First researches of the underwater ecosystem communities of an underground channel built in 1950s (Balaklava bay, Sevastopol)

2021 ◽  
Vol 39 ◽  
pp. 30-45
Author(s):  
Nelly G. Sergeeva ◽  
Yuriy S. Tarariev ◽  
Roman V. Gorbunov ◽  
Nikolay K. Revkov ◽  
Natalya A. Boltachova ◽  
...  
Keyword(s):  
Black Sea ◽  
Species Abundance ◽  
Group Development ◽  
Open Water ◽  
Taxonomic Diversity ◽  
Average Density ◽  
The Black Sea ◽  
Underground Channel ◽  
Higher Taxa ◽  
Biological Studies

The results of the first studies of the ecosystem state of the underwater part of the channel, artificially created in the middle of the 20th century on the western shore of the Balaklava Bay (Sevastopol) as a naval base of the Black Sea Fleet for the submarines repair, are presented. Channel's ecosystem is determined by uniqueness of anthropogenic formation and considered as analogue of natural Black Sea cave. Hydrospelological survey of the channel and biological studies allowed assessing its current state, the nature of biofouling of its walls and anthropogenic and technical pollution of the bottom. Macrofauna of the channel wall biofouling is represented by the Mytilaster lineatus community, which has a high level of species abundance (about 80 species have been registered) and quantitative development. Both in taxonomic diversity and in quantitative terms, this community is comparable to the rocky substrate community near open Crimean coasts, but with a smaller share of crustacean group development. Due to weakened hydrodynamics, well developed fauna of bryozoans forming plurannual crusty structures and single sponges is observed on the channel's walls. In contrast to the channel walls biofouling, its bottom macrofauna has relatively lower quantitative and qualitative composition. Meiobenthos in the channel’s wall biofouling is represented by 18 higher taxa (type, class, order) of Protozoa and Metazoa with predominance of harpacticoids by abundance. Meiobenthos of the soft bottom of underground channel is represented by 15 higher taxa with predominance of free-living nematodes and harpacticoids by abundance. Average density of meiobenthos in the channel’s bottom sediments is comparable with similar parameters of its development in open water areas and Sevastopol bays.

scholarly journals CURRENT VIEWS ON THE DIVERSITY AND DISTRIBUTION OF DEEP-WATER MEIOBENTHOS AT THE TURKISH SHELF (BLACK SEA)

2017 ◽  
Vol 14 ◽  
pp. 60-73
Author(s):  
Nelli G. Sergeeva ◽  
Derya Ürkmez
Keyword(s):  
Black Sea ◽  
Deep Water ◽  
Benthic Fauna ◽  
Taxonomic Diversity ◽  
The Black Sea ◽  
Depth Range ◽  
Free Living ◽  
Higher Taxa ◽  
Strong Current ◽  
High Level

Deep-water meiobenthos of Turkish shelf has been evaluated at the Black Sea exit of İstanbul Strait (Bosphorus) and off Sinop peninsula as a result of three scientific cruises. Taxonomic diversity of meiobenthos communities was studied at the Black Sea exit of Bosphorus on a transect with a depth range of 75-300 m. The bottom sediments were collected at the area during two cruises, on board RV "Arar'' (of Turkey) and ''Maria S. Merian" (of Germany) in November 2009 and April 2010, respectively. Data on meiobenthos inhabiting both normoxic and extreme conditions was collected in the studied area and meiobenthos composition included 26 high level taxa. In addition, 2-3 morphotypes of benthic fauna were recorded as incertae sedis, which require further study. The number of higher taxa decreased from 22 to 14-8 when switching from oxygenic conditions (50-125 m) to the anoxic hydrogen sulphide environment (226-300 m). The constant components of meiobenthos included protists (Ciliophora, Gromiidea and soft-shelled Foraminifera), and metazoans were constantly represented by Nematoda and Harpacticoida. In 2011, a quantitative study on meiobenthic composition of the oxic/anoxic interface at the western part off Sinop Peninsula (Southern Black Sea) has also been investigated. The material was collected by ROVs during the expedition (Black Sea Leg) of the exploration vessel (E/V) Nautilus. Results showed that the taxa composition of meiobenthos ranged from 4 to 10 major groups. Free-living marine nematodes were numerically the dominant taxon at each station. Total abundances decreased in parallel to increasing water depth, hence decreasing oxygen levels.

Host use pattern and life history of Liopetrolisthes mitra, a crab associate of the black sea urchin Tetrapygus niger

2000 ◽  
Vol 80 (4) ◽  
pp. 639-645 ◽  
Author(s):  
J.A. Baeza ◽  
M. Thiel
Keyword(s):  
Sea Urchin ◽  
Black Sea ◽  
Sea Urchins ◽  
Austral Summer ◽  
Average Density ◽  
The Black Sea ◽  
Reproductive Pattern ◽  
Host Use ◽  
Austral Spring ◽  
Use Pattern

The porcellanid crab Liopetrolisthes mitra is a common associate of the black sea urchin, Tetrapygus niger in north central Chile. The host-use pattern, population dynamics and reproductive pattern of L. mitra on sea urchins were examined between January 1996 and February 1997. Each month, between 60 and 95 per cent of all collected urchins hosted crabs, with the highest frequency of cohabitation occurring during the austral summer (January to March). Group sizes of crabs on individual urchins ranged from 1 to 25 crabs per host. The average density of crabs on the urchins ranged from 2 to 5.5 crabs per host. Large urchins were inhabited by crabs more frequently than small urchins but urchin size had no effect on the number or size of crabs. The sex ratio of adult crabs was ˜1:1 during most months. Reproduction occurred throughout the year but was most intense during the austral spring and summer (October to March), when the highest percentage of ovigerous females were found. Similarly, recruitment of L. mitra occurred throughout the year but reached a peak during austral summer and early autumn (January to May). All life stages of L. mitra including recently settled megalopae and reproductive adults were found on urchins. Size–frequency analysis indicated that many crabs live >1.5 years. The results of this study confirm that the association between L. mitra and T. niger is strong and persists throughout the benthic life of the commensal crab.

scholarly journals Reconciling Trends of Mean Trophic Index and Mean Temperature of the Catch in the Eastern Mediterranean and Black Seas

2018 ◽  
Vol 19 (1) ◽  
pp. 79 ◽  
Author(s):  
ÇETIN KESKIN ◽  
DANIEL PAULY
Keyword(s):  
Black Sea ◽  
Eastern Mediterranean ◽  
The Black Sea ◽  
Trophic Index ◽  
Higher Taxa ◽  
Mean Temperature ◽  
The Mean ◽  
Mean Trophic Level ◽  
Mediterranean And Black Seas ◽  
The Impact

  The mean trophic level, i.e., the Mean Trophic Index (MTI) and Mean Temperature of the Catch (MTC) were estimated for Turkish waters in the Eastern Mediterranean and the Black Sea based on the reconstructed marine fisheries catches (consisting of N = 88 species and/or higher taxa) of in Turkish waters for the year 1950 to 2010. The MTI decreased in both regions of Turkey, following expectations, but the MTC showed different trends in these two regions. It increased (by 0.48 °C·decade-1), along with the SST in the Eastern Mediterranean, while it fluctuated in the Black Sea. This fluctuating behaviour, however, was similar to the fluctuating tendency of SST in the Black Sea. This suggests that the MTI and MTC can be relied upon as indicators of fisheries impacts on ecosystems, and of the impact of changing temperatures on fisheries, respectively. 

Using line transect sampling to detect cetaceans and floating litter during vessel survey in western Black Sea

2021 ◽  
Author(s):  
Romulus-Marian Paiu ◽  
Arda M. Tonay ◽  
Costin Timofte ◽  
Angelica Paiu ◽  
Mihaela Mirea Candea ◽  
...  
Keyword(s):  
Black Sea ◽  
Average Density ◽  
The Black Sea ◽  
Line Transect ◽  
Common Dolphin ◽  
Line Transect Sampling ◽  
Delphinus Delphis ◽  
Transect Sampling ◽  
Continuous Survey ◽  
Similar Density

<p>                The quality of the Black Sea ecosystem is partly but importantly dependent on the survival and sustainability of the top predator populations. It is difficult to foresee all consequences for the regional biodiversity if cetaceans disappear as it had happened with the Mediterranean monk seals in the past. During 7 days, between 30 September and 7 October, 2019, a joint oceanographical survey was made with a multipurpose R/V Mare Nigrum in offshore as well as deep sea locations, within the Romanian (RO), Bulgarian (BG) and western Turkish (TK) national waters of the Black Sea in the frame of ANEMONE project. The total track line was around 700 nautical miles and the sampled area covered 9754,58 km<sup>2</sup>. Observations were made of cetaceans and floating litter, following line transect sampling method, with a single platform (2 observers, on the left and right of the vessel bridge) over 380.44 km of transects. A total of 54 cetacean sightings and 81 floating litter items were recorded. All the three species, short-beaked common dolphin (<em>Delphinus delphis</em> ssp. <em>ponticus</em>), Black Sea bottlenose dolphin (<em>Tursiops truncatus</em> ssp. <em>ponticus</em>), and Black Sea harbour porpoise (<em>Phocoena phocoena </em>ssp. <em>relicta</em>), were registered with a similar density (individuals/km<sup>2</sup>), 0.012 for RO sector and 0.013 for BG-TK sector. The number of debris varied between 1 and 24 items, reaching 5.26± 5.93 items on average. Among the transects, 53% contained less than 5 items and only 13% were with more than 10 items. Based on these results, the average density of floating macro-litter in BG waters was found 2.43 ± 2.4 items/km<sup>2</sup>, 1.73 ± 1.24 items/km<sup>2 </sup>in the RO waters and 2.43±2.17 items/km<sup>2</sup> in TR waters. This study was the first to make a joint and continuous survey effort for both cetaceans and litter simultaneously in the Black Sea.</p><p><strong>Key words:</strong>  Black Sea, cetaceans, marine litter, joint cruise, ANEMONE project.</p>

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the northern Black Sea. Part V: Annelida (Polychaeta)

2021 ◽  
Vol 6 (2) ◽  
pp. 18-32
Author(s):  
I. P. Bondarev ◽  
N. A. Boltachova
Keyword(s):  
Black Sea ◽  
Native Species ◽  
Taxonomic Diversity ◽  
Research Area ◽  
Water Area ◽  
The Black Sea ◽  
Rapana Venosa ◽  
Number Of Species ◽  
Plastic Bag ◽  
Rapa Whelk

The study of Annelida (Polychaeta) taxocene – epibionts of the invasive gastropod Rapana venosa – continues the cycle of publications describing the composition of the consortium of the largest gastropod of the Black Sea benthos. R. venosa consortium is still a poorly investigated and unaccounted component in the structure of the Black Sea shelf biocenoses. The aim of this work is to study the complex of polychaetes of R. venosa consortium. The objectives of this stage are as follows: compiling a list of Annelida (Polychaeta) taxa – rapa whelk epibionts; studying taxocene biogeographic and trophic structure; and analyzing ecological relationships of polychaetes with the consortium core. To study the consort community of rapa whelk, sampling was conducted in seven areas of the northern Black Sea: 1 – Mamaia, Romania; 2 – northwestern Black Sea, Crimea offshore; 3 – Sevastopol; 4 – Alupka; 5 – Yalta – Alushta; 6 – Karadag; 7 – Kerch Strait. In the coastal area down to a depth of 15 m, R. venosa was sampled totally using surface-supplied diving equipment; in the deeper-water area (up to 40 m), samples were taken with an “Ocean-50” bottom grab from the board of the RV “Professor Vodyanitsky”. Each rapa whelk specimen (sample) was placed in a separate plastic bag, with the indication of the area, depth, and biotope. In total, 2,411 samples were taken and analyzed: 977 – rock rapa whelks and 1434 – sand rapa whelks. R. venosa shell coverage with epibionts (fouling intensity) was determined as a percentage of the total area of the outer shell surface. Polychaeta taxocene of R. venosa consortium includes 31 species representing 31 genera of 15 families of 2 subclasses. Most species (18) belong to Errantia, and half of them are representatives of the families Nereididae and Syllidae. Sedentaria includes 13 species; by the largest number of species (4), the family Serpulidae is represented. Polychaeta taxocene of R. venosa consortium is represented by three biogeographic groups: native species of the Mediterranean-Atlantic genesis (84 %), the Black Sea endemics (10 %), and recent invaders of various geographical genesis (6 %). On sand rapa whelk, 31 Polychaeta species were found; on rock rapa whelk, only 5 species were recorded. The indicators of Polychaeta fauna development differ significantly by the depth and research area. The most diverse polychaetes are those in bays of Sevastopol (the area No. 3) at depths of 2–10 m; the maximum depth of Polychaeta finding (40 m) corresponds to the greatest depth of rapa whelk sampling. The area of shell coverage with polychaetes reaches 70 %; occurrence in several areas is up to 95 %. The maximum number of species found at a single rapa whelk specimen is 8; on average, 2–4 Polychaeta species are recorded at R. venosa individuals. Taxonomic diversity and abundance of polychaetes determine their significance in R. venosa consortium. Due to the invasive predatory mollusc R. venosa, polychaetes get additional opportunities for spread on the Black Sea shelf.

scholarly journals The structural basis of regional differences in taxonomic diversity of benthic diatoms (Bacillariophyta) of the Black Sea

2016 ◽  
Vol 1 (1) ◽  
pp. 43-63
Author(s):  
E. L. Nevrova
Keyword(s):  
Black Sea ◽  
Taxonomic Diversity ◽  
Average Level ◽  
Benthic Diatoms ◽  
Structural Basis ◽  
The Black Sea ◽  
Species Number ◽  
Hierarchical Tree ◽  
Diatom Flora ◽  
Flora Diversity

The important aim for preservation of the Black Sea microalgae is evaluation of diatom flora diversity and revelation of its formation patterns. The focus of this paper is analysis of benthic diatoms diversity in the regions of Northern shelf of the Black Sea and disclosure of the causes for their differences on the different hierarchical levels within each of the three classes of Bacillariophyta. Based on the own sampling surveys results and published sources, the revision of benthic diatom flora of the Black Sea was evaluated and current taxonomic diversity was estimated by using of Taxonomical Distinctness Indices (TaxDI). Updated diatom inventory from 5 regions (Bulgarian, Romanian, North-Western, Crimean and Caucasian shelf) holds 1094 species and intraspecific taxa, pooled in 953 species, 149 genera, 61 families, 32 order and 3 classes Bacillariophyta. Current taxonomic richness of the Black Sea benthic diatoms has 1094 species and intraspecific taxa (953 species, 149 genera, 61 families, 32 orders and 3 classes). At the Crimean coast registered 884 species (81 % of the total species number), at NWBS – 556 (51 %) off the coast of Bulgaria – 271 (25 %), Romania – 358 (33 %), the Caucasus – 310 (28 %). Mean TaxDI values (∆+ and Λ+) for diatom assemblages from these regions were calculated and its deviation from expected average level, corresponding to Black Sea master-list, was assessed. Deviation of the index from expected average level in each of the three classes was found to depend on the structure of the phylogenetic branches. The greatest influence on the hierarchical tree of Bacillariophyta is revealed to bring the mono- and oligospecies branches. Character of deviation of the regional diatom flora structure fromexpected average level is caused of the species, which forming a mono- or oligospecies branches up to the node of order. Suchlike species (33) with high rank of taxonomic exclusiveness are highlighted from the several regions. Disappearance of such species leads to reducing of entire phylogenetic branch from the regional tree of Bacillariophyta. Among mono- and oligospecific taxa the group of 12 species was marked out particularly. These species have the highest rank of taxonomic exclu-siveness and were cited once in the only regions. Elimination of these species from the regional flora entails to dis-appearance of the monospecies branch (including genus, family and order) from the Black Sea flora. It would deter-mine the decrease of taxonomic diversity and significant changes in hierarchical tree of Bacillariophyta as the con-crete region as well the whole Black Sea. Structure of regional tree of Crimean region almost approached the ex-pected mode for the whole Black Sea diatom flora. The value of ∆+ for Crimean coast was the lowest (81.38). It may evidence about great share of polyspecies branches in the hierarchical tree and the maximum value of species/genus ratio (7) and lead to decreasing the vertical evenness in diatom taxocene structure for Crimea. On the contrary, the value of ∆+ for Romania coast was highest (85.9). It were caused of great number of oligospecies branches closingup on genus and family taxonomic levels and minimum value of this ratio (4) and determined more flattened pattern of taxonomical tree structure.

scholarly journals On recording of Atlantic mackerel Scomber scombrus Linnaeus, 1758 (Scombridae) in the coastal zone of Sevastopol and prospects for the revival of its fishing

2019 ◽  
Vol 4 (2) ◽  
pp. 3-10
Author(s):  
A. R. Boltachev ◽  
E. P. Karpova
Keyword(s):  
Coastal Zone ◽  
Black Sea ◽  
The Black Sea ◽  
Commercial Fishing ◽  
Complete Disappearance ◽  
Mediterranean Population ◽  
North Caucasus ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
Biological Studies

Information on catching of Atlantic mackerel Scomber scombrus Linnaeus, 1758, which has become very rare in the Black Sea in the last 50 years, is considered. Several specimens were found in the period from June 7 to 15, 2018 in the catches of commercial fixed nets in the lower part of the Balaklava Bay and in the coastal zone near the Bay. One specimen was given to the authors for the study; the results of morphometric and biological studies of this specimen are given in the work. The features of the area of Atlantic mackerel are briefly considered, the distribution and biology of four main populations of this species inhabiting European waters are given, with the main attention paid to the Black Sea population. Information on the level of modern fishing of this species in the world as a whole and separately in the Republic of Turkey is given. A retrospective analysis of the catching of mackerel in the Black Sea, in particular, near the coast of Crimea, is made. The reasons for the complete disappearance of its Black Sea population in the late 1960s in the Black and Marmara seas are analyzed. The conclusion was made that, despite the increase in some cases of mackerel catchings off the coast of Crimea, the North Caucasus and Turkey, the Black Sea population of this species either completely disappeared or is in a very depressed state, and the probability of its commercial fishing recovery in the region is minimal. The preliminary conclusion on the basis of the analysis of the given material has been made that the specimen caught in the Sevastopol region may belong to the Mediterranean population of Atlantic mackerel.

scholarly journals Dynamics of macrozoobenthos in the Southern Bulgarian Black Sea coastal and open-sea areas

2001 ◽  
Vol 2 (1) ◽  
pp. 27 ◽  
Author(s):  
S. STOYKOV ◽  
S. UZUNOVA
Keyword(s):  
Water Quality ◽  
Species Diversity ◽  
Black Sea ◽  
Average Density ◽  
The Black Sea ◽  
Anthropogenic Influence ◽  
Open Sea ◽  
Average Biomass ◽  
Seasonal Basis

The paper presents results of analysis of 96 macrozoobenthic samples, collected on a seasonal basis in Bourgas Bay and in open-sea areas offshore Cape Emine (Bulgarian Black Sea) in 1996 and 1998. In total 96 taxa were established, distributed in four groups: Polychaeta, Mollusca, Crustacea and “Diversa”. The average density of populations was 1756 ind.m-2 with a predominating abundance of Polychaeta species. The average biomass estimated was 183.02 g.m-2, formed mainly by representatives of Mollusca. The latter species were measured together with the shells, which appraised their individual weights. Seven of the species found had a coefficient of constancy more than 50%. These were the most adapted species to the environmental conditions of the investigated areas. The quantitative and qualitative assessments in this study demonstrate an increasing tendency in the parameters obtained (density, biomass, species diversity) in comparison with previous investigations in the early 1990-s, when intensive anthropogenic influence was widely perceived to misbalance the Black Sea ecosystem.The method of Warwick (1986) applied to characterize the water quality of the studied areas allowed us to define them as rather clean or moderately polluted aquatories.

scholarly journals The taxonomic diversity of mycobiota in the coastal waters of Crimea (the Black Sea)

2016 ◽  
Vol 1 (2) ◽  
pp. 27-38
Author(s):  
N. I. Kopytina ◽  
I. A. Dudka
Keyword(s):  
Black Sea ◽  
Bottom Sediments ◽  
Coastal Waters ◽  
Taxonomic Diversity ◽  
Fungal Species ◽  
The Black Sea ◽  
Taxonomic Distinctness ◽  
Distinctive Features ◽  
New Information ◽  
Water Bottom

New information about fungi distribution, change of genera names and change of the systematic attribution of some species determine the necessity of revision of the Crimean coastal waters mycobiota. The purpose of this work is to conduct a revision of fungi names synonymy, to reveal specific richness, to give quantitative evaluation and to perform comparative analysis of the taxonomic diversity of mycobiota of different regions and biotopes in the Black Sea sector of the Crimean coastal waters and west khalistaza on the base of literature and our own data. The following biotopes have been studied: water, bottom sediments, algae, integument of invertebrates, dolphins’ skin, Zostera marina and wood. The taxonomic list of marine mycobiota included 275 species from 105 genera, 40 families, 26 orders, 15 classes, 5 phylum. The number of species in areas has changed from 19 (6.9 % of composition) in west khalistaza to 147 (53.4 %) in Kazach’ya Bay, in biotopes – from 17 (6.2 %) on the skin of dolphins to 157 (57.1 %) in bottom sediments. The valuation of fungal species variety was made with the usage of Taxonomic Distinctness Indices TaxDI (Δ+ and Λ+). The complexity of the minimum taxonomic diversity (Δ+ = 66.4) was identified in the west khalistaza, the maximum – in the Sevastopol’skaya Bay (Δ+ = 80.2). The minimum value of the index (Δ+ = 70.0) was identified in the fragments of wood, the maximum (Δ+ = 86.2) – on invertebrates. The less taxonomic variety was revealed in the complexes, in which the basis of the composition (81.8–89.5 % in areas and 76.5–87.1 % in biotopes) was presented by polyspecies branches of mycobiota from the “leading” families and genera. The number of examined biotopes has determined the distinctive features of the hierarchic diversity of mycobiota. The obligate aquatic fungi isolated from invertebrates and from fragments of wood has affected the structure of fungal complexes. Maximal similarity of mycocomplexes at all taxonomical levels was registered in Kazach’ya and Kamyshovaya bays, minimal – in mycocomplexes of west khalistaza and Sevastopol’skaya Bay. The greatest similarity of structure was registered in biotopes of water and bottom sediments, the smallest – in biotopes of water and wood.

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