Paleogeography of the Pontic Lowland and northwestern Black Sea shelf for the past 25 k.y.

Author(s):  
Evgeny Larchenkov ◽  
Sergey Kadurin
Keyword(s):  
2011 ◽  
Vol 8 (4) ◽  
pp. 1695-1722 ◽  
Author(s):  
G. K. Korotaev ◽  
V. L. Dorofeev ◽  
S. V. Motyzhev ◽  
V. N. Belokopytov ◽  
A. Palazov ◽  
...  

Abstract. Regular observations in the Black Sea basin started in the past century, and quite good multidisciplinary observing system operated in the 70–80ies based on the ship observations. Modern oceanographic observing system in the basin is built according to the GOOS principles. It includes space remote sensing observations, data of free floating buoys and costal observational network. Integration of the observing system and its real-time operation were started within the framework of the FP5 ARENA project and later were improved during the FP6 ASCABOS project. The coastal observing system which includes time series from the coastal platforms and multidisciplinary surveys of the coastal areas fulfilled by the research vessels was set up during the ECOOP. Paper describes all components of the Black Sea observing system operated during the ECOOP project and its applications in the framework of the project.


Author(s):  
Aleksandre Gogaladze ◽  
Mikhail Son ◽  
Matteo Lattuada ◽  
Vitaliy Anistratenko ◽  
Vitaly Syomin ◽  
...  

Aim The unique aquatic Pontocaspian (PC) biota of the Black Sea Basin (BSB) is in decline. Lack of detailed knowledge on the status and trends of species, populations and communities hampers a thorough risk assessment and precludes effective conservation. This paper aims to review PC biodiversity trends using endemic molluscs as a model group. We aim to assess changes in PC habitats, community structure and species distribution over the past century and to identify direct anthropogenic threats. Location Black Sea Basin (Bulgaria, Romania, Moldova, Ukraine and Russia). Methods Presence/absence data of target mollusc species was assembled from literature, reports and personal observations. PC biodiversity trends in the NW BSB coastal regions were established by comparing 20th and 21st century occurrences. Direct drivers of habitat and biodiversity change were identified and documented. Results A very strong decline of PC species and communities during the past century is driven by a) damming of rivers, b) habitat modifications negatively affecting salinity gradients, c) pollution and eutrophication, d) invasive alien species and e) climate change. Four out of 10 studied regions, namely, the Danube Delta – Razim Lake system, Dniester Liman, Dnieper-South Bug Estuary and Taganrog Bay-Don Delta contain the entire spectrum of ecological conditions to support PC communities and still host threatened endemic PC mollusc species. Distribution data is incomplete, but the scale of deterioration of PC species and communities is evident from the assembled data, as are major direct threats. Main conclusions PC biodiversity in the BSB is profoundly affected by human activities. Standardised observation and collection data as well as precise definition of PC biota and habitats are necessary for targeted conservation actions. This study will help to set the research and policy agenda required to improve data collection to accommodate effective conservation of the unique PC biota.


1952 ◽  
Vol 14 (3) ◽  
pp. 639-668 ◽  
Author(s):  
Paul Wittek

The steppe which stretches between the Lower Danube and the Black Sea, from the Delta southward as far as the foothills of the Emine Dagh, and which since the middle of the 14th century has been called, after the Bulgarian prince Dobrotitsa, the Dobruja, is the homeland of a small Turkish-speaking people, the Gagauz. It is because of their religion that they appear as a distinct group among the Turks: they are Christians belonging to the Greek Orthodox Church. In the past the Gagauz may have constituted, among the various ethnic elements of the region, a group of considerable importance, especially in the southern and middle Dobruja, from Varna and Kaliakra towards Silistria on the Danube. Besides, small isolated groups of them are to be found also in the Balkans (where they are more commonly known by the name of Sorguch): in Eastern Thrace, round Hafsa, to the south-east of Adrianople, and in Macedonia, to the east and west of Salonica, round Zikhna (near Serres) and round Karaferia (Verria). In modern times the Gagauz of the Dobruja have shrunk to a feeble minority chiefly as a result of a prolonged and massive emigration into Bessarabia. To-day even this remnant is rapidly dwindling.


2020 ◽  
Vol 5 (2) ◽  
pp. 67-75
Author(s):  
A. V. Melnik ◽  
V. V. Melnikov ◽  
L. A. Melnik ◽  
O. V. Mashukova

In the second half of the XX century, Black Sea ecosystem has undergone significant changes: a number of storm winds and upwellings decreased, precipitation abundance increased, coastal waters salinity decreased, temperature increased; moreover, ctenophores invaded. As a result, in the late 1980s, Black Sea pelagic ecosystem abruptly got restructured. This research is based on the studies performed in 1965–1966 and 2007–2012 near Sevastopol (Western Crimea) using the remote sensing data. Analysis of satellite data over the past 20 years showed the presence of positive dynamics in surface water temperature in Sevastopol water area. In the mid-1960s, the annual bioluminescence was characterized by seasonal peaks of dinophytes luminescence. In recent years, this rhythm has changed due to ctenophores invasion. The increase in Mnemiopsis leidyi abundance leads to a decrease in bioluminescence of luminous microalgae being consumed by these ctenophores. Due to Beroe ovata invasion and reproduction, M. leidyi biomass decreased; as a result, bioluminescence increased.


2019 ◽  
pp. 363-375 ◽  
Author(s):  
Abdulaziz Güneroğlu ◽  
Osman Samsun ◽  
Muzaffer Feyzioğlu ◽  
Mustafa Dihkan

2019 ◽  
Vol 16 (12) ◽  
pp. 2423-2442 ◽  
Author(s):  
Sabrina van de Velde ◽  
Elisabeth L. Jorissen ◽  
Thomas A. Neubauer ◽  
Silviu Radan ◽  
Ana Bianca Pavel ◽  
...  

Abstract. Palaeoecological records are required to test ecological hypotheses necessary for conservation strategies as short-term observations can insufficiently capture natural variability and identify drivers of biotic change. Here, we demonstrate the importance of an integrated conservation palaeobiology approach when making validated decisions for conservation and mitigating action. Our model system is the Razim–Sinoie lake complex (RSL) in the Danube Delta (Black Sea coast, Romania), a dynamic coastal lake system hosting unique Pontocaspian mollusc species that are now severely under threat. The Pontocaspians refer to an endemic species group that evolved in the Black Sea and Caspian Sea basins under reduced salinity settings over the past few million years. The natural, pre-industrial RSL contained a salinity gradient from fresh to mesohaline (18 ppm) until human intervention reduced the inflow of mesohaline Black Sea water into the lake system. We reconstruct the evolution of the RSL over the past 2000 years from integrated sedimentary facies and faunal analyses based on 11 age-dated sediment cores and investigate the response of mollusc species and communities to those past environmental changes. Three species associations (“marine”, “Pontocaspian” and “freshwater”) exist and their spatio-temporal shifts through the system are documented. Variable salinity gradients developed, with marine settings (and faunas) dominating in the southern part of the system and freshwater conditions (and faunas) in the northern and western parts. Pontocaspian species have mostly occurred in the centre of the RSL within the marine–freshwater salinity gradient. Today, freshwater species dominate the entire system, and only a single Pontocaspian species (Monodacna colorata) is found alive. We show that the human-induced reduced marine influence in the system has been a major driver of the decline of the endemic Pontocaspian biota. It urges improved conservation action by re-establishing a salinity gradient in the lake system to preserve these unique species.


2016 ◽  
Vol 1 (1) ◽  
pp. 93-101 ◽  
Author(s):  
S. E. Anosov ◽  
S. M. Ignatyev

The history of the decapods crustaceans study in Pontus region over the past two centuries is described by analysis based on the source literary. The description shows how researcher’s attitudes at the composition and origin of the fauna of the Black Sea have changed over the time. The contribution of non-native species in biodiversity of decapods region is estimated. The results of the modern revision of the species composition of these crustaceans are made.


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