav Keldysh in September 2007. The studied area covered the northern, central, and southwestern parts of the Kara Sea and the Obskaya Guba (Ob River estuary). Quantitative characteristics of total bacterial population and activity of microbial processes in the water column and bottom sediments were obtained. Total abundance of bacterioplankton (BP) varied from 250000 cells/ml in the northern Kara Sea to 3000000 cells/ml in the Obskaya Guba. BP abundance depended on concentration of suspensded matter. Net BP production was minimal in the central Kara Sea (up to 0.15-0.2 µg C/l/day) and maximal (0.5-0.75 µg C/l/day) in the Obskaya Guba. Organic material at the majority of stations at the Ob transect predominantly contained light carbon isotopes (-28.0 to -30.18 per mil) of terrigenous origin. Methane concentration in the surface water layer varied from 0.18 to 2.0 µl CH4/l, and methane oxidation rate varied from 0.1 to 100 nl CH4/l/day. Methane concentration in the upper sediment layer varied from 30 to 300 µl CH4/dm**3; rate of methane formation was varied from 44 to 500 nl CH4/dm**3/day and rate of methane oxidation - from 30 to 2000 nl CH4/dm**3/day. Rate of sulfate reduction varied from 4 to 184 µg S/dm**3/day.