scholarly journals Biotic links in the fouling community of Odessa Bay (Black Sea)

2018 ◽  
Vol 26 (1) ◽  
pp. 24-29
Author(s):  
A. Y. Varigin
Keyword(s):  
Black Sea ◽  
Ecosystem Engineer ◽  
Three Dimensional ◽  
The Black Sea ◽  
Fouling Community ◽  
The Core ◽  
Leading Role ◽  
Food Reserves ◽  
Sessile Organisms

This paper reveals the character of the biotic links between the various organisms that compose the fouling community of Odessa Bay (Black Sea). The fouling community of solid substrates is formed by 62 species of invertebrates and 12 species of macrophytes. The edificator species of the community is the Black Sea mussel Mytilus galloprovincialis Lamarck, 1819. The environment-forming role of the mussel, which is represents the core of the corresponding consortia, was examined. The leading role of sessile organisms in the formation of a superorganismic structure that significantly modifies the properties of the environment was revealed. Together with the mussel, this structure is formed by the bivalve mollusc Mytilaster lineatus (Gmelin, 1791) and the barnacle crustacean Amphibalanus improvisus (Darwin, 1854). The proportion of sessile organisms accounts for 24.6% of the total number of species in the community. In this case, they significantly dominate in relative abundance and biomass (78.9% and 98.8%, respectively). The mussels during the process of growth form complexly organized druses, which are peculiar three-dimensional formations, consisting of mussels of different sizes, fastened together with a substrate by an entire network of strong byssus threads. These formations increase the level of heterogeneity of the substrate and increase the variety of available habitats for other animals. The aggregate of these druses is a kind of sedimentary trap in which particles of nutritive detritus accumulate. The availability of accessible habitats, convenient shelters and food reserves attracts various species of invertebrates to the community. Around the core of the consortia a cluster of organisms formed associated with edificator species. An important role is played by trophic links between different mobile organisms and the phyto-component of the community. The ability of the Black Sea mussel to condition the environment, creating favourable conditions for the development of other organisms, characterizes it as an autogenic ecosystem engineer. Trophic and mediopathic links between the organisms that compose the fouling community go beyond it and extend to the inhabitants of the pelagic environment.

scholarly journals Climate change induced a new intermittent regime of convective ventilation that threatens the Black Sea oxygenation status

2020 ◽  
Author(s):  
Arthur Capet ◽  
Luc Vandenbulcke ◽  
Marilaure Grégoire
Keyword(s):  
Black Sea ◽  
Regime Shift ◽  
Cold Water ◽  
The Black Sea ◽  
Leading Role ◽  
Oxygen Budget ◽  
Intermediate Layers ◽  
Water Formation ◽  
Oxygenation Status

Abstract. The Black Sea is entirely anoxic, except for a thin (∼ 100 m) ventilated surface layer. Since 1955, the oxygen content of this upper layer has decreased by 44 %. The reasons hypothesized for this decrease are, first, a period of eutrophication from mid 70's to early 90's and, second, a reduction in the ventilation processes, suspected for the recent years. Here we show that the Black Sea convective ventilation regime has been drastically altered by atmospheric warming during the last decade. Since 2008, the prevailing regime is below the range of variability recorded since 1955, and is characterized by consecutive years during which the renewal of intermediate waters does not occur. Oxygen records from the last decade indicate a clear relationship between cold water formation events and oxygenation status at different pycnal levels, suggesting a leading role of convective ventilation in the oxygen budget of the upper intermediate layers. We thus suggest that this regime shift has a significant impact on the oxygenation structure of the Black Sea and on its biogeochemical balance.

Role of suspended matter in controlling beryllium-7 (7Be) in the Black Sea surface layer

2021 ◽  
pp. 103513
Author(s):  
Dmitrii A. Kremenchutskii ◽  
Gennady F. Batrakov ◽  
Illarion I. Dovhyi ◽  
Yury A. Sapozhnikov
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Suspended Matter ◽  
Sea Surface ◽  
The Black Sea

Georgian Historians and the Ideological Confrontation Between East and West

2021 ◽  
Vol 30 (1) ◽  
pp. 153-164
Author(s):  
George Gotsiridze
Keyword(s):  
Soviet Union ◽  
Cultural Values ◽  
Black Sea ◽  
The Black Sea ◽  
Black Sea Region ◽  
The Soviet Union ◽  
Long Time ◽  
Science And Culture ◽  
East And West

The work, on the one hand, highlights the mission of Europe, as an importer of knowledge, which has for centuries been the center of gravity for the whole world, and, on the other hand, the role of the Black Sea Region, as an important part of the Great Silk Road, which had also for a long time been promoting the process of rap-prochement and exchange of cultural values between East and West peoples, until it became the ‘inner lake’ of the Ottoman Empire, and today it reverts the function of rapproching and connecting civilizations. The article shows the importance of the Black Sea countries in maintaining overall European stability and in this context the role of historical science. On the backdrop of the ideological confrontation between Georgian historians being inside and outside the Iron Curtain, which began with the foundation of the Soviet Union, the research sheds light on the merit of the Georgian scholars-in-exile for both popularization of the Georgian culture and science in Eu-rope and for importing advanced (European) scientific knowledge to Georgia. Ex-change of knowledge in science and culture between the Black Sea region and Europe will enrich and complete each other through impact and each of them will have unique, inimitative features.

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part I: Porifera, Cnidaria, Bryozoa, Chordata

2017 ◽  
Vol 2 (2) ◽  
pp. 20-33 ◽  
Author(s):  
I. P. Bondarev ◽  
N. K. Revkov
Keyword(s):  
Surface Area ◽  
Coastal Zone ◽  
Black Sea ◽  
The Black Sea ◽  
Bottom Fauna ◽  
Depth Range ◽  
Shell Surface ◽  
Rapana Venosa ◽  
The Core ◽  
Rapa Whelk

Gastropod mollusk-invader Rapana venosa (Valenciennes, 1846) in the 1940s took a free ecological niche terminal predator in benthic communities of the Black Sea shelf and has become an important element of the ecosystem. The ability of rapa whelk to have a devastating impact on the biocenosis filter feeders determines the necessity of constant monitoring of this species populations’ state. The study of rapa whelk showed that the ecological role of this species is not limited to predation. Fairly large shell R. venosa is a solid substrate for alga, attached and restrictedly movable (sedentary) benthic animal organisms, among which mobile free-living forms sometimes find shelter. The aim of the work is to describe specific complex of epibiotic organisms formed on rapa-whelk shells, which is regarded as a consortium, where of R. venosa is the core. To study the consort community of R. venosa a sampling was made in 7 regions of the northern part of the Black Sea: 1 – Mamaia beach, Romania, 2 – the north-western part of the Black Sea (NWBS), Crimean sector, 3 – Sevastopol, 4 – Alupka, 5 – Yalta – Alushta, 6 – Karadag, 7 – the Kerch Strait. The sampling in the coastal zone (less then 15 m depth) was carried out by SCUBA and snorkel diving, deeper (up to 40 m) was used “Ocean-50”grab corer was used. Totally of 856 specimens of R. venosa were collected and analyzed. The main bulk of the material in the amount of 750 specimens of R. venosa was sampled in the coastal zone in Sevastopol vicinity (south-western Crimea) at the depth range of 1.5–10.0 m. The collection of the rapa whelk specimens was carried out totally and each specimen was placed in a separate plastic bag indicating the collection area, depth and biotope. Along with the mollusks sampling, visual observations and photographic fixation of hydrobionts in situ were carried out. Based on the research results the taxonomic list of rapa whelk epibiotic organisms was extended and for the first time the taxonomic composition of the mobile forms permanently or temporarily present in the R. venosa consortium was given. The first part of the investigation provides a list of rapa whelk epibionts taxa relating to four (Porifera, Cnidaria, Bryozoa, Chordata) of the seven detected Phyla with indication of sampling depths and bottom type and comments on the frequency of occurrence, the quantity and of their interaction with the consortium core. Phylum Porifera is represented by 1, Bryozoa – 3 Cnidaria – 2 and Chordata – 4 species. The drilling sponge Pione vastifica was found in all the investigated areas, except region 2 (NWBS), with a frequency of 20 to 90 % and the shell surface area damage was up to 100 % (average 30–35 %). Not numerous representatives of Cnidaria were found singly in the region 3 (Actinia equina) and in the region 5 (Diadumene lineata). Bryozoans are the most common group of animal-consorts of rapa whelk present in all the areas of our research. The frequency of their occurrence ranged from 10 to 100 %, the covering area of the shell surface was from 0 to 85 %. More than 90 % of the total surface area of rapana shell cover with bryozoans and their occurrence is in Cryptosula pallasiana. The second bryozoans’ species on development indices is Conopeum seurati, which was found in areas 3, 6 and 7, where the occurrence was up to 30 % and the coverage was up to 25 %. The other 3 species of bryozoans (Schizomavella auriculata, Bowerbankia imbricata, Hippothoa sp.) were found rarely. Representatives of Chordata – 2 species of ascidians (Botryllus schlosseri, Ciona intestinalis) and 3 species of fish (Diplecogaster bimaculata, Parablennius tentacularis, Scorpaena porcus) were recorded singly in regions 2, 3, 5. For the four Phyla of animal organisms considered the consorts list of R. venosa of the sandy bottom biotopes (10 species) is twice more numerous than that of the rocky eco-form (5 species). The organisms studied are of a different degree and nature of relations with the core consortium from commensalism to parasitism. Generalized information on periphyton and total coverage of rapa whelk shells with epibiotic complex is given. The results of the work show that in the Black Sea R. venosa has become an important element of the ecosystem, increasing biological diversity of the bottom fauna due to the formation of its own consortium complexes of epibiontic organisms.

scholarly journals A study of long-term changes in Black Sea ecosystems based on data assimilation of remote measurements in a numerical model

2019 ◽  
Vol 46 (1) ◽  
pp. 58-69
Author(s):  
V. L. Dorofeev ◽  
L. I. Sukhikh
Keyword(s):  
Black Sea ◽  
Marine Ecosystem ◽  
Three Dimensional ◽  
The Black Sea ◽  
Regular Grid ◽  
Remote Measurements ◽  
Biogeochemical Parameters ◽  
Color Scanner

Herein, we present a simulation of the dynamics of Black Sea ecosystems using a three-dimensional interdisciplinary model that assimilates satellite color scanner measurements. Calculations were performed for the fifteen years from 1998 and a set of 3-d biogeochemical fields of the Black Sea were generated on a regular grid with a discreteness time of 1 day. Analyses of core biogeochemical parameters of the marine ecosystem were then performed. The qualities of received fields were evaluated using comparisons with existing data from in situ measurements.

scholarly journals Ecological interrelations of Rapana venosa (Gastropoda: Muricidae) with ichthyofauna in the Black Sea

2016 ◽  
Vol 1 (4) ◽  
pp. 76-77
Author(s):  
I. P. Bondarev
Keyword(s):  
Black Sea ◽  
Marine Ecosystem ◽  
Fish Fauna ◽  
The Black Sea ◽  
Sandy Bottom ◽  
Rapana Venosa ◽  
New Information ◽  
Bottom Zone

Systematic monitoring of ecologically significant species – predatory mollusc Rapana venosa Valenciennes, 1846 populations – is an important part of the Black Sea monitoring. The study of the role of R. venosa in contemporary marine ecosystem is of considerable interest. In June-September 2015-2016 the study of consorting relations of rapana was conducted in situ with a parallel sampling by diver. In the course of research new information about the interaction of R. venosa with the fish fauna has been obtained. Of particular importance for fishes is the presence of rapana in the sandy bottom zone, where there are no natural shelters, and food resources are limited. The most important for the fish is the presence on the rapana shells of algal fouling and epiphyton. The shells of invader – R. venosa – and its fouling create additional opportunities for the survival of some fish fauna representatives juveniles of the Black Sea. The data obtained extend the concepts of ecological role of mollusc – invader R. venosa, as well as the ecology and ethology of several fish species.

The Role of the Black Sea Commission in the Sustainable Management of the Marine Living Resources

2015 ◽  
pp. 306-326
Author(s):  
Iryna Makarenko
Keyword(s):  
Black Sea ◽  
Marine Environment ◽  
Sustainable Management ◽  
Institutional Structure ◽  
The Black Sea ◽  
Global Level ◽  
Current Trends

In this chapter, the role of the Black Sea Commission in the preservation of marine environment will be considered. Particular emphasis will be placed on the activities related to management of the marine living resources, the legal gaps in the documents and institutional structure, as well the current trends and challenges on the regional and global level. An overview of relevant Black Sea Commission's observers and partners will be provided; existing and possible future arrangements with them will be further described and analyzed. Some concrete recommendations on the improvements in the management of marine living resources in the Black Sea basin will be proposed.

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