scholarly journals Nutrient exchange fluxes between the Aegean and Black Seas through the Marmara Sea

2002 ◽  
Vol 3 (1) ◽  
pp. 33 ◽  
Author(s):  
S. TUGRUL ◽  
T. BESIKTEPE ◽  
I. SALIHOGLU
Keyword(s):  
Black Sea ◽  
Lower Layer ◽  
Chemical Properties ◽  
Late Summer ◽  
Aegean Sea ◽  
The Black Sea ◽  
Marmara Sea ◽  
Nutrient Inputs ◽  
Deep Basin ◽  
Layer Flow

Long-term data obtained in the Turkish Strait System (TSS) including the Sea of Marmara, the Dardanelles and Bosphorus straits, during 1990-2000, have permitted us to calculate seasonal and annual fluxes of water and nutrients (nitrate, phosphate) exchanged between the Aegean and Black Seas through the TSS. Two-layer flow regimes in the TSS introduce the brackish waters of the Black Sea into the Aegean basin of the northeastern Mediterranean throughout the year. A counter flow in the TSS carries the salty Mediterranean water into the Black Sea via the Marmara deep basin. The annual volume influx from the Black Sea to the Marmara upper layer is nearly two-fold the salty water exported from the Marmara to the Black Sea via the Bosphorus underflow. The brackish Black Sea inflow is relatively rich in nitrate and phosphate in winter, decreasing to the lowest levels in late summer and autumn. Biologically labile nutrients of Black Sea origin are utilized in photosynthetic processes in the Marmara Sea and are partly exported to the Marmara lower layer. Eventually, the brackish Black Sea waters reach the Dardanelles Strait, with modified bio-chemical properties. On the other hand, the salty Mediterranean waters with low concentrations of nutrients enter the Marmara deep basin. During threir 6-7 year sojourn in the Marmara basin, the salty waters become enriched in nitrate (DIN) and phosphate (DIP), due to oxidation of planktonic particles sinking from the Marmara surface layer. The annual nutrient inputs from the Black Sea to the Marmara basin were estimated as 8.17x108 moles of DIN and 4.25x107 moles of DIP, which are much less than the importation from the Marmara lower layer via the Bosphorus undercurrent. The salty Aegean water introduces nearly 6.13x108 moles of DIN and 2.79x107 moles of DIP into the Marmara lower layer. The estimated DIP outflux from the Aegean Sea is nearly 2 times less than the importation from the Marmara Sea via the Dardanelles Strait.

scholarly journals Seasonal and interannual variability of the water exchange in the Turkish Straits System estimated by modelling

2015 ◽  
Vol 16 (2) ◽  
pp. 444 ◽  
Author(s):  
V. MADERICH ◽  
Y. ILYIN ◽  
E. LEMESHKO
Keyword(s):  
Interannual Variability ◽  
Black Sea ◽  
Lower Layer ◽  
Aegean Sea ◽  
The Black Sea ◽  
Freshwater Flux ◽  
Marmara Sea ◽  
Layered Model ◽  
Seasonal And Interannual Variability ◽  
Turkish Straits System

A chain of simple linked models is used to simulate the seasonal and interannual variability of the Turkish Straits System. This chain includes two-layer hydraulic models of the Bosphorus and Dardanelles straits simulating the exchange in terms of level and density difference along each strait, and a one-dimensional area averaged layered model of the Marmara Sea. The chain of models is complemented also by the similar layered model of the Black Sea proper and by a one-layer Azov Sea model with the Kerch Strait. This linked chain of models is used to study the seasonal and interannual variability of the system in the period 1970-2009. The salinity of the Black Sea water flowing into the Aegean Sea increases by approximately 1.7 times through entrainment from the lower layer. The flow entering into the lower layer of the Dardanelles Strait from the Aegean Sea is reduced by nearly 80% when it reaches the Black Sea. In the seasonal scale, a maximal transport in the upper layer and minimal transport in the bottom layer are during winter/spring for the Bosphorus and in spring for the Dardanelles Strait, whereas minimal transport in upper layer and maximal undercurrent are during the summer for the Bosphorus Strait and autumn for the Dardanelles Strait. The increase of freshwater flux into the Black Sea in interannual time scales (41 m3s-1 per year) is accompanied by a more than twofold growth of the Dardanelles outflow to the North Aegean (102 m3s-1 per year).

Evaluation of hydrodynamic characteristics of the Bosphorus regarding the performance of the marine outfall systems

1995 ◽  
Vol 32 (2) ◽  
pp. 85-93
Author(s):  
Adnan Akyarli ◽  
Yalçin Arisoy
Keyword(s):  
Environmental Impact ◽  
Impact Assessment ◽  
Black Sea ◽  
Lower Layer ◽  
Hydrodynamic Characteristics ◽  
The Black Sea ◽  
Marine Outfall ◽  
Oceanographic Data ◽  
Layer Flow ◽  
Reliable Design

Considering strong interrelations between hydrodynamic features of the Bosphorus and the tube-tunnel crossing which may affect the performance of marine outfall systems, the Institute of Marine Science and Technology (IMST) conducted a comprehensive meteo-oceanographic data acquisition campaign to collect information both for the reliable design of marine outfall systems and for the environmental impact assessment (EIA) of the railroad tunnel, on the joint request of the owners of the projects. The main objectives of this paper are to outline the results of the EIA, and also to discuss the newly adopted plan which proposes to divert the sewage collected in the Kadìköy drainage area to Riva, located along the Black Sea. Recent evaluations by the authors on the blocking of lower layer flow, and findings presented on the mixing along the Bosphorus, have been included as scientific evidences in this discussion.

scholarly journals Assessment of goatfish fisheries in Turkey based on the microdata set of official landing statistics

2021 ◽  
Vol 38 (3) ◽  
pp. 303-309
Author(s):  
Nuray Çelik Mavruk ◽  
Sinan Mavruk ◽  
Dursun Avşar
Keyword(s):  
Mediterranean Sea ◽  
Black Sea ◽  
Large Scale ◽  
Aegean Sea ◽  
Bottom Trawl ◽  
The Black Sea ◽  
Marmara Sea ◽  
Trawl Fishery ◽  
Red Mullet ◽  
The Mediterranean

Although goatfishes (Mullidae Rafinesque, 1815) are among the most important commercial fishes in Turkey, no research has been found investigating the characteristics and spatial patterns of goatfish fishery. Here, we assessed the goatfish fishery of Turkey based on the microdata set of Turkish National Fishery Statistics gathered by Turkish Statistical Institute (TÜİK) between 2014 and 2017. In this context, we investigated the variation of total goatfish catch by cities. In addition, we compared the contribution of small (boat <10m) and large scale (boat >10m) fishers as well as different fishing techniques to the total goatfish catch in Turkey. Finally, an evaluation was made on the discard rates recorded in the official landing statistics. The results showed that higher red mullet (Mullus barbatus Linnaeus, 1758) catch was reported in the eastern Mediterranean, whereas surmullet (Mullus surmuletus Linnaeus, 1758) catch was significantly higher in the western Black Sea. On the other hand, fishery-independent investigations revealed that the Turkish fishery fleet mostly catches red mullet throughout the coasts of Turkey. Therefore, the separate records of red mullet and surmullet in the landing statistics likely represent the local names of red mullet rather than two different species. Large scale fishers were the main source of fishery pressure in the Mediterranean Sea, the Aegean Sea and the Black Sea. However, the majority of the catch was landed by small scale fishers in the Marmara Sea. The bottom trawl fishery landed 88, 92 and 87% of total goatfish catch in the Black Sea, the Aegean Sea and the Mediterranean Sea, respectively. Purse seiners provided the largest part of total goatfish catch (40%) in the Marmara Sea, where the bottom trawl fishery is prohibited. The overall average for the discard rate was found to be 0.47%. There were no statistically significant differences among the discard rates of two species, marine regions or fishing methods.

Quantitative comparison of the influxes of nutrients and organic carbon into the Sea of Marmara both from anthropogenic sources and from the Black Sea

1995 ◽  
Vol 32 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Suleyman Tugrul ◽  
Colpan Polat
Keyword(s):  
Organic Carbon ◽  
Black Sea ◽  
Lower Layer ◽  
Vertical Mixing ◽  
Anthropogenic Sources ◽  
Chemical Pollution ◽  
The Black Sea ◽  
Marmara Sea ◽  
Sea Of Marmara ◽  
Golden Horn

The Sea of Marmara, an intercontinental basin with two narrow and shallow straits permitting the exchange of the Mediterranean and Black Sea waters, receives 2.8×104 tons TP (total phosphorus), 2.7×105 tons TN (total nitrogen) and 1.9×106 tons TOC (total organic carbon) per year from the Black Sea inflow, from the lower layer by vertical mixing and from anthropogenic inputs of various origins including riverine discharges. The Black Sea input through the Bosphorus constitutes about 35, 64 and 77 %, respectively, of the total annual loads of TP, TN and TOC entering the Marmara surface waters. Pollution loadings from Istanbul make up a major fraction (40-65%) of the total anthropogenic discharges. The biochemical properties of the productive Marmara upper layer appear to be dominated by the inputs both from its lower layer by vertical mixing and from the Black Sea throughout the year. Pollution discharges from Istanbul have secondary importance for the nutrient and organic carbon pools of the Marmara Sea; however, the land-based chemical pollution has drastically modified the ecosystem of coastal margins and semi-enclosed bays (e.g. Golden Horn, Izmit and Gemlik) where water exchanges with the open sea are limited. Biologically labile nutrients increasingly exported from the Black Sea in the spring-early summer, are compensated by importation from the Marmara Sea through the Bosphorus underflow. The less labile dissolved organic nitrogen and carbon input from the Black Sea appears to reach as far as the Aegean basin of the Northeastern Mediterranean in 4-5 months without contributing to the net production in the Marmara Sea.

scholarly journals A Model of Black Sea Circulation with Strait Exchange (2008–2018)

2019 ◽  
Author(s):  
Murat Gunduz ◽  
Emin Özsoy ◽  
Robinson Hordoir
Keyword(s):  
Black Sea ◽  
Lower Layer ◽  
Circulation Model ◽  
Open Boundary ◽  
The Black Sea ◽  
Marmara Sea ◽  
Open Boundary Conditions ◽  
Medium Resolution ◽  
Water Mass Formation ◽  
High Space

Abstract. The Bosphorus exchange is of critical importance for hydrodynamics of the Black Sea. In this study, we report on the development of a medium resolution circulation model of the Black Sea, making use of up-to-date topography, atmospheric forcing with high space and time resolution, climatic river fluxes and strait exchange enabled by adding the Bosphorus Strait with an artificial box on the Marmara Sea side. Particular attention is given to circulation, mixing, convective water mass formation processes compared with observations. The present formulation with temperature and salinity relaxed to the observed seasonal climatology of the Marmara box and open boundary conditions are found to enable Bosphorus exchange with upper, lower layer and net fluxes comparable to the observed range. This in turn enables to capture the trend of rapid climatic change observed in the Black Sea in the last decade.

scholarly journals A model of Black Sea circulation with strait exchange (2008–2018)

2020 ◽  
Vol 13 (1) ◽  
pp. 121-138 ◽  
Author(s):  
Murat Gunduz ◽  
Emin Özsoy ◽  
Robinson Hordoir
Keyword(s):  
Black Sea ◽  
Lower Layer ◽  
Climatic Variability ◽  
Circulation Model ◽  
Open Boundary ◽  
The Black Sea ◽  
Marmara Sea ◽  
Open Boundary Conditions ◽  
Medium Resolution ◽  
High Space

Abstract. The Bosphorus exchange is of critical importance for hydrodynamics and hydroclimatology of the Black Sea. In this study, we report on the development of a medium-resolution circulation model of the Black Sea, making use of surface atmospheric forcing with high space and time resolution, climatic river fluxes and strait exchange, enabled by adding elementary details of strait and coastal topography and seasonal hydrology specified in an artificial box on the Marmara Sea side. Particular attention is given to circulation, mixing and convective water mass formation processes in the model, which are then compared with observations. Open boundary conditions relaxed to seasonal hydrology specified in the artificial box are found to enable Bosphorus exchange with a proper upper layer, lower layer and net fluxes comparable to the observed ranges. These improvements at the artificial boundary and in the interior evolution of the Black Sea allow the study to capture daily, seasonal to decadal climatic variability and change observed in the Black Sea in the last few decades.

CORRELATION OF THE BLACK, MARMARA AND AEGEAN SEAS DURING THE HOLOCENE

2017 ◽  
Author(s):  
Nikolay Esin ◽  
Nikolay Esin ◽  
Vladimir Ocherednik ◽  
Vladimir Ocherednik
Keyword(s):  
Mathematical Model ◽  
Sea Level ◽  
Black Sea ◽  
Aegean Sea ◽  
The Black Sea ◽  
Sea Level Changes ◽  
The Holocene

A mathematical model describing the change in the Black Sea level depending on the Aegean Sea level changes is presented in the article. Calculations have shown that the level of the Black Sea has been repeating the course of the Aegean Sea level for the last at least 6,000 years. And the level of the Black Sea above the Aegean Sea level in the tens of centimeters for this period of time.

A voyage to Ancient Greek Harbours on board Limenoscope

2007 ◽  
Vol 7 (1) ◽  
pp. 253-260 ◽  
Author(s):  
T. Theodoulou ◽  
C. Memos
Keyword(s):  
Black Sea ◽  
General Public ◽  
Aegean Sea ◽  
Relevant Information ◽  
The Black Sea ◽  
Ancient Greek ◽  
Web Based ◽  
Database Structure ◽  
Historical Role ◽  
Concise Information

Limenoscope is a web based database aiming at promoting the cultural heritage regarding ancient Greek harbours and disseminate the relevant information equally to the general public and to researchers with an interest in that particular cognitive field. The scope of the project is the realization of a database, where one can search for concise information relevant to the historical role, the topography, the morphology, as well as the technical works and installations of ancient harbours in the Mediterranean and the Black Sea. The Database started off with the registration of harbours located in the Aegean Sea and Cyprus, dating from Archaic to Byzantine times. Special emphasis is laid on the bibliographical update of the data forms of the harbour sites, as well as on the related references in ancient literature. The database enables the locating of these sites on a general map, where photographs, plans etc. are also archived. The principles of the database structure are briefly presented along with an example, that of the harbour of Phalasarna, among the harbours registered therein.

The Black Sea factor influencing the wastewater disposal strategy for Istanbul

1995 ◽  
Vol 32 (7) ◽  
pp. 63-70
Author(s):  
I. Ethem Gönenç ◽  
Oguz Müftüoglu ◽  
Bilsen Beler Baykal ◽  
Ertugrul Dogan ◽  
Hüseyin Yüce ◽  
...  
Keyword(s):  
Black Sea ◽  
Satellite Images ◽  
The Black Sea ◽  
Marmara Sea ◽  
Research Institutions ◽  
Trophic Conditions ◽  
Wastewater Disposal ◽  
The World ◽  
Collaborative Efforts

Unlike other seas of the world, the Black Sea shows unique quality and trophic properties. Fortunately, only the upper layer water of the Black Sea is introduced into the Bosphorus and has a significant effect on the quality and trophic conditions of the Marmara Sea. These effects are discussed in the light of data obtained from collaborative efforts of Turkish and Romanian research institutions and processed satellite images. In conjunction with these discussions, recommendations for a suitable effluent disposal strategy for Istanbul's wastewater have been given.

Environmental model studies for the Istanbul master plan. Part I: hydrodynamical design basis and marine disposal of wastewater

1995 ◽  
Vol 32 (2) ◽  
pp. 141-148 ◽  
Author(s):  
I. S. Hansen ◽  
H. J. Vested ◽  
M. A. Latif
Keyword(s):  
Black Sea ◽  
Layer Structure ◽  
The Black Sea ◽  
Marmara Sea ◽  
Junction Area ◽  
3 Dimensional ◽  
Model Studies ◽  
Model Set ◽  
Characteristic Features ◽  
Set Up

A modelling study of the hydrodynamics and spreading of wastewater from existing and future outfalls in the Bosphorus region has been conducted applying a 3-Dimensional model. The modelling is based on SYSTEM 3, which is a general modelling system for baroclinic flow simulating unsteady currents, waterlevels, salinity and temperature within the model area. The model set-up covers the Black Sea-Bosphorus-Marmara Sea junction area. The set-up is calibrated by data from a dedicated field program and previous field experience. The model is designed to describe the characteristic features of the flow in the junction area such as the effects of variations in waterlevel differences between the Sea of Marmara and the Black Sea on the important two-layer structure in the strait and the flow fields generated by the upper layer jet in the Bosphorus-Marmara junction. This model has been applied for evaluation of disposal of wastewater and for the subsequent water quality studies. The general use of a baroclinic 3-D hydrodynamic model to simulate disposal of wastewater is discussed. Examples of the application of the model of the junction area to evaluate the different strategies for disposal of wastewater are presented.

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