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.

Abundance and biomass of mesozooplankton from the Romanian littoral during DANUBS_2002 in spring and autumn 2002

The Danubs 2002 dataset contains zooplankton data collected in April, June,September and October 2002 in 11 station allong 5 transect in front of the Romanian littoral. Zooplankton sampling was undertaken at 11 stations where samples were collected 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.

(Table 1) Dissolved organic carbon, water temperature and conductivity in three subarctic ponds near Kilpisjärvi, North Finland

Daphnia was collected from five subarctic ponds which differed greatly in their DOC contents and, consequently, their underwater light (UV) climates. Irrespective of which Daphnia species was present, and contrary to expectations, the ponds with the lowest DOC concentrations (highest UV radiation levels) contained Daphnia with the highest eicosapentaenoic acid (EPA) concentrations. In addition, EPA concentrations in these Daphnia generally decreased in concert with seasonally increasing DOC concentrations. Daphnia from three of the ponds was also tested for its tolerance to solar ultraviolet radiation (UVR) with respect to survival. Daphnia pulex from the clear water pond showed, by far, the best UV-tolerance, followed by D. longispina from the moderately humic and D. longispina from the very humic pond. In addition, we measured sublethal parameters related to UV-damage such as the degree to which the gut of Daphnia appeared green (as a measure of their ability to digest algae), and whether their guts appeared damaged. We developed a simple, noninvasive scoring system to quantify the proportion of the gut in which digestive processes were presumably active. This method allowed repeated measurement of the same animals over the course of the experiment. We demonstrated, for the first time, that sublethal damage of the gut precedes mortality caused by exposure to UVR. In a parallel set of experiments we fed UV-exposed and non-exposed algae to UV-exposed and non-exposed daphnids. UVR pretreatment of algae enhanced the negative effects of exposure to natural solar UV-irradiation in Daphnia. These UV-related effects were generally not specific to the species of Daphnia.

Abundance of plant macrofossils, mollusca and ostracoda in sediments obtained near Tessin, north Germany

A depression filled with Late Glacial and Holocene sediments was excavated during the geological exploration and recovery of a dump area near Tessin close to Rostock, and initiated the studies of the present paper. Pebble analysis of three exposed or respectively drilled till horizons as well as pollenanalytical, carpological and faunistical studies carried out allow the stratigraphical subdivision of the Quaternary sequence of the dump area. The basal till was probably the result of dead ice decay, and was lithostratigraphically assigned to the Pomerian Stage (qw2). The palynological results of boreholes RKS 19/93 and A/92 reveal pre-Allerod and other sediments instead of the expected interweichselian deposits. Based on the palynological and carpological findings, we correlated the beginning of the late glacial development in the locality with the end of the Meiendorf-lnterstadial sensu Menke in Bock et al. (1985, doi:10.3285/eg.35.1.18). The limnic-telmatic sedimentation could be observed pollen floristically probably starting with the Meiendorf-lnterstadial (Hippophae-Betula nana-phase) followed by the Bolling-(Betula nana-B. alba s.l.-Artemisia-Helianthemum-Poaceae-phase) and the Allerad-lnterstadial [Betula alba s.l.-(Pinus)-Cyperaceae-phase] lasting up to the Younger Dryas (Juniperus-Artemisia-Poaceae-phase). Sedimentation closed during the Younger Dryas with the accumulation of fine sands. It was reactivated later during the Holocene due to the anthropogene influence (Older and Younger Subatlantic, dampness of the depression by clearing).

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.

Barremian-Aptian dinoflagellate cyst assemblages

Quantified organic-walled dinoflagellate cyst (dinocyst) assemblages are presented for two sedimentary successions deposited in neritic environments of the Tethys Ocean during the Barremian and Aptian in an attempt to reconcile established dinocyst biostratigraphic schemes for Tethyan and Austral regions. One section is at Angles, southeast France (the Barremian stratotype section); the other is at Deep Sea Drilling Project Site 263, off northwest Australia. We also construct a carbon isotope record for Site 263 using bulk organic carbon. Both sections contain abundant, well-preserved dinocyst assemblages. These are diverse, with 89 taxa identified at Angles and 103 taxa identified at Site 263. Of these, more than 93% are cosmopolitan. When combined with other work at Angles and Site 263, we found that nine dinocysts have their first occurrence (FO) or last occurrence (LO) at both locations. These dinocyst events are, in alphabetical order: LO of Cassiculosphaeridia magna, FO of Criboperidinium? tenuiceras, LO of Kleithriasphaeridium fasciatum, LO of Muderongia staurota, FO of Odontochitina operculata, LO of Phoberocysta neocomica, FO of Prolixosphaeridium parvispinum, FO of Pseudoceratium retusum var. securigerum, and FO of Tehamadinium sousense. Although these events support a Barremian-Aptian age for both sections, their stratigraphic order is not the same in the sections. The d13Corg record at Site 263 displays a characteristic series of changes that have also been recorded in other carbon isotope curves spanning the Late Barremian-Early Aptian. Such independent dating (along with ammonite zones at Angles) suggests that three of the nine dinocyst events are approximately isochronous at Angles and Site 263: the LO of K. fasciatum in the mid Barremian, the FO of P. retusum var. securigerum and the FO of C.? tenuiceras in the earliest Aptian; the other six dinocyst events are diachronous. Dinocyst assemblages at Site 263 can be loosely placed within existing Australian zonation schemes, providing much-needed calibration. Our data suggest that the Muderongia testudinaria Zone ends in sediments of mid Barremian age, the succeeding Muderongia australis Zone extends into the Early Aptian, and the younger Odontochitina operculata Zone begins in Early Aptian deposits. The boundary between the M. australis and O. operculata zones, and the Ovoidinium cinctum (as Ascodinium) Subzone, positioned at the top of the M. australis Zone when present, could not be recognized incontrovertibly. Interestingly, however, this horizon broadly correlates with the onset and extent of the Selli Event, a time of major biogeochemical change.

Physical, biological and chemical characteristics of Canadian and Danish lakes during summer

1. Winter temperatures differ markedly on the Canadian prairies compared with Denmark. Between 1 January 1998 and 31 December 2002, average weekly and monthly temperatures did not drop below 0 °C in the vicinity of Silkeborg, Denmark. Over this same time, weekly average temperatures near Calgary, Alberta, Canada, often dropped below -10 °C for 3-5 weeks and the average monthly temperature was below 0 °C for 2-4 months. Accordingly, winter ice conditions in shallow lakes in Canada and Denmark differed considerably. 2. To assess the implications of winter climate for lake biotic structure and function we compared a number of variables that describe the chemistry and biology of shallow Canadian and Danish lakes that had been chosen to have similar morphometries. 3. The Danish lakes had a fourfold higher ratio of chlorophyll-a: total phosphorus (TP). Zooplankton : phytoplankton carbon was related to TP and fish abundance in Danish lakes but not in Canadian lakes. There was no significant difference in the ratio log total zooplankton biomass : log TP and the Canadian lakes had a significantly higher proportion of cladocerans that were Daphnia. These differences correspond well with the fact that the Danish lakes have more abundant and diverse fish communities than the Canadian lakes. 4. Our results suggest that severe Canadian winters lead to anoxia under ice and more depauperate fish communities, and stronger zooplankton control on phytoplankton in shallow prairie lakes compared with shallow Danish lakes. If climate change leads to warmer winters and a shorter duration of ice cover, we predict that shallow Canadian prairie lakes will experience increased survivorship of planktivores and stronger control of zooplankton. This, in turn, might decrease zooplankton control on phytoplankton, leading to 'greener' lakes on the Canadian prairies.