scholarly journals Decline of unique Pontocaspian biodiversity in the Black Sea Basin: a review

2021 ◽  
Author(s):  
Aleksandre Gogaladze ◽  
Mikhail Son ◽  
Matteo Lattuada ◽  
Vitaliy Anistratenko ◽  
Vitaly Syomin ◽  
...  
Keyword(s):  
Black Sea ◽  
Species Distribution ◽  
The Black Sea ◽  
Distribution Data ◽  
Past Century ◽  
Detailed Knowledge ◽  
The Past ◽  
Mollusc Species ◽  
Anthropogenic Threats ◽  
Effective Conservation

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.

scholarly journals Contribution of the Black Sea observing system to ECOOP

2011 ◽  
Vol 8 (4) ◽  
pp. 1695-1722 ◽  
Author(s):  
G. K. Korotaev ◽  
V. L. Dorofeev ◽  
S. V. Motyzhev ◽  
V. N. Belokopytov ◽  
A. Palazov ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Time Series ◽  
Black Sea ◽  
The Black Sea ◽  
Past Century ◽  
Network Integration ◽  
The Past ◽  
Time Operation ◽  
Real Time Operation ◽  
Set Up

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.

scholarly journals A conservation palaeobiological approach to assess faunal response of threatened biota under natural and anthropogenic environmental change

2019 ◽  
Vol 16 (12) ◽  
pp. 2423-2442 ◽  
Author(s):  
Sabrina van de Velde ◽  
Elisabeth L. Jorissen ◽  
Thomas A. Neubauer ◽  
Silviu Radan ◽  
Ana Bianca Pavel ◽  
...  
Keyword(s):  
Black Sea ◽  
Environmental Changes ◽  
Sea Water ◽  
Salinity Gradient ◽  
Conservation Strategies ◽  
The Black Sea ◽  
Freshwater Species ◽  
Lake System ◽  
The Past ◽  
Mollusc Species

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.

scholarly journals A conservation palaeobiological approach to assess faunal response of threatened biota under natural and anthropogenic environmental change

2019 ◽  
Author(s):  
Sabrina van de Velde ◽  
Elisabeth L. Jorissen ◽  
Thomas A. Neubauer ◽  
Silviu Radan ◽  
Ana Bianca Pavel ◽  
...  
Keyword(s):  
Black Sea ◽  
Environmental Changes ◽  
Sea Water ◽  
Salinity Gradient ◽  
Conservation Strategies ◽  
The Black Sea ◽  
Freshwater Species ◽  
Lake System ◽  
The Past ◽  
Mollusc Species

Abstract. Palaeoecological records are required to test ecological hypotheses necessary for conservation strategies as short-term observations can be insufficiently to capture natural variability and identify drivers of biotic change. Here, we demonstrate the importance of an integrated conservation palaeobiology approach to make 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 interventions 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, freshwater) exist and their spatiotemporal 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 for improved conservation actions by re-establishing a salinity gradient in the lake system to preserve these unique species.

Yazijioghlu 'Alī on the Christian Turks of the Dobruja

1952 ◽  
Vol 14 (3) ◽  
pp. 639-668 ◽  
Author(s):  
Paul Wittek
Keyword(s):  
Black Sea ◽  
Distinct Group ◽  
The Black Sea ◽  
Orthodox Church ◽  
Greek Orthodox ◽  
14Th Century ◽  
The Balkans ◽  
Modern Times ◽  
The Past ◽  
Greek Orthodox Church

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.

The Black Sea—The Past, Present, and Future Status

2019 ◽  
pp. 363-375 ◽  
Author(s):  
Abdulaziz Güneroğlu ◽  
Osman Samsun ◽  
Muzaffer Feyzioğlu ◽  
Mustafa Dihkan
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
The Past ◽  
Future Status

scholarly journals History of the studying of fauna of Ponticus decapods

2016 ◽  
Vol 1 (1) ◽  
pp. 93-101 ◽  
Author(s):  
S. E. Anosov ◽  
S. M. Ignatyev
Keyword(s):  
Species Composition ◽  
Black Sea ◽  
Native Species ◽  
The Black Sea ◽  
The Past ◽  
History Of

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.

scholarly journals Historic-geographical evolution of Bessarabia on the data of the old maps

2021 ◽  
Vol 27 (4) ◽  
pp. 415-433
Author(s):  
Evgeniy Paskary ◽  
Andrey Herzen
Keyword(s):  
Middle Ages ◽  
Black Sea ◽  
The Black Sea ◽  
Territorial Development ◽  
Black Sea Region ◽  
The Past ◽  
Black Sea Coast ◽  
Territorial Claims ◽  
Geographical Maps ◽  
Sea Coast

Problems of research of the territorial development of the old-developed regions are due to the duration and extraordinary saturation of historical processes that flowed and continue in them. The study of changes in the territories of states and various entities is important not only for understanding the past: local and regional conflicts whose roots often go deep into centuries, remain for a long time and continue these days, territorial claims are relevant now. This is especially evident on the example of such regions of oldest development, as the Black Sea region. Historic-cartographical studies, systematization of previously known and newly identified sources, the analysis of old geographical maps and plans allow us to form a holistic picture of the evolution of space, its territorial structure, as well as the functional role of one or another place in the past and present. In the article on the example of Bessarabia—the historic-geographical region of the North-Western Black Sea coast—the most important cartographic works presented, being key for certain stages of its historic-geographical evolution and development of cartography as a whole: the Antiquity and the Middle Ages (when the first geographical maps appeared), the 15th–18th centuries (when the toponym under study was first applied into maps, and detailed topographic maps began to be created) and the 19th–20th centuries (when political events again changed the semantics of the toponym Bessarabia). It is shown how geographical representations of the region transformed during different historical periods. The content of the toponym denoting region is considered, at different times related to different sections of the Black Sea coast and included various territories, as well as its use today as a political tool reflecting actual territorial claims.

What Controls Atmospheric Oxygen Concentrations?

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Black Sea ◽  
Atmospheric Oxygen ◽  
Fundamental Question ◽  
The Black Sea ◽  
Microbial Process ◽  
The Past ◽  
Carbon Burial ◽  
Organic Carbon Burial

This chapter deals with the fundamental question of why there is oxygen in the atmosphere at all. It seeks to identify the main processes controlling the oxygen concentration. Plants and cyanobacteria produce the oxygen, but it accumulates only because some of the original photosynthetically produced organic matter is buried and preserved in sediments. Another oxygen source is an anaerobic microbial process called sulfate reduction that respires organic matter using sulfate and produces sulfide. This process is quite common in nature but are most prominent in relatively isolated basins like the Black Sea, and in most marine sediments at depths where oxygen has been consumed by respiration. If there is iron around, the sulfide reacts with the iron, forming a mineral called pyrite. While organic carbon burial has been the main oxygen source to the atmosphere over the past several hundred million years, for some intervals further back in time, pyrite burial may well have dominated as an oxygen source.

scholarly journals History of expansion and anthropogenic collapse in a top marine predator of the Black Sea estimated from genetic data

2012 ◽  
Vol 109 (38) ◽  
pp. E2569-E2576 ◽  
Author(s):  
Michaël C. Fontaine ◽  
Alodie Snirc ◽  
Alexandros Frantzis ◽  
Emmanuil Koutrakis ◽  
Bayram Öztürk ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Black Sea ◽  
Anthropogenic Activities ◽  
Marine Ecosystem ◽  
Genetic Data ◽  
Ice Age ◽  
The Black Sea ◽  
Marine Predator ◽  
The Past ◽  
History Of

Two major ecological transitions marked the history of the Black Sea after the last Ice Age. The first was the postglacial transition from a brackish-water to a marine ecosystem dominated by porpoises and dolphins once this basin was reconnected back to the Mediterranean Sea (ca. 8,000 y B.P.). The second occurred during the past decades, when overfishing and hunting activities brought these predators close to extinction, having a deep impact on the structure and dynamics of the ecosystem. Estimating the extent of this decimation is essential for characterizing this ecosystem’s dynamics and for formulating restoration plans. However, this extent is poorly documented in historical records. We addressed this issue for one of the main Black Sea predators, the harbor porpoise, using a population genetics approach. Analyzing its genetic diversity using an approximate Bayesian computation approach, we show that only a demographic expansion (at most 5,000 y ago) followed by a contemporaneous population collapse can explain the observed genetic data. We demonstrate that both the postglacial settlement of harbor porpoises in the Black Sea and the recent anthropogenic activities have left a clear footprint on their genetic diversity. Specifically, we infer a strong population reduction (∼90%) that occurred within the past 5 decades, which can therefore clearly be related to the recent massive killing of small cetaceans and to the continuing incidental catches in commercial fisheries. Our study thus provides a quantitative assessment of these demographically catastrophic events, also showing that two separate historical events can be inferred from contemporary genetic data.

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