The relationship between somatic growth and otolith dimensions of Mediterranean horse mackerel (Trachurus mediterraneus ) from the Black Sea

2012 ◽  
Vol 29 (1) ◽  
pp. 230-233 ◽  
Author(s):  
N. Kasapoglu ◽  
E. Duzgunes
Keyword(s):  
Black Sea ◽  
Somatic Growth ◽  
Horse Mackerel ◽  
The Black Sea ◽  
The Relationship

The construction of Xerxes' bridge over the Hellespont

1996 ◽  
Vol 116 ◽  
pp. 88-107 ◽  
Author(s):  
N.G.L. Hammond ◽  
L.J. Roseman
Keyword(s):  
Mechanical Engineer ◽  
Black Sea ◽  
Weather Conditions ◽  
The Black Sea ◽  
Classical Scholar ◽  
The Mediterranean ◽  
The Relationship

The bridging of the Hellespont by Xerxes was a unique achievement. How was it done? The Chorus of Elders in Aeschylus' Persians expressed their wonder at ‘the flax-bound raft’, and Herodotus described the construction of the two bridges, each with warships as pontoons, with cables well over a kilometre long, and with a roadway capable of carrying a huge army. Classical scholars have generally found these accounts inadequate and even inexplicable, especially in regard to the relationship between the pontoons and the cables. The Hellespont has strong currents which vary in their direction, turbulent and often stormy waters, and exposure to violent winds, blowing sometimes from the Black Sea and sometimes from the Mediterranean. How were the warships moored in order to face the currents and withstand the gales? Did the warships form a continuous platform, or was each ship free to move in response to weather conditions? What was the function of the enormous cables? How and where were they made? Did they bind the pontoons together? Did they carry the roadway? How were they fixed at the landward ends? This article attempts an answer to these questions through the collaboration of a classical scholar and a mechanical engineer.

Let whose people go? Subjecthood, sovereignty, liberation, and legalism in eighteenth-century Russo-Ottoman relations

2012 ◽  
Vol 3 (2) ◽  
pp. 196-228 ◽  
Author(s):  
Will Smiley
Keyword(s):  
Nineteenth Century ◽  
Eighteenth Century ◽  
International Relations ◽  
Black Sea ◽  
Slave Trade ◽  
The Black Sea ◽  
The Many ◽  
The Relationship ◽  
Release Processes

This article considers the relationship between law, diplomacy, and identity in delineating slavery and freedom in the Black Sea imperial milieu. Examining the release processes for captives which followed each of the many wars between the Ottoman and Russian empires in the eighteenth century, I argue that these matters were increasingly handled according to written and unwritten legal understandings, rather than through ransoms or threats. The two empires agreed that the Ottoman state would set free enslaved Russian subjects, even those in private hands, but also that the Russians would not demand the release of others. This discussion, therefore, offers a window on the legalization of international relations, and on the growing importance of individuals’ relationship with central states. Moreover, these understandings endured, consciously or unconsciously, into the nineteenth century, arguably shaping Russo-Ottoman and Ottoman-European relations on issues of intervention and the slave trade.

scholarly journals Gelatinous macroplankton of the open pelagial and shelf of the Black Sea: Distribution in autumn 2016 and interannual changes in biomass and abundance

2019 ◽  
Vol 4 (3) ◽  
pp. 3-14 ◽  
Author(s):  
B. E. Anninsky ◽  
S. M. Ignatyev ◽  
G. A. Finenko ◽  
N. A. Datsyk
Keyword(s):  
Black Sea ◽  
Oxygen Sensor ◽  
Abiotic Factors ◽  
Lower Boundary ◽  
Somatic Growth ◽  
Sea Surface ◽  
The Black Sea ◽  
Mnemiopsis Leidyi ◽  
Trophic Relations ◽  
Order Of Magnitude

The gelatinous macroplankton community of the Black Sea renews annually and functionates differently depending on the complicated system of trophic relations and interannual fluctuations of biotic and abiotic factors. Its monitoring is necessary for the evaluation of the current state and possible vectors of evolution of the whole pelagic ecosystem. For this purpose the data on the composition and distribution of gelatinous organisms were collected on the 89th cruise of the RV “Professor Vodyanitsky” (September – October of 2016) at 62 stations located in coastal areas and in the open sea to the south and southwest of Crimea. Samples were taken with the Bogorov – Rass net (inlet area of 0.5 m², mesh of 300 µm) using vertical net hauls from the bottom to the sea surface in the shallow shelf and from the lower boundary of the oxygen zone [according to the dissolved oxygen sensor CTD SBE plus (Sea Bird)] to the sea surface – in deepwater areas. Aurelia aurita and 3 ctenophore species (Mnemiopsis leidyi, Pleurobrachia pileus, and Beroe ovata) were present together in the 90 % of the samples (on 56 stations). In spite of some increase in average biomass of every species in deep sea areas, and, particularly, of A. aurita up to 260 g per m², there was no difference between the data of 2016 and 2010 (p > 0.05). The abundance of A. aurita increased by about one order of magnitude (p < 0.001); the abundance of P. pileus increased 2–5 times (p < 0.001); of B. ovata – 3–15 times (p < 0.01). M. leidyi abundance increased only at the outer Black Sea shelf; in other regions it could have been restricted by B. ovata predation. A. aurita linear specific growth rate in 2016 was one of the lowest for the last 15 years. Slow somatic growth of the jellyfish indicates unfavorable conditions for this species in 2016. However, the jellyfish biomass was higher than that of previous years because of the huge abundance of the spring generation. The weakening competition with planktivorous ctenophores may lead to even greater increase in the ecological valence of A. aurita among other gelatinous predators in the nearest future.

Stock dynamics and predator–prey effects of Atlantic bonito and bluefish as top predators in the Black Sea

2020 ◽  
Author(s):  
Georgi M Daskalov ◽  
Nazli Demirel ◽  
Aylin Ulman ◽  
Yoana Georgieva ◽  
Mustafa Zengin
Keyword(s):  
Black Sea ◽  
Prey Species ◽  
Maximum Sustainable Yield ◽  
Ecological Impacts ◽  
Reference Points ◽  
Production Model ◽  
Horse Mackerel ◽  
The Black Sea ◽  
Commercial Catch ◽  
General Decline

Abstract This study uses surplus production model-based methods to assess data-poor stocks and estimate key reference points for Atlantic bonito (Sarda sarda) and bluefish (Pomatomus saltatrix) in the Black Sea. Our results demonstrate that the catch maximum sustainable yield (CMSY) method, using catch data only, yields similar results to the more accurate Bayesian Schaefer model (BSM) method, fitted with commercial catch-per-unit-of-effort data, and therefore is suitable in assessing data-poor stocks. We explore the ecological impacts of the two stocks on other commercial species and compare impacts of predation and fishing. Prior to 1995, the consumption of bonito and bluefish on anchovy, horse mackerel, and sprat exceeded the removal of those prey species by the fisheries. Later on, the trends reversed, with catches of prey species becoming more than three times higher than their predation by bonito and bluefish. Horse mackerel, the main prey of bluefish, has declined to critical levels since 1995, which is likely contributing to the general decline in bluefish, along with overfishing. Heavy fishing of bonito and bluefish has caused their current depleted states and combined with their significant impact on prey fish contributed to the ecosystem regime shift in the Black Sea. Due to the present steady positioning of low stock regimes, the recovery of the two stocks need decisive and possibly prolonged rebuilding measures, including a reduction in fishing pressure, efficient control of under-sized catch, and ensuring sufficient prey biomass availability.

scholarly journals Ichthyofauna of the Black Sea coastal zone in the Laspi Bay area (Crimea)

2021 ◽  
Vol 6 (2) ◽  
pp. 3-17
Author(s):  
E. R. Abliazov ◽  
A. R. Boltachev ◽  
E. P. Karpova ◽  
A. N. Pashkov ◽  
O. N. Danilyuk
Keyword(s):  
Coastal Zone ◽  
Black Sea ◽  
Fish Species ◽  
Neogobius Melanostomus ◽  
Horse Mackerel ◽  
The Black Sea ◽  
Mean Annual Temperature ◽  
Fishing Gear ◽  
Ecological Groups ◽  
Crimean Peninsula

The ongoing processes of the Black Sea salinization and fluctuations in mean annual temperature have already caused the natural dispersal of various representatives of the Mediterranean Basin and Indian Ocean fauna and led to a change in species composition and structure of fish communities, inhabiting the coastal zone of the Crimean Peninsula. As a result, it became necessary to study modern composition of fish fauna and indicators of its species richness and diversity. The Laspi Bay was chosen as a model polygon for the following reasons: relatively low level of anthropogenic load; the fact that its part belongs to the specially protected natural areas, as well as the absence of fishing activity with coastal fixed fishing gear; constant free entry of pelagic fish species; biotopes diversity; and smooth change in depth. These peculiarities of the Laspi Bay allow assessing the presence of fish from different ecological groups and provide conditions for monitoring. The study was carried out in the spring-autumn periods of 1990–1994 and 2017–2018. The material was sampled with net fishing gear, hook tackle, and traps. The nets were set at various depths both perpendicular and parallel to the shoreline during the day (10:00 to 18:00) and at nighttime (18:00 to 06:00). Visual observations were also carried out. In total, 70 fish species were registered. Out of them, 14 species were previously not recorded for this area; 5 of them [salema Sarpa salpa (Linnaeus, 1758), red-mouthed goby Gobius cruentatus Gmelin, 1789, Bath’s goby Pomatoschistus bathi Miller, 1982, mystery blenny Parablennius incognitus (Bath, 1968), and chestnut goby Chromogobius quadrivittatus (Steindachner, 1863)] are recent invaders, actively spreading in the Black Sea over the past 15–20 years only. Most of the analyzed species (64) are marine euryhaline fish. The brackish-water group is represented by three species, indigenous to the Black Sea: mushroom goby Ponticola eurycephalus (Kessler, 1874), round goby Neogobius melanostomus (Pallas, 1814), and knout goby Mesogobius batrachocephalus (Pallas, 1814). Out of anadromous fish, starry sturgeon Acipenser stellatus Pallas, 1771 is registered, as well as two Clupeidae species: Black Sea shad Alosa tanaica (Grimm, 1901) and Pontic shad Alosa immaculata Bennett, 1835. As established, the observed seasonal dynamics of species diversity indices within the studied water area is associated with fluctuations in the abundance of horse mackerel Trachurus mediterraneus (Steindachner, 1868). In April – May, when this species headed to shallow water for feeding and breeding, the indices have the lowest values; in August, when the abundance of horse mackerel decreases, the maximum values are observed.

scholarly journals GREEN KUBAN IN DAYS OF THE CIVIL WAR IN RUSSIA

2017 ◽  
pp. 108-111
Author(s):  
S. M. Sivkov
Keyword(s):  
Civil War ◽  
Black Sea ◽  
Negative Attitude ◽  
Armed Forces ◽  
The Black Sea ◽  
Penal Policy ◽  
Black Sea Coast ◽  
Relationship Of ◽  
The Relationship ◽  
Vivid Description

In a review of military memoirs, I. G., Savchenko a brief description of the work, its relevance, reveals the controversial biography of the author of the memoirs, explains the importance of memories to the modern reader. The main events of memories takes place in the Kuban and black sea in 1920. The author of the memoir failed to disclose the difficult contradictions between the peasants of the black sea and Kuban Cossacks. Reveals position of a number of leaders polanskogo movement on relationships with General P. N. Wrangel and the Menshevik Georgia. Indicated the position of the leaders of the Kuban of the Bolsheviks in relation to military experts. Savchenko, in his memoirs touched on this little-known story of the civil war, how the relationship of red and green. Celebrated and complex relationship between the Kuban Rada and the General command of the Armed forces of South Russia. The book is a vivid description of the events of the era of the civil war in the Kuban and black sea coast. The author was able to objectively evaluate the changes that occurred in the camp of the red in three years of Civil war, including those associated with changes in the field of penal policy. However, in General, felt his negative attitude to the new government, the hope for her downfall in the next few years.

scholarly journals Population Dynamics of Horse Mackerel (Trachurus Mediterraneus Ponticus) in the Bulgarian Black Sea Coast

ISRN Zoology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Maria Yankova
Keyword(s):  
Black Sea ◽  
Growth Parameters ◽  
Total Mortality ◽  
Growth Function ◽  
Horse Mackerel ◽  
The Black Sea ◽  
Growth Coefficient ◽  
Von Bertalanffy Growth Function ◽  
Black Sea Coast ◽  
Commercially Important

The horse mackerel Trachurus mediterraneus is a commercially important pelagic fish species in the Black Sea fishery. The present investigation was carried out between May and December 2010 along the Bulgarian coast of the Black Sea. Population parameters of horse mackerel from the trawl and fishing nets catches were estimated from length frequency data, by using ELEFAN-I computer program. The ELEFAN-I analysis gave the following Von Bertalanffy Growth Function (VBGF) parameters: the asymptotic length  cm, growth coefficient value was , and the hypothetical age at which length is zero was . Based on these growth parameters, the total mortality coefficient () during the study period was estimated to be 2.99. The estimated value for natural mortality () was 1.08; hence, the fishing mortality coefficient () was 1.91. The estimated value for the exploitation rate () using the length converted catch curve was 0.64. The estimated sizes of T. mediterraneus at 25, 50, and 75 percent probabilities of capture were 16.80 cm, 18.72 cm, and 20.64 cm, respectively.

Sign in / Sign up

Export Citation Format

Share Document