scholarly journals Ecological State of the Eastern Sivash Waters in Early Summer of 2020

Author(s):  
R. V. Borovskaya ◽  
S. S. Zhugaylo ◽  
D. O. Krivoguz ◽  
V. A. Shlyakhov ◽  
◽  
...  

The paper studies the ecosystem of the Eastern Sivash in the context of natural and anthropogenic influence. The data collected during the expedition of the Azov-Black Sea Branch of the FSBSI “VNIRO” conducted in early summer 2020 were used as original empirical evidence. Specific features of hydrological and hydrochemical conditions, as well as species composition, distribution, and abundance of ichthyoplankton were indicated. It was shown that the values of pH, nitrates, nitrites, and phosphates did not exceed MPCs established for fishery water bodies within the entire water area under study; the range of dissolved oxygen content was wide: 3.63–9.13 mg/dm3 . By comparison of the environmental status of the biocoenoses during early summer 2020 with the data collected during a similar survey in 2019, it was found that the water temperature at site 4 is lower by 1.9–2.7 °C. Further salinization of the Sivash was recorded: the lowest salinity in 2019 ranged within 32–38 ‰ and the highest one ranged within 83–86 ‰; in 2020, these values were 36–43 ‰ and 91–97 ‰, respectively. In terms of spatial distribution, the range of the increase in salinity was 4.36–16.69 ‰, with the highest value being recorded at site 2 (11.51–16.69 ‰) and the eastern part of site 3 (13.22 ‰). To a lesser extent (by 4.36–6.26 ‰), an increase in salinity was recorded at site 4 and the western part (5.27 ‰) of site 3. The results of plankton net surveys showed that ichthyoplankton was represented almost exclusively by larvae of big-scale send smelt, which had the densest distribution at site 1 at a salinity of 89 ‰, and on the border between sites 2 and 3 at a salinity of 74 ‰. The upper limit of salinity at which this fish reproduction is possible lies within the range 75–90 ‰. The absence of so-iuy mullet eggs and juveniles at a salinity higher than 32–36 ‰ in May – June of 2019–2020 during the peak of so-iuy mullet spawning does not provide a reason to include the Sivash Bay among the Azov Sea areas important for reproduction of this fish species

2021 ◽  
Author(s):  
Sergey V. Kholodkevich ◽  
Maxim K. Motruk ◽  
Vasiliy A. Lyubimtsev ◽  
Olga N. Susloparova

The objects of bioindication of the ecological state were 3 channels of the Volga Delta, located both directly in Astrakhan and in the Astrakhan region. The aim of the work was to conduct a comparative bioelectronic diagnosis of the ecological state of the selected channels with different local anthropogenic loads, both by type and size, based on assessments of the functional state (health) of the bivalve mollusks Anodonta anatina living in them, estimated on the basis of an analysis of their cardiorhythm, measured using an original fiber-optic bioelectronic system. It was found that shellfish selected from different water areas, after 1hour functional load, restore the original heart rate for different times, but in the range from 117 to 166 minutes, which is typical for shellfish living in significantly polluted reservoirs of the same ecological status - "Bad". This characteristic of the water areas completely coincides with the characteristic of the ecological state of the channels of the Volga River Delta specified in the State Report "On the state and on Environmental Protection of the Russian Federation in 2017". The authors proposed and justified the possibility of using the water area of the Gandurino River as a conditional reference for the Volga Delta region. In this case, according to the value of the environmental quality coefficient EQR, the channels of the Urban Branch and the Small Channel can be attributed to the regional environmental status - "Good".


Author(s):  
Irina Mesenzeva ◽  
Irina Mesenzeva ◽  
Elena Sovga ◽  
Elena Sovga ◽  
Tatyana Khmara ◽  
...  

The ability of a bay and gulf ecosystems to self-purification was estimated and the current ecological state of the Sevastopol Bay in whole and the separated parts of the bay was given as an example. A zoning by type of anthropogenic impact subject to the water exchange with the open sea and an influence of the Chernaya River run-off were taken into account. A comparative analysis of assimilation capacity of the most environmentally disadvantaged part of the Sevastopol Bay (the Southern Bay) and the clean water area, bordering on the open sea, was carried out. The hydrodynamic regime of the Sevastopol Bay was described using numerical modelling. The prospect, opportunity and examples of the methodology for assessing the assimilation capacity of marine ecosystems are demonstrated.


Author(s):  
V.V. Latun ◽  
◽  
G.Y Sklyarenko

The water areas of the Lower Don and the Taganrog Bay of the Azov Sea are of great ecological and economic importance. They are located in a zone of powerful anthropogenic impact. The work shows the generalized results of environmental monitoring of these water bodies, carried out in 2019-20.


Author(s):  
Irina Mesenzeva ◽  
Irina Mesenzeva ◽  
Elena Sovga ◽  
Elena Sovga ◽  
Tatyana Khmara ◽  
...  

The ability of a bay and gulf ecosystems to self-purification was estimated and the current ecological state of the Sevastopol Bay in whole and the separated parts of the bay was given as an example. A zoning by type of anthropogenic impact subject to the water exchange with the open sea and an influence of the Chernaya River run-off were taken into account. A comparative analysis of assimilation capacity of the most environmentally disadvantaged part of the Sevastopol Bay (the Southern Bay) and the clean water area, bordering on the open sea, was carried out. The hydrodynamic regime of the Sevastopol Bay was described using numerical modelling. The prospect, opportunity and examples of the methodology for assessing the assimilation capacity of marine ecosystems are demonstrated.


2018 ◽  
Vol 33 (3) ◽  
pp. 173-185 ◽  
Author(s):  
Dmitry S. Saburin ◽  
Tatiana G. Elizarova

Abstract A new model for calculation of circulation in shallow water basins is created based on the shallow water equations taking into account the Coriolis force and quadratic friction on the bottom. Wind effects are taken into account as forcing. The main feature of the model is a new numerical method based on regularized shallow water equations allowing one to construct the simple and sufficiently accurate numerical algorithms possessing a number of advantages over existing methods. The paper provides a detailed description of all construction steps of the model. The developed model was implemented for the water area of the Azov Sea. The paper presents the modelling of extreme surges in March 2013 and September 2014, the results of calculations are compared with observation data of hydrometeorological stations in Taganrog and Yeysk.


1964 ◽  
Vol 96 (7) ◽  
pp. 925-943 ◽  
Author(s):  
Wm. L. Putman ◽  
D. H. G. Herne

AbstractIn peach orchards undisturbed by pesticides and where phytophagous mites were at endemic densities, spring populations of Typhlodromus caudiglans were small and remained so during early summer until phytophagous mites, especially Aculus cornutus, began to increase. T. caudiglans reached maximal densities in September. In such orchards T. caudiglans appears to be an important factor in maintaining Panonychus ulmi at low density levels. On trees where DDT applied the previous year had caused P. ulmi to build up and which could be repopulated by T. caudiglans from neighbouring trees, the predator increased very rapidly but appeared to reach an upper limit of density fixed by intrinsic factors, possibly cannibalism. Under these conditions T. caudiglans could not bring P. ulmi to endemic densities in one season, though it appeared to slow the mite’s rate of increase and to reduce its maximal seasonal density.


1975 ◽  
Vol 15 (73) ◽  
pp. 241-250 ◽  
Author(s):  
F. Müller ◽  
H. Blatter ◽  
G. Kappenberger

AbstractIce and water surface temperatures were measured with an airborne radiation thermometer PRT-5 over the North Water polynya during three missions between late winter and early summer 1974. Error corrections, problems of data analyses and mapping are discussed. Attempts are made to relate the main types of sea ice to temperature ranges, which then are used in conjunction with satellite pictures to produce surface temperature maps.


Author(s):  
O.  I. Bronskov ◽  
◽  
K.  V. Kuzhel ◽  
V.  K. Kuzhel ◽  
◽  
...  

The territory of Ukraine is located between the areas of two subspecies of Moustached Warbler Acrocephalus melanopogon (Temminck, 1823) - A. m. melanopogon (Temminck, 1823) and A. m. albiventris (Kazakov, 1974). In the North-West Black Sea region, the nesting of the nominative subspecies has been proven, while the second one nests in the East Azov Sea region. By 2016, neither in the North Azov Sea region, nor in the South-East of Ukraine, this species was not observed. However, there are certain meetings of solitary birds in the adjacent regions during migrations on the Eastern Syvash on 21.10.2006 and westwards of the Don mouth on the Mius River bank on 05.09.2011. It was photographed for the first time on 24.04.2016 on the Shaitanka River near the Novodonetske village Velykonovosilkivskyi district of Donetsk region. Its nesting is reliably proven on 30.04.2020 on the Mokri Yaly River of the same region. On this river, there are plant communities with different proportions of common reed (Phragmites australis) and narrowleaf cattali (Typha angustifolia) grow in some places around open areas of the water area. It's on such sections of the river the Moustached Warbler males were observed. On a 600 m long section of the river, 3-4 males were observed. 2 males were caught, which were assigned to the subspecies of A. m. albiventris by color and measurements. On 19.05.2020 there were 5 eggs in one of the found nests. Egg sizes, mm: 18.0x13.0; 18.0x12.9; 16.9x12.9; 17.6x12.9; 17.9x12.9. The nest was located at a height of 250 mm above the water. Nest measurements, mm: D=85; d=50; H=53; h=43. It is suggested that in the South-East of Ukraine, birds appeared on nesting grounds due to the increase in the range of the subspecies in the north-west direction over the last 20 years due to climate warming. It is quite likely to find new localities of the Moustached Warblers on small rivers, large ponds or reservoirs in the southern part of Donetsk, eastern part of Zaporizhzhia or south – eastern part of Dnipropetrovsk regions.


2020 ◽  
Vol 193 ◽  
pp. 02012
Author(s):  
Alena Zhidkova ◽  
Vladimir Podberesnij ◽  
Rimma Zarubina

The work provides a comprehensive environmental assessment of the eutrophic biogenic load on a water body using the example of the Gulf of Taganrog of the Sea of Azov. This study is carried out with the aim of a deeper understanding of the ecological state of the waters of the Gulf of Taganrog, the processes of its eutrophication. The assessment of the biogenic load on the water area is carried out. The conducted researches showed that the eutrophication of the Gulf of Taganrog northeastern part depends on the salinity, water temperature, ammonium, and nitrate and phosphate concentrations. The level of the internal and external loads of phosphorus in the waters of the Gulf of Taganrog is approximately equal.


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