scholarly journals LONG - TERM VARIATIONS IN MACROBENTHOS DIVERSITY AT THE ISTANBUL STRAIT’S (BOSPORUS) OUTLET AREA OF THE BLACK SEA

2017 ◽  
Vol 14 ◽  
pp. 80-91
Author(s):  
Sofia Mazlumyan ◽  
Natalia Boltachоva
Keyword(s):  
Black Sea ◽  
Benthic Fauna ◽  
Oxygen Depletion ◽  
In Situ Monitoring ◽  
The Black Sea ◽  
Limiting Factor ◽  
Large Species ◽  
Comparison Interval ◽  
Living Organisms

This work continues a series of studies on deep-water benthos in the Istanbul Strait’s (Bosporus) outlet area of the Black Sea, conducted within the framework of the EU 7th FP project HYPOX (In situ monitoring of oxygen depletion in hypoxic ecosystems of coastal and open seas, and land-locked water bodies) EC Grant 226213. The aim of that study was the analysis of long-term changes in diversity and structure of the benthic fauna inhabiting the depth zone where the oxic/anoxic interface zone meets the sea floor. Time comparison interval covers the period from 1958 to 2010. In general, the diversity or densities of macrozoobenthos were positively related with environmental factors such as sediment, depth and oxygen concentration. Outcome of the long- term environmental degradation period was the loss of diversity. Macrobenthos communities Terebellides stroemi – Amphiura stepanovi and Modiolula phaseolina essentially rebuilt its structure. Unstable hydrodynamics and oxygen depletion are two crucial factors of decrease diversity in T. stroemi – A. stepanovi community. The species composition of M. phaseolina community at the border of the hydrogen sulfide area is distinct from those dwelling in oxic areas of the Black Sea. Living organisms of macrobenthos were not found at the oxygen content near 12 μmol L-1 (160 m). This confirms that oxygen depletion at great depths is the limiting factor of life in the Black Sea. During MSM/15-cruise (2010) was found a large species of the polychaete Sabella pavonina (Savigny, 1822). This species was new record for the Black Sea.

Oithona davisae: naturalization in the Black sea, inter-annual and seasonal dynamics, effect on the structure of the planktonic copepod community

2019 ◽  
Vol 59 (6) ◽  
pp. 1008-1015
Author(s):  
A. D. Gubanova ◽  
O. A. Garbazey ◽  
D. A. Altukhov ◽  
V. S. Mukhanov ◽  
E. V. Popova
Keyword(s):  
Black Sea ◽  
Coastal Waters ◽  
Native Species ◽  
Significant Decline ◽  
Acartia Tonsa ◽  
The Black Sea ◽  
Copepod Community ◽  
Oithona Davisae ◽  
Sevastopol Bay

Long-term (20032014) routine observations of zooplankton in Sevastopol Bay (the Black Sea) have allowed the naturalization of the invasive copepod Oithona davisae to be studied in the Black Sea coastal waters. Inter-annual and seasonal variability of the species and their impact on the native copepod community have been analyzed. The invasion of O. davisae and their undoubted dominance in terms of abundance were shown to alter the community structure but, at the same time, the abundances of the native species did not decrease, excepting the Black Sea earlier invader Acartia tonsa. A significant decline in A. tonsa numbers over the stages of O. davisae establishment and naturalization provided evidence of competition between the species. O. davisae have been demonstrated to gain competitive advantage over A. tonsa, that ensured their fast dispersal in the Black Sea, acclimatization in the new habitat and the successful competition over native species.

scholarly journals Long term trends in the sea surface temperature of the Black Sea

Ocean Science ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 491-501 ◽  
Author(s):  
G. I. Shapiro ◽  
D. L. Aleynik ◽  
L. D. Mee
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
The North ◽  
Sst Variability ◽  
Long Term Trends ◽  
Cooling Trend

Abstract. There is growing understanding that recent deterioration of the Black Sea ecosystem was partly due to changes in the marine physical environment. This study uses high resolution 0.25° climatology to analyze sea surface temperature variability over the 20th century in two contrasting regions of the sea. Results show that the deep Black Sea was cooling during the first three quarters of the century and was warming in the last 15–20 years; on aggregate there was a statistically significant cooling trend. The SST variability over the Western shelf was more volatile and it does not show statistically significant trends. The cooling of the deep Black Sea is at variance with the general trend in the North Atlantic and may be related to the decrease of westerly winds over the Black Sea, and a greater influence of the Siberian anticyclone. The timing of the changeover from cooling to warming coincides with the regime shift in the Black Sea ecosystem.

Air recirculation and ventilation in the coastal regions of the Black Sea

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Galina Surkova
Keyword(s):  
Black Sea ◽  
Eastern Coast ◽  
The Black Sea ◽  
Additional Risk Factor ◽  
Additional Risk ◽  
Sea Breezes ◽  
North Eastern ◽  
Favorable Conditions ◽  
Parameter Values

AbstractAn initial investigation of recirculation is carried out for the coast of the Black Sea. The local mesoscale circulations (land-sea breezes, mountain and valley winds) in coastal areas are shown to be an additional risk factor in creating favorable conditions for air stagnation and accumulation of air pollutants in the surface atmosphere layer. Two types of annual recirculation patterns are revealed for northern and north-eastern coast of the Black Sea. Long-term changes in recirculation are investigated. It is shown that the recirculation parameter values remained quasistable until the mid-1970s. Since 1976–1977, steady intensification of recirculation in both winter and summer is identified.

Long-term ecological changes in Romanian coastal Waters of the Black Sea

1996 ◽  
Vol 32 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Adriana Cociasu ◽  
Liliana Dorogan ◽  
Christoph Humborg ◽  
Luci Popa
Keyword(s):  
Black Sea ◽  
Coastal Waters ◽  
The Black Sea ◽  
Ecological Changes

scholarly journals Basic Regularities of the Haline Stratification Long-Term Evolution in the Black Sea

2019 ◽  
Vol 26 (6) ◽  
Author(s):  
A. I. Mizyuk ◽  
M. V. Senderov ◽  
G. K. Korotaev ◽  
◽  
◽  
...  
Keyword(s):  
Black Sea ◽  
Long Term Evolution ◽  
The Black Sea ◽  
Term Evolution

scholarly journals On the possible presence of oxygen in the upper sediment layer of the hydrogen sulfide zone in the Black Sea

2019 ◽  
Vol 59 (1) ◽  
pp. 166-169
Author(s):  
P. A. Stunzhas ◽  
M. B. Gulin ◽  
A. G. Zatsepin ◽  
E. A. Ivanova
Keyword(s):  
Black Sea ◽  
Benthic Fauna ◽  
Water Layer ◽  
Bottom Layer ◽  
The Black Sea ◽  
Depth Range ◽  
Sediment Layer ◽  
Bottom Water Layer ◽  
Long Time ◽  
Eukaryotic Organisms

In the northeastern Black Sea the search was performed for living eukaryotic organisms (micro- and meiobenthos) in hypoxic and anoxic conditions as well as measurement of O2 in the bottom water layer and in the upper layer of sediments. The results have shown the presence of a deep maximum abundance of zoobenthos in a depth range of 215–244 m. This aggregation of benthic fauna occupies a layer of 30 m along the vertical. In general, the proportion of active meiobenthos was no greater than 1.5% of the total number of organisms recorded from the sample.The presence of aerobic benthos near the upper boundary of the H2S zone can be explained by: sliding down of sediments from a higher depth; quasi-periodic O2 supply due to fluctuations in the position of the isopycna and/or sinking of waters downslope in the bottom Ekman layer. Also, in the case of physical entry of oxygen into the bottom layer, it can remain for a relatively long time in the upper part of the H2S zone due to the lack of deep Mn+2 flux and reaction with it.

scholarly journals A study of long-term changes in Black Sea ecosystems based on data assimilation of remote measurements in a numerical model

2019 ◽  
Vol 46 (1) ◽  
pp. 58-69
Author(s):  
V. L. Dorofeev ◽  
L. I. Sukhikh
Keyword(s):  
Black Sea ◽  
Marine Ecosystem ◽  
Three Dimensional ◽  
The Black Sea ◽  
Regular Grid ◽  
Remote Measurements ◽  
Biogeochemical Parameters ◽  
Color Scanner

Herein, we present a simulation of the dynamics of Black Sea ecosystems using a three-dimensional interdisciplinary model that assimilates satellite color scanner measurements. Calculations were performed for the fifteen years from 1998 and a set of 3-d biogeochemical fields of the Black Sea were generated on a regular grid with a discreteness time of 1 day. Analyses of core biogeochemical parameters of the marine ecosystem were then performed. The qualities of received fields were evaluated using comparisons with existing data from in situ measurements.

scholarly journals BALLAST WATER POLLUTION RISK ASSESSMENT IN THE BLACK SEA

2021 ◽  
Vol 10 (4) ◽  
pp. 35-40
Author(s):  
Vasile RAŢᾸ ◽  
Liliana RUSU
Keyword(s):  
Risk Assessment ◽  
Black Sea ◽  
Marine Environment ◽  
Ballast Water ◽  
Safety Net ◽  
The Black Sea ◽  
Natural Food ◽  
Economic Activities ◽  
Living Organisms ◽  
The Stability

Since the emergence of humanity, the marine environment has provided a safety net in many ways, has fostered socio-economic development, creating links between states, between continents. In the same time, it represents a priority source of food for a considerable percentage of the population. The same marine environment also creates solutions to current global problems, as a potential source of sustainable energy for the future. In recent decades, the stability of this ecosystem has been  considerably shaken by the various types of pollution resulting from human activities. The Black Sea is not immune to these results from economic activities, such as the transport of goods by water, which creates the context for the migration of living organisms from one geographical region to another. The threat of ecosystems has been intensified by the process of globalization, by changing the natural food chains following the accidental introduction of non- indigenous marine life by discharging ballast water from ship tanks. Risk assessment to limit the effects of this biohazard problem is the first step in a normal regional chain of action..

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