Macrophytobenthos of the coastal water area at the Cape Kara-Mrun (Crimean Peninsula, the Black Sea)

Algologia ◽  
2017 ◽  
Vol 27 (3) ◽  
pp. 261-276
Author(s):  
S.Ye. Sadogurskiy ◽  
Author(s):  
N.A. Andreeva ◽  
◽  
E.A. Grebneva ◽  

Preliminary studies of cultivated phytoplankton microalgae were carried out in water samples collected during four expeditions at oceanographic stations of the coastal waters of the northwestern and northeastern parts of the Black Sea in different seasons of 2019-2020. Some features of the development of the algological component in conditions of changing oceanological characteristics of the environment have been established. In spring, the most active growth of diatoms was revealed in the area from Balaklava to the water area of the Sevastopol Bay.


2021 ◽  
Author(s):  
Emil Oynakov ◽  
Liliya Dimitrova ◽  
Lyubka Pashova ◽  
Dragomir Dragomirov

<p>Low-laying territories along the Black Sea coastal line are more vulnerable to the possible high (long) waves due to tsunami events caused by strong earthquakes in the active seismic regions. Historically, such events are rare in the Black Sea region, despite some scientific evidence of tsunamis and their recordings through continuous sea-level observations with tide gauges built in certain places along the coast. This study analyses seismic data derived from different international earthquake catalogues - NEIC, ISC, EMSC, IDC and Bulgarian national catalogue (1981 - 2019). A catalogue of earthquakes within the period covering the historical to the contemporary seismicity with magnitudes M ≥ 3 is compiled. The data are processed applying the software package ZMAP, developed by Stefan Wiemer (http://www.seismo.ethz.ch/en/research-and-teaching/products-software/software/ZMAP/index.html). The catalogues' completeness is calculated to assess the reliability of the historical data needed to assess the risk of rare tsunami events. The prevailing part of the earthquakes' epicentres are in the seismically active regions of Shabla, the Crimean peninsula, the east and southeast coast of the Black Sea forming six main clusters, which confirmed previous studies in the region. In these areas, several active and potentially active faults, which can generate tsunamigenic seismic events, are recognized.</p><p><strong>Acknowledgements: </strong>The authors would like to thank the Bulgarian National Science Fund for co-funding the research under the Contract КП-СЕ-КОСТ/8, 25.09.2020, which is carried out within framework of COST Action 18109 “Accelerating Global science In Tsunami HAzard and Risk analysis” (AGITHAR; https://www.agithar.uni-hamburg.de/).</p>


2019 ◽  
Vol 59 (2) ◽  
pp. 319-320
Author(s):  
N. N. Dmitrevskiy ◽  
R. A. Ananyev

In May and October 2017, expeditionary research was carried out in the area of Gelendzhik in the Black Sea at the R/V «Ashamba». The main tasks were the mapping of the seabed and the search for small-sized objects at the bottom of the water area using a WASSP WMB-3250 multibeam echo sounder. Surveys included areal surveying and drawing up bathymetric maps of test sites in Gelendzhik Bay and in the transition zone from the shelf to the continental slope. In addition, the echo sounder was used to search and determine the exact coordinates of the bottom seismograph installed at the seabed near the Divnomorskoye village in May 2016. The article presents the results of the work carried out.


2016 ◽  
Vol 1 (4) ◽  
pp. 12-21
Author(s):  
V. E. Giragosov ◽  
M. M. Beskaravainy

The relevance of the study of hydrophilic birds in the urban areas of the Black Sea coast is due to their important role in the coastal biocoenosis structure and the need to preserve biodiversity in the conditions of anthropogenic transformation of Crimean coastal zone. The dynamics of species composition and abundance of birds in Kruglaya (Omega) Bay (Sevastopol) were investigated. The results of regular and episodic monitoring carried out in 1995 and 2005–2016 were used in this work. Quantitative accounting was carried out only in January and February (1–2 times per winter season) in 2005–2008, episodically in 2009–2013 and weekly in December — May 2014/2015 and September — May 2015/2016. Number of specimens per species was registered, and the ratio of young and adult specimens in mute swan (Cygnus olor), sex ratio in mallard (Anas platyrhynchos), common pochard (Aythya ferina) and tufted duck (Aythya fuligula) were determined. Russian and Latin names of birds are represented by L. S. Stepanian. Kruglaya Bay is one of Sevastopol bays which form the northern coastline of the Heraclea Peninsula, and it is a place of seasonal concentrations of hydrophilic birds. The basic morphometric characteristics of the bay are the following: the water area — 0.64 km2, length — 1.3 km, maximum width — 0.8 km, the average depth — 4.5 m. The water area of the bay did not freeze usually, only its inner part was covered with ice in extremely cold winters. Benthic macrophyte species are represented by two associations: Cystoseira crinita and C. barbata on stones and rocks, and Zostera noltii and Z. marina on sandy and silty areas. Two local areas of common reed (Phragmites australis) beds are located in the inner part of the bay. The zoobenthos is a significant part of the food supply of birds and includes 97 species, mainly polychaetes, molluscs and crustaceans. The ichthyofauna is represented by 42 fish species. 51 species of aquatic and semi-aquatic birds across 8 Orders were identified. The winter bird community was most diverse and numerous (32 species: 14 Anseriformes, 7 Charadriiformes, 5 Podicipediformes, 3 Gruiformes, 2 Pelecaniformes, 1 Gaviiformes). Eight species dominate regularly in winters and quantitatively — mute swan, mallard, common pochard, tufted duck, eurasian coot (Fulica atra), black-headed gull (Larus ridibundus), caspian gull (Larus cachinnans) and common gull (Larus canus). Rare species wintering in the Mountain Crimea, including horned grebe (Podiceps auritus), Bewick’s swan (Cygnus bewickii), red-breasted goose (Rufibrenta ruficollis), white-headed duck (Oxyura leucocephala), knot (Calidris canutus), is of great interest. The average ratio of young and adult mute swans in the main wintering period (December — February) was 61 : 39 % in 2014/2015 and 45 : 55 % in 2015/2016, respectively. The ratio of males and females were as follows: in mallard 49.5 : 50.5 % in 2014/2015, and 51.4 : 48.6 % in 2015/2016; in common pochard 54.8 : 45.2 % in 2014/2015, and 60.5 : 39.5 % in 2015/2016; in tufted duck 51.0 : 49.0 % in 2014/2015, and 51.4 : 48.6 % in 2015/2016, respectively. Formation of the winter bird community began in October, sometimes at the end of September when single specimens of mallard, coot, tufted duck, red-breasted merganser (Mergus serrator), black-necked grebe (Podiceps nigricollis) appeared. Common gull, great crested grebe (Podiceps cristatus) and the common pochard come flying in November; the mute swan appears at the beginning of December. Maximum and relatively stable number of most species was typical for January and the first half of February. Maximum number of specimens of all bird species was registered in January 13, 2015 (1288), and February 7, 2016 (1531 specimens). The feeding conditions of Kruglaya Bay allow overwintering of the birds with different feeding specializations. The benthophages (most of Anseriformes and Coot) rank first in species richness (at least 13 species) and in quantitative terms. Five species (black-throated diver (Gavia arctica), great cormorant (Phalacrocorax carbo), common sheg (Phalacrocorax aristotelis), red-breasted merganser, Sandwich tern (Thalasseus sandvicensis)) form the group of ichthyophages. The Grebes occupy an intermediate position between benthophages and ichthyophages: small fish and benthic invertebrates are present in their diet. Four species of gull (black-headed, Caspian, common, Mediterranean gull (Larus melanocephalus)) constitute a group of omnivores. The rare visitors in Kruglaya Bay are zoophagous and omnivorous birds foraging in the surf zone and at shallow depths, such as water rail (Rallus aquaticus), common moorhen (Gallinula chloropus), dunlin (Calidris alpina), knot (Calidris canutus), and herbivores which prefer to feed in terrestrial habitats — red-breasted goose (Rufibrenta ruficollis). The nutritional requirements of birds are compensated to a certain extent by additional feeding carried out by townspeople. In general 30 passing and nomadic species, mainly Charadriiformes (11), Anseriformes (7) and Ciconiiformes (5), were registered. A nesting bird community was absent, and only the nesting of little bittern (Ixobrychus minutus) was registered in 2016 for the first time in city zone. The spring migration took place from late February to May, the autumn migration — from August until the first decade of November. Kruglaya Bay is a valuable natural and ecological educational place and deserves status as a natural park.


2020 ◽  
Vol 5 (1) ◽  
pp. 20-28
Author(s):  
N. A. Davidovich ◽  
O. I. Davidovich

Distribution of diatom algae is limited by their tolerance to environmental factors. Although a genus Toxarium has been evolving for more than 100 million years, it is represented by only two species. Toxarium undulatum is widely spread in tropical and subtropical seas, and it can be also found in the Black Sea, the salinity of which is twice lower than the oceanic one. Ecological and psychological characteristics research of this species is of great interest in terms of its relationship to salinity. T. undulatum clonal cultures were sampled in the Donuzlav Lake connected to the Black Sea (southwest of the Crimean Peninsula) and on Gran Canaria coast (Canary Islands archipelago). Experiments on the salinity tolerance limits showed, that the Black Sea clones were viable in a range of at least 30 ‰ (12 to 42 ‰). The same wide range of salinity tolerance with slightly higher values was observed among oceanic clones of this species. Optima of vegetative growth and sexual reproduction were determined. Optima of the Black Sea clones appeared to be 27.8 and 27.2 ‰, respectively, which was significantly higher than salinity observed in population habitat. Similar higher optima of vegetative growth and sexual reproduction, compared with those salinity values, at which natural population developed, were observed for a number of other Black Sea diatoms, which proved their oceanic (Mediterranean) origin. It was concluded that T. undulatum, along with other species, began to populate the Black Sea basin about seven thousand years ago after Mediterranean Sea water started to flow into the freshened Novoevksinsky Sea-Lake through the Bosporus Strait. However, the evolution rate did not allow bringing physiological and ecological characteristics of the species studied into full agreement with environmental conditions. Oceanic origin is evidently seen in its physiological reactions to salinity. Possibility of speciation due to settlement of the Black Sea with oceanic species is discussed.


Author(s):  
E. A. Tikhonova ◽  

As part of the 113th cruise of the R/V “Professor Vodyanitsky”, research was conducted on organic pollution of bottom sediments in the coastal areas of Crimea and the Caucasus, as well as the water area in front of the Kerch Strait. Concentration of chloroformextractable substances was determined by the weight method and that of petroleum hydrocarbons was determined using infrared spectrometry. Both in 2020 and 2016 (the 83d cruise of the R/V “Professor Vodyanitsky”), properties of the bottom sediments of the Crimean and Caucasian coasts were typical of the marine soils of this region. This indicates that the studied water areas are generally in good condition. In accordance with the regional classification of bottom sediment pollution, the maximum concentrations of chloroform-extractable substances obtained for both the Black Sea and the Sea of Azov coast indicate pollution level III (23% of analysed samples). These values were found in bottom sediments in the Sevastopol water area (225 mg·100 g-1), in the coastal area of Cape Tarkhankut (120 mg·100 g-1) and Karadag (120 mg·100 g-1), the southern part of the Sea of Azov (125 mg·100 g-1) and Tuapse (110 mg·100 g-1). The content of chloroform-extractable substances in bottom sediments off the Black Sea coast of the Caucasus and the Sea of Azov coast is slightly lower than that off the Crimean coast. Pollution level II is assigned to bottom sediments in 46 % of the samples, with an average concentration of 72 mg·100 g-1 of air-dry solids. The rest (31 %) of the studied area was classified as conditionally clean (pollution level I, i. e. less than 50 mg·100 g-1). There has been a slight increase in the concentration of petroleum hydrocarbons in the bottom sediments of both the Black Sea and the Sea of Azov and their share in the total amount of chloroformextractable substances. In general, the level of pollution of bottom sediments by organic matter remained unchanged if compared with previous years, in particular with the data from 2016


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