Current state and long-term changes in the mesozooplankton community of the Ukrainian and Georgian parts of the Black Sea as indicators of its ecological status

Water quality assessment is a key task of any measures in the field of water use, environmental management and protection. Thus, it is necessary to conduct systematic monitoring to assess the ecological state in the marine waters and to develop a strategy for its recovery. Anthropogenic impacts of various types leading to eutrophication and pollution of the Black Sea are changing the main characteristics of all components of the aquatic ecosystem. Zooplankton plays a key role in the pelagic food web. This article presents the results of the research on the state of zooplankton which was conducted during the Ukrainian-Georgian expedition in the framework of the international project “Emblas-plus” during 2016, 2017 and 2019. The ecological quality class of the investigated Black Sea waters was determined by the zooplankton integrated index (IZI). In Ukrainian waters in total, 49 taxa of zooplankton were registered. In 2017 taxonomic composition of zooplankton was more diverse (36 taxa in 2016, 35 in 2019). In Georgian waters in 2019, 40 taxa of mesozooplankton were registered, most of them are widespread forms in the Black Sea. The most diverse group is Crustacea (Cladocera and Copepoda).The most prevalent crustaceans were the eurythermic species, an important representative of forage zooplankton – Acartia (Acartiura) clausi Giesbrecht, 1889 and two thermophilic species of Calanoida – Acartia (Acanthacartia) tonsa Dana, 1849 and Centropages ponticus Karavaev, 1895. In Ukrainian waters average abundance and biomass of zooplankton in 2019 was similar to those in 2016 and much higher than in 2017. Dominant taxa and spatial distribution of zooplankton in 2019 were similar to those in 2016 and 2017. Average biomass of forage zooplankton in 2019 was approximately 10 times higher than in 2016 and 2017. In the Georgian coastal waters annual average abundance and biomass of mesozooplankton decreased, due to a sharp decline in the abundance of Noctiluca scintillans (Macartney) Kofoid & Swezy, 1921. It was found that at most of the stations the dominant role in the formation of zooplankton biomass was played by the organisms of forage zooplankton. By the IZI index, the subdivision Northwestern Black Sea Bays had “Good”, “Poor” and “Moderate” water quality in spring, summer and autumn respectively. The subdivision’s deepwater shelf and shallow shelf had “Bad” water quality. The subdivision Danube-Dnieper interfluve coastal waters had “High” water quality. The Danube Avandelta area had “High”, “Good” and “High” water quality in spring, summer and autumn respectively. The best ecological class status was in 2019 and the worst – in 2016. The main tendencies in changes in the mesozooplankton community in the Black Sea are decrease in the percentage of N. scintillans in the total zooplankton biomass and increase in the percentage of Copepoda. Those tendencies indicate decrease in the pressure of the negative eutrophication factor and show positive changes in the forage base of commercial planktophagous fish and the ecological status of the Black Sea waters

Marine fishes in the Black Sea: recent conservation status

A revised checklist of the fish fauna of the Black Sea is reported. This paper is the first attempt to present an actual Check List of the fishes in the Black Sea according to the data available in the Black Sea countries, as well as their current conservation status, enlisted in IUCN. The total number of the Black Sea fish species is 189. Concerning the conservation status only two species (1.06 %) are extinct (Acipenser nudiventris and A. sturio), 3.70 % are critically endangered, 16.40 % are vulnerable, 1.06% are endangered, for 10.58 % there is a lack of data, 26.46% has been classified in the category “Least concern”, 2.65 % are “Near threatened” and 38. 10% are “Not evaluated”

Age and date for early arrival of the Acheulian in Europe (Barranc de la Boella, la Canonja, Spain)

The first arrivals of hominin populations into Eurasia during the Early Pleistocene are currently considered to have occurred as short and poorly dated biological dispersions. Questions as to the tempo and mode of these early prehistoric settlements have given rise to debates concerning the taxonomic significance of the lithic assemblages, as trace fossils, and the geographical distribution of the technological traditions found in the Lower Palaeolithic record. Here, we report on the Barranc de la Boella site which has yielded a lithic assemblage dating to ,1 million years ago that includes large cutting tools (LCT). We argue that distinct technological traditions coexisted in the Iberian archaeological repertoires of the late Early Pleistocene age in a similar way to the earliest sub-Saharan African artefact assemblages. These differences between stone tool assemblages may be attributed to the different chronologies of hominin dispersal events. The archaeological record of Barranc de la Boella completes the geographical distribution of LCT assemblages across southern Eurasia during the EMPT (Early-Middle Pleistocene Transition, circa 942 to 641 kyr). Up to now, chronology of the earliest European LCT assemblages is based on the abundant Palaeolithic record found in terrace river sequences which have been dated to the end of the EMPT and later. However, the findings at Barranc de la Boella suggest that early LCT lithic assemblages appeared in the SW of Europe during earlier hominin dispersal episodes before the definitive colonization of temperate Eurasia took place.The research at Barranc de la Boella has been carried out with the financial support of the Spanish Ministerio de Economı´a y Competitividad (CGL2012- 36682; CGL2012-38358, CGL2012-38434-C03-03 and CGL2010-15326; MICINN project HAR2009-7223/HIST), Generalitat de Catalunya, AGAUR agence (projects 2014SGR-901; 2014SGR-899; 2009SGR-324, 2009PBR-0033 and 2009SGR-188) and Junta de Castilla y Leo´n BU1004A09. Financial support for Barranc de la Boella field work and archaeological excavations is provided by the Ajuntament de la Canonja and Departament de Cultura (Servei d’Arqueologia i Paleontologia) de la Generalitat de Catalunya. A. Carrancho’s research was funded by the International Excellence Programme, Reinforcement subprogramme of the Spanish Ministry of Education. I. Lozano-Ferna´ndez acknowledges the pre-doctoral grant from the Fundacio´n Atapuerca. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Marine fishes in the Black Sea: recent conservation status

A revised checklist of the fish fauna of the Black Sea is reported. This paper is the first attempt to present an actual Check List of the fishes in the Black Sea according to the data available in Black Sea countries, as well as their current conservation status, enlisted in IUCN. The total number of Black Sea fish species is 189. Concerning the conservation status, only two species (1.06 %) are extinct (Acipenser nudiventris and A. sturio), 3.70 % are critically endangered, 16.40 % are vulnerable, 1.06% are endangered; for 10.58 % there is a lack of data, 26.46% has been classified in the category “Least concern”, 2.65 % are “Near threatened” and 38. 10% are “Not evaluated”

New 40Ar/39Ar, unspiked K/Ar and geochemical constraints on the Pleistocene magmatism of the Samtskhe-Javakheti highlands (Republic of Georgia)

International audienceThe Samtskhe-Javakheti volcanic plateau (Republic of Georgia) is the northernmost and youngest expression of the magmatism following the Arabia-Eurasia collision. Here, we present whole rock elemental and twenty-one new unspiked K/Ar and 40Ar/39Ar ages for the volcanic sequence well exposed east of the plateau. Based on our new radio-isotopic ages, we have identified three magmatic episodes. The oldest one (2.84–1.08 Ma), corresponding to the “Javakheti plateau s.s.”, is mainly constituted of medium-K alkaline mafic lavas (basalt, basaltic trachyandesite) and of intermediate composition domes (dacite). The more recent volcanic activity has constructed an impressive N–S trending volcanic ridge (Samsari s.s.) composed of evolved rocks (medium-K dacite to rhyolite). Within this ridge, two main periods of activity could be depicted: Middle Pleistocene (439–189 ka) and Late Pleistocene (90–13 ka). The youngest activity is restricted to the northern edge of this prominent magmatic structure and linked to the Tavkvetili volcano activity. According to these young ages, this area can be considered as a potential zone of volcanic hazards. The oldest volcanic activity shaping the Javakheti plateau is distributed between major strike slip faults in pull-apart position. The emplacement of the volcanism is controlled by a localized upper crustal extension. This is particularly outlined by the N–S linear array of domes that constitutes the Samsari ridge. This volcanic structure emplaced indeed on top of two major N–S faults that have probably played a key role to control the Middle to Late Pleistocene volcanism. The new 40Ar/39Ar ages date between 2.32 and 1.54 Ma the fauna assemblage of the Tsalka paleontological site. Rocks from the Samtskhe-Javakheti volcanic plateau derived from a low degree of melting of a metasomatized lithospheric mantle source (spinel facies). Except the obsidians from the Chickiani dome, they all derived from this source and evolved following a crystallization sequence involving mainly clinopyroxene, garnet, and/or amphibole. A crustal contamination component modified the composition of the youngest products (Samsari ridge rocks). According to the geochemical signature of these rocks, it seems that the magmatism does not fit with models involving asthenospheric upwelling in this region

Charge-Transfer Complexes of Linear Acenes with a New Acceptor Perfluoroanthraquinone. The Interplay of Charge-Transfer and F···F Interactions

© 2019 American Chemical Society. Two charge-transfer bicomponent 1:1 crystals of polycyclic aromatic hydrocarbons (anthracene and tetracene) with a new acceptor molecule (perfluoroanthraquinone) were grown by slow evaporation from solutions in toluene. In both crystals, π-πstacks of alternating donor and acceptor molecules are observed. In the tetracene-perfluoroanthraquinone complex, face-to-face stacking is the prevailing intermolecular interaction, while in the complex of anthracene-perfluoroanthraquinone multiple interactions (stacking, F···H, O···H, F···F) of similar energy are observed, as revealed by the Quantum Theory of Atoms in Molecules method, resulting in the formation of polymorphic modifications, as determined by X-ray single crystal diffraction and differential scanning calorimetry. The charge-transfer degree was estimated to be equal to 0.04 and 0.08 e in anthracene- and tetracene-containing complexes, respectively

Charge-Transfer Complexes of Linear Acenes with a New Acceptor Perfluoroanthraquinone. The Interplay of Charge-Transfer and F···F Interactions

© 2019 American Chemical Society. Two charge-transfer bicomponent 1:1 crystals of polycyclic aromatic hydrocarbons (anthracene and tetracene) with a new acceptor molecule (perfluoroanthraquinone) were grown by slow evaporation from solutions in toluene. In both crystals, π-πstacks of alternating donor and acceptor molecules are observed. In the tetracene-perfluoroanthraquinone complex, face-to-face stacking is the prevailing intermolecular interaction, while in the complex of anthracene-perfluoroanthraquinone multiple interactions (stacking, F···H, O···H, F···F) of similar energy are observed, as revealed by the Quantum Theory of Atoms in Molecules method, resulting in the formation of polymorphic modifications, as determined by X-ray single crystal diffraction and differential scanning calorimetry. The charge-transfer degree was estimated to be equal to 0.04 and 0.08 e in anthracene- and tetracene-containing complexes, respectively

ADDENDUM : New Ar-40/Ar-39, unspiked K/ar and geochemical constraints on the Pleistocene magmatism of the Samtskhe-Javakheti highlands (Republic of Georgia)

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