Upper Miocene Ostracods of the Turiec Basin (Slovakia) - subfamily Cyclocypridinae

Six species of the sub-family Cyclocypridinae were found in the Upper Miocene of the Turiec Basin, 4 of which are new Cypria isosceles, C. lenticulata, C. polyphema, C. bodergatiae. The differences in arrangement of the zone of the fusion on ventral margin were used to distinguish the species. The genus Cypria is represented in whole area of the Turiec Basin but the species are restricted to the ecologically well determined biotopes. Valve shape is compared with ecological stability of the paleobiotopes

Water sources, mixing and evaporation in the Akyatan lagoon, Turkey

Akyatan lagoon, located southeast of Turkey along the Mediterranean coast, is a choked and hypersaline lagoon, and hosts a large and specific biodiversity including endangered sea turtles and migrating birds. Physicochemical properties of this lagoon were investigated by measuring temperature, salinity, and hydrogen and oxygen isotope ratios of its waters at a seasonal scale during years 2006 and 2007. Winter and spring seasons were dominated by mixing processes between freshwaters and Mediterranean seawater. The majority of spring season waters are formed by evapoconcentration of brackish water at moderate temperatures of 22 ± 2 °C. During summer, hypersaline waters result from evaporation of seawater and brackish waters formed during spring. Evaporation over the Akyatan lagoon reaches up to 76 wt% based on salinity measurements and operated with a dry (relative humidity of 0.15-0.20) and hot (44 ± 6 °C) air. These residual waters were characterized by the maximal seasonal isotopic enrichment in both deuterium and 18O relative to VSMOW. During autumn, most lagoonal waters became hypersaline and were formed by evaporation of waters that had isotopic compositions and salinities close to that of seawater. These autumnal hypersaline waters result from an air humidity close to 0.45 and an atmospheric temperature of evaporation of 35 ± 5 °C, which are responsible for up to 71 wt% of evaporation, with restricted isotopic enrichments relative to VSMOW. During the warm seasons, the combination of air humidity, wind velocity and temperature were responsible for a large kinetic component in the total isotopic fractionation between water liquid and water vapour. © 2012 Elsevier Ltd.Institut Universitaire de France Centre National de la Recherche ScientifiqueThis work was funded by the French “Centre National de la Recherche Scientifique” , the “Institut Universitaire de France” , the University of Adana and the French Embassy in Turkey . Fig. 1 was designed with the contribution of Charles Camarda. The authors thank S. Halas and one anonymous reviewer who helped us to improve the scientific quality of this work

Oxygen isotope variability in calcite shells of the ostracod Cyprideis torosa in Akyatan Lagoon, Turkey

The euryhaline ostracod Cyprideis torosa lives in Akyatan Lagoon, Turkey, which is exposed to large spatial and seasonal variations in water salinity, ?18O, and temperature. Hydrogen and oxygen isotope measurements of waters reveal that the large range of salinity (15-80 g L-1) in the lagoon results from a combination of evaporation and mixing between Mediterranean seawater and Seyhan River input. Round sieve-pore relative abundance in C. torosa provides a robust proxy for water salinity (S) from 15 to 80 g L-1, according to the equation: S = 161.41 (±4.52) * log10(% rounded pores) - 94.04 (±3.44) (R2 = 0.937; p = 10-31). Seasonal sampling and isotope analysis of C. torosa in waters of known ?18O values (-4.7 to +6.9 ‰ V-PDB) and temperatures (15-35 °C) yielded a weak positive correlation (r = 0.71) between 1000 ln?(calcite-water) ‰ V-SMOW) and 103 * T-1. Specimens of C. torosa collected during the mild and warm seasons have oxygen isotope compositions close to those of inorganic calcite precipitated in equilibrium with ambient water. The large oxygen-isotope variability observed during any season of the year most likely results from shell calcification in water bodies of highly variable salinity, alkalinity, Mg/Ca and water saturation relative to calcite. Indeed, distinct water bodies in the Akyatan Lagoon are generated by mixing of fresh and marine waters, which are exposed to different evaporation rates at the seasonal scale. © 2014 Springer Science+Business Media Dordrecht.Institut Universitaire de France Centre National de la Recherche ScientifiqueAcknowledgments This work was funded by the French ‘‘Centre National de la Recherche Scientifique,’’ the ‘‘Institut Universitaire de France,’’ the University of C¸ ukurova, and the French Embassy in Turkey. Figure 1 was designed with the contribution of C. Camarda. We thank E. Canakci and O. Ataman for assistance in the field. The authors are deeply grateful to two anonymous reviewers who helped improve the scientific content of this study

Freshwater ostracods as environmental tracers

This paper revises the response of freshwater ostracods to different environmental conditions and anthropogenic impacts, with a worldwide overview of the potential use of these microcrustaceans as bioindicators and several examples of applications in different scenarios. The development of either a single species or an ostracod assemblage is influenced by physical-chemical properties of waters (salinity, temperature, pH, dissolved oxygen), hydraulic conditions, bottom grain sizes or sedimentation rates. In addition to population and community changes, morphological and geochemical changes can also be detected in the ostracod carapace, which serves as a tracer of the water quality. All these features permit to delimit the spatial effects of urban sewages, mining effluents, agricultural wastes, watershed deforestation or road building. These data are the basis for the palaeoenvironmental reconstruction of cores, with an interesting application to archaeology. In addition, favourable results of recently developed bioassays, coupled with an important variability of local assemblages under changing conditions in both waters and sediments, suggest that these microcrustaceans may included between the most promising sentinels groups in freshwater areas. These microcrustaceans show high sensitivity to pesticides, herbicides, heavy metal pollution and oil inputs