scholarly journals Taxonomic diversity and environmental assessment of benthic diatoms at Balaklava Bay (South-Western Crimea, the Black Sea, Ukraine)

Algologia ◽  
2014 ◽  
Vol 24 (1) ◽  
pp. 47-66
Author(s):  
E.L. Nevrova ◽  
Keyword(s):  
Black Sea ◽  
Environmental Assessment ◽  
Taxonomic Diversity ◽  
Benthic Diatoms ◽  
The Black Sea

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 Benthic Diatom Composition in Coastal Zone of Black Sea, Sasyk Reservoir (Ukraine)

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 458
Author(s):  
Olena P. Bilous ◽  
Agata Z. Wojtal ◽  
Natalia O. Ivanova ◽  
Petro M. Tsarenko ◽  
Olga V. Burova ◽  
...  
Keyword(s):  
Coastal Zone ◽  
Black Sea ◽  
Ecological Status ◽  
Assessment Method ◽  
Benthic Diatoms ◽  
The Black Sea ◽  
Salinity Changes ◽  
The Status ◽  
Freshwater Reservoir ◽  
First Time

The Sasyk Reservoir is one of the largest seaside reservoirs in Ukraine, artificially maintained as a freshwater area including various floodplain areas. The Reservoir originated from an estuary to now being an almost freshwater reservoir. The diatoms (Bacillariophyta) in benthos were investigated for analyzing the coastal zone diversity of the Black Sea inside the borders of Ukraine. The indicated diatom composition was formed by 97 species (100 infraspecies taxa). Some rare marine and freshwater taxa were noted, as well as three species reported in Ukrainian territory for the first time (Navicula vandamii Schoeman et R.E.M. Archibald, Sellaphora difficillima (Hustedt) C.E. Wetzel, L. Ector et D.G. Mann, and Mastogloia laterostrata Hustedt). The bioindicative characteristics of the diatom composition testified to the freshwater condition of the reservoir. Changes to the salinity level of the Sasyk Reservoir were exposed due to the composition of benthic diatoms. The presence of mesohalobous species (7 taxa) acknowledges conditions that are typical for estuaries and mouths of rivers and reveals the salinity changes in the Sasyk Reservoir. Likewise, the prevailing number of oligohalobous diatoms (61 taxa) reveal presence of freshwater in the reservoir. The implementation of the Polish phytobenthos lake assessment method for the nearby Ukrainian Reservoir was conducted for the first time. The multimetric Diatom Index for lake values varied from 0.39 to 0.76, and revealed alterations in the status over the Sasyk sites, ranging from good, moderate, to poor. Thus, it may be concluded that the current ecological status relating to the composition of benthic diatoms of the reservoir located in the coastal zone of the Black Sea is evaluated as having a moderate status class with some exceptions.

Development of a Web-based GIS monitoring and environmental assessment system for the Black Sea: application in the Danube Delta area

2016 ◽  
Vol 188 (8) ◽  
Author(s):  
Ilias N. Tziavos ◽  
Thomas K. Alexandridis ◽  
Borys Aleksandrov ◽  
Agamemnon Andrianopoulos ◽  
Ioannis D. Doukas ◽  
...  
Keyword(s):  
Black Sea ◽  
Environmental Assessment ◽  
Assessment System ◽  
The Black Sea ◽  
Danube Delta ◽  
Web Based ◽  
Delta Area

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.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document