The Global Plankton Database: an inventory and data from the Former Soviet Union expeditions

At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.

Pollen record from Muggesfelder See and Plussee in Germany

A basaltic tephra layer consisting of brownish-olive glass shards. and about 0.2 mm thick. was found in cores from four lakes in northwest Germany. According to pollen analysis it was deposited during the early Boreal period (corresponding to about 8700 BP). The petrographic properties. the geochemical composition and the age agree with those of the Saksunarvatn tephra. which was first found on the Faroe Islands. The position of the tephra layer in the pollen stratigraphy and in the absolute time-scale is discussed. Procedures for locating the tephra in other cores are suggested.

Minerals and geochemistry abundance and occurance, as well as K-Ar determinations for DSDP Site 92-597 basalts

Preliminary studies of hydrothermally altered massive basalts formed at the fast-spreading Mendoza Rise and recovered from DSDP Holes 597B and 597C indicate the presence of three secondary mineral assemblages which formed in the following order: (1) trioctahedral chlorite and talc, (2) goethite and smectite, and (3) calcite and celadonite. The sequential precipitation of these mineral assemblages denotes high water:rock ratios and time-varying conditions of temperature (early >200°C to late <30°C) and state of oxidation (early nonoxidative to late oxidative). A decrease in the relative proportion of oxidative mineral assemblages with depth to 70 m in Site 597 basement indicates a zone of oxidative alteration that became shallower with time as the deeper, more constricted fracture systems were filled by secondary mineralization. In this report we present the first results of the K-Ar dating of celadonite formation age; celadonite formation reflects end-stage hydrothermal alteration in Site 597 basement. Three celadonite dates obtained from Site 597 samples include 13.1 ± 0.3 m.y. from 17 m basement depth (Hole 597B), 19.9 ± 0.4 m.y. from 18 m basement depth (Hole 597C), and 19.3 ± 1.6 m.y. from 60 m basement depth (Hole 597C). The age of host rock crystallization (28.6 m.y.) and the K-Ar dates of celadonite formation establish that hydrothermal alteration in the upper 70 m of Site 597 basement continued for at least 10 m.y. and possibly as long as 16 m.y. after basalt crystallization at the ridge crest. Assuming a half-spreading rate of 55 km/m.y., we calculate that hydrothermal circulation was active in shallow basement at a distance of at least 550 km off ridge crest and possibly as far as 1000 km off ridge crest.

Chloroflexus spp. and Sulfurihydrogenibium spp. in microbial mats of the Nakabusa hot spring, Japan

Microbial mats develop in a wide range of aquatic habitats, such as geothermal hot springs, hypersaline ponds, marine cold seeps or hydrothermal vents. The Nakabusa hot spring is located in the Nagano Prefecture, Japan (36.3875N, 137.75E), dense olive-green microbial mats develop in regions where the slightly alkaline, sulfidic effluent has cooled to 65°C. The microbial community of such mats was analyzed by focusing on the diversity, as well as the in situ distribution and function of bacteria involved in sulfur cycling. Microbial mat samples were kept in sterile plastic tubes (for molecular analysis) or glass bottles completely filled with hot spring water to avoid oxidation. Samples were transferred to the laboratory on ice and used for physiological experiments within 8h. Quantification of cell biovolumes was carried out based on images of mat sections hybridized with Sulfurihydrogenibium- and Chloroflexi-specific probes, and stained with DAPI. In situ hybridizations (CARD-FISH) of thin matsections showed a heterogeneous vertical distribution of Sulfurihydrogenibium and Chloroflexus. Sulfurihydrogenibium dominated near the mat surface (50% of the total mat biovolume), while Chloroflexus dominated in deeper layers (up to 64% of the total mat biovolume).

Abundance and biomass of phytoplankton in the western part of the Black Sea during Branimir Ormanov cruise BO092000 in September 2000

The samples were concentrated down to 50 cm**3 by slow decantation after storage for 20 days in a cool and dark place. The species identification was done under light microscope OLIMPUS-BS41 connected to a video-interactive image analysis system at magnification of the ocular 10X and objective - 40X. A Sedgwick-Rafter camera (1ml) was used for counting. 400 specimen were counted for each sample, while rare and large species were checked in the whole sample (Manual of phytoplankton, 2005). Species identification was mainly after Carmelo T. (1997) and Fukuyo, Y. (2000). Taxon-specific phytoplankton abundance and biomass were analysed by Moncheva S., B. Parr, 2005. Manual for Phytoplankton Sampling and Analysis in the Black Sea. The cell biovolume was determined based on morpho-metric measurement of phytoplankton units and the corresponding geometric shapes as described in detail in (Edier, 1979).

Magnetic properties of ODP Site 191-1179 sediments

As reported by Shipboard Scientific Party (2001b, doi:10.2973/odp.proc.ir.191.104.2001) in the Site 1179 chapter of the Initial Reports volume, Leg 191 Site 1179 is located on abyssal seafloor northwest of Shatsky Rise, ~1650 km east of Japan. This part of the Pacific plate was formed during the Early Cretaceous, as shown by northeast-trending M-series magnetic lineations that become younger toward the northwest (Larson and Chase, 1972, doi:10.1130/0016-7606(1972)83[3627:LMEOTW]2.0.CO;2; Sager et al., 1988, doi:10.1029/JB093iB10p11753; Nakanishi et al., 1989, doi:10.1029/1999JB900002). The site is situated on magnetic Anomaly M8 (Nakanishi et al., 1999, doi:10.1029/1999JB900002), corresponding to an age of ~129 Ma and the Hauterivian stage of the Early Cretaceous (Gradstein et al., 1994, doi:10.1029/94JB01889; 1995). The sediments recovered at Site 1179 are split into four lithostratigraphic units based on composition and color (Shipboard Scientific Party, 2001b, doi:10.2973/odp.proc.ir.191.104.2001). Unit I (0-221.52 meters below seafloor [mbsf]) is a dominantly olive-gray clay- and radiolarian-bearing diatom ooze. Unit II (221.52-246.0 mbsf) is a yellowish brown to light brown clay-rich and diatom-bearing radiolarian ooze. Unit III (246.0-283.53 mbsf) is composed of brown pelagic clay. Unit IV (283.53-377.15 mbsf) is composed of chert and some porcellanite; any softer sediments present were washed out of the core barrel by the fluid circulating during the coring process.

Chemistry of very young basalts from ODP Hole 106-648B

Basalts in Hole 648B, located in the rift valley of the Mid-Atlantic Ridge at 23°N in crust estimated to be less than 100,000 years old, are mainly fresh, but small amounts of secondary phases are found on fracture surfaces and in alteration halos within the rocks. The halos are defined by dark bands 1-4 mm thick that have developed parallel to fracture surfaces or pillow margins and which in some cases have migrated some centimeters into the rock. The dark bands are the principal locus of secondary phases. The secondary phases are olive-green and yellow protoceladonites, of composition and structure intermediate between celadonite and iron-rich saponite, red (Mn-poor) to opaque (Mn-rich) iron oxyhydroxides, mixtures of protoceladonite and iron oxyhydroxide, and rare manganese oxides. These phases occur mainly as linings or fillings of open spaces in the basalt within the dark bands. Sulfides and intersertal glass are the only primary phases that can be seen to have been altered. Where dark bands have migrated into the rock, the rock behind the advancing band is almost devoid of secondary phases, implying redissolution. The potassium and magnesium in the secondary phases could have been supplied from ambient seawater. The aluminum in the protoceladonites must have been derived from local reaction of intergranular glass. The source of iron and silica could have been intergranular glass or low temperature mineralizing solutions of the type responsible for the formation of deposits of manganese oxides and iron oxyhydroxides and silicates on the seafloor.

(Table 2) Age determination of sediment cores from the continental shelf of Mac Roberston Land, East Antarctica

Geochemical records are presented for five sediment cores from basins on the continental shelf of Mac. Robertson Land, East Antarctica. The cores contain 2-4 m thick sequences of hemipelagic, siliceous mud and ooze (SMO) deposited under seasonally open marine conditions. The inner and middle shelf SMO sequences are massive dark olive green material, whereas the outer shelf SMO sequences are dark olive material interspersed with light olive green layers ~1-10 cm thick. The biogenic material is dominated by marine diatoms including Fragilariopsis curta, Fragilariopsis cylindrus, and Chaetoceros spp. in the dark-colored SMO and Corethron criophilum in the light-colored layers. Radiocarbon dates suggest that the cores provide continuous accumulation records extending from < 1 kyr before present (B.P.) back as far as 4-15 kyr B.P., with estimated accumulation rates of 0.07-5 mm/yr. The three core records from the middle and outer shelf suggest six episodes of increased accumulation of biogenic material at ~5.5 kyr B.P. (all three cores), 1, 2, and 6.2 kyr B.P. (two of the three cores), and 3.8 and 10.8 kyr B.P. (one core), most of which coincide with Corethron layers. We interpret these features as the result of enhanced diatom production over the outer shelf, possibly related to climatic warm periods. The absence of such features in the inner shelf core records is thought to reflect a relatively constant level of seasonal diatom production in adjacent waters maintained by a coastal polynya.

Investigations on sediment coring site PS1823 in the Riiser-Larsen Sea, Southern Ocean

Physical and sedimentological investigations were carried out on a 14 m long gravity core and a 0.5 m long box core from 4440 m water depth off Queen Maud Land, East-Antarctica. Strongly bioturbated hemipelagic muds of predominantly terrigenous origin and a very small biogenic part build up the 'Normal-Facies'. Several sandy to silty layers are inserted in the 'Normal-Facies'. These layers are seperated by lithology, structure and the investigated parameters of this study and are interpreted as turbidites. The source area for the turbidity currents is supposed to be at the uppermost continental margin, close to the shelf break and there is evidenee for this gravity transport within the erosive Ritscher-Canyon, which extends close to the core position. The distribution of biogenic components indicates an age of 1.3 million years or more, with an average sedimentation rate of about 1 cm/1000 years. Early diagenetic proeesses caused water loss by compaction, errosion and dissolution of biogenic components and precipitation and recrystallization of manganese micronodules. Cyclic fluctuations of the sediment-parameters within the 'Normal-Facies' enable the distinction of a 'Glazial'- and an 'Interglazial'-Facies. The 'Glazial'-Facies reflects glacial sedimentary conditions and shows a dark olive gray colour, high susceptibility, low silt/clay-ratios, only a few biogenic components and the regular occurence of interrelated turbidite layers. In contrast, the 'Interglazial'-Facies is dominated by a light olive or olive-brown colour, low susceptibility, high silt/clay-ratios and an increased number of biogenic components. This facies corresponds to interglacial conditions. Three main processes are supposed to have been responsible for the observed facies changes: (1) the bottom water mass circulation, (2) the gravity transport by turbidity currents and (3) the biogenic surface production. These processes are related to the quaternary climatic changes. The extension of the ice shelves directed the gravity transport to the deep sea and the formation of Antarctic Bottom Water, which in turn influenced the silt/clay-ratios in the sediment record. Fluctuations in sea ice coverage controlled the biogenic surface production.

Climate variability in the Aegean Sea (marine record M2, Athos basin) during the past 1500 years

We provide new evidence on sea surface temperature (SST) variations and paleoceanographic/paleoenvironmental changes over the past 1500 years for the north Aegean Sea (NE Mediterranean). The reconstructions are based on multiproxy analyses, obtained from the high resolution (decadal to multi-decadal) marine record M2 retrieved from the Athos basin. Reconstructed SSTs show an increase from ca. 850 to 950 AD and from ca. 1100 to 1300 AD. A cooling phase of almost 1.5 °C is observed from ca. 1600 AD to 1700 AD. This seems to have been the starting point of a continuous SST warming trend until the end of the reconstructed period, interrupted by two prominent cooling events at 1832 ± 15 AD and 1995 ± 1 AD. Application of an adaptive Kernel smoothing suggests that the current warming in the reconstructed SSTs of the north Aegean might be unprecedented in the context of the past 1500 years. Internal variability in atmospheric/oceanic circulations systems as well as external forcing as solar radiation and volcanic activity could have affected temperature variations in the north Aegean Sea over the past 1500 years. The marked temperature drop of approximately ~2 °C at 1832 ± 15 yr AD could be related to the 1809 ?D 'unknown' and the 1815 AD Tambora volcanic eruptions. Paleoenvironmental proxy-indices of the M2 record show enhanced riverine/continental inputs in the northern Aegean after ca. 1450 AD. The paleoclimatic evidence derived from the M2 record is combined with a socio-environmental study of the history of the north Aegean region. We show that the cultivation of temperature-sensitive crops, i.e. walnut, vine and olive, co-occurred with stable and warmer temperatures, while its end coincided with a significant episode of cooler temperatures. Periods of agricultural growth in Macedonia coincide with periods of warmer and more stable SSTs, but further exploration is required in order to identify the causal links behind the observed phenomena. The Black Death likely caused major changes in agricultural activity in the north Aegean region, as reflected in the pollen data from land sites of Macedonia and the M2 proxy-reconstructions. Finally, we conclude that the early modern peaks in mountain vegetation in the Rhodope and Macedonia highlands, visible also in the M2 record, were very likely climate-driven.

Descriptions of 104 gravity and piston sediment cores from POLARSTERN expedition ARK-VIII/3 to the Arctic Ocean

Sediment descriptions and lithostratigraphy (chapter 6.4) NANSEN BASIN The upperrnost 20-50 cm of sedirnents in the Nansen Basin norrnally cornprise soft dark brown, brown-grayish and brown clay. Except for the toprnost clay, the four piston cores retrieved, contained quite different lithologies: a rnuddy diarnicton with outsized clasts (PS2157-6), sandy-silt beds alternating with clay beds (PS2159-6), and silty clay beds of brownish and grayish colours (PS2161-3). Core PS2208-3 was retrieved frorn a plateau on a searnount. The plateau was serni-encircled by hills. The upper 250 cm of this core cornprise brown and olive brown clays. Below these are several sandlayers and a 74 cm thick unit of a sandy mud with rnud-clasts up to 20 cm in diameter. GAKKEL RIDGE The uppermost 20-50 cm of sediments on the Gakkel Ridge comprise soft dark brown, brown, grayish brown clay. In most of the cores there are two horizons of brown clay separated by olive brown clay. The upper horizon is darker. The older stratigraphy is rather varied. Core PS2165-1 contains several thin gray sandlsilt layers, probably distal turbidites. The sarne is found in Core PS2167-1. This core also has a thick (approx. 2 rn) coarse grained turbidite containing large rnud clasts and basaltic rock fragrnents. The color of the turbiditic layers is dark gray. There are several horizons of hernipelagic sandylsilty clays with quite a variety in colours; black, gray, olive, brown, yellowish brown and reddish. The colour variation rnay be due to hydrotherrnal activity or provenance or a shift in redox potential. Cores PS2168-2 and PS2169-1 have typical sequences of very dark gray sandy mud with sharp lower boundaries grading upwards into olive brown clay. Below the lower boundary is often a thin (1-2 cm) gray clay layer. AMUNDSEN BASIN The giant box cores (GKG) provided in most cases excellently preserved sedirnent surfaces which consisted in the entire Amundsen Basin of dark brown to dark grayish brown silty clay with few dropstones and common calcareous microfossils (foraminifers and calcareous nannofossils). The brown and grayish brown color of the sediment surface is a result of the oxidizing conditions at the seafloor due to the rapid renewal of the bottom water rnasses. Planktic forarninifers and calcareous nannofossils are relatively frequent and well preserved despite the rernote location of the basin and its water depths of >4000 rn. Srnear slide descriptions have shown that the surface sedirnents consist dorninantly of clays to silty rnuds with clay rninerals and quartz as the rnost important constituents. The coarse fractions contained besides planktic and benthic forarninifers and coarse clastic rnaterials, rare bivalves, dropstones and mud clasts. The Station PS2190 at the North Pole is a particular good exarnple of the type of sedirnents deposited at the sea floor surface of the Arnundsen Basin, with hornogenous dark brown soft clay covering a sedirnent sequence of highly variable cornposition. Nurnerous giant box cores also provide insight into the detailed lithostratigraphy of the upperrnost sedirnent layers. Twelve box cores have been collected frorn the Arnundsen Basin. Below the youngest unit of 5-20 crn thick silty clays deposits of variable stratigraphies have been found, rnostly consisting of clays or silty clays. In a few instances turbidites have been observed. Benthic forarninifers have not been found in the surface sedirnents. Other fossils were extrernely rare. Bioturbation is weakly developed on all stations. Benthic anirnals seern to live only in and on the upperrnost 2 cm of the uppermost sediment layer. They cornprise amphipods (on all stations) and holothurians, bryozoans, polychaetes, and porifers at one station each. LOMONOSOV RIDGE Sediments from the Lomonosov Ridge show a variety of colors and textures. Following smear slide analyses they are composed mostly of clay minerals and quartz with mica and feldspars, especially in the siltier and sandier parts. Volcanic glass, microcrystalline carbonate, opaque minerals and green amphibole are occasional accessories. The sediments from the Lomonosov Ridge show a noticeable difference from sediments collected from the surrounding basins. Lomonosov Ridge sediments are richer in silt and sand than basin sediments. Occasional turbidites occur in ridge sediments but these must be of entirely local origin. The ridge sediments include frequent layers of "cottage cheese" texture made up of what appear to be small, angular mud clasts of a variety of colors.