scholarly journals Sediment composition within relict and modern spits of the Late-Holocene Kiliya delta of the Danube

2020 ◽  
Vol 101-102 (3-4) ◽  
pp. 52-59
Author(s):  
Yuriy Shuisky ◽  
Halyna Vykhovanets ◽  
Liliya Gyzhko ◽  
Liudmyla Organ
Keyword(s):  
Average Concentration ◽  
Middle Part ◽  
Coastal Sediments ◽  
The Black Sea ◽  
Sieve Analysis ◽  
Primary Role ◽  
Danube Delta ◽  
Coastal Marine ◽  
Study Results ◽  
Different Ages

The authors aimed to perform granulometric analysis of coastal sediments in the area of scattering of long-shore drift in the Jebriani bay within the Danube delta on the basis of mass sampling on the ancient relict and modern accumulative forms. The present study used the standard lithodynamic research methods. The paper presents the study results of sand deposit samples on ancient relict and modern sandy spits (‘grindu’) in the northern part of the mouth of the Danube. Overall, 24 samples were analyzed: 12 samples were collected on the tops of the aeolian hills and the other 12 – between the hills and ridges. In addition to this at the middle part of the Jebriani spit a typical cross-section was made, where 24 samples were retrieved based on microrelief features. For the first time in coastal literature, comparisons of the granulometric composition of sediments which compose ancient and modern generations of wave shafts within the Kiliya part of the Danube Delta have been carried out. The obtained samples were processed in the laboratory using standard methods of water and sieve analysis. The results were presented in the form of histograms and other types of graphics which allowed to us to compare and analyze the ratio of the composition of the relic and recent grindu. The obtained results revealed that ancient generations of grindu were composed of sediments from the same sources and in accordance to the same laws as modern ones. They are both composed of the same minerals, among which the primary role is taken by quartz, calcite, feldspar, magnetite, with a corresponding density (2.6-2.7 g/cm3, increased in calcite). In recent decades, the so-called beaches and borders of the grindu have disappeared. “Carpathian gravels”, which are fragments of the Early-Holocene terrace of the ancient Dniester, are today located at the bottom of the Black Sea in offshore environment. The synthetic composition of modern grindu branches is characterized by a reduced content of fractions ≥ 0.5 mm and ≤ 0.1 mm. The primary fraction is 0.25-0.5 mm (56-61%), although in the ancient relict form it reaches 69-75%. The average concentration of the second fraction of 0.1-0.25 mm is surprisingly stable in the grindu of different ages, namely 20-22%, including on the beaches, on the tops of the shafts and in the inter-shaft lowlands. The shapes of particles are very similar on the forms of different ages, rounding points value 3-4 are of leading importance. The particle size distribution in the area of sediment flow scattering allows to determine the behaviour of rock particles in a moving marine environment, the structure of sediments and sedimentary rocks of coastal, marine and aeolian origin.

Blood Analysis Requests of Patients’ and Clinical Reflections in Primary Care

2020 ◽  
Vol 9 (2) ◽  
pp. 96-102
Author(s):  
Zerrin Gamsizkan ◽  
Mehmet Ali Sungur ◽  
Yasemin Çayır
Keyword(s):  
Chronic Disease ◽  
Blood Test ◽  
Family Health ◽  
Cross Sectional Study ◽  
Blood Analysis ◽  
Primary Role ◽  
Cross Sectional ◽  
High Expectations ◽  
Blood Tests ◽  
Study Results

Aim: The aim of the study is to determine the factors that may affect the demands of patients who come with the request to have a blood test without any chronic disease or a planned examination check. Methods: The data of this descriptive, cross-sectional study, were collected with a questionnaire that was prepared to examine the opinions of the patients who claim to have a blood test by coming to the family health center without any complaints. Patients over 18 years of age, who did not have any chronic disease and had no scheduled examination appointments were included in the study. Results: A total of 278 patients who wanted to have a blood test within the 6-months period were included in the study. Female patients who wanted to have a blood test were significantly more than male patients. When we look at the causes of patients who wanted to have a blood test; 61.2% (n=170) patients stated that they are concerned about their health and 6.1% (n=17) stated that they were affected by media warnings. There was no significant relationship between the frequency of blood test requests of patients and their age, gender, education, and general health status. Conclusion: Patients with high expectations and anxiety may be more willing to perform blood tests at inappropriate intervals. Family physicians, whose primary role is preventive medicine, have consultancy and information duties in order to protect their patients from the risk of over-examination and diagnosis. Keywords: blood tests, patient, screening, routine diagnostic tests

scholarly journals Late-Holocene landscape evolution and human presence in the northern Danube delta (Chilia distributary lobes)

The Holocene ◽  
2021 ◽  
pp. 095968362110191
Author(s):  
Luminița Preoteasa ◽  
Alfred Vespremeanu-Stroe ◽  
Anca Dan ◽  
Laurențiu Țuțuianu ◽  
Cristian Panaiotu ◽  
...  
Keyword(s):  
Middle Ages ◽  
Economic History ◽  
Late Holocene ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Sedimentary Facies ◽  
The Black Sea ◽  
Danube Delta ◽  
Human Presence ◽  
Historical Texts

This paper documents the Late-Holocene environmental changes and human presence in the northern Danube delta using a multidisciplinary approach that combines geoscientific data with archaeological findings, historical texts, and maps. It follows the formation and progression of the Chilia distributary and the reconfiguration of socioeconomic activities. Sedimentary facies identified on five new cores by changes in texture properties, magnetic susceptibility, geochemistry, and macro- and microfauna composition together with the newly obtained chronology constrain the complex evolution of the Chilia branch as filling in a long-lasting bay and then of a giant lagoon (Thiagola) which covered most of the northern delta since the Old Danube lobe inception (ca. 7500 yrs BP) till modern Chilia development. It initiated during the Greek Antiquity (ca. 2500 yrs ar BP) at the delta apex, while in Roman times (ca. 1800 yrs BP) it pursued its slow flowing into the vast Thiagola Lagoon. The most dramatic transformations occurred in the last 800 years when the river passed east of the Chilia promontory, rapidly went through the present-day Matița-Merhei basin (several decades), and created its first open-sea outlet. Solid discharge increased in two distinct periods, once in the Middle Ages (ca. 750 yrs BP) and then in the Modern Period (ca. 150 yrs BP) due to human-induced land-use changes in the Danube watershed. The chronology of the cultural remains on the pre-deltaic Chilia promontory and the multiproxy analysis of a sediment core retrieved nearby downstream suggest the terrestrial connection of the island with the mainland in ancient times. The hitherto contended issue of the old Thiagola Lagoon and its location are redefined here, as are the original identifications of ancient and medieval toponyms and hydronyms, especially for Chilia-Licostomo, Byzantine, Genoese, Moldavian, Ottoman, and Russian trading point of great importance in the political and economic history of the Black Sea and neighboring regions.

scholarly journals The Black Sea Trout, Salmo labrax Pallas, 1814 (Pisces: Salmonidae) in Romanian Waters

2020 ◽  
Vol 77 (2) ◽  
pp. 9
Author(s):  
Călin LAȚIU ◽  
Daniel COCAN ◽  
Paul UIUIU ◽  
Andrada IHUȚ ◽  
Sabin Alexandru NICULA ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Danube Delta ◽  
Meristic Characters ◽  
Sea Trout ◽  
Research Fields ◽  
New Information ◽  
Rivers And Lakes ◽  
Recorded Data ◽  
New Hypothesis

The review assembles chronological data on Black Sea trout (Salmo labrax) from Romanian waters and brings up-to-date information related to the distribution of the species. The information used dates from 1909 to 2020 and includes books, articles, digital databases, field observations, and notes from different research fields such as ichthyology, biogeography, genetics, aquaculture, conservation, and ecology. Global distribution, migration, meristic characters, and aquaculture of the species were analyzed based on the recorded data from the specialty literature. New information related to a possible population of Salmo labrax inside the Carpathian Arch was discussed. In Romanian waters the species is found in the Black Sea, Danube, Danube Delta but the current paper proposes a new hypothesis, namely that resident populations can be found in rivers and lakes adjacent to the Carpathian Arch. The highest migration point of the Black Sea trout in the Danube was recorded near Corabia locality, Olt County, (43°46′25″N- 24°30′12″E). In the Danube Delta, it was caught in all the three branches (Sulina, Sf. Gheorghe and Chilia), and lagoonary complexes such as Razim-Sinoe. Sexually matured females were caught especially in Spring Season while unmatured specimens were caught in all seasons. Even if the species is protected under Romanian legislation, fishermen and anglers should report its presence when caught accidentally.

scholarly journals Enrichment of novel Verrucomicrobia, Bacteroidetes and Krumholzibacteria in an oxygen-limited, methane- and iron-fed bioreactor inoculated with Bothnian Sea sediments

2020 ◽  
Author(s):  
Paula Dalcin Martins ◽  
Anniek de Jong ◽  
Wytze K. Lenstra ◽  
Niels A. G. M. van Helmond ◽  
Caroline P. Slomp ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Coastal Sediments ◽  
Ecosystem Functions ◽  
Marker Genes ◽  
Iron Cycling ◽  
Low Oxygen ◽  
Coastal Marine ◽  
Metabolic Versatility ◽  
Comprehensive Knowledge ◽  
Bothnian Sea

AbstractMicrobial methane oxidation is a major biofilter preventing larger emissions of this powerful greenhouse gas from marine coastal areas into the atmosphere. In these zones, various electron acceptors such as sulfate, metal oxides, nitrate or oxygen can be utilized. However, the key microbial players and mechanisms of methane oxidation are poorly understood. In this study, we inoculated a bioreactor with methane- and iron-rich sediments from the Bothnian Sea in order to investigate microbial methane and iron cycling under low oxygen concentrations. Using metagenomics, we observed shifts in the microbial community over approximately 2.5 years of bioreactor operation. Marker genes for methane and iron cycling, as well as respiratory and fermentative metabolism, were investigated. Metagenome-assembled genomes representing novel Verrucomicrobia, Bacteroidetes and Krumholzibacteria were recovered and revealed potential for methane oxidation, organic matter degradation, and iron cycling, respectively. This work brings new insights into the identity and metabolic versatility of microorganisms that may be members of such functional guilds in coastal marine sediments and highlights that the methane biofilter in these sediments may be more diverse than previously appreciated.ImportanceDespite the essential role of microorganisms in preventing most methane in the ocean floor to reach the atmosphere, comprehensive knowledge on the identity and the mechanisms employed by these microorganisms is still lacking. This is problematic because such information is needed to understand how the ecosystem functions in the present and how microorganisms may respond to climate change in the future. Here, we enriched and identified novel taxa potentially involved in methane and iron cycling in an oxygen-limited bioreactor inoculated with methane- and iron-rich coastal sediments. Metagenomic analyses provided hypotheses about the mechanisms they may employ, such as the use of oxygen at very low concentrations. The implication of our results is that in more shallow sediments, where oxygen-limited conditions are present, the methane biofilter is potentially composed of novel, metabolically versatile Verrucomicrobia that could contribute to mitigating methane emissions from coastal marine zones.

scholarly journals Environmental Investigations and Tissue Bioaccumulation of Heavy Metals in Grey Mullet from the Black Sea (Bulgaria) and the Ionian Sea (Italy)

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1739
Author(s):  
Francesco Fazio ◽  
Claudio D’Iglio ◽  
Gioele Capillo ◽  
Concetta Saoca ◽  
Katya Peycheva ◽  
...  
Keyword(s):  
Black Sea ◽  
Marine Pollution ◽  
Total Concentration ◽  
Essential Elements ◽  
Analytical Determination ◽  
The Black Sea ◽  
Ionian Sea ◽  
Grey Mullet ◽  
Coastal Marine ◽  
Fish Samples

The environmental monitoring of chemical toxicants has been a widely studied topic in the last few decades. The main aim of the present study was to determine the total concentration of nine elements (Cd, Cr, Pb, Ni, Al, Cu, Fe, Mn, and Zn) in the fish species grey mullet (M. cephalus) and in the coastal marine waters collected from various sampling points along the Black Sea (Bulgaria) and the Ionian Sea (Italy). Further, those results were applied to predict the pollution degree in those coastal marine environments. The fish samples were subject to acid digestion followed by appropriate analytical determination. The metal concentrations in marine water samples collected from the Black Sea (Bulgaria) and the Ionian Sea (Italy) were also analyzed. Unpaired Student’s t-test and the one-way ANOVA were applied for the statistical analysis of the data. The statistical results revealed a significant variation (p < 0.0001) in the concentration of various fish tissues. The accumulation of toxic and essential elements differs significantly in grey mullet species caught from the Black Sea (Bulgaria) and the Ionian Sea (Italy). The results from this study may serve as a convenient approach during marine pollution programs set by both countries (Italy and Bulgaria).

scholarly journals An Overview of the Expected Shoreline Impact of the Marine Energy Farms Operating in Different Coastal Environments

2020 ◽  
Vol 8 (3) ◽  
pp. 228
Author(s):  
Alina Raileanu ◽  
Florin Onea ◽  
Eugen Rusu
Keyword(s):  
Case Studies ◽  
Wave Action ◽  
The Black Sea ◽  
Coastal Protection ◽  
Real Problem ◽  
Danube Delta ◽  
Nearshore Processes ◽  
Portuguese Coast ◽  
Longshore Currents ◽  
Marine Energy

The aim of the present work is to provide an overview of the possible implications involving the influence of a generic marine energy farm on the nearshore processes. Several case studies covering various European coastal areas are considered for illustration purposes. These include different nearshore areas, such as the Portuguese coast, Sardinia Island or a coastal sector close to the Danube Delta in the Black Sea. For the case studies related to the Portuguese coast, it is noted that a marine energy farm may reduce the velocity of the longshore currents, with a complete attenuation of the current velocity for some case studies in the coastal area from Leixoes region being observed. For the area located close to the Danube Delta, it is estimated that in the proposed configuration, a marine energy farm would provide an efficient protection against the wave action, but it will have a relatively negligible impact on the longshore currents. Summarizing the results, we can conclude that a marine energy farm seems to be beneficial for coastal protection, even in the case of the enclosed areas, such as the Mediterranean or Black seas, where the erosion generated by the wave action represents a real problem.

scholarly journals Evaluation of Different Simulation Methods for Analyzing Flood Scenarios in the Danube Delta

2020 ◽  
Vol 10 (23) ◽  
pp. 8327
Author(s):  
Alexandru Banescu ◽  
Maxim Arseni ◽  
Lucian Puiu Georgescu ◽  
Eugen Rusu ◽  
Catalina Iticescu
Keyword(s):  
Flood Control ◽  
Dynamic Method ◽  
Static Method ◽  
Water Levels ◽  
The Black Sea ◽  
General Interest ◽  
Danube Delta ◽  
Simulation Accuracy ◽  
Discharge Area ◽  
Investment Promotion

The present work is focused on the analysis of flood scenarios for the settlements near the Danube discharge area into the Black Sea. From this perspective, the aim of the research is the development of flood extension maps for localities in the Danube Delta. The emphasis is on collecting the data and information needed for the entire analysis process, such as hydrological data on Danube flows and water levels (which were analyzed for 51 years), topo-bathymetric data (where 1685 cross sections were processed, measured on an 87-km section of the Danube), a digital terrain model (DTM), and others. Two methods of flood scenario analysis for the localities targeted were used in this paper. The first method was an analysis of the flood scenarios by modeling a real scenario, where it was supposed that a 20 m breach appeared in the dam which protects the localities and remained present for 24 h. The second method consisted of a Geographic Information System (GIS) analysis (static from a hydraulic point of view), where the maximum water level was superimposed over the DTM. This corresponded to a scenario in which the breach in the flood-control levee remains present for a longer period. The validated results show that the dynamic method is more efficient than the static method, both in terms of estimated flooded surfaces and in terms of simulation accuracy (taking into account more input parameters than the static method). Thus, from the obtained simulations it was observed that applying the dynamic method resulted in smaller flooded surfaces in the settlements analyzed than when considering the static method. In some cases, the differences between the flooded surfaces reached up to about 22%. This information is important and of general interest since it can be used in various fields of work, such as flood defense strategies, and investment promotion activities in the Danube discharge area or similar locations.

Development of a Web-based GIS monitoring and environmental assessment system for the Black Sea: application in the Danube Delta area

2016 ◽  
Vol 188 (8) ◽  
Author(s):  
Ilias N. Tziavos ◽  
Thomas K. Alexandridis ◽  
Borys Aleksandrov ◽  
Agamemnon Andrianopoulos ◽  
Ioannis D. Doukas ◽  
...  
Keyword(s):  
Black Sea ◽  
Environmental Assessment ◽  
Assessment System ◽  
The Black Sea ◽  
Danube Delta ◽  
Web Based ◽  
Delta Area

scholarly journals Reinekea marinisedimentorum gen. nov., sp. nov., a novel gammaproteobacterium from marine coastal sediments

2004 ◽  
Vol 54 (3) ◽  
pp. 669-673 ◽  
Author(s):  
Lyudmila A. Romanenko ◽  
Peter Schumann ◽  
Manfred Rohde ◽  
Valery V. Mikhailov ◽  
Erko Stackebrandt
Keyword(s):  
Marine Sediment ◽  
Sequence Similarity ◽  
Phospholipid Fatty Acid ◽  
Fatty Acid Analysis ◽  
Coastal Sediments ◽  
Physiological Data ◽  
Organic Substrates ◽  
Coastal Marine ◽  
Novel Genus And Species ◽  
Marine Sediment Sample

A Gram-negative, oxidase- and catalase-positive, rod-shaped bacterium, designated strain KMM 3655T, was isolated from a coastal marine sediment sample. The novel bacterium required sodium ions for growth and grew between 0·5 and 5 % NaCl and at 4–37 °C, but not at 40 °C. It reduced nitrate, formed acids from glucose under aerobic and anaerobic conditions, utilized a limited spectrum of organic substrates and did not produce gelatinase, caseinase, amylase or chitinase. The major isoprenoid quinone was Q8. Polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and an unknown phospholipid. Fatty acid analysis of strain KMM 3655T revealed C16 : 0, C16 : 1 ω7c and C18 : 1 ω7c as predominant components. The G+C content of the DNA was 51·1 mol%. Phylogenetic analysis of the 16S rDNA sequence placed the new isolate within the γ-Proteobacteria as a separate deep branch, with about 90 % sequence similarity to representatives of the genus Oceanospirillum and other remotely related genera. Combined phylogenetic and physiological data show that the new marine sediment isolate, KMM 3655T, represents a novel genus and species, for which the name Reinekea marinisedimentorum gen. nov., sp. nov. is proposed. The type strain is KMM 3655T (=DSM 15388T).

scholarly journals Spatio-temporal variations of lateral and atmospheric carbon fluxes from the Danube Delta

2020 ◽  
Author(s):  
Marie-Sophie Maier ◽  
Cristian R. Teodoru ◽  
Bernhard Wehrli
Keyword(s):  
Surface Area ◽  
Black Sea ◽  
Carbon Emissions ◽  
Danube River ◽  
The Black Sea ◽  
Danube Delta ◽  
Carbon Turnover ◽  
Carbon Yield ◽  
River Deltas ◽  
Net Export

Abstract. River deltas with their mosaic of ponds, channels and seasonally inundated areas act as the last continental hotspots of carbon turnover along the land-ocean aquatic continuum. There is increasing evidence for the important role of riparian wetlands in the transformation and emission of terrestrial carbon to the atmosphere. The considerable spatial heterogeneity of river deltas, however, forms a major obstacle for quantifying carbon emissions and their seasonality. While river reaches crossing the delta can serve as reference systems, delta lakes are often dominated by aquatic production and channels act as collection systems for carbon exported from adjacent wetlands. In order to quantify carbon turnover and emissions in the complex mosaic of the Danube Delta, we conducted monthly field campaigns over two years at 19 sites spanning river reaches, channels and lakes. Here we report greenhouse gas fluxes (CO2 and CH4) from the freshwater systems of the Danube Delta and present the first seasonally resolved estimates of its freshwater carbon emissions to the atmosphere. Furthermore, we quantify the lateral carbon transport of the Danube River to the Black Sea. We estimate the delta’s CO2 and CH4 emissions to be 65 GgC yr−1, of which about 8 % are released as CH4. The median CO2 fluxes from river branches, channels and lakes are 25, 93 and 5.8 mmol m−2 yr−1, respectively. Median total CH4 fluxes amount to 0.42, 2.0 and 1.5 mmol m−2 yr−1. While lakes do have the potential to act as CO2 sinks in summer, they are generally the largest emitters of CH4. Small channels showed the largest range in emissions including a CO2 and CH4 hotspot sustained by adjacent wetlands. The channels thereby contribute disproportionately to the delta’s emissions considering their limited surface area. In terms of lateral export, we estimate the net export of the Danube Delta to the Black Sea to about 160 GgC yr−1, which only marginally increases the carbon load from the upstream river catchment (8490 GgC yr−1) by about 2 %. While this contribution of the delta seems small, deltaic carbon yield (45.6 gC m−2 yr−1, net export load/surface area) is about 4-fold higher than the riverine carbon yield from the catchment (10.6 gC m−2 yr−1).

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