Incidental by-catch of Delphinus delphis in the Black Sea

2019 ◽  
Vol 166 ◽  
pp. 145
Author(s):  
R.I. Rizac ◽  
A.C. Stoian ◽  
D.G. Soare ◽  
C. Gal ◽  
T. Soare
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Delphinus Delphis ◽  
By Catch

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 Cetaceans of the Black Sea: where did they survive glacial?

2020 ◽  
Author(s):  
Davit Dekanoidze ◽  
Natia Kopaliani ◽  
Zurab Gurielidze ◽  
Levan Ninua ◽  
Nana Devidze ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Population Modelling ◽  
Effective Population ◽  
Cetacean Species ◽  
Mediterranean Populations ◽  
Migration Rates ◽  
Delphinus Delphis ◽  
Mitochondrial Haplotypes ◽  
Winter Time

AbstractThree species of cetaceans, Phocoena phocoena, Delphinus delphis and Tursiops truncatus ponticus are found in the Black Sea. The Black Sea populations of all three species show morpho-ecological peculiarities that leaded to their subspecific status: P. p. relicta (PPR), D. d. ponticus (DDP), and T. t. ponticus (TTP). It is not clear how long-lasting was their isolation from the core conspecific populations that ensured the development of adaptive features of PPR, DDP, and TTP. The analysis of mitochondrial haplotypes of PPR suggests that the split time of the at least maternal lineage of the Black Sea population of harbour porpoise lasted for over 100 ky (i.e. they should survive at least the latest glacial maximum within the Black Sea). However, the analysis of multiple microsatellite genotypes leaded some authors to suggest that the isolation is much less long, since middle Holocene. We re-analysed published mitochondrial sequences of all three Black Sea cetaceans along with several tens of sequences obtained from the stranded cetaceans. Our analyses suggest that Black Sea populations of all three cetacean species have an important input of populations that survived the last (and maybe earlier) glacial maxima within the Black Sea, most likely in its south-eastern fragment, which did not freeze in winter time even during the glacial peaks. This analysis is supported by both molecular clock approach and simple population modelling based on the assumption on the effective population size range. Different from the PPR, whose Black Sea population is currently fully isolated, there is a limited migration between the Black Sea and Atlantic populations of T. truncatus and D. delphis, through the Mediterranean “bridge” population. However, the migration rates are not sufficient to overweight differential selection between the Black Sea and Mediterranean populations, and the local morpho-ecological specifics is successfully maintained.

Epizootic of morbilliviral disease in common dolphins (Delphinus delphis ponticus) from the Black Sea

1999 ◽  
Vol 144 (4) ◽  
pp. 85-92 ◽  
Author(s):  
A. Birkun ◽  
T. Kuiken ◽  
S. Krivokhizhin ◽  
D. M. Haines ◽  
A. D. M. E. Osterhaus ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Delphinus Delphis ◽  
Common Dolphins

scholarly journals A new grid-net design to eliminate by-catch for the veined rapa whelk beam trawl fisheries in the south-eastern Black Sea

2018 ◽  
Author(s):  
AHMET RAIF ERYAŞAR
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Beam Trawl ◽  
The South ◽  
South Eastern ◽  
Sea Beam ◽  
The Mean ◽  
By Catch ◽  
Trawl Fisheries ◽  
Rapa Whelk

            The beam trawl fisheries in the Black Sea only target the veined rapa whelk (Rapana venosa) individuals, and other species like fishes and crabs are thrown back into the sea dead or alive. Furthermore, small bivalves and crabs are packed with the target species without any elimination. In this study, a grid-net design (GND) with two different bar spacing was tested to reduce the by-catch. In total 30 hauls (15 hauls for each bar spacing) were carried out in the south-eastern Black Sea between 17 and 26 August 2017. A commercial diamond mesh and one of the grid-net beam trawls were towed simultaneously onboard a commercial vessel to compare the by-catch compositions. Results showed that there were statistically significant (p<0.01) 78% and 83% decreases in the mean weight of the by-catch for 20 and 30 mm grid-nets, respectively. When compared to the conventional gear, a commercial loss of 14% in the 20 mm GND, and 39% in the 30 mm GND in landing values were estimated. In conclusion, use of grid-nets in south-eastern Black Sea beam trawl fisheries can significantly reduce the by-catch of most benthic species. However, it also causes some commercial loss which might be compensated by providing some compensation to fishers such as extension of the fishing season.

MÖSSBAUER AND CHEMICAL ANALYSES OF SOME SEDIMENTS FROM THE ROMANIAN SHORE OF THE BLACK SEA

1979 ◽  
Vol 40 (C2) ◽  
pp. C2-445-C2-448
Author(s):  
D. Barb ◽  
L. Diamandescu ◽  
M. Morariu ◽  
I. I. Georgescu
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Chemical Analyses

Modeling of ecological conditions in the Euxine Basin in the Sarmatian and Maeotian by methods of diatom analysis

2019 ◽  
pp. 257-261
Author(s):  
Eleonora P. Radionova
Keyword(s):  
Black Sea ◽  
Late Miocene ◽  
The Black Sea ◽  
Subtidal Zone ◽  
Diatom Analysis ◽  
Diatom Flora ◽  
North West ◽  
Ecological Conditions ◽  
The North

The associations and ecological conditions of the existence of modern diatoms of the North-West (Pridneprovsky), Prikerchensky and Eastern regions of the subtidal zone of the Black Sea are considered. Based on the unity of the composition of the Present and Sarmatian-Meotian diatom flora, an attempt has been made to model some of the ecological c situation of the Late Miocene Euxinian basin.

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