Composition and Seasonal Succession of Phytoplankton of Taganrog Bay in the Sea of Azov and the Downstream Reaches of the Don River under a Changing Climate

2020 ◽  
Vol 13 (1) ◽  
pp. 23-30 ◽  
Author(s):  
L. G. Korneva ◽  
G. Yu. Glushchenko
2016 ◽  
Vol 12 (1) ◽  
pp. 3-28 ◽  
Author(s):  
A.V. Ponomarev ◽  
◽  
E.V. Prokopenko ◽  
P.P. Ivliev ◽  
V.Yu. Smatko ◽  
...  

2018 ◽  
Vol 3 (3) ◽  
pp. 70-76
Author(s):  
D. N. Kutsyn ◽  
A. V. Startsev

The aim of the work was to describe the first catch of Scophthalmus maeoticus (Pallas, 1814) in the Don River estuary (47°3′57′′N, 39°12′39′′E) and to analyze it in the context of salinity increasing in the Sea of Azov. The study was carried out using two turbot specimens caught on July 16, 2016, and on September 1, 2016, by a net with a mesh 55 mm. Assessment of the chalinic conditions of the Sea of Azov was carried out through annual monitoring at 3 hydrometeorological stations in Don River delta and in the eastern part of the Taganrog Bay. The article presents main meristic and plastic features of the turbots studied in comparison with published data. The dynamics of the salinity in the Sea of Azov and in the Taganrog Bay is analyzed. Find of the turbot in the estuary of the Don River is an evidence of ichthyocene transformation in response to salinity increasing (up to 12.5 ‰ in the Sea of Azov and up to 6 ‰ in the Taganrog Bay). The first catch of the turbot corresponds with trend of increasing of marine and brackish-water species share and with a decrease in the number of native semi-anadromous fish species.


Author(s):  
Vitaly Syomin ◽  
Andrey Sikorski ◽  
Ralf Bastrop ◽  
Nicole Köhler ◽  
Boris Stradomsky ◽  
...  

Alien polychaetes belonging to the genus Marenzelleria were recorded from the mouth of the Don River and Taganrog Bay in the Sea of Azov in February–March 2014. Morphological characteristics varied greatly and matched those of two species: M. neglecta and M. arctia. Some individuals did not match the descriptions of both species. A genetic study using different sequences (primarily COI, but also 16S, 28S, cytb and nuclear histone 3a) showed that only M. neglecta was present despite some morphological mismatches. A morphological description of the species according to the new data is presented, together with a revised table of variability of the key numeric characters. Since 2014, Marenzelleria has spread swiftly and become dominant in a considerable part of the Taganrog Bay, making up to 91% of the total abundance/biomass (6800 ind. m−2 and 31.2 g m−2, respectively). Monodominant sites were also present. Its occurrence is 100% in recent surveys. Such a sharp increase seems to be due to a lack of detritophages in the bay; this is supported by the fact that M. neglecta has not formed its specific assemblage. The community structure, if M. neglecta is excluded, is equal to that before the invasion. In the Sea of Azov itself, M. neglecta is not as abundant, but occurs up to the Strait of Kertch and at some sites in the Black Sea. Its spread further into the Black Sea seems possible, as well as into the Caspian Sea via the Volga-Don Canal.


Author(s):  
Yuri Fedorov ◽  
Yuri Fedorov ◽  
Irina Dotsenko ◽  
Irina Dotsenko ◽  
Leonid Dmitrik ◽  
...  

The distribution and behavior of certain of trace elements in sea water is greatly affected by both physical, chemical and hydrometeorological conditions that are showed in the scientific works of prof. Yu.A. Fedorov with coauthors (1999-2015). Due to the shallow waters last factor is one of the dominant, during the different wind situation changes significantly the dynamics of water masses and interaction in the system “water – suspended matter – bottom sediments”.Therefore, the study of the behavior of the total iron in the water of the sea at different wind situation is relevant. The content of dissolved iron forms migration in The Sea of Azov water (open area) varies from 0.017 to 0.21 mg /dm3 (mean 0.053 mg /dm3) and in Taganrog Bay from 0.035 to 0.58 mg /dm3 (mean 0.11 mg /dm3) and it is not depending on weather conditions.The reduction in the overall iron concentration in the direction of the Taganrog Bay → The Sea of Azov (open area) is observed on average more than twice. The dissolved iron content exceeding TLV levels and their frequency of occurrence in the estuary, respectively, were higher compared with The Sea of Azov (open area).There is an increase in the overall iron concentration in the water of the Azov Sea on average 1.5 times during the storm conditions, due to the destruction of the structure of the upper layer and resuspension of bottom sediments, intensifying the transition of iron compounds in the solution.


2013 ◽  
Vol 9 (2) ◽  
pp. 329-332
Author(s):  
N.I. Bulysheva ◽  
◽  
M.V. Nabozhenko ◽  
A.I. Savikin ◽  
I.V. Shokhin ◽  
...  

Author(s):  
Andrey Kuznetsov ◽  
Andrey Kuznetsov ◽  
Yury Fedorov ◽  
Yury Fedorov ◽  
Paul Fattal ◽  
...  

Bottom sediments formed in the water bodies under the technogenic impact are important environmental factors affecting water quality and hydrobiota. Usually they consist of natural and technogenic material and differ from natural formations by their morphology, chemical and lithological composition, physicochemical and biochemical properties. In the present paper we use the term “sediment layer of anthropogenic impact” to define the sediment layer containing technogenic material and/or chemical pollutants. The determination of its location in the sediment cores, its thickness and accumulation chronology is an important scientific problem. In the paper the results of layer by layer study of Cs-137, Am-241, Pb-210 specific activities as well as concentrations of petroleum components, lead and mercury in 48 sediment cores of the Sea of Azov and the Don River are examined. The sediment core layers are dated by radiological methods. In all the sediment cores the peak of Cs-137 specific activity related to the Chernobyl accident was detected. In the Sea of Azov, this peak is located in the upper sediment layer up to 10 cm thick, however, in the delta and in the near-delta part of the Don River, where the sedimentation rates are more important, it is found at 20 to 40 cm depth. Also in certain sediment cores the second peak of Cs-137 related to the global nuclear fallout of the 1960s was found. The most of petroleum components, lead and mercury quantities are concentrated in the upper sediment layer formed in the last 50 to 70 years, i.e. in the period of the most important anthropogenic pressure. So, this complex approach based on the data on the vertical distribution of technogenic radionuclides and common pollutants in the sediment cores made it possible to identify and delineate the sediment layer of high anthropogenic impact as well as to assess the duration of this impact.


Author(s):  
Lyudmila G. Korneva ◽  
Galina Yu. Glushchenko

The work presents the results of a study of phytoplankton in Taganrog Bay of the Sea of Azov and the downstream reaches of the Don River (January, April – November 2017). During the study was identified the modern taxonomic composition (210 species of eukaryotic algae and cyanobacteria). Ecological and geographical analysis was showed the stability of the general structure of the plankton algoflora of the studied area compared with previous years of the study (1980s to early 2000s). The work also presents a characteristic of the seasonal dynamics of taxonomic, size structures, and coenotic composition of phytoplankton. During the study was noted the temporary and qualitative changes in composition of phytoplankton, which are indicate a high level of organic matter in the studied reservoirs and an increase in the heterotrophic component in the functioning of the Lower Don ecosystem. It was found that in the studied water bodies the important factor in the formation of composition and the structure of phytoplankton is salinity.


Purpose. The physico-chemical processes in river mouth area, which include the Don and Kuban rivers, limited the transport capacity of the main ports of the Sea of Azov as a result of the silting by suspended matter by the river runoff. The fall of the depths in the the ports and marine channels is one of the key problems of the functioning of the ports. Dredging works and dumping linked with shipping as well as shipping linked with the world economy. It is impossible to abandon shipping, as well it is impossible to abandon the dredging and damping. For this reason, the purpose of the work is to assess the optimal dredging works for the exploitation of the ports of Ukraine in the Sea of Azov. Methods. The comparative analysis of modern hydrometeorological conditions, including the dominant influence of wind activity, the velocity and the direction of currents according to actual data, the transparency of sea water, the runoff the river Kalmius had been done. The available images of DigitalGlobe’s remote sensing satellites and dredging results, which were periodically performed to support the depths on the sea marine channel to the port water area, were examined. Modern and retrospective data of bathymetric surveys using GIS processing technologies for comparing the results, as well as standard methods of statistical data processing were also used. Results. During the investigated period, the images of the Earth's remote sensing satellites from DigitalGlobe were studied. An anthropogenic impact to the silting in the study area was revealed (the turning point between 0 km of the marine channel of the port and the shallow water area of the port of Azovstal). For compare the depths in the investigated area which is under the the river Kalmius influence positions of the surveyed post had been established. As result of analysis of direct measurement data and graphic material the permanent silting of the marine channel was not established as well as the direct statistical relationship between the silting and the river run incoming with suspended matter with Kalmius river. The main process of sedimentation determines by the Don river. The upper limit of maximum sedimentation is 5–7 ‰, coincides with the investigated area, where theoretically one should expect the process of accumulation of bottom sediments. Conclusion. The result of comparing Kalmius river runoff with depths in the marine channel of the port of Azovstal, in the area of area of river mouth, revealed there is not representative statistical relationship. It is necessary monitoring data for a long period of data for representative comparing the runoff Kalmius river and siling processes. In modern period the runoff of the Don river is significantly deformed under the influence of anthropogenic factors and the representative statistical estimation have to be done using only the direct measurements, which are fairly limited. Nevertheless, the reduction of Don river runoff and, thus, the direct impact on the recording capacity of the studied water area determines the need for and technological accessibility of dredging at a significantly lower the cost of wokrs at the present stage.


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