Abundance of mesozooplankton in the western part of the Black Sea in 1995 during the Cooperative Marine Science Program for the Black Sea (CoMSBlack)

The "CoMSBlack-95" dataset is based on samples collected in the summer of 1995. The whole dataset is composed of 81 samples (28 stations) with data of zooplankton species composition, abundance and biomass. Samples were collected in discrete layers 0-10, 0-20, 0-50, 10-25, 25-50, 50-100 and from bottom up to the surface at depths depending on water column stratification and the thermocline depth. Zooplankton samples were collected with vertical closing Juday net,diameter - 36 cm, mesh size 150 µm. Tows were performed from surface down to bottom meters depths in discrete layers. Samples were preserved by a 4% formaldehyde sea water buffered solution. Sampling volume was estimated by multiplying the mouth area with the wire length. Mesozooplankton abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Asen Konsulov and Lyudmila Kamburska using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972). Taxon-specific abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Copepods and Cladoceras were identified and enumerated; the other mesozooplankters were identified and enumerated at higher taxonomic level (commonly named as mesozooplankton groups). Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Asen Konsulov and Lyudmila Kamburska using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972).

Mid-Pliocene diatom and palynological assemblages north-northeast of Cape Adare, Antarctica

Microfossil assemblages in Pliocene sediments from DSDP Site 274 (68°59.81'S, 173°2564'E) provide data on the age of the sediments and suggest the presence of Nothofagus (southern beach) in Antarctica during the Pliocene. A suite of 17 samples was collected in an interval from Samples 28-274-6R-1, 83-87 cm to 28-274-11R-4, 73-77 cm (48.33-100.29 mbsf). Biostratigraphic study of the abundant diatom assemblages combined with published radiolarian data indicates that the sample interval ranges in age from 5.0 to 2.2 Ma, with an apparent unconformity between about 3.8 and 3.2 Ma. Nothofagidites (the genus for fossil pollen referable to Nothofagus) occurs throughout the interval, as well as pollen and spores with known stratigraphic ranges that unequivocally indicate reworking from older rocks. Species of Nothofagidites recovered include N. asperus, N. brachyspinulosus, N. flemingii, N. senectus, and N. sp. cf. N. lachlaniae; the latter form is previously known from the Sirius Group in the Transantarctic Mountains. Abundant palynomorphs were recovered in only three of the samples from Site 274 (Samples 28-274-9R-2,15-19 cm; 28-274-9R-2,48-52 cm; and 28-274-9R-2,65-69 cm). Based on the diatom and radiolarian biostratigraphic data, the ages of these samples range from 3.00 to 3.01 Ma. The relative abundance of N. sp. cf. N. lachlaniae in the three samples is an order of magnitude higher than relative abundances for the other species of Nothofagidites in the same samples. The signiticantly higher relative abundance of N. sp. cf. N. luchlaniae suggests that this pollen was derived from trees of Nothofugus that were living in Antarctica during the mid Pliocene. Diatom assemblages from these three samples indicate that sediments in this interval were rapidly deposited as biogenic oozes in an open-ocean setting relatively free of sea ice, thus decreasing the possibility of reworking from a single source bed rich in N. sp. cf. N. lachlaniae. Clearly, more detailed work in additional well-dated cores from around Antarctica is needed before a clear picture of the Neogene history of Antarctic terrestrial vegetation emerges.

Silicoflagellates of early Paleocene to early Miocene sediments of the subantarctic South Atlantic

Nearly complete Paleogene sedimentary sequences were recovered by Leg 114 to the subantarctic South Atlantic. Silicoflagellate assemblages from the Paleogene and immediately overlying lower Neogene from Sites 698 (Northeast Georgia Rise), 700 (East Georgia Basin), 702 (Islas Orcadas Rise), and 703 (Meteor Rise) were examined. The described assemblage from Hole 700B represents the most complete yet described from the Paleocene, encompassing planktonic foraminifer Zones Plb (upper part) through P4 and Subchrons C25N to C23N. All lower Eocene sediments are barren as a result of diagenesis, except for a single sample from Hole 698A. Middle Eocene silicoflagellates described from Hole 702B range in age from early middle Eocene (P10) to late Eocene (PI5), with correlations to Subchrons C21N to C18N. Hole 703A contains late Eocene through early Miocene assemblages, with paleomagnetic control from Subchrons C16R to C6AAN. Leg 114 biosiliceous sequences contain exceptionally diverse assemblages of silicoflagellates. Approximately 155 species and separate morphotypes are described from the Paleogene and earliest Neogene. New taxa described from Leg 114 sediments include Bachmannocena vetula n. sp., Corbisema animoparallela n. sp., Corbisema camara n. sp., Corbisema constricta spinosa n. subsp., Corbisema delicata n. sp., Corbisema hastata aha n. subsp., Corbisema praedelicata n. sp., Corbisema scapana n. sp., Corbisema triacantha lepidospinosa n. subsp., Dictyocha deflandreifurtivia n. subsp., Naviculopsis biapiculata nodulifera n. subsp., Naviculopsis cruciata n. sp., Naviculopsis pandalata n. sp., Naviculopsis primativa n. sp., and Naviculopsis trispinosa eminula n. subsp. Taxonomic revisions were made to the following taxa: Corbisema constricta constricta emended, Corbisema disymmetrica crenulata n. comb., Corbisema jerseyensis emended, and Distephanus antarcticus n. comb. Silicoflagellate assemblages from the Paleogene and earliest Neogene of Holes 698A, 699A, 700B, 702B, and 703A are the basis of a silicoflagellate zonation spanning the interval from 63.2 to 22.25 Ma. Silicoflagellate zones recognized in this interval include the Corbisema hastata hastata Zone, Corbisema hastata aha Zone, Dictyocha precarentis Zone, Naviculopsis constricta Zone, Naviculopsis foliacea Zone, Bachmannocena vetula Zone, Dictyocha grandis Zone, Naviculopsis pandalata Zone, Naviculopsis constricta-Bachmannocena paulschulzii Zone, Bachmannocena paulschulzii Zone, Naviculopsis trispinosa Zone with subzones a and b, Corbisema archangelskiana Zone, Naviculopsis biapiculata Zone, Distephanus raupii Zone, Distephanus raupii-Corbisema triacantha Zone, and Corbisema triacantha mediana Zone.

Abundance and biomass of zooplankton from 1981-1985 collected in front of Constanta city, Black Sea

The Est Constanta 1981-1985 dataset contains zooplankton data collected allong a 5 station transect in front of the city Constanta (44°10'N, 28°41.5'E - EC1; 44°10'N, 28°47'E - EC2; 44°10'N, 28°54'E - EC3; 44°10'N, 29°08'E - EC4; 44°10'N, 29°22'E - EC5). Zooplankton sampling was undertaken at 5 stations where samples were collected using a Juday closing net in the 0-10, 10-25, 25-50m layer (depending also on the water masses). The dataset includes samples analysed for mesozooplankton species composition and abundance. Sampling volume was estimated by multiplying the mouth area with the wire length. Taxon-specific mesozooplankton abundance was count under microscope. Total abundance is the sum of the counted individuals. Total biomass Fodder, Rotifera , Ctenophora and Noctiluca was estimated using a tabel with wet weight for each species an stage.

Abundance and biomass of zooplankton from the Romanian littoral collected in April, May and June 1997

The SHELF 1997 dataset contains zooplankton data collected in April, May and June 1997 5 transect in front of the Romanian littoral . Zooplankton sampling was undertaken using a Juday closing net in the 0-10, 10-25, and 25-50m layer (depending also on the water masses). The dataset includes samples analysed for mesozooplankton species composition and abundance. Sampling volume was estimated by multiplying the mouth area with the wire length. Taxon-specific mesozooplankton abundance was count under microscope. Total abundance is the sum of the counted individuals. Total biomass Fodder, Rotifera , Ctenophora and Noctiluca was estimated using a tabel with wet weight for each species an stage.

Abundance and biomass of zooplankton collected in front of the Danube Delta in May and September 1979

The Gurile Dunarii 1979 dataset contains zooplankton data collected in May and September 1979 in 13 station allong 3 transect in front of the Danube Delta (45°05' - 44°45'N, 30°02'- 29°27'E). Zooplankton sampling was undertaken at 13 stations where samples were collected using a Juday closing net in the 0-10, 10-20, 20-30, 30-40 and 40-50m layer (depending also on the water masses). The dataset includes samples analysed for mesozooplankton species composition and abundance. Sampling volume was estimated by multiplying the mouth area with the wire length. Taxon-specific mesozooplankton abundance was count under microscope. Total abundance is the sum of the counted individuals. Total biomass Fodder, Rotifera , Ctenophora and Noctiluca was estimated using a tabel with wet weight for each species an stage.

Abundances and contents of major silicoflagellates from IODP Holes of Exp302

The silicoflagellate taxa obtained in IODP Expedition 302 (ACEX) were identified and counted in order to establish the silicoflagellate biostratigraphy in the central Arctic Ocean. These microfossils in the ACEX samples were preserved in the Lithology Units 1/6 and 2, which are dark silty clay and biosiliceous ooze, respectively. The silicoflagellate skeletons in the ACEX samples are assigned to 56 taxa. Seven taxa were described as new species, which were abundant in Lithology Unit 2. Comparison with several study cases outside the Eocene Arctic Ocean suggested that the silicoflagellate assemblages in ACEX were unique in Lithology Unit 2. The dominance of silicoflagellate taxa varied throughout the lithological section. Based on the cluster analysis by Morishita similarity index C(Lambda), the silicoflagellate assemblageswere divided into nine assemblage groups. The silicoflagellate datum event of the first occurrence of Corbisema hexacantha in the lower part of Lithology Unit 1/6 is regarded. Based on the datum events for silicoflagellate and palynomorphs, the assigned epoch of Lithology Units 1/6 and 2 is the middle Eocene.

Radiolarian chronology and fauna across the middle/late Eocene boundary at ODP Hole 171-1052A

Quantitative radiolarian assemblage analysis has been conducted on middle and upper Eocene sediments (Zones RP16 to RP18) from Ocean Drilling Program Site 1052 in order to establish the radiolarian magnetobiochronology and determine the nature of the faunal turnover across the middle/late Eocene boundary in the western North Atlantic Ocean. We recognize and calibrate forty-five radiolarian bioevents to the magneto- and cyclo-stratigraphy from Site 1052 to enhance the biochronologic resolution for the middle and late Eocene. Our data is compared to sites in the equatorial Pacific (Leg 199) to access the diachrony of biostratigraphic events. Eleven bioevents are good biostratigraphic markers for tropical/subtropical locations (south of 30°N). The primary markers (lowest occurrences of Cryptocarpium azyx and Calocyclas bandyca) which are tropical zonal boundary markers for Zones RP17 and RP18 provide robust biohorizons for correlation and age determination from the low to middle latitudes and between the Atlantic and Pacific Oceans. Some other radiolarian bioevents are highly diachronous (<1 million years) between oceanic basins. A significant faunal turnover of radiolarians is recognized within Chron C17n.3n (37.7 Ma) where 13 radiolarian species disappear rapidly in less than 100 kyr and 4 new species originate. The radiolarian faunal turnover coincides with a major extinction in planktonic foraminifera. We name the turnover phase, the Middle/Late Eocene Turnover (MLET). Assemblage analysis reveals the MLET to be associated with a decrease in low-mid latitude taxa and increase in cosmopolitan taxa and radiolarian accumulation rates. The MLET might be related to increased biological productivity rather than to surface-water cooling.