Abundance and biomass of mesozooplankton from the S-R01 cruise in the western part of the Black Sea in April 2008

The SESAME dataset contains mesozooplankton data collected during April 2008 in the North-West Black Sea (between 44°46' N and 42°29'N latitude and 28°64'E and 30°59'E longitude). Mesozooplankton sampling was undertaken at 9 stations where samples were collected using a Nansen closing net in the 0-10, 10-25, 25-50, 50-100, 100-150, 150-180 m layer. The dataset includes 28 samples analysed for mesozooplankton species composition, species abundance and total biomass. The Taxon-specific mesozooplankton abundance sample or aliquots were analyzed under the binocular microscope. Taxonomic identification was done according to Morduhai-Boltovskii et al. 1968. Total biomass was estimated using a tabel with wet weight for each species an stage (Petipa method).

Abundance and biomass of mesozooplankton from the S-R02 cruise in the western part of the Black Sea in September 2008

The SESAME dataset contains mesozooplankton data collected during September 2008 in the North-West Black Sea (between 44°46' N and 42°29'N latitude and 28°64'E and 30°59'E longitude). Mesozooplankton sampling was undertaken at 9 stations where samples were collected using a Juday net in the 0-10, 10-25, 25-50, 50-100, 100-150, 150-200 m layer. The dataset includes 30 samples analysed for mesozooplankton species composition, species abundance and total biomass. Sampling volume was estimated by multiplying the mouth area with the wire length. The Taxon-specific mesozooplankton abundance sample or aliquots were analyzed under the binocular microscope. Taxonomic identification was done according to Morduhai-Boltovskii et al. 1968. Total biomass was estimated using a tabel with wet weight for each species an stage (Petipa method).

Annotated record of the detailed examination of Mn deposits from the SO 79 (SEDIPERU - TUSCH) expedition from R/V Sonne

The research cruise SO79 with RV SONNE (April 18 to June 09 1992) aimed to assess the impact of a potential mining activity on the sensitive deep-sea ecosystem of the Peru Basin. Up to now only results of reconnaissance surveys of the extended manganese nodule field discovered in 1978 in the Peru Basin are available. The hydroacoustic, sedimentological, and geochemical studies on data and sample material of SO79 came to the following results: a small-scaled variation in thickness respectively type of surface sediments shown by the sediment echosounder respectively the side-scan-sonar is assumably due to variations in deposition or erosion. The composition of sediments is controlled by climatic cycles of different length which were caused by the variable influence of glaciation of the northern hemisphere. We think that during the quaternary a deep-water circulation reduced in intensity and O2-content may have produced a suboxic diagenetic environment which led to a remobilization and redeposition of Mn forming manganese nodules in the oxic surface sediments. Near the distinct redox boundary at about 10 cm depth the growth conditions for nodules are extremely favourable. Due to the great variability of sediments the impact of deep-sea mining will be highly variable and the disturbance of the seafloor will change the ecosystem considerably.

(Fig 1, page 350) A manganese nodule in the top part of the CHUBASCO station 17 core taken in the Pacific Ocean

The vast extent of pelagic deposits, covering about 70 per cent of the ocean floor, thus about half of the earth, makes them of obvious importance to all Earth Science. All the pelagic (eupelagic) sediments, whether largely of plankton remains or fine inorganic particles, have certain distinctive characteristics to reflect their environment of accumulation. The great segregation of manganese in pelagic sediments presents many problems. It is hypothesized that in the formation of present day nodules a relatively slow accumulation in order to permit deposition of more of the manganese as large nodules, rather than as the disseminated micronodules that are in larger proportion in the Tertiary.

Relative abundance of dinoflagellate cysts in surface sediments and dinoflagellate counts from three sediment cores from the Atlantic sector of the Southern Ocean

In this study we investigate the potential of organic-walled dinoflagellate cysts (dinocysts) as tools for quantifying past sea-surface temperatures (SST) in the Southern Ocean. For this purpose, a dinocyst reference dataset has been formed, based on 138 surface sediment samples from different circum-Antarctic environments. The dinocyst assemblages of these samples are composed of phototrophic (gonyaulacoid) and heterotrophic (protoperidinioid) species that provide a broad spectrum of palaeoenvironmental information. The relationship between the environmental parameters in the upper water column and the dinocyst distribution patterns of individual species has been established using the statistical method of Canonical Correspondence Analysis (CCA). Among the variables tested, summer SST appeared to correspond to the maximum variance represented in the dataset. To establish quantitative summer SST reconstructions, a Modern Analogue Technique (MAT) has been performed on data from three Late Quaternary dinocyst records recovered from locations adjacent to prominent oceanic fronts in the Atlantic sector of the Southern Ocean. These dinocyst time series exhibit periodic changes in the dinocyst assemblage during the last two glacial/interglacial-cycles. During glacial conditions the relative abundance of protoperidinioid cysts was highest, whereas interglacial conditions are characterised by generally lower cyst concentrations and increased relative abundance of gonyaulacoid cysts. The MAT palaeotemperature estimates show trends in summer SST changes following the global oxygen isotope signal and a strong correlation with past temperatures of the last 140,000 years based on other proxies. However, by comparing the dinocyst results to quantitative estimates of summer SSTs based on diatoms, radiolarians and foraminifer-derived stable isotope records it can be shown that in several core intervals the dinocyst-based summer SSTs appeared to be extremely high. In these intervals the dinocyst record seems to be highly influenced by selective degradation, leading to unusual temperature ranges and to unrealistic palaeotemperatures. We used the selective degradation index (kt-index) to determine those intervals that have been biased by selective degradation in order to correct the palaeotemperature estimates. We show that after correction the dinocyst based SSTs correspond reasonably well with other palaeotemperature estimates for this region, supporting the great potential of dinoflagellate cysts as a basis for quantitative palaeoenvironmental studies.