scholarly journals Modeling long-term changes of the Black Sea ecosystem characteristics

2012 ◽  
Vol 9 (3) ◽  
pp. 2039-2080 ◽  
Author(s):  
V. L. Dorofeyev ◽  
T. Oguz ◽  
L. I. Sukhikh ◽  
V. V. Knysh ◽  
A. I. Kubryakov ◽  
...  
Keyword(s):  
Black Sea ◽  
Inorganic Nitrogen ◽  
The Black Sea ◽  
Mnemiopsis Leidyi ◽  
Biogeochemical Model ◽  
Food Web Structure ◽  
Decadal Scale ◽  
Basin Scale ◽  
Long Term Changes

Abstract. A three dimensional coupled physical-biological model is provided for the Black Sea to investigate its long-term changes under the synergistic impacts of eutrophication, climatic changes and population outbreak of the gelatinous invader Mnemiopsis leidyi. The model circulation field is simulated using the high frequency ERA40 atmospheric forcing as well as assimilation of the available hydrographic and altimeter sea level anomaly data for the 30 yr period of 1971–2001. The circulation dynamics are shown to resolve well the different temporal and spatial scales from mesoscale to sub-basin scale and from seasonal peaks to decadal scale trend-like changes. The biogeochemical model includes the main vertical biological and chemical interactions and processes up to the anoxic interface zone. Its food web structure is represented by two phytoplankton and zooplankton size groups, bacterioplankton, gelatinous carnivores Mnemiopsis and Aurelia, opportunistic species Noctiluca scientillans. The nitrogen cycling is accommodated by the particulate and dissolved organic nitrogen compartments and the dissolved inorganic nitrogen in the forms of ammonium, nitrite and nitrate. The ecosystem model is able to simulate successfully main observed features and trends of the intense eutrophication phase (from the early 1970s to the early 1990s), but points to its modification to simulate better the ecosystem conditions of the post-eutrophication phase.

scholarly journals First record of Pseudodiaptomus marinus (Copepoda: Calanoida: Pseudodiaptomidae) in the Black Sea (Sevastopol Bay)

2016 ◽  
Vol 1 (4) ◽  
pp. 78-80 ◽  
Author(s):  
O. A. Garbazey ◽  
E. V. Popova ◽  
A. D. Gubanova ◽  
D. A. Altukhov
Keyword(s):  
Black Sea ◽  
Structural Changes ◽  
The Black Sea ◽  
Mnemiopsis Leidyi ◽  
Northwestern Pacific ◽  
Basin Scale ◽  
Wide Range ◽  
Sevastopol Bay ◽  
Pseudodiaptomus Marinus

Pseudodiaptomus marinus was initially discovered at the end of September 2016 in a sample taken during a long-term plankton survey of Sevastopol Bay started in 2002. We found 6 females and 12 copepodites (I-V stages) of P. marinus at the center of Sevastopol Bay (St. 3) on September 22. At the mouth of Bay (St. 2) the species was not found. Both females and copepodite stages I-V of P. marinus were found at the both stations on November 11. Abundance of P. marinus increased to 1236 individuals in sample (1373 ind/m3) at the center of the bay. Moreover, two individuals of P. marinus nauplii identified by Sazhina, were found in this sample. At the mouth of the bay abundance of the invasive species reached 103 individuals in sample (103 ind/m3). It is considered to be native to the Northwestern Pacific Ocean, but now species is widespread across the world. Brilinski described in details its distribution in the World's oceans. Recently P. marinus has been found in the Atlantic Ocean in the North Sea and in the Mediterranean Sea. P. marinus is a typical estuarine coastal copepod, living in shallow eutrophic inshore waters. It is tolerant to a wide range of salinity (2.5-35 ptt) and temperature (5-28 ºC) and has the highest invasive potential. Thus species is adapted to relatively low salinities and low winter temperatures of the Black Sea. Copepodite stages at both stations indicate the existence of reproducing populations. Thus, very likely P. marinus is the new established species in coastal area of the Black Sea. As other recent pelagic invaders – the copepods Acartia tonsa Dana 1849, Oithona davisae Ferrari F. D. & Orsi 1984; ctenophores Mnemiopsis leidyi A. Agassiz, 1865 and Beroe ovata Bruguiere, 1789 - P. marinus was most probably brought into Sevastopol Bay in the ballast water of ships. Long-term studies at basin scale are needed to estimate the structural changes in the Black Sea zooplankton community.

Long -Term Changes in the Fish Fauna of the Karkinitsky Gulf of the Black Sea

2020 ◽  
Vol 46 (6) ◽  
pp. 452-460
Author(s):  
R. E. Belogurova ◽  
E. P. Karpova ◽  
E. R. Ablyazov
Keyword(s):  
Black Sea ◽  
Fish Fauna ◽  
The Black Sea ◽  
Long Term Changes

Long-term Changes in Sevastopol Bay (the Black Sea) with Particular Reference to the Ichthyoplankton and Zooplankton

2001 ◽  
Vol 52 (1) ◽  
pp. 1-13 ◽  
Author(s):  
A.D. Gordina ◽  
E.V. Pavlova ◽  
E.I. Ovsyany ◽  
J.G. Wilson ◽  
R.B. Kemp ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Sevastopol Bay ◽  
Long Term Changes

Biogeochemical controls on the Black Sea oxygen dynamics : relevant diagnostics, key processes and adequacy of the monitoring infrastructure.

2020 ◽  
Author(s):  
Arthur Capet ◽  
vandenbulcke Luc ◽  
Grégoire Marilaure
Keyword(s):  
Black Sea ◽  
3D Models ◽  
The Black Sea ◽  
Biogeochemical Model ◽  
Model Parameters ◽  
Biogeochemical Processes ◽  
Low Oxygen ◽  
Future Evolution ◽  
Basin Scale ◽  
Set Up

<p>An important deoxygenation trend has been described in the Black Sea over the five past decades from in-situ observations [1]. While the implications for basin-scale biogeochemistry and possible future trends of this dynamics are unclear, it is important to consolidate our means to resolve the dynamics of the Black Sea oxygen content in order to assess the likelihood of future evolution scenario, and the possible morphology of low-oxygen events. </p><p>Also, it is known that current global models simulate only about half the observed oceanic O2 loss and fail in reproducing its vertical distribution[2]. In parts, unexplained O2 losses could be attributed to illy parameterized biogeochemical processes within 3D models used to integrate those multi-elemental dynamics.</p><p>Biogeochemical processes involved in O2 dynamics are structured vertically and well separated in the stratified Black Sea. O2 sources proceed from air-sea fluxes and photosynthesis in the<br>photic zone. Organic matter (OM) is respired over a depth determined by its composition and<br>sinking, via succeeding redox reactions. Those intricate dynamics leave unknowns as regards the biogeochemical impacts of future deoxygenation on associated cycles, for instance on the oceanic carbon pump. Here we use the Black Sea scene to derive model-observation strategies to best address the global deoxygenation concern.</p><p>First, we decipher components of the O2 dynamics in the open basin, and discuss the way in which O2-based indicators informs on the relative importance of processes involved. Using 1D biogeochemical model set-up, we then conduct a sensitivity analysis to pin-point model parameters, ie. biogeochemical processes, that bears the largest part in the uncertainty of simulated results for those diagnostics. Finally, we identify among the most impacting parameters the ones that can most efficiently be constrained on the basis of modern observational infrastructure, and Bio-Argo in particular. </p><p>The whole procedure aims at orienting the development of observations networks and data assimilation approaches in order to consolidate our means to anticipate the marine deoxygenation challenge. </p><p>[1] Capet A et al., 2016, Biogeoscience, 13:1287-1297<br>[2] Oschlies A et al., 2018, Nature Geosci, 11(7):467–473</p>

Long-term changes in nutrient supply of phytoplankton growth in the Black Sea

2013 ◽  
Vol 117-118 ◽  
pp. 53-64 ◽  
Author(s):  
Alexander S. Mikaelyan ◽  
Andrey G. Zatsepin ◽  
Valeriy K. Chasovnikov
Keyword(s):  
Black Sea ◽  
Nutrient Supply ◽  
Phytoplankton Growth ◽  
The Black Sea ◽  
Long Term Changes

scholarly journals LONG-TERM CHANGES IN THE PRESIPITATION AT THE BLACK SEA COAST OF THE CAUCASUS

2020 ◽  
Vol 1 (5) ◽  
pp. 161-167
Author(s):  
A.V. Parfenova ◽  
◽  
L.V. Dashkevich ◽  
Keyword(s):  
Black Sea ◽  
Coefficient Of Variation ◽  
Meteorological Station ◽  
The Black Sea ◽  
The Caucasus ◽  
Modern Period ◽  
Black Sea Coast ◽  
Long Term Changes ◽  
Sea Coast

Long-term changes in the amount of precipitation on the Black Sea coast of the Caucasus according to data of the hydro-meteorological stations Anapa, Tuapse and Sochi are considered. The observation data analysis of for the selected periods revealed an increase in the average yearly precipitation from the beginning of the twentieth to the beginning of the twenty-first centuries for all hydro-meteorological stations with a slight decrease in the coefficient of variation. Seasonal changes in precipitation regime are pronounced in the region. The highest increase in seasonal precipitation was noted at the Anapa hydro-meteorological station for winter, then for spring and autumn. At the Tuapse and Sochi hydro-meteorological stations also tended to increase precipitation in spring and autumn, but was noted a slight decrease in winter in the modern period. At the same time, for all seasons such growth is provided mainly by an increase in the minimum seasonal values (for all stations), as well as maximum ones in spring (for all stations) and autumn (hydro-meteorological station Anapa). In modern period relative to the twentieth century it is possible to note a slight decrease in the coefficient of variation in winter and spring (for all hydro-meteorological stations), and an increase in summer (for hydro-meteorological stations Anapa and Tuapse). The redistribution of precipitation by seasons was revealed from the beginning of the twentieth to the beginning of the twentyfirst centuries. The most significant changes affected the hydro-meteorological station Tuapse: the share of autumn and spring precipitation increased from 25 to 31 % and from 18 to 22 %, respectively, while the share of summer precipitation decreased from 26 to 18 %. The share of winter precipitation increased from the first to the third selected periods (from 30 to 35 %), after which it decreased to 29 % in the modern period.

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