scholarly journals Distribution of Cystoseira s. l. species in the Sea of Azov

Algologia ◽  
2020 ◽  
Vol 30 (4) ◽  
pp. 359-381
Author(s):  
S.Yu. Sadogurskiy ◽  
◽  
S.S. Sadogurska ◽  
T.V. Belich ◽  
S.O. Sadogurskaya ◽  
...  
Keyword(s):  
Open Water ◽  
First Record ◽  
Distribution Range ◽  
Conservation Strategies ◽  
Limiting Factor ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
The Past ◽  
Kerch Strait ◽  
Hard Substrates

The information on distribution of the Cystoseira s. l. species in the Sea of Azov (SA) is presented based on the results of our own research and literature data. It is shown that the first record was made 100 years ago at Cape Khroni and at the Kazantyp Peninsula (Crimean coast). Currently, 22 reports from 18 sites have been registered along the Southern coast of the SA (17 along the Crimean coast and one at the Taman Peninsula). Treptacantha barbata (Stackh.) Orellana et Sansón (= Cystoseira barbata (Stackh.) C.Agardh) is the most widespread of the two species (17 sites). It forms dense communities with a biomass of 1.5–3.5 kg/m2. Carpodesmia crinita (Duby) Orellana et Sansón (= Cystoseira crinita Duby) was found in a small number only at two locations. It was found that the modern boundaries of the Azov fragment of the Cystoseira s. l. distribution range coincide with the boundaries of the Pre-Strait area of the SA, where salinity significantly higher, than in other areas. The distribution range has a linear configuration: it covers the Crimean coast from Cape Krasny Kut in the west to Cape Khroni in the east; is interrupted by the open water area of the Kerch Strait, and continues further on the Taman coast from Cape Achilleion to Cape Pekly. Outside the specified area, Cystoseira s. l. do not occur even if hard substrates are present. This shows, that salinity is limiting factor for the distribution of T. barbata and C. crinita in SA. In the past the system of marginal seas of the Mediterranean basin (to which SA also belongs) went through a series of transgressive and regressive phases. As a result, the boundaries, ecological conditions, and composition of biota have been changed several times in the entire basin and in its individual parts. The assumption was made that in the past Cystoseira s. l. species several times settled in the modern boundaries of the SA. The last invasion into the Pre-Strait area of SA (and inhabiting it up to the present time) should have happened in the Late Holocene 3.4–3.1 thousand years ago. Further alternation of regressions and transgressions, certainly, was accompanied by fluctuations of the distribution range boundaries, which either receded from the SA to the Kerch Strait, or again came back to its southern shores. At present, they can also fluctuate to a limited extent, following the salinity fluctuations. It is mostly relevant to the Crimean coast, where hard substrates are widespread. Considering the continuing salinization of the SA due to the climatically caused decrease in river runoff, the spread of Cystoseira s. l. species is possible on the Akmonay coast up to the top of the Arabat Bay. All this does not allow us to classify them as alien species in SA. However, in SA under modern conditions, the sustainable vegetation of the Cystoseira s. l. species with the formation of dense communities at a considerable distance from the Pre-Strait area is impossible. This must be taken into account when artificial reefs are installed and conservation strategies are developed.

Influence of the Kerch Strait on surge phenomena and currents induced by cyclonic disturbances in the Sea of Azov

2009 ◽  
Vol 19 (4) ◽  
pp. 197-210 ◽  
Author(s):  
V. A. Ivanov ◽  
V. V. Fomin ◽  
L. V. Cherkesov ◽  
T. Ya. Shul’ga
Keyword(s):  
Sea Of Azov ◽  
The Sea Of Azov ◽  
Kerch Strait ◽  
Cyclonic Disturbances ◽  
Surge Phenomena

Study of water exchange in Kerch strait using NEMO model of Black Sea

2021 ◽  
Author(s):  
Roman Sedakov ◽  
Barnier Bernard ◽  
Jean-Marc Molines ◽  
Anastasiya Mershavka
Keyword(s):  
Water Flow ◽  
Black Sea ◽  
Water Exchange ◽  
Discharge Rate ◽  
The Black Sea ◽  
External Forcing ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
The North ◽  
Kerch Strait

<p>The Sea of Azov is a small, shallow, and freshened sea that receives a large freshwater discharge. Under certain external forcing conditions brackish water from the Sea of Azov flow into the north-eastern part of the Black Sea through the narrow Kerch Strait and form a surface-advected buoyant plume. Water flow in the Kerch Strait also regularly occurs in the opposite direction, which results in the spreading of an advected plume of saline and dense water from the Black Sea into the Sea of Azov. Using a regional Black Sea Azov Sea model based on NEMO we study physical mechanisms that govern water exchange through the Kerch Strait and analyze the dependence of its direction and intensity on external forcing conditions. We show that water exchange in the Kerch Strait is governed by a wind-induced barotropic pressure gradient. Water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time. Outflow from the Sea of Azov to the Black Sea is induced by moderate and strong northerly winds, while flow into the Sea of Azov from the Black Sea is induced by southerly winds. The direction and intensity of water exchange have wind-governed synoptic and seasonal variability, and they do not depend on the variability of river discharge rate to the Sea of Azov on an intraannual timescale.</p>

scholarly journals Water exchange between the Sea of Azov and the Black Sea through the Kerch Strait

Ocean Science ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Ivan Zavialov ◽  
Alexander Osadchiev ◽  
Roman Sedakov ◽  
Bernard Barnier ◽  
Jean-Marc Molines ◽  
...  
Keyword(s):  
Water Flow ◽  
Black Sea ◽  
Water Exchange ◽  
The Black Sea ◽  
External Forcing ◽  
Sea Of Azov ◽  
Buoyant Plume ◽  
The Sea Of Azov ◽  
The North ◽  
Kerch Strait

Abstract. The Sea of Azov is a small, shallow, and freshened sea that receives a large freshwater discharge. Under certain external forcing conditions low-salinity waters from the Sea of Azov flow into the north-eastern part of the Black Sea through the narrow Kerch Strait and form a surface-advected buoyant plume. Water flow in the Kerch Strait also regularly occurs in the opposite direction, which results in the spreading of a bottom-advected plume of saline and dense waters from the Black Sea into the Sea of Azov. In this study we focus on the physical mechanisms that govern water exchange through the Kerch Strait and analyse the dependence of its direction and intensity on external forcing conditions. Analysis of satellite imagery, wind data, and numerical modelling shows that water exchange in the Kerch Strait is governed by a wind-induced barotropic pressure gradient. Water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time. Outflow from the Sea of Azov to the Black Sea is induced by moderate and strong north-easterly winds, while flow into the Sea of Azov from the Black Sea occurs during wind relaxation periods. The direction and intensity of water exchange have wind-governed synoptic and seasonal variability, and they do not depend on the rate of river discharge to the Sea of Azov on an intra-annual timescale. The analysed data reveal dependencies between wind forcing conditions and spatial characteristics of the buoyant plume formed by the outflow from the Sea of Azov.

Results of Monitoring of Temperature Conditions of Migration and Fishing of the Azov Khamsa

2020 ◽  
pp. 71-77
Author(s):  
Boris N. Panov ◽  
Elena O. Spiridonova ◽  
Michail M. Pyatinskiy ◽  
Aleksandr S. Arutyunyan
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Water Temperature ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
Kerch Strait ◽  
Flood Zone

The paper presents the results of monitoring the process of migration and fishing of the Azov khamsa in April-May and October-November, 2019. The research used daily maps of sea surface temperature (SST) of the Black and Azov seas, built in the hydrometeorological Center of Russia according to NCDC/NOAA (Operational module Yessim - hmc.meteorf.ru/sea/black/sst/sst_black.htm) and daily fishing information of the Center for Monitoring of Fisheries and Communications. It is shown that in the spring, khamsa clusters begin to disperse and move to feeding places after the water temperature reaches 11 °C, and at a water temperature of 14-15 °C, the fish becomes much more mobile and the clusters finally disperse. In autumn, the Azov khamsa began to concentrate in the pre-flood zone of the Sea of Azov at an average SST of 16-17 °C, with a SST of 14-16 °C, the khamsa went out into the Kerch Strait. The active output of the khamsa into the Black Sea began at the SST of the pre-flood zone of 15 °C and almost stopped at the SST of about 13 °C. The average SST in the Kerch Strait dropped to 11 °C these days.

scholarly journals CHANGES IN THE DOMINANT SPECIES AND SIZE STRUCTURE OF DIATOMS FROM THE SURFACE BOTTOM SEDIMENTS OF THE SEA OF AZOV OVER THE PAST 20 YEARS

2021 ◽  
Vol 1 (6) ◽  
pp. 96-103
Author(s):  
G.V. Kovaleva ◽  
◽  
I.Yu. Gavrilova
Keyword(s):  
Bottom Sediments ◽  
Size Structure ◽  
Sharp Decrease ◽  
Marine Species ◽  
Sea Of Azov ◽  
Diatom Analysis ◽  
The Sea Of Azov ◽  
The Past ◽  
The Stability ◽  
Radical Transformation

The paper presents the results of diatom analysis of surface bottom sediments selected with a range of 20 years. Samples of surface sediments of the Sea of Azov collected in 1998 (before the salinization period) and in 2019 were studied. The results of the diatom analysis of the bottom sediments showed that the sediments were dominated by spores of diatoms from the genus Chaetoceros and stomatocysts of golden algae. In addition to spores and stomatocysts, diatoms from the genus Thalassiosira sp., Coscinodiscus sp., Ditylum brightwellii, Pseudosolenia calcar-avis and Thalassionema nitzschioides were often found in the surface soils of 1998. In the sediments selected in 2019, medium – and large-sized taxa (Actinoptychus senarius, Actinocyclus octonarius, Thalassiosira sp., Coscinodiscus sp.) began to predominate in frequency of occurrence and abundance. The appearance of these species can be associated with an increase in the average salinity of the waters of the Sea of Azov, since most of the representatives of the above taxa belong to marine and brackish-water-marine species. A decrease in freshwater runoff and an increase in salinity in the Sea of Azov can lead not only to a radical transformation of the native microalgae community, but also increases the risk of alien marine species of plankton and benthos. Large-sized diatoms are less attractive as a food base for zooplankton, which can also lead to changes in the native biota of the Sea of Azov. In general, these dangerous transformations can lead to a sharp decrease in the stability of the ecosystem of the Sea of Azov and irreversible consequences.

scholarly journals Problems of delimitation of the Sea of Azov and the Kerch Strait

2020 ◽  
pp. 365-369
Author(s):  
Iryna Panchenko
Keyword(s):  
International Law ◽  
Russian Federation ◽  
Negotiation Process ◽  
Foreign Affairs ◽  
The Black Sea ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
Kerch Strait ◽  
The Russian Federation ◽  
The Hague

The article gradually considers the negotiation process between Ukraine and the Russian Federation on the delimitation of theSea of Azov and the Kerch Strait from 1991 to the present. It was established that according to the map of the inter-republican borderbetween the Ukrainian SSR and the Russian SSR, and according to the division of maritime waters on the basis of international law,Russia should get a smaller part of the Sea of Azov. That is why Russia was not interested in the rapid establishment of a state borderon water. It was advantageous for Russia to delay the negotiation process on this issue and use the Sea of Azov on the same terms asbefore the collapse of the USSR.The article also focuses on numerous attempts of Ukrainian diplomats to achieve legal certainty in the delimitation of the Sea ofAzov and the Kerch Strait. A total of 36 rounds of border talks about the Sea of Azov and the Kerch Strait, held from 1996 to 2012under the leadership of the Ministry of Foreign Affairs of Ukraine, showed that Russia was ready to delimit the Sea of Azov only onits own terms but not on the basis of international maritime law.After the annexation of Crimea, a new round of relations begins regarding the division of the Black Sea. Russia acted quicklyand in March 2014 announced a tender for a construction project of a bridge that would connect mainland Russia and the CrimeanPeninsula, which at that time had already been illegally incorporated into the Russian Federation. Moscow has stated that the KerchStrait should be fully controlled by them, as both shores are Russian.In 2016, Ukraine filed a lawsuit against Russia in the Hague Arbitration Court for breaking the UN Convention on the Law ofthe Sea in the Black and Azov Seas and in the Kerch Strait. For today we don’t know what decision will be made by the Hague tribunal,but there is reason to believe that the chances for winning of Ukraine are high.The problem of the Sea of Azov and the Kerch Strait has no simple solution. For today the only option is to wait for a decisionof the Arbitration Tribunal. Only on its basis Ukraine will be able to achieve the best strategy of the relations with Russia on the delimitationthe Sea of Azov and the Kerch Strait.

Microphytobenthos as an indicator of water quality and organic pollution in the western coastal zone of the Sea of Azov

2019 ◽  
Vol 48 (2) ◽  
pp. 125-139 ◽  
Author(s):  
Sophia Barinova ◽  
Anna Bondarenko ◽  
Larisa Ryabushko ◽  
Sergey Kapranov
Keyword(s):  
Water Quality ◽  
Species Composition ◽  
Eastern Mediterranean ◽  
Organic Pollution ◽  
The Sea Of Japan ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
Kerch Strait ◽  
Water Ph ◽  
Seawater Quality

AbstractBioindication of organic pollution and seawater quality was carried out for the first time in the western part of the Sea of Azov on the basis of species composition and quantitative characteristics of microphytobenthos. A total of 229 algal samples were collected at 17 sites over the period of 2005-2014 on three different substrates in three areas under study: Sivash Gulf, the Kerch Strait and Cape Kazantip. In total, 200 taxa of algae were found, which belong to six taxonomic divisions with a predominance of diatoms. Among those, 108 taxa are indicators of substrate, water temperature, salinity, water pH, trophic state, the type of nutrition and organic pollution of water. It has been shown that the most active self-purification of water takes place in communities on stony substrates. The largest number of algae species (50%) occurs in the cleanest waters of the Kazantip Nature Reserve (Water Quality Classes I–II). The species composition of organic pollution indicators in Sivash Gulf corresponds to waters of Classes III–IV, which are more polluted than those of the Kerch Strait and Cape Kazantip. All the studied areas of the Sea of Azov are cleaner compared to some waters of the Eastern Mediterranean and the Sea of Japan.

Microplastics in Beach Sediments of the Sea of Azov: Morphological and Morphometric Features

2021 ◽  
Author(s):  
A. E. Glushko ◽  
L. A. Bespalova ◽  
◽  
Keyword(s):  
Morphological Features ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
Modified Method ◽  
Kerch Strait ◽  
Morphometric Features ◽  
Beach Sediments ◽  
Stereo Microscope ◽  
Size Of Particles ◽  
The Village

This paper aims at assessment of microplastics concentrations on the beaches of the Sea of Azov and research of morphological features, size of particles, level and ways of degradation (or destruction) of microplastics. During the study, 126 samples of beach deposits were taken at 14 points of the beaches of the Sea of Azov and Kerch Strait. The samples were processed using the modified method NOAA. The analysis showed pollutant’s presence in 100 % of the samples. The concentration of microplastics particles in sand samples from different areas of the beach varies from 12 to 112 pieces per 1 m2 . The highest concentration was found on the beaches in Taganrog and the village of Ilyich. Morphological features of the particles were studied using a stereo microscope (Micromed MC-1 2C Digital). Translucent fibres and membranes prevailed in all the samples. Study of size frequency showed that the most frequently observed are particles of 0.2 mm, the median of size range being 0.5 mm. Types of microplastics degradation were determined using a scanning electron microscope (VEGA II LMU). Dissection, fracturing, and splitting were recorded

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