scholarly journals SPECIFIC MICROBIOLOGY SPECTRUM OF WHITE SAND MUSSELS FROM KEY SAMPLE SPOTS FROM BULGARIAN BLACK SEA AQUATORY

2021 ◽  
Vol 27 (4) ◽  
pp. 4077-4083
Author(s):  
Borislava K. Pavlova ◽  
◽  
Sevginar F. Ibryamova ◽  
Dаrina Bachvarova ◽  
Dimitar D. Doichev ◽  
...  

The "white sand mussels" are edible bivalves inhabiting the littoral shores usually buried in the sand. Тhey are invasive species for the Bulgarian waters of the Black Sea. The samples for this study were collected from different points on the northern and southern Black Sea Bulgarian coast in the period January 2020 to December 2020. The study of different types of microorganisms was performed by using the microbial identification system model: MicroLog M® BIO45101 BiologInc and the software product GEN III. The physic-chemical parameters of the waters – temperature, pH, salinity and dissolved O2 were also determined. In the different species, we had detected specific microbiological complexes. The species Pseudomonas viridilivida and Citrobacter farmer were isolated only from Donax trunculus. The species Escherichia hermannii was found only in Mya arenaria, and Acinetobacter johnsonii was detected only in Chamelea gallina. The isolated species Acinetobacter gyllenbergii and Acinetobacter johnsonii are related to humans and are indicators for pollution of the water with channel waste waters. Our results demonstrated an increase ofhe quantity of the coliforms the region of Sveti Vlas from August, where they were 50 the norms. In the region of Arkutino in July and Ahtopol in August, the quantity of the fecal coliforms is 190 and 30 times the norms prescribed in the Ordinanceo. 4 from 20.10.2000 for the quality of fisheries water and the breeding of shellfish (the amount of fecal coliforms in the inter-shell content should be less than 300 NVB). We noticed also seriousollution of the Varna lake even months after an accident with a leaky pipe.

2021 ◽  
Author(s):  
Marilaure Grégoire ◽  

<p>The Black Sea is a small enclosed basin where coastal regions have a large influence and mesoscale signals dominate the dynamics (the Rossby radius of deformation is about 20km). Large riverine inputs, mainly on the northwestern shelf, induce well-marked horizontal gradients in the distribution of the Black Sea salinity and optical characteristics: coastal and shelf waters have very low salinity and contain large amounts of optically active materials (e.g. coloured dissolved organic matter) and its oligotrophic deep sea has a salinity around 18.2. The presence of these contrasting water characteristics in a relatively small enclosed environment, combined with land contamination and the specificities of its atmospheric composition(e.g. high cloud coverage, aerosols) make the Black Sea a challenging area for the development of high quality satellite products. </p><p> </p><p>We present first results from a 2-year on-going ESA-funded project, EO4SIBS (Earth Observation for Science and Innovation in the Black Sea) dedicated to the development, and subsequent scientific analysis, of new algorithms and products. In particular, ocean colour products (chlorophyll-a and total suspended matter concentrations, turbidity) were produced from Sentinel 3 (S3) OLCI data combining different algorithms selected based on an automatic water mass classification procedure (case-1 versus case-2 waters). In specific areas, S3-OLCI and Sentinel 2-MSI data were merged to address local features. A revised gridded altimetry product based on 5-Hz along track data (combining Cryosat and S3 SAR) was produced and validated in the coastal zone with tide gauge data. Sea Surface Salinity was derived from the L-Band measured by SMOS and compared with in-situ surface salinity data from field sampling and Argo. </p><p> </p><p>All these products are now being integrated to further understand the Black Sea physical and biogeochemical functioning (e.g., plume and productivity patterns, mesoscale dynamics, deoxygenation). For instance, the Black Sea mesoscale dynamics are inferred from the 5-Hz altimetry product using an eddy detection and tracking algorithm. The quality of the eddy mapping is assessed by comparison with visible and infrared satellite products while the derived velocities are compared with drifters. Also, the benefit of assimilating ocean colour data in the Black Sea operational model (also known as CMEMS BS-MFC BIO) for the prediction of the Black Sea ecosystem will  be illustrated.</p><p> </p><p>Gridded products are archived as CF-compliant NetCDF files and disseminated through ncWMS protocol. In-situ data are modeled as vector points in a PostGIS database. A web portal is being implemented in order to propose an efficient spatiotemporal exploration of both data sources in a user-friendly interface, including interactive map layers and export possibilities.</p><p> </p><p>We conclude with a set of recommendations for observational requirements needed  to increase the quality of satellite products in the Black Sea and to be able to use the full potential of current and new information provided by  satellites. </p><p> </p>


Author(s):  
Е.Е. ИВАНОВА ◽  
Е.А. ДУБИНЕЦ ◽  
А.Л. БОЧАРОВА-ЛЕСКИНА

Для стабилизации показателя биологической эффективности исследована возможность повышения количества полиненасыщенных жирных кислот (ПНЖК) за счет снижения количества насыщенных жирных кислот (НЖК) в жирнокислотном составе жира из печени черноморской акулы-катрана в летний период вылова (с мая по октябрь). С целью повышения содержания омега-3 ПНЖК в продукте применен способ винтеризации. Кристаллизацию жира из печени акулы-катрана проводили в специальном охладителе при температуре от 0 до –5°С. Во время охлаждения жир медленно перемешивали (скорость вращения мешалки 20–25 об/мин) для равномерного охлаждения по всему объему. Полная кристаллизация НЖК при этих условиях проходила за 5–6 ч. Охлажденный жир немедленно направляли на осадительную центрифугу. В качестве параметров оптимизации процесса были выбраны: качество жира – прозрачность при температуре 15°С и степень ненасыщенности – йодное число жира. Установлено, что факторами, существенно влияющими на йодное число и органолептические показатели жира, являются: температура охлажденного жира, продолжительность центрифугирования, число оборотов барабана центрифуги. Для моделирования значений йодного числа и органолептического показателя в области изменения указанных факторов применена схема полного факторного двухуровневого эксперимента, в результате которого определены натуральные значения факторов, отвечающие наилучшему значению показателя качества жира: температура охлаждения жира –4°С, продолжительность центрифугирования 30 мин, частота вращения барабана центрифуги 6000 об/мин. Общая ненасыщенность жидкой фракции возросла с 122,2–138,0 до 131,0–145,0% йодного числа жира. Полученный очищенный жир был прозрачен, имел светло-желтый цвет, низкие значения кислотного и перекисного чисел. Содержание ПНЖК в полученном продукте увеличилось на 10–30%. Содержание неомыляемых веществ в нем, в том числе биологически активных веществ алкилглицеролов, при этом не снизилось. Биологическая эффективность жира увеличилась с 0,6 до 0,9. To stabilize the increased biological effectiveness the possibility of increasing the amount of polyunsaturated fatty acids (PUFA) by reducing the amount of saturated fatty acids (SFA) in the fatty acid composition of fat from the liver of the black sea shark-katran in the summer fishing period (May – October) is investigated. With the aim of increasing the content of omega-3 PUFA in the product method of winterization was applied. Crystallization of fat from the liver of sharks-katran dogfish was conducted in a special chiller with temperature from 0 to –5°C. During cooling, the fat is slowly stirred (speed of rotation of the mixer 20–25 rpm) for uniform cooling throughout. Full crystallization of SFA under these conditions was held for 5–6 h. The cooled fat was immediately sent to precipitating in the centrifuge. Quality of fat – transparency at a temperature of 15°C and unsaturation – iodine number of fat was selected as the optimization parameters of the process. It is established that: the temperature of the refrigerated fat, the duration of centrifugation, the number of drum rotations of the centrifuge are factors that significantly affect the iodine number and the organoleptic indicators of fat. Scheme two-level full factorial experiment was applied for modeling the values of iodine number and organoleptic indicator in changing these factors. Natural values of factors corresponding to the best value of indicator of the quality of the fat: temperature of cooling fat –4°C, duration of centrifugation 30 min, and the speed of rotation of the drum centrifuge 6000 rpm were determined in the experiment. The result of this treatment, the total unsaturation of the liquid fraction increased from 122,2–138,0 up to 131,0–145,0% of iodine number. The purified obtained fat was transparent, had a light yellow color, low acid value and peroxide values. In the obtained product the content of PUFA increased by 10–30%. The content of unsaponifiables in it, including biologically active substances alkylglycerols, was not decreased. The biological effectiveness of fat increased from 0,6 to 0,9.


Author(s):  
L.V. Stelmakh ◽  
◽  
I.M. Mansurova ◽  

The possibility of using cultures of Black Sea planktonic microalgae of different taxonomic affiliation to assess the quality of the aquatic environment based on the assessment of their functional state is shown. The research was carried out on the diatom Phaeodactylum tricornutum, three dinoflagellates species Prorocentrum cordatum, Prorocentrum pusillum and Gyrodinium fissum, as well as the coccolithopho-ride Emiliania huxleyi. It was found that the waters of the Sevastopol Bay in the period from May to August 2021 in 50% of cases had a weak inhibitory effect on the growth of the tested species. In other cases, algae growth was either stimulated or the effect of pollution on cultures was not revealed. The need for using several types of algae in carrying out complex work on water biotesting of the coastal are-as of the Black Sea is highlighted.


2011 ◽  
Vol 8 (2) ◽  
pp. 701-722 ◽  
Author(s):  
A. A. Kubryakov ◽  
S. V. Stanichny

Abstract. Mean Dynamic Topography (MDT) is a crucial parameter for estimating dynamic topography, and, therefore, geostrophic circulation from satellite altimetry Sea Level Anomalies (SLA). In this work we use drifting buoy measurements, hydrographic profiles and SLA to reconstruct MDT of the Black Sea by "synthetic" method. Obtained mean dynamic topography shows higher gradients of sea level and resolves a lot of mesoscale processes in comparison to previous works, mostly based on climatic hydrological measurements. Verification of dynamic topography determined by altimetry SLA and estimated MDT, with independent dynamic heights and drifter buoy velocities shows good quantitative and qualitative coincidence for all Black Sea basin and improvements compare to previous fields of MDT. New MDT for the Black Sea will improve quality of altimetry derived geostrophic velocities for better understanding of the spatial and temporal features of the upper layer dynamics.


1999 ◽  
Vol 39 (8) ◽  
pp. 9-12
Author(s):  
G. A. Mirinchev ◽  
Tz. V. Tzankov ◽  
I. S. Kostova ◽  
M. G. Mirincheva

In the Bulgarian part of the Black Sea coast there are seventeen rivers and three lakes which contribute to the pollution and eutrophication of the Black Sea. The hydrophysical and hydrological characteristics of these rivers are described. The variation in the concentration of heavy metals during recent years (data up to 1996) has been determined. The total annual quantity of some pollutants and their percentage distribution are presented. Conclusions are made based on the variation of water quality of the rivers and their impact on the heavy metal pollution of the Black Sea.


2020 ◽  
Vol 15 (1) ◽  
pp. 16-27
Author(s):  
Zh. P. Selifonova ◽  
V. K. Chasovnikov ◽  
E. Z. Samyshev ◽  
P. R. Makarevich

Aim. To study the state of the marine ecosystem of the recreational‐tourist zone of the Caucasian sector of the Black Sea through the example of a beach near the mouth of the Agoy River.Material and Methods. Phytoplankton, heterotrophic bacterioplankton, infusoria, holoplankton, meroplankton, ichthyoplankton, zoobenthos of loose bottom sediments and hydrochemistry samples of the water and bottom sediments were collected in June 2012 on three sections from the mouth of the Agoy River to the coastal runoff zone (depths 2.5–7.5 m). The identification of species of plankton and of the zoobenthos and of the chemical parameters of water and sediments was carried out according to standard methods. Results. It was revealed that most of the beach area, where psammophilic biocenoses of Lucinella divaricate and Chamelea gallina (Bivalvia) were located, was in satisfactory condition. An increase in the density of Lucinella divaricate, a rare species in the late 1990s, was noted. In the runoff zone, there was observed the appearance of cyanobacteria and the suppression of zoobenthos, expressed through the replacement of mollusc biocenoses by the biocenosis of the polychaete, Capitella capitate, with a biomass two orders of magnitude lower than the average for the area. High numbers of heterotrophic bacterioplankton (4.5 million cell/ml) and infusoria (64 million ind./m3) could indicate bacterial contamination of this zone. The negative impact of waste water on plankton is manifested in a decrease in the population of netted zooplankton, their abnormal development, and the increasing role of microheterotrophs.Conclusions. The results obtained give an image of the state of marine coastal ecosystems of recreational‐tourist and cordoned areas of the Caucasus and can be useful for the further monitoring of this region.


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