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

Author(s):  
J. Guillou ◽  
P. G. Sauriau

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).

2014 ◽  
Vol 41 ◽  
pp. 95-109 ◽  
Author(s):  
Maria Gurova ◽  
Clive Bonsall

 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.


Zootaxa ◽  
2017 ◽  
Vol 4329 (3) ◽  
pp. 281
Author(s):  
VICTOR SURUGIU ◽  
GUILLERMO SAN MARTÍN

During a study of fauna associated with a shallow-water Zostera (Zosterella) noltei bed from the southern part of the Romanian Black Sea coast, among the identified material collected in 2015, a syllid polychaete belonging to the subfamily Exogoninae, Sphaerosyllis taylori Perkins, 1981, represents a new record for the Black Sea. Re-examination of available specimens previously identified as Sphaerosyllis bulbosa Southern, 1914 revealed that they belong to an unknown species, described herein as Sphaerosyllis pontica sp. nov. The new species is characterized by the median antenna inserted more posteriorly than the lateral antennae, dorsal cirri with bulbous bases and very short tips, shorter than the parapodial lobes, dorsal cirri absent on chaetiger 2, parapodial glands with fibrillar material from chaetiger 4 onwards, compound chaetae with short blades and smooth shafts, anterior parapodia with two aciculae each, one straight and one with bent tip. Descriptions of both species are provided together with a key to all Sphaerosyllis species known from the Black Sea.  


Author(s):  
DENIS COPILAȘ-CIOCIANU ◽  
GAVRIL MARIUS BERCHI ◽  
LEVAN MUMLADZE

We present findings from the first survey of shallow-water amphipods conducted along the Black Sea coast in Georgia. Eight species from five families have been identified, all but one being new for the Georgian fauna. Although most are usual inhabitants of the Black and Mediterranean seas, we report the first record of the invader Melita nitida in this region. This North American species was previously known in Europe only from the Atlantic and Baltic coasts. Its finding in the Black Sea implies either jump dispersal, or a more widespread, but cryptic distribution. Given that the total number of species reported in Georgia is lower than in the other countries neighbouring the Black Sea, we anticipate the discovery of new taxa in future surveys. Our study highlights the importance of faunistic exploration in previously overlooked regions for detecting potentially cryptic invasions and corroborating biogeographical patterns.


2000 ◽  
Vol 1 (1) ◽  
pp. 65
Author(s):  
A. KORTCHEVA ◽  
G. KORTCHEV ◽  
J. M. LEFEVRE

In this paper the discrete spectral shallow water wave model named VAGBUHL1 is presented. This model is used for real-time Black Sea state forecasting. The model was verified against satellite ERS-2 altimeter wave height data.


Author(s):  
В. Денисов ◽  
V. Denisov ◽  
Ю. Ткаченко ◽  
Yu. Tkachenko

Using sediment traps (ST) in marine research expeditions from 1986 to 2010, 188 samples of suspended matter were analyzed. All the samples were received from the shallow-water area (2 to 50 meters depth) of the Black sea shelf. Sedimentary matter from the catch basins was singled out by means of direct, high vacuum, membranous ultrafiltration with nuclear filters having 0,45 μm diameter pinholes produced by the United Institute of Nuclear Investigations in Dubna (UINI). The suspended matter received was dried till weight stabilizing, scaled and underwent analytical research. The material composition of the sedimentary matter is represented by the clayed-carbonated-micaceous matter. Biogenous minerals are represented by three carbon types: tiff, aragonite and siderite. The amount of the chiselly biogenous minerals has a subordinate meaning and serves as adulteration in suspended matter. The amount of ore minerals in the suspended matter compositionreaches 2–3 % (ferric oxide – 1 %, ferric hydroxide – up to 2 %, etc.). Geochemical composition of the suspended matter is tightly related to the bioproduction and biofiltration, impact of river flow, shallow-water sediment detachment and inflow of aerosolized matter. The industrial factor plays an important part in formation of modern chemical suspended matter composition.


2021 ◽  
pp. SP523-2021-48
Author(s):  
M. Namık Çağatay ◽  
K. Kadir Eriş ◽  
Zeynep Erdem

AbstractThe Bosphorus (Istanbul Strait) is natural strait that connects the Black Sea with the Aegean Sea via the Sea of Marmara and Dardanelles Strait. It is a 31 km long and 3.5 km wide winding channel, with an irregular bottom morphology. It has depressions up to -110 m deep, and two sills with depths of -35 and -58 m in the south and north, respectively.Presently, a two-layer water exchange exists through the strait, with the Mediterranean and Black Sea waters forming the lower and upper layers, respectively. The Bosphorus channel extends as shelf valleys on the Black Sea and Sea of Marmara shelves. However, it operated as a river valley or an estuary during the stadial low-stand periods.The infill sedimentary succession of the Bosphorus channel is up to ∼100 m thick above the Palaeozoic-Cretaceous basement with an irregular topography. The oldest sediments are sandy to muddy fluvial-lacustrine facies of late Pleistocene age, which are preserved only in up to -160 m-deep scoured depressions of the basement. They are overlain by mid-late Holocene estuarine-marine shelly sandy to muddy sediments with patches of bioherms and shelly lag deposits.The Bosphorus outlet areas of the Black Sea and Sea of Marmara are characterized by a submarine fan and a shelf valley, respectively. The fan system in the Black Sea started depositing ∼900 yr after the initial vigorous marine water incursion at ∼8.4 14C kyr BP. On the Marmara shelf, extension of the Bosphorus channel is a sinuous shelf valley with a channel-leveé complex, which was deposited by the Black Sea outflow during the 11-10 14C kyr BP. Catastrophic floodings of the Sea of Marmara by torrential Black Sea outflows during the Greenland Interstadial melt water pulses, as well as the strong Mediterranean current towards the Black Sea during the interglacial periods, were responsible for carving the Bosphorus channel and the shelf valleys, as well as removing the sediments belonging to the earlier periods.


2021 ◽  
Vol 42 ◽  
pp. 96-102
Author(s):  
Nelly G. Sergeeva ◽  
Tatiana N. Revkova

The first finding of the genus Greeffiella Cobb 1922 (Greeffiellinae, Desmoscolecidae) in the Black Sea is presented. Two mature females were collected in Northwestern Shelf of Crimea in strongly silted fine sand with detritus at a water depth of 56 m. Greeffiella sp. is described and illustrated. The absence of males in the collections does not allow the authors to present it as a new species for science or to identify it as one of the known species of the genus Greeffiella. Black sea specimen is distinguished from the other known species of the genus Greeffiella with the presence of 8 pairs of thicker specific setae along the body, the basis of which looks like a small lamina, but without hairs, which was previously described for G. pierri Schrage & Gerlach, 1975 and G. australis Schrage & Gerlach, 1975. The short esophagus at the base has two salivary glands and a cardia. Cardia has not been mentioned before for the known species of the genus Greeffiella.


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