The Evolution of Danube Delta After Black Sea Reconnection to World Ocean

Author(s):  
Alfred Vespremeanu-Stroe ◽  
Luminiţa Preoteasa ◽  
Florin Zăinescu ◽  
Florin Tătui
Keyword(s):  
Author(s):  
Călin LAȚIU ◽  
Daniel COCAN ◽  
Paul UIUIU ◽  
Andrada IHUȚ ◽  
Sabin Alexandru NICULA ◽  
...  

The review assembles chronological data on Black Sea trout (Salmo labrax) from Romanian waters and brings up-to-date information related to the distribution of the species. The information used dates from 1909 to 2020 and includes books, articles, digital databases, field observations, and notes from different research fields such as ichthyology, biogeography, genetics, aquaculture, conservation, and ecology. Global distribution, migration, meristic characters, and aquaculture of the species were analyzed based on the recorded data from the specialty literature. New information related to a possible population of Salmo labrax inside the Carpathian Arch was discussed. In Romanian waters the species is found in the Black Sea, Danube, Danube Delta but the current paper proposes a new hypothesis, namely that resident populations can be found in rivers and lakes adjacent to the Carpathian Arch. The highest migration point of the Black Sea trout in the Danube was recorded near Corabia locality, Olt County, (43°46′25″N- 24°30′12″E). In the Danube Delta, it was caught in all the three branches (Sulina, Sf. Gheorghe and Chilia), and lagoonary complexes such as Razim-Sinoe. Sexually matured females were caught especially in Spring Season while unmatured specimens were caught in all seasons. Even if the species is protected under Romanian legislation, fishermen and anglers should report its presence when caught accidentally.


2005 ◽  
Vol 15 (1) ◽  
pp. 63-71 ◽  
Author(s):  
I. SCHOGOLEV ◽  
A. RUDENKO ◽  
A.J. CRIVELLI

The status of breeding pelicans and cormorants is assessed in the area from the Danube delta (Romania) to the northern part of the Crimean peninsula. Four breeding species occur in inland and coastal wetlands: Dalmatian Pelican Pelecanus crispus, Great White Pelican Pelecanus onocrotalus, Great Cormorant Phalacrocorax carbo and Pygmy Cormorant Phalacrocorax pygmeus. Data on clutch size and breeding success are given. Historically, all four species were restricted to the Danube delta. Currently, with the exception of Dalmatian Pelican, they all breed successfully on the eastern Black Sea coast in the Ukraine. There are many conservation problems that will jeopardize the breeding of these species in the future if nothing is done.


Author(s):  
Ilias N. Tziavos ◽  
Thomas K. Alexandridis ◽  
Borys Aleksandrov ◽  
Agamemnon Andrianopoulos ◽  
Ioannis D. Doukas ◽  
...  

2020 ◽  
Author(s):  
Marie-Sophie Maier ◽  
Cristian R. Teodoru ◽  
Bernhard Wehrli

Abstract. River deltas with their mosaic of ponds, channels and seasonally inundated areas act as the last continental hotspots of carbon turnover along the land-ocean aquatic continuum. There is increasing evidence for the important role of riparian wetlands in the transformation and emission of terrestrial carbon to the atmosphere. The considerable spatial heterogeneity of river deltas, however, forms a major obstacle for quantifying carbon emissions and their seasonality. While river reaches crossing the delta can serve as reference systems, delta lakes are often dominated by aquatic production and channels act as collection systems for carbon exported from adjacent wetlands. In order to quantify carbon turnover and emissions in the complex mosaic of the Danube Delta, we conducted monthly field campaigns over two years at 19 sites spanning river reaches, channels and lakes. Here we report greenhouse gas fluxes (CO2 and CH4) from the freshwater systems of the Danube Delta and present the first seasonally resolved estimates of its freshwater carbon emissions to the atmosphere. Furthermore, we quantify the lateral carbon transport of the Danube River to the Black Sea. We estimate the delta’s CO2 and CH4 emissions to be 65 GgC yr−1, of which about 8 % are released as CH4. The median CO2 fluxes from river branches, channels and lakes are 25, 93 and 5.8 mmol m−2 yr−1, respectively. Median total CH4 fluxes amount to 0.42, 2.0 and 1.5 mmol m−2 yr−1. While lakes do have the potential to act as CO2 sinks in summer, they are generally the largest emitters of CH4. Small channels showed the largest range in emissions including a CO2 and CH4 hotspot sustained by adjacent wetlands. The channels thereby contribute disproportionately to the delta’s emissions considering their limited surface area. In terms of lateral export, we estimate the net export of the Danube Delta to the Black Sea to about 160 GgC yr−1, which only marginally increases the carbon load from the upstream river catchment (8490 GgC yr−1) by about 2 %. While this contribution of the delta seems small, deltaic carbon yield (45.6 gC m−2 yr−1, net export load/surface area) is about 4-fold higher than the riverine carbon yield from the catchment (10.6 gC m−2 yr−1).


2017 ◽  
Vol 51 (1) ◽  
pp. 73-74
Author(s):  
B. Alexandrov

Abstract Bivalve marine mollusc Barnea candida (= Pholas candidus) from Pholadidae family is sensitive to the high concentration of organic matter in sea water and recently has been included into the list of indicator species for the Black Sea (Alexandrov, Zaitsev, 2016). Its recording in Ukrainian part of the Danube Delta after more than 60 years since its first registration is probably the evidence of reduction of eutrophication and gradual restoration of local aquatic ecosystem biodiversity.


2000 ◽  
Vol 1 (1) ◽  
pp. 45 ◽  
Author(s):  
G. MUNGOV ◽  
P. DANIEL

The frequency of the storm surges in the Black Sea is lower than that in other regions of the World Ocean but they cause significant damages as the magnitude of the sea level set-up is up to 7-8 times greater than that of other sea level variations. New methods and systems for storm surge forecasting and studying their statistical characteristics are absolutely necessary for the purposes of the coastal zone management. The operational forecasting storm surge model of Meteo-France was adopted for the Black Sea in accordance with the bilateral agreement between Meteo-France and NINMH. The model was verified using tide-gauge observations for the strongest storms observed along the Bulgarian coast over the last 10 years.


2006 ◽  
Vol 6 (3) ◽  
pp. 3611-3626 ◽  
Author(s):  
K. Kourtidis ◽  
I. Kioutsioukis ◽  
S. Rapsomanikis

Abstract. Methane in air and seawater was measured in the Eastern Black Sea during the 10–18 December 1999 BIGBLACK project cruise. The measurements allowed for the calculation of supersaturation ratios and methane fluxes across the air-sea interface. CH4 mixing ratios in air were generally in the 1.8–2.0 ppmv range, while surface (4 m depth) seawater concentrations varied from 5 to 100 ppmv. Above active seep areas, the water was supersaturated at around 500% with respect to the overlying atmosphere. Accordingly, flux densities varied greatly and were up to 4000 umol m-2 day-1. In the Sevastopol harbour, supersaturations up to around 3000%, similar to those at the Danube Delta, were observed, while in the Istanbul harbour supersaturations could not be determined because the very high values of water concentrations have led to detector saturation. Simple modelling shows that the observed fluxes do not have any substantial impact in the methane content of the Black Sea atmosphere, as they could only raise its concentrations by less than 1 ppb. On the other hand, calculations performed as part of the CRIMEA project, show that mud volcano eruptions could episodically raise the methane concentrations well above their regional background for several tens of kilometres downwind.


Author(s):  
Н. Есин ◽  
N. Esin ◽  
Н. Есин ◽  
N. Esin ◽  
О. Сорокина ◽  
...  

A method of calculation on local curves of the World ocean eustatic (absolute) variations is presented in this paper. It is shown that vertical motions of the Earth's Crust considerably distort eustatic curve of the sea level change (up to the contrary result). Thus, the local curves present little volume of information. A method of extraction of tectonic component from local curves is proposed. The World ocean level change in Holocene is calculated on local curves of the Mediterranean Sea. It was ascertained that the process of an active erosion of the Black Sea shelf began 3–4 ka.


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