scholarly journals The effect of environmental conditions on the distribution of eggs and larvae of anchovy (Engraulis encrasicolusL.) in the Black Sea

1999 ◽  
Vol 56 ◽  
pp. 58-64 ◽  
Author(s):  
A KIDEYS
Keyword(s):  
Black Sea ◽  
Environmental Conditions ◽  
The Black Sea ◽  
Eggs And Larvae

scholarly journals ‘Pre-Neolithic’ in Southeast Europe: a Bulgarian perspective

2014 ◽  
Vol 41 ◽  
pp. 95-109 ◽  
Author(s):  
Maria Gurova ◽  
Clive Bonsall
Keyword(s):  
Black Sea ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Balkan Peninsula ◽  
The Black Sea ◽  
Future Research ◽  
Upper Palaeolithic ◽  
Southeast Europe ◽  
Site Distribution

 This paper discusses why large areas of the central and northern Balkans lack evidence of Mesolithic settlement and what implications this holds for future research into the Neolithization of the region. A marked shift in site distribution patterns between Upper Palaeolithic and Mesolithic is interpreted as a response to changing environmental conditions and resource availability. It is suggested that some important questions of the pattern, processes and timing of the transition to farming across the Balkan Peninsula may only be answered through new archaeological surveys of the Lower Danube valley and exploration of submerged landscapes along the Black Sea, Aegean and Adriatic coasts.

Some Observations on the Biology and the Ecology of a Venus Striatula Population in the Bay of Douarnenez, Brittany

1985 ◽  
Vol 65 (4) ◽  
pp. 889-900 ◽  
Author(s):  
J. Guillou ◽  
P. G. Sauriau
Keyword(s):  
Shallow Water ◽  
Black Sea ◽  
Environmental Conditions ◽  
Ecological Factors ◽  
Fine Sand ◽  
The Black Sea ◽  
High Exposure ◽  
Lofoten Islands ◽  
Muddy Sediments ◽  
Latitudinal Range

INTRODUCTIONVenus striatula (da Costa) (= Venus gallina L.) occurs in high densities in shallow water on a bottom of clean fine sand in the Bay of Douarnenez. The environmental conditions are characterized by an obvious sediment instability due to a high exposure to westerly swells (Guillou & Le Moal, 1978). This species is preferentially distributed in the fine sands (Petersen, 1913; Thorson, 1957), but is relatively tolerant towards certain ecological factors and so is sometimes found in very muddy sediments. It also shows an extended latitudinal range, since it is recorded from the Lofoten Islands to the Canaries, in the Mediterranean and the Black Sea (Tebble, 1966).

Summer ichthyoplankton, food supply of fish larvae and impact of invasive ctenophores on the nutrition of fish larvae in the Black Sea during 2000 and 2001

2005 ◽  
Vol 85 (3) ◽  
pp. 537-548 ◽  
Author(s):  
A.D. Gordina ◽  
Ju.A. Zagorodnyaya ◽  
A.E. Kideys ◽  
L. Bat ◽  
H.H. Satilmis
Keyword(s):  
Black Sea ◽  
Coastal Waters ◽  
Negative Impact ◽  
Fish Larvae ◽  
Late Summer ◽  
The Black Sea ◽  
Species Number ◽  
Mnemiopsis Leidyi ◽  
Short Period ◽  
Eggs And Larvae

Qualitative composition and abundance of both ichthyoplankton and small forms of zooplankton were evaluated by field studies in the northern (the Crimea near Sevastopol) and southern (Sinop region and TEEZ) Black Sea during the summers 2000 and 2001. A tendency of increasing the species richness, abundance of fish eggs and larvae as well as zooplankton (which is the food for fish larvae) was observed over a period of Mnemiopsis leidyi and Beroe ovata co-existence. The eggs and larvae of the Mediterranean migrants—bonito and bluefish appeared again in the coastal waters near Sevastopol, which testified to favourable conditions for the spawning and nutrition of these fish species and their larvae. Aborigen copepod Oithona nana was found in the Crimean coastal waters although earlier in the 1990s it had completely vanished. Although rare in the 1990s copepods Centropages ponticus and Paracalanus parvus appeared in inshore waters as well as Pontellids species. Observed increases in species number and abundance of both ichthyoplankton and small zooplankton (≤500 μm), which promoted survival and development of fish larvae, were attributed to reduced predatory impact of Mnemiopsis on prey zooplankton after the arrival of Beroe in the late 1990s. However, the influence of Mnemiopsis continued to be significant during the short period of its peak occurrence in late summer. When this period coincided with the appearance of fish larvae, a negative impact on their survival could be predicted due to a low concentration of food items for larvae feeding.

On Postlarvae and Pelagic Juveniles of Rocklings Gaidropsaurus Mediterraneus and G. Biscayensis

1982 ◽  
Vol 62 (3) ◽  
pp. 647-665 ◽  
Author(s):  
Neclå Demir
Keyword(s):  
Life History ◽  
Black Sea ◽  
Standard Length ◽  
The Black Sea ◽  
Sea Of Marmara ◽  
Larval Stages ◽  
History Of ◽  
The Mediterranean ◽  
Eggs And Larvae ◽  
Pelagic Juveniles

Little is known about the life history of the species of Gaidropsaurus Rafinesque, 1810. Two species of this genus, G. mediterraneus (Linnaeus, 1758) and G. biscayensis (Collett, 1890) = Antonogadus megalokynodon Kolombotovic, 1894 occur in the Sea of Marmara. The egg, larvae and pelagic juveniles of G. biscayensis have never been described. Egg, prelarval and early postlarval stages attributed to G. mediterraneus have been described and illustrated by many workers, but there has been confusion in their identifications.Three species of Gaidropsaurus, G. mediterraneus, G. biscayensis and G. vulgaris (Cloquet, 1824) are recorded from the Mediterranean. Raffaele (1888) made artificial fertilizations of eggs of Naples specimens that he identified as Motella tricirrata Nilsson, 1832 = G. vulgaris. Holt (1899) found some eggs which are similar to those described and figured by Raffaele in the plankton off Marseille, but he considered it impossible to distinguish whether the larvae which hatched out from those eggs were Motella tricirrata i.e. G. vulgaris or Motella mediterranea Lütken, 1882 i.e. G. mediterraneus. Ehrenbaum (1905–9) who re-examined the various records of eggs and larval stages of Gaidropsaurus believes that those figured by RafFaele (1888) and Holt (1899) as well as the larvae referred to Phycis Artedi, 1792 and a pleuronectid by Emery (1886) and Marion (1894) respectively probably belong to Onos (Gaidropsaurus) mediterraneus. Aboussouan (1964) who worked on ichthyoplankton of the Gulf of Marseille also attributed some eggs and larvae to G. mediterraneus and figured one of those postlarvae which is 2·65 mm in standard length.The eggs and prelarval stage of G. mediterraneus have more precisely been described and illustrated by Soviet investigators (Vodyanitskii & Kazanova, 1954; Duka, 1958; Dekhnik, 1973)> from the Black Sea.

scholarly journals CHARACTERISTICS OF THE VEGETATION COMPOSITION OF THE ABRASION COAST OF THE NORTHWESTERN PART OF THE BLACK SEA COAST OF THE CAUCASUS

2021 ◽  
Vol 31 (1) ◽  
pp. 16-26
Author(s):  
S.V. Krylenko ◽  
A.I. Lukinykh
Keyword(s):  
Plant Community ◽  
Black Sea ◽  
Environmental Conditions ◽  
Vascular Plants ◽  
Vascular Plant ◽  
The Black Sea ◽  
Northwestern Part ◽  
Northwestern Caucasus ◽  
Black Sea Coast ◽  
Sea Coast

Abrasion coasts (cliffs) are characterized by heterogeneity of the spatial structure and mobility of the substrate, which creates specific environmental conditions for plants. Nevertheless, plant communities of cliffs of the Black Sea coast of the Northwestern Caucasus are well developed due to the presence of a large number of Mediterranean species that are well adapted to such conditions. Communities are also supplemented by local endemics and representatives of petrophytic vegetation of adjacent areas. As a result, a specific plant community is formed on the cliff, represented by species from different floristic areas. Thus, the aim of this work was to analyze the species composition of higher vascular plants of the abrasion shore area of the Black Sea coast of the Northwestern Caucasus. On the studied cliff, 131 species of vascular plants were found, including 5 Crimean-Novorossiysk and 6 Novorossiysk endemic, as well as 6 species found in the Red List of the Russian Federation. Extreme unevenness in the density distribution of vegetation was noted, which may be due to the heterogeneity of the relief and the mobility of the substrate. Analysis of supraspecific taxa (families) showed the predominance of representatives of the Apiaceae, Fabaceae, and Poaceae families in the plant community. In addition, chorological analysis of vascular plant species was performed. The data of the performed chorological analysis confirm the relation of the studied territory to the Crimean Novorossiysk province. Thus, despite the specific environmental conditions, the plant community of the studied cliff is rich in species, including endemic species.

scholarly journals Spatial distribution of ichthyoplankton near the Crimean Peninsula in the summer spawning season 2013

2019 ◽  
Vol 4 (1) ◽  
pp. 63-80
Author(s):  
T. N. Klimova ◽  
A. A. Subbotin ◽  
V. V. Melnikov ◽  
A. N. Serebrennikov ◽  
P. S. Podrezova
Keyword(s):  
Spatial Distribution ◽  
Species Diversity ◽  
Black Sea ◽  
Fish Larvae ◽  
Spawning Season ◽  
The Black Sea ◽  
Species Number ◽  
Crimean Peninsula ◽  
Eggs And Larvae ◽  
The Crimean Peninsula

Data obtained in five complex cruises of RV “Professor Vodyanitsky”, carried out from May to September 2013, in the summer spawning season, are analyzed. The dynamics of ichthyoplankton species diversity and spatial distribution depending on hydrological regime peculiarities in different regions of the shelf and open waters of the Black Sea off the Crimean Peninsula is presented. Totally 17 species of fish eggs and larvae from 13 families were identified in ichthyoplankton, maximum number of species was observed in June. Average eggs and larvae numbers during the spawning season were 50.5 and 9.2 specimen per m², respectively. Maximum abundance of eggs and larvae was observed in July (109.9 and 9.2 specimen per m², respectively). Eggs and larvae of anchovy Engraulis encrasicolus (Linnaeus, 1758) dominated: their proportion in open waters in the height of the spawning season amounted 96 and 94 %, respectively. Maximum indexes of species diversity and evenness (significance of each species) were observed in May, at the beginning of spawning season, when dominant species had just started their spawning and their abundance in ichthyoplankton was comparatively low. Species richness indexes reached the maximum value in June, when maximum species number in ichthyoplankton was observed. Species composition and spatial distribution of ichthyoplankton depended on the thermohydrodynamic structure of the sea in the studied regions, and decline of jelly plankton pressing on ichthyoplankton fodder base contributed to the survival of fish larvae. The most significant factors determining the thermohydrodynamic structure of the sea in the summer spawning season 2013 were: regional peculiarities of the sea surface warming up regime in spring-summer period and its cooling in autumn hydrological season; advective contribution of surface currents (first of all, the Main Black Sea Current); wind-driven processes (upwelling and vortex dipole) in the coastal regions; local thermohaline inhomogeneities in the areas of freshened river water mixing with shelf waters in the north-western part of the Black Sea and the Sea of Azov waters at the beginning of the Kerch Strait mixing with open sea waters.

scholarly journals UUVs support to naval operations

2020 ◽  
Vol XXIII (1) ◽  
pp. 47-54
Author(s):  
Valerian Novac
Keyword(s):  
Black Sea ◽  
Environmental Conditions ◽  
The Black Sea ◽  
Underwater Communications ◽  
Introductory Part ◽  
Naval Operations ◽  
Aerial Platforms ◽  
Littoral Area

The article analyzes the environmental conditions present in the Black Sea basin and, in this view, the opportunity of employment of unmanned underwater platforms, especially in the contested littoral area. The introductory part of the article is presented up to date UUVs platforms in use with their capabilities and limitations. Then, the paper identifies the shortfalls and opportunities to engage unmanned platforms to operate independently or paired with other undersea, surface, unmanned aerial platforms, or fixed arrays. The closing section analyzes the types of payloads, missions, and capabilities of actual vehicles, and some ways ahead are underlined, especially regarding future sensors, weapons, navigation, and underwater communications capabilities.

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