Abundance and biomass of mesozooplankton in the eastern Mediterranean Sea in March and April 2008 during SES_GR1

The dataset is based on samples taken during March-April 2008 in Libyan Sea, in Southern Aegean Sea and in Northern Aegean Sea. Sampling volume was estimated by the net mouth surface and the towing distance for WP-2. Taxon-specific mesozooplankton abundance and total abundance: The sample was split on board in two halves by using the beaker approach. The first sub-sample was immediately fixed and preserved in a seawater formalin solution containing about 4% buffered formaldehyde to allow the determination of species composition abundance. Pipette for the subsamples used in the taxonomic analysis of zooplankton under binocular microscope.

Calcareous nannofossil species richness across the Paleocene-Eocene Thermal Maximum

The Paleocene-Eocene Thermal Maximum (PETM, ~5 million years ago) was an interval of global warming and ocean acidification attributed to rapid release and oxidation of buried carbon. We show that the onset of the PETM coincided with a prominent increase in the origination and extinction of calcareous phytoplankton. Yet major perturbation of the surface-water saturation state across the PETM was not detrimental to the survival of most calcareous nannoplankton taxa and did not impart a calcification or ecological bias to the pattern of evolutionary turnover. Instead, the rate of environmental change appears to have driven turnover, preferentially affecting rare taxa living close to their viable limits.

Abundance of mesozooplankton in the Alboran Sea during Almofront-2

The ALMOFRONT2 dataset contains mesozooplankton data collected in 1997 - 1998 in the Alboran Sea (South Western Mediterranean Sea) between : 37° 00' N, 2° 54' W and 35° 18' N, 0°00' E.

Calcareous nannofossils of ODP Holes 114-699A and 114-700B

Ocean Drilling Program (ODP) Leg 114 recovered nannofossil-bearing sediments from seven sites in the high latitudes of the South Atlantic Ocean. Cretaceous sections were recovered from Sites 698 and 700, located on the Northeast Georgia Rise and its lower flanks, respectively. These contain distinctive high-latitude nannofossil floras similar to those from high-latitude areas of the Northern Hemisphere. Most of the biostratigraphic datums used to date the upper Campanian to Maestrichtian interval appear to lie at approximately the same level in both hemispheres. The FAD of Nephrolithus frequens is confirmed to be diachronous with an earlier occurrence in high latitudes. The LAD of Monomarginatus primus n. sp. also appears to be diachronous with a later LAD in the high latitudes of the Southern Hemisphere. Fossiliferous Paleocene to lowermost Miocene sediments were recovered at all seven sites, from the Northeast Georgia Rise in the west to the Meteor Rise in the east. These nannofossil floras, although restricted in diversity and only poorly preserved, are sufficiently distinctive to allow the recognition of 19 zones and three subzones, which are used to date and correlate the cores recovered. Only Site 704 on the Meteor Rise yielded a substantial section of Miocene to Quaternary nannofossil-rich sediments. The nannofossil floras of this section are of very low diversity, with usually fewer than eight species present. Some stratigraphic ranges of important biostratigraphic datum species are observed to be different in the high-latitude sections from those recorded from low-latitude areas. The LAD of Reticulofenestra bisecta, when calibrated by magnetostratigraphy, appears to occur earlier in Hole 699A (within Chron C6CR) than in Hole 703A and possibly Hole 704B and in other published accounts of lower latitude sites in the South Atlantic. The FAD of Nannotetrina fulgens/N. cristata appears to occur later in Hole 702B (Chron C20R) than it does in other published accounts of lower latitude sites in the South Atlantic. Diachroneity is also suspected in the stratigraphic ranges of Chiasmolithus solitus and Chiasmolithus oamaruensis, although poor magnetostratigraphic results through the critical interval prevent confirmation of this. Differences in the relative stratigraphic ranges of lsthmolithus recurvus and Cribrocentrum coenurumlC. reticulatum at Sites 699 and 703 are noted. These possibly suggest warmer surface waters on the eastern side (Site 703) of the middle to late Eocene South Atlantic than those on the western side (Site 699). The diversities of the nannofossil floras and the presence of the warm-water genera Discoaster, Sphenolithus, Helicosphaera, and Amaurolithus reflect the changing surface water temperatures throughout the Cenozoic. Warmer periods are inferred for the late Paleocene to early middle Eocene, late middle Eocene to late Eocene, latest Oligocene to earliest Miocene, and possibly the Pliocene. Colder periods are inferred for the middle Eocene, most of the Oligocene, and the Miocene. Dramatic changes in the nannofossil floras of the Pleistocene of Site 704 are thought to reflect a rapidly changing environment. Monomarginatus primus, a new species from the Upper Cretaceous strata of Hole 700B, is described.

Cretaceous and Paleogene calcareous nannofossils from ODP Leg 123

Two of five holes drilled at two separate sites during Leg 123 of the Ocean Drilling Program intersected thick and relatively complete sections of Upper Cretaceous-Paleogene nannofossiliferous sediments. Although dominated by turbidite deposition in the upper part, Hole 765C contains a thick and relatively complete Albian-Oligocene section, including a particularly thick Aptian interval, with abundant and fairly well-preserved nannofossils. Several unconformities are confidently interpreted in this section that span much of the Santonian, late Campanian, Maestrichtian, late Eocene, and early Oligocene. Hole 766A contains a thick and relatively complete Albian-lower Eocene section having generally abundant and well-preserved nannofossils. Several unconformities also have been identified in this section that span much of the Coniacian, early Campanian, Maestrichtian, and late Eocene through early Pliocene. The chronostratigraphic position and length of all these unconformities may have considerable significance for reconstructing the sedimentary history and for interpreting the paleoceanography of this region. A particularly thick section of upper Paleocene-lower Eocene sediments, including a complete record across the Paleocene/Eocene boundary, also was cored in Hole 766A that contains abundant and diverse nannofossil assemblages. Although assemblages from this section were correlated successfully using a standard low-latitude zonation, difficulties were encountered that reduced biostratigraphic resolution. Several lines of evidence suggest a mid-latitude position for Site 766 during this time, including (1) high assemblage diversity characteristic of mid-latitude zones of upwelling and (2) absence of certain ecologically controlled markers found only in low latitudes.

Calcareous nannofossil stratigraphy, nannofossil events and carbon isotopic ratios of ODP Leg 183 sites

Cores from Sites 1135, 1136, and 1138 of Ocean Drilling Program Leg 183 to the Kerguelen Plateau (KP) provide the most complete Paleocene and Eocene sections yet recovered from the southern Indian Ocean. These nannofossil-foraminifer oozes and chalks provide an opportunity to study southern high-latitude biostratigraphic and paleoceanographic events, which is the primary subject of this paper. In addition, a stable isotope profile was established across the Cretaceous/Tertiary (K/T) boundary at Site 1138. An apparently complete K/T boundary was recovered at Site 1138 in terms of assemblage succession, isotopic signature, and reworking of older (Cretaceous) nannofossil taxa. There is a significant color change, a negative carbon isotope shift, and nannofossil turnover. The placement of the boundary based on these criteria, however, is not in agreement with the available shipboard paleomagnetic stratigraphy. We await shore-based paleomagnetic study to confirm or deny those preliminary results. The Paleocene nannofossil assemblage is, in general, characteristic of the high latitudes with abundant Chiasmolithus, Prinsius, and Toweius. Placed in context with other Southern Ocean sites, the biogeography of Hornibrookina indicates the presence of some type of water mass boundary over the KP during the earliest Paleocene. This boundary disappeared by the late Paleocene, however, when there was an influx of warm-water discoasters, sphenoliths, and fasciculiths. This not only indicates that during much of the late Paleocene water temperatures were relatively equable, but preliminary floral and stable isotope analyses also indicate that a relatively complete record of the late Paleocene Thermal Maximum event was recovered at Site 1135. It was only at the beginning of the middle Eocene that water temperatures began to decline and the nannofossil assemblage became dominated by cool-water species while discoaster and sphenolith abundances and diversity were dramatically reduced. One new taxonomic combination is proposed, Heliolithus robustus Arney, Ladner, and Wise.