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The cellular carbon content based on the cell biovolume of a total of 61 microalgal species determined in a eutrophic estuary (Golden Horn, Sea of Marmara) was estimated in seawater samples taken during two different sampling periods. Cell biovolume according to geometric dimensions of the cells was then converted to phytoplankton carbon using an appropriate conversion factor. The range of diatom biovolume, in which the majority had small cell sizes (<50 μm), was much wider than that of dinoflagellate biovolume, in which the majority had large cell sizes (>50 μm). The cell biovolume and carbon content ranged from 35 to 4.88 × 105 μm3 and 5 to 1.18 × 104 pgC cell−1 for diatoms and from 3.66 × 102 to 8.68 × 105 μm3 and 55 to 8.14 × 104 pgC cell−1 for dinoflagellates, respectively. The mean carbon density for diatoms and dinoflagellates (excl. Noctiluca scintillans) varied between 0.027 and 0.099 pgC μm−3 0.096 and 0.136 pgC μm−3, respectively. The mean cell carbon content and carbon density of dinoflagellates (6.73 × 103 pgC cell−1 and 0.115 pgC μm−3) were approximately 10 and 2 times greater than those of diatoms, respectively. The carbon content of the other phytoflagellates was lower, whereas their carbon density was higher. As a result, the findings from this study will provide a significant contribution to the assessment and estimation of carbon biomass during algal blooms in this study area. [ABSTRACT FROM AUTHOR]

The North Anatolian Fault Zone (NAFZ) is the most prominent active fault system in Northwestern Turkey. It is a major fracture that traverses the Northern part of Asia Minor and marks the boundary between the Anatolian tectonic plate and the larger Eurasian continental block, and has been the source of numerous large earthquakes throughout history. The NAFZ splits into three strands at the eastern part of the Marmara Sea. The northern strand passes through Izmit Bay, traverses the Marmara Sea and reaches to the Saros Gulf. The central fault zone passes through Izmit Bay, traverses the Sea of Marmara and reaches the Saros Gulf to the southeast. Earthquakes on this zone involve primarily horizontal ground motions (strike-slip type of faulting). Because of this unstable tectonic system, the area is considered to be as one of the most seismically active zones of the world. In the last hundred years, numerous large earthquakes have also occurred along the NAFZ, in the western part of Turkey. Beginning with an earthquake in 1939, several more quakes - with Richter magnitudes greater than 6.7 - struck in progression along adjacent segments of the great fault. The August 17, 1999 Izmit earthquake was the eleventh of such a series that have broken segments of the NAFZ, in both eastward and westward direction. The epicenter of the 1999 earthquake was near Izmit, as well as the location of previous events. The sequence of historic events indicates that the next destructive tsunamigenic earthquake could occur west of the 1999 event in the Sea of Marmara. The present study incorporates the results of a subsequent 2001 study which uses standardized remote sensing techniques and GIS-methods - based on Digital Elevation Model (DEM) data, and on geomorph metric parameters that influenced local site conditions in the Sea of Marmara, as determined with Digital elevation data of the Shuttle Radar Topography Mission (SRTM), and with high resolution ASTER-data. With such remote sensing methods, areas that are potentially vulnerable areas in the Sea of Marmara were detected, so that disaster mitigation strategies can be implemented more effectively in the future. Based on such technology, local site conditions, which exacerbated earthquake intensities and collateral disaster destruction in the Marmara Sea region, were identified. Also reviewed by the present study are the similarities of NAFZ with the San Andreas fault in California in the USA, for the formation of an active transform boundary of the strike-slip type, with the two sides moving horizontally and continuously past each other. Finally examined is the tectonic and continuing geodynamic evolution and collision between the Arabian Plate and Eurasia, which places in danger many cities in southeastern Turkey and NorthWest Syria - which is are located on the boundary with the Arabian tectonic plate, as evidenced by the recent disastrous earthquake of 8 February 2023 along the Eastern Anatolian Fault Zone (EAFZ). [ABSTRACT FROM AUTHOR]

Based on morphobathymetric and seismic reflection data, we studied a large landslide body from the eastern Sea of Marmara (NW Turkey), along the main strand of the North Anatolian Fault, one of the most seismically active geological structures on Earth. Due to its location and dimensions, the sliding body may cause tsunamis in case of failure possibly induced by an earthquake. This could affect heavily the coasts of the Sea of Marmara and the densely populated Istanbul Metropolitan area, with its exposed cultural heritage assets. After a geological and geometrical description of the landslide, thanks to high-resolution marine geophysical data, we simulated numerically possible effects of its massive mobilization along a basal displacement surface. Results, within significant uncertainties linked to dimensions and kinematics of the sliding mass, suggest generation of tsunamis exceeding 15–20 m along a broad coastal sector of the eastern Sea of Marmara. Although creeping processes or partial collapse of the landslide body could lower the associated tsunami risk, its detection stresses the need for collecting more marine geological/geophysical data in the region to better constrain hazards and feasibility of specific emergency plans. [ABSTRACT FROM AUTHOR]

The study deals with the growth pattern, mortality, and reproduction of common sole, Solea solea (Linneaus, 1758), from the Sea of Marmara (Turkey). A total of 580 fish specimens were sampled monthly from October 2017 to September 2018. The total length of all sampled individuals ranged from 11.1 to 29.5 cm, corresponding to ages from 1 to 3 years. The length–weight relationship was expressed as W = 0.022 TL2.6838, where the slope indicated negative allometric growth. Growth parameters were L∞ = 33.7 cm, k = 0.48, and t0 = −0.18 for all samples. A seasonally oscillating growth model, indicating the amplitude of oscillations, revealed an important seasonal growth pattern. Total, natural, and fishing mortality rates were calculated as 1.42, 0.47, and 1.01, respectively. The exploitation ratio (E = 0.68) indicates that the fishing pressure on the common sole in the Sea of Marmara was high. The sex ratio (♀/♂) was 1.18. The gonadosomatic index (GSI) for females showed that two main spawning seasons were observed: one in spring (May) and one in autumn (September–October). Sizes at the onset of sexual maturity were estimated for both females and males at 21.6 and 18.6 cm, respectively. [ABSTRACT FROM AUTHOR]

Newly collected high-resolution seismic reflection and magnetic data collected offshore of the Ganos Fault (NW Turkey) in the western Sea of Marmara, along the submerged portion of the North-Anatolian Fault, highlight the presence of a complex fault pattern. Based on these data, we propose a new tectonic model for this key region, connecting the onshore fault pattern to the transtensional basins of the deepest Sea of Marmara. According to this new model, three main faults control the deformation pattern of this region, fault SF1, a tectonic element that shapes the Tekirdağ Basin, and fault SF2, which although not affecting the sea floor, is structurally related to SF1. Another fault we called SF3, connects the offshore to the Ganos fault onshore creating a transtensional pattern nearby the shelf. All such kinematic indicators witness an incipient activity, and a seismogenic potential that should be determined by a detailed mapping of both the surficial expression of fault at the seafloor, and the deformation pattern observed in the post-glacial sedimentary sequence. The active fault pattern detected nearby the coastal areas and their structural relationships with the Tekirdağ basin show that it could be interpreted as a negative flower structure, which accommodates strain partitioning. This observation is crucial to seismic hazard assessments in this region that has been the site of destructive earthquakes in the recent and remote past. [ABSTRACT FROM AUTHOR]

One of the economically important species is Penaeus kerathurus (Forskål, 1755), which is widespread in the Mediterranean ecosystem. This paper presents results of research on reproductive biology of Penaeus kerathurus in the Sea of Marmara. A total of 1404 specimens were dissected to determine the maturity stages, reproduction time, and length at first reproduction. The female-to-male ratio was 1:0.9. A high percentage of mature females was determined in April, May and July. Moreover, the value of the gonadosomatic index (GSI) decreased after July. The spawning period was observed between April and July, and its intensity increased in July. The carapace length at first sexual maturity was determined to be 39 mm. [ABSTRACT FROM AUTHOR]

The Marmara is the most highly trafficked region in Turkey in terms of seaway and highway transport congestion. The transport mode-based CO2 emissions budget for the region needs to take more environmentally friendly measures. In this study, 13 ro-ro and ferry lines (RFLs) are evaluated in the Sea of Marmara to compare ship-generated CO2 emissions with road transport as if the carried vehicles had used the highway instead of transport by RFL. Additionally, this study revealed the management strategies for CO2 emissions reduction for both transport modes under current conditions. The total CO2 emissions budget of 13 RFLs in the Sea of Marmara is higher than the potential CO2 emissions of their carried vehicles. Using the methods of Entec UK Ltd and Trozzi and Vaccaro, the amount of CO2 emissions generated by the RFLs is 204,470.99 and 170,459.85 t/year, respectively. The potential CO2 emissions of road vehicles carried in 2017, 2018 and 2019 are computed by applying Tier 1 methods as 121,690.54, 106,844.89, and 100,921.95 t/year, respectively. It is observed that shifting trucks from the highway to the seaway contributes to a reduction of the yearly CO2 emissions budget generated from the transport sector to provide sustainable transportation management in the region. [ABSTRACT FROM AUTHOR]

Nerocila orbignyi (Isopoda, Cymothoidae) is reported for the first time on Mugil cephalus Linnaeus, 1758 (Pisces, Mugilidae) from Bandırma Bay (the Sea of Marmara, Turkey) during 2020. This paper aims to present the morphological characters of male of N. orbignyi from Turkey. Hosts infested with N. orbignyi are commented according to taxonomical status (order, families), ecological behaviours (habitat selections, feeding habits, school-solitary), morphological characters (scale types) according to current records. It may be said that N. orbignyi has been reported more frequently on fish belonging to the Perciformes order and Mugilidae and Sparidae families. It may also be said that this parasite selects also the fishes with carnivorous, demersal, schools, and migratory character. [ABSTRACT FROM AUTHOR]

This study reported the mass mortality events (MMEs) of Pinna nobilis based on diving surveys in Turkey. Data were collected across 12 sites in the Aegean Sea, and one site in the Sea of Marmara, within the period of June‐September 2019. The results showed that a low mortality rate of 10% was found in the Sea of Marmara, and a MME was not detected for this area. In contrast, 97% mortality was recorded for the P. nobilis population distributed in the Turkish Aegean Sea. This discrepancy might be related to the seawater temperature and salinity values of these two seas. The waters of the Sea of Marmara were colder and less salty than the Aegean Sea. The findings highlighted the importance of protecting the healthy population of critically endangered fan mussels in the Sea of Marmara. It was recommended that sound management plans comprising of monitoring, enforcement and public awareness activities could be implemented in order to achieve this. [ABSTRACT FROM AUTHOR]

Within the scope of this paper, seismic reflection and bathymetry studies were carried out in the shallow marine area forming the westernmost part of the Tekirdağ Basin using the R/V Selen Research Vessel within the MTA Marine Research Department. In the study area, ~ 500 km length bathymetry data and ~191 km shallow seismic profiles (41 lines) were collected. By means of the data, tectonic structures and deformation textures of the North Anatolian Fault System (NAFS) in the marine area of Gaziköy were examined. As a result of the processing and interpretation of the seismic sections, compression structures occurring due to the SW rotation of the NAFS in the study area, the morphology of the Ganos depression that formed as a result of faulting and also three different stratigraphic units were distinguished. These units are separated from each other by distinct unconformity surfaces and each unit presents different deformation structures. One of the most significant results obtained from the seismic data is that the unconformity surface that separates the current sediments of the seafloor from the older units is represented by the overlapping structures indicate sea level changes. It has been assessed that this situation occurred as a result of the erosional process developed during sea level fall. [ABSTRACT FROM AUTHOR]

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Excluding the jellyfish from the bunt-end is a common slipping process used in the Sea of Marmara purse seine fishery. For this aim, a sheet of netting piece, larger mesh size and thicker diameter, is rigged on the bunt-end of the purse seine net. The jellyfish mass on the netting piece are slipped by rolling over the headline (floating line) after partially hauling or drying-up the net while it is still in the water. In this study, the catch amount of this slipping was roughly estimated with the introduction of the slipping process only used by the purse seiners in the Sea of Marmara. There were eight successful purse seine operations conducted between 8 and 11 September 2018 in depth ranged 77 to 677 m. The percentage of landed species versus to jellyfish varied between 23% and 85%. The mean landed anchovy amount is 4379 (±3756.6) kg for per operation. The mean slipped amount of jellyfish is 3812.5 (±2404.4) kg. However, both anchovy (99.8%) and jellyfish (96.3%) are the vast majority species that landed and slipped, respectively. In the operations totally 100 boxes of anchovy (1180 kg) unintentionally was slipped with the jellyfish. In addition, two sharks with larger size were slipped to the sea as alive over the floating line of the net. Although slipping practised rarely in Turkey, all the purse seiner in the Sea of Marmara have to use the adapted slipped process to get rid of jellyfish. However, there are no records and scientific findings regarding slipped amount of the jellyfish. For this reason, this study is important to presented preliminary results regarding amount of the jellyfish. In conclusion, this study is extended completely the Sea of Marmara practised to understand the dimensions of jellyfish amount and slipping process. [ABSTRACT FROM AUTHOR]

The Bosphorus, located at the junction of Asia and Europe, controls the transports of water, material, and energy between the Black Sea (BS) and the Mediterranean Sea. The Canal Istanbul (CI), planned by Republic of Turkey (TR), is a gigantic project which bisects the current European side of Istanbul, thus forming a secondary waterway parallel to the existing natural channel of the Bosphorus. The environmental impact of this project has been a major concern since the very beginning. To address this concern, a 3D hydrodynamic modeling study is carried out to investigate the impact of CI on the hydrodynamics and salinity of the northern Sea of Marmara (SM) by using the route and cross-section (CS) of canal, which was recently made public by the TR. An extensive set of model calibration is performed in a model where only the Bosphorus Strait links the Black Sea and Marmara Sea. Once the calibration process is completed, the future canal is added into the grid and new simulations are performed to analyze the influence of CI on hydrodynamics and salinities in the SM. It was found that the shallow water depth of CI is the limiting factor constraining the two-layer flow. Thus the vertical current structure of CI appears mostly as one-layer flow from the BS to the SM. One-layer flow from the SM toward the BS is rarely observed. In such cases, strong northerly storms caused water level setup at the SM and set down at the BS. Adding the CI in the model is responsible for a salinity decrease of ~1 ppt in the surface layer of SM. The salinity difference between the two models decreases gradually with the depth and it diminishes at the depth of 25 m. [ABSTRACT FROM AUTHOR]

This study presents the first record of a jellyfish of the genus Drymonema from the Istanbul coast of the Sea of Marmara, Turkey, in February 2020. While exceedingly rare in the second half of the 20th Century in the Mediterranean Basin, a specimen of the genus Drymonema (D. dalmatinum) has been recorded in the Gulf of İzmir and Foça (Turkey), but it has never been recorded as far into the Sea of Marmara. A role of citizen science in terms of spotting such rare species is highlighted. [ABSTRACT FROM AUTHOR]

The present work describes microalgal blooms that occurred in a eutrophic estuary (Golden Horn, Sea of Marmara, Turkey) between October 2013 and September 2014 following a remediation effort. The relationships between bloom-forming microalgal species and environmental factors were investigated during the study period. The changing environmental conditions (e.g. increasing water transparency and salinity) after seawater transfer to the Golden Horn Estuary stimulated phytoplankton growth with dense algal blooms. Annual average values of Secchi depth, salinity and dissolved oxygen increased in comparison with those in an earlier study in 2009–2010. Nine microalgal species, which consisted of four diatoms, two dinoflagellates, one cryptophycean, one raphidophycean and one euglenophycean, formed the blooms with water discolorations during spring and summer. The species that reached the highest bloom density were Plagioselmis prolonga (62.4 × 106 cells l−1) among crytophyceans, Heterocapsa triquetra (21.8 × 106 cells l−1) among dinoflagellates and Skeletonema marinoi (39 × 106 cells l−1) among diatoms. The abundance of dinoflagellates and phytoflagellates increased particularly in the upper estuary when compared to diatoms and their rapid growth and bloom formation revealed that they have a wide range of tolerance to changing environmental conditions and a strong ability to compete with other species in this study area. [ABSTRACT FROM AUTHOR]

Mapping benthic habitats is an essential, actually a sine qua non, tool for marine spatial planning and management. Posidonia oceanica (Linnaeus) Delile is an important endemic seagrass species in the Mediterranean Sea. In this study, all mapping efforts along the Turkish coasts have been reviewed through the publications and summarized including locations and coverage information. Consequently, a total of 14 486.20 ha of P. oceanica coverage was reported in 16 studies until 2019. However, this figure seems to be remarkably underestimated. It is therefore determined that the mapping of Posidonia seagrass beds in Turkey has not yet provided exploitable information and data for marine spatial planning and still remains as an urgent task. [ABSTRACT FROM AUTHOR]

Abstract Plastic is produced today in large quantities and used for many purposes. At the end of use, a large part of it gets into the environment, often into the sea and there it is fragmented into the smallest fragments, so-called microplastic (MP). MPs pose a serious challenge to the marine environment such as the sources and properties of MP particles, their impact on marine organisms, and the challenges of environmental pollution. This work, carried out in the fourteen sites in the area, is the first reference to the detection of MP distribution at surface waters in the Sea of Marmara, Turkey. As a result of this study, the average level of MP in the surface was determined to be 1.263 item/m2. The results were higher compared of the most other adjacent regions and show that the Sea of Marmara started to face that problem. Highlights • First study on microplastic in the Sea of Marmara surface waters • Case study from the highly human impacted Sea of Marmara • Surface microplastic concentration was found to be quite high. • We show the current situation of surface MPs concentration of Sea of Marmara. [ABSTRACT FROM AUTHOR]

This study reports a third maximum length record for bluefish Pomatomus saltatrix (Linnaeus, 1766) for the Turkish water. The P. saltatrix specimen was captured in the Biga Peninsula in the southwestern Sea of Marmara. Its length was 73.4 cm and weight was 3600 g. The age was determined by the otolith as 6 years old. This is the first study to examine otolith of such a large specimen in Turkey. [ABSTRACT FROM AUTHOR]

We studied spatiotemporal b -value variations along the North Anatolian Fault Zone (NAFZ) in northwestern Turkey with a focus on the combined 1999 Izmit and Düzce rupture and the eastern Sea of Marmara. We used a local seismicity catalog of the Izmit-Düzce region covering a time span from 2.5 years prior to the Izmit until 14 months after the Düzce mainshock and a four-year hypocenter catalog in the eastern Sea of Marmara. We consistently calculated moment magnitudes to ensure a homogeneous dataset and applied strict quality criteria. This allows studying variations of b -values throughout the region and at different stages of the seismic cycle. With a standard gridding technique b -value maps, depth sections and time series were calculated which reveal a very heterogeneous b -value distribution in the study area. The variety of b -value observations cannot be interpreted unambiguously, given that the b -value most likely depends on a combination of fault-zone characteristics like local stress conditions, heterogeneity of the crust and damage distribution. By presenting a comprehensive set of possible interpretations we point out that a biased discussion of the results towards stress or another individual parameter may lead to erroneous conclusions. Furthermore, the applied data discretization scheme influences the appearance of the final b -value distribution leading to potential misinterpretations. [ABSTRACT FROM AUTHOR]

This study attempted to determine certain characteristics of the species caught in the boat seine fishery in the İstanbul Strait during the 2009–2010 fishing season, including catch composition, commercial and nontarget catch ratios, catch per unit effort (CPUE), and the length distributions of commercial species. A survey of 20 boat seine operations detected species belonging to the following 3 different taxonomic groups: 26 Osteichthyes, 2 Crustacea, and 1 Mollusca. Of all of the nontarget species, 13 were commercial, 14 were noncommercial, and only 1 was under threat. Of the total catch, the proportion of the commercial species in the nontarget catch was 31.3% and that of the discarded catch, which the fishermen did not take into account, was 2.8%. According to the Spearman rank correlation test, there was a significant correlation between the total catch and the discarded catch (r = 0.759); the size of discarded catch increased as the catch increased (P = 0.000). It was clear from the data that overfishing was seen in the commercial species. [ABSTRACT FROM AUTHOR]

The distribution of tintinnid species and their associations with environmental variables were evaluated in the eutrophic Golden Horn estuary ecosystem. The samples were collected from two stations monthly between October 2009 and September 2010. The study determined 17 tintinnid species belonging to five families and nine genera. In the study, the results of environmental variables such as temperature, salinity, dissolved oxygen, pH, Secchi disk, chlorophyll- a , and nutrients were recorded synchronously with tintinnid samples. Also, the Shannon-Weaver diversity index, canonical correspondence analysis (CCA) and the two-way indicator species analysis (TWINSPAN) were applied to the data. According to this statistical analysis, the diversity was high in spring and summer, and it was determined that temperature was the main factor affecting tintinnid composition. Also, Tintinnopsis beroidea could be used as a potential indicator species in ascertaining the NH 4 –N, and Codonellopsis schabi and Tintinnopsis acuminata were detected to be winter and spring seasons indicators. • Tintinnid diversity was high in spring and summer in the Golden Horn Estuary. • The temperature was the main factor affecting tintinnid composition. • Tintinnopsis beroidea could be used as a potential indicator species in ascertaining NH 4 –N. • Codonellopsis schabi , and T. acuminata were detected to be indicators of the winter and spring seasons. [ABSTRACT FROM AUTHOR]

The presence, bioconcentration, and health risk via seafood consumption of 11 pharmaceutical compounds belonging to different therapeutic groups (anti-inflammatory, antiepileptic, lipid regulators, and hormones) were investigated in the muscle tissues of fish and the meat of shrimp in the Sea of Marmara. Six biota species (Merlangius merlangus, Trachurus meditterraneus, Serranus hepatus, Pomatomus saltatrix, Parapenaeus longirostris, Spratus sprattus) were collected from the five stations in October and April 2019. Ultrasonic extraction method followed by solid phase extraction was used for extraction of pharmaceutical compounds from biota samples and then analyzed using high-performance liquid chromatography. Of the 11 compounds, 10 were detected in biota species. Ibuprofen was the most frequently detected pharmaceutical in the biota tissues at high concentrations (<3.0–1225 ng/g, dw). The other widely detected compounds were fenoprofen (<3.6–323 ng/g, dw), gemfibrozil (<3.2–480 ng/g, dw), 17α-ethynylestradiol (<2.0–462 ng/g, dw), and carbamazepine (<7.6–222 ng/g, dw). The bioconcentration factors of the selected pharmaceuticals calculated in various aquatic organisms ranged from 9 to 2324 L/kg. The estimated daily intakes of anti-inflammatories, antiepileptics, lipid regulators, and hormones via seafood consumption were 0.37–568, 1.1–324, 8.5–197, 3–340 ng/kg bw. Day, respectively. Based on hazard quotients, estrone, 17β-estradiol, and 17α-ethynylestradiol may pose a health risk to humans through the consumption of this seafood. [Display omitted] • Pharmaceutical levels were quantified in biota in a semi-enclosed sea. • Ibuprofen, gemfibrozil, and 17α-ethynylestradiol were frequently detected. • Based on bioconcentration factors, ibuprofen is potentially bioaccumulative. • Estrone and 17α-ethynylestradiol may pose a health risks for humans. [ABSTRACT FROM AUTHOR]

Occurrence of micro- (<5 mm) and mesoplastics (5–25 mm) in twelve fish species caught off Gulf of İzmit in the Sea of Marmara was investigated. Plastics were found in the gastrointestinal tracks of all the analysed species: Trachurus mediterraneus, Chelon auratus, Merlangius merlangus, Mullus barbatus, Symphodus cinereus, Gobius niger, Chelidonichthys lastoviza, Chelidonichthys lucerna, Trachinus draco, Scorpaena porcus, Scorpaena porcus, Pegusa lascaris, Platichthys flesus. From a total of 374 individuals examined plastics were found in 147 individuals (39%). The average plastic ingestion was 1.14 ± 1.03 MP. fish−1 (considering all the analysed fish) and 1.77 ± 0.95 MP. fish−1 (considering only the fish with plastic). Fibres were the primary plastic types found in GITs (74%), followed by films (18%) and fragments (7%), no foams and microbeads were found. A total of ten different colours of plastics were found with blue (62%) being the most common colour. Length of plastics ranged from 0.13 to 11.76 mm with an average of 1.82 ± 1.59 mm. A total of 95.5% of plastics were microplastics, and 4.5% as mesoplastics. The mean frequency of plastic occurrence was higher in pelagic fish species (42%), followed by demersal (38%) and bentho-pelagic species (10%). Fourier-transform infrared spectroscopy confirmed that 75% of polymers were synthetic with polyethylene terephthalate being the most common polymer. Our results indicated that carnivore species with a preference for fish and decapods were the highest impacted trophic group in the area. Fish species in the Gulf of İzmit are contaminated with plastics, representing a potential risk to ecosystem and human health. Further research is needed to understand the effects of plastic ingestion on biota and possible pathways. Results of this study also provide baseline data for the implementation of the Marine Strategy Framework Directive Descriptor 10 in the Sea of Marmara. [Display omitted] • Microplastics were found 39% of the 12 fish species. • Fibres were the main shapes of ingested plastics. • Most common polymers found in GITs was polyethylene terephthalate. • MPs ingestion were higher in carnivore species with a preference for fish and decapods. [ABSTRACT FROM AUTHOR]

The anaerobic oxidation of methane, a key geochemical process that is involved in the cycling of sulfate and iron (oxyhydr)oxides in marine sediments, results in the formation of iron sulfides. Although ferrimagnetic iron sulfides have been identified in seepage systems, the link between iron migration and sediment magnetic properties remains poorly understood. Here, we investigate two cores from the Sea of Marmara to evaluate biogeochemical iron cycling and iron sulfide mineralogy in gas hydrate-bearing sediments. Magnetic analyses indicate the presence of greigite and pyrrhotite in a core from a hydrate-rich site with a high hydrocarbon flux, which contrasts with a lack of these minerals in a core characterized by only mild seepage. This is supported by the results of rock magnetic and scanning electron microscope analyses of the sediments. The presence of authigenic greigite is critical for assessing local redox records and together with the occurrence of monoclinic pyrrhotite may suggest specific diagenetic processes in gas hydrate environments. Our analysis demonstrates the usefulness of these ferrimagnetic minerals, with a high saturation isothermal remanent magnetization to magnetic susceptibility ratio (SIRM/χ > 15 kAm−1) and a high index of hysteresis parameters (D JH > 0.2) indicative of magnetic mineralogy changes, for evaluating variability in the intensity of seepage fluxes and for estimating gas hydrate distributions. • Two sediment cores with a similar original terrigenous source have contrasting magnetic properties. • A reducing and strong flux environment caused iron-driven AOM and formation of authigenic magnetic minerals in the sediments. • Greigite and monoclinic pyrrhotite are identified as the major magnetic minerals formed in hydrate-bearing sediments. [ABSTRACT FROM AUTHOR]

In this study, new occurrence of two cryptobenthic goby species belonging to genus Chromogobius in the Sea of Marmara and Turkish coast of the Black Sea are reported. While Chromogobius zebratus (Kolombatovic 1891) is a new record for the Sea of Marmara and Turkish coast of the Black Sea, the other species C. quadrivittatus (Steindachner 1863) is the first record for Turkish coast of the Black Sea. Some morphological - ecological properties of these gobies were examined. Juvenile coloration of C. quadrivittatus and differences between adults and juveniles are also described for the first time in the present study. [ABSTRACT FROM AUTHOR]

Scaled 3D sandbox models have been used to investigate the 3D geometry and evolution of transtensional pull-apart basins. In this paper two representative analogue models were constructed to simulate the evolution of a 5° transtensional pull-apart basin formed above an underlapping, 45° strike-slip releasing bend basement stepover. Model 1 had 1:1 relative motion between opposing plates whereas Model 2 had 2:1 relative plate motion. In both experiments, a rhomboidal pull-apart basin developed with one central depocentre that was bounded by en-echelon basin margin faults. The early stages of basin evolution were characterised by basin subsidence and the nucleation of en-echelon normal faults. In the latter stages strike-slip occurred along the en-echelon normal faults, a cross-basin strike-slip fault formed and incremental basin subsidence decreased. Model 1 developed a symmetric basin whereas Model 2 developed a weakly asymmetric basin that had very active basin margin faults above the faster moving plate and a segmented cross-basin strike-slip fault system. The models were compared to the Cinarcik basin, Sea of Marmara. Both the analogue models and the natural prototype were characterised by basin margins bounded on one side by a simple, steeply-dipping normal fault and on the other side by an en-echelon array of steeply-dipping normal faults. The Model 1 showed similarities to the central and eastern part of the Cinarcik basin. [ABSTRACT FROM AUTHOR]

The current status of marine fishes distributed along the Turkish coasts is reviewed and an updated checklist including 512 species is presented. In this study, 5 species are recorded for the first time from Turkey (Lepidion lepidion (Risso, 1810); Bathophilus nigerrimus Giglioli, 1882; Gonostoma denudatum Rafinesque, 1810; Solea aegyptiaca Chabanaud, 1927; and Gobius roulei de Buen, 1928), while 7 species are new to the Turkish Aegean Sea coast (Notacanthus bonaparte Risso, 1840; Nettastoma melanurum Rafinesque, 1810; Apletodon dentatus (Facciolà, 1887); Apletodon incognitus Hofrichter & Patzner, 1997; Callionymus filamentosus Valenciennes, 1837; Cynoglossus sinusarabici (Chabanaud, 1931); Torquigener flavimaculosus Hardy & Randall, 1983) and 3 species are newly reported from the Levantine coast (Dysomma brevirostre (Facciolà, 1887); Apletodon dentatus (Facciolà, 1887); Zebrus zebrus (Risso, 1827)). [ABSTRACT FROM AUTHOR]

This recent checklist of marine arthropods found on the coasts of Turkey represents a total of 1531 species belonging to 7 classes: Malacostraca (766 species), Maxillopoda (437 species), Ostracoda (263 species), Pycnogonida (27 species), Arachnida (26 species), Branchiopoda (7 species), and Insecta (5 species). Seventy-five species were classified as alien species in the region. This paper also includes the first record of the amphipod Melita valesi from the Levantine coast of Turkey (Kaş, Gulf of Antalya). [ABSTRACT FROM AUTHOR]

Abstract: Sedimentary earthquake records of the last 2400a, including that of the devastating 17 August 1999 İzmit earthquake (Mw=7.4), were studied in cores from the 210m-deep central Karamürsel Basin of the İzmit Gulf in the eastern Sea of Marmara, using laser grain-size, physical properties, stable O and C isotopes and XRF Core Scanner analyses, and dated by radionuclide and radiocarbon methods. The earthquake records are represented by turbidite–homogenite mass-flow units (THU) that commonly contain a basal coarse layer, a middle laminated silt layer and an overlying homogeneous mud layer. The coarse basal part has a sharp and sometimes scoured lower boundary, and includes multiple coarse (sand/silt) layers or laminae showing normal size grading. Multiple coarse layers and occasional bi-directional cross-bedding suggest deposition from a bed-load during water column oscillations, or seiche effect. The grain-size characteristics of the overlaying laminated silt and the homogeneous mud units indicate deposition from weak oscillating currents and homogeneous suspension, respectively. High Mn value just below the base of THUs suggests diagenetic enrichment at oxic/anoxic redox boundary before the mass-flow event. Sharp decrease in Mn with very low values within the THUs suggests transient redox conditions following the mass-flow. Variable geochemical compositions of the basal coarse layers indicate different sediment sources for different THUs. Eight sedimentary earthquake records observed in the last 2400a in the İzmit Gulf can be confidently correlated with the historical earthquakes of 1999, 1509AD (Ms=7.2), 1296AD (I=VII), 865AD (I=VIII), 740AD (I=VIII), 268AD (I=VIII), 358AD (I=IX), and 427 BC. This gives an earthquake recurrence time of ca. 300a, with the interval between consecutive events ranging from 90 to 695a. [Copyright &y& Elsevier]

Abstract: A giant RV Marion Dufresne piston core MD01-2425 recovered from the 1276m-deep Çınarcık Basin of the Sea of Marmara documents characteristics of deep basin sedimentation influenced by large-scale gravity-controlled mass-wasting processes and associated turbidite deposition during the Late Pleistocene to Holocene. A visual lithological description of the core reveals twenty major seismoturbidite layers (>20cm thick), intercalated in hemipelagic-type fine-grained calcareous and slightly siliceous clays. The thickness and frequency of the sesimoturbidite layers deposited during the lacustrine period (prior to 12.3calka BP) is much greater than during the Holocene marine period. The sedimentary processes during deposition of seismoturbidites in the basin have been determined in this study using a combination of grain-size parameters. Often the seismoturbidites show strong grain segregation with a sharp boundary between a coarse lower and a homogeneous upper part. The traction carpet deposits formed at the base of a turbulent suspension and were produced in the lower coarse-grained part, whereas the homogeneous upper part was deposited by uniform suspensions following bedload deposition. [Copyright &y& Elsevier]

After the 1999 Izmit earthquake (Mw7.4), along the North-Anatolian Fault (NAF), an increase in gas emissions from the seafloor of the Sea of Marmara was observed. Using a multidisciplinary approach, that includes a combined analysis of high-resolution marine geophysical and gas-geochemical data, we determined the character of gas/fluid emissions and their spatial relationship with tectonic structures in the Darıca Basin (Gulf of Izmit), close to the western termination of the 1999 earthquake surface rupture. Data collected during several oceanographic expeditions allowed us to investigate the fine structure of active fault branches, as well as the geochemical signature of the cold seeps. We observed that gas emissions at the seafloor of the Darıca Basin are mostly constituted by biogenic CH4, and are aligned along strike-slip and transtensional fault segments. Although maximum CH4 concentrations were measured in correspondence of transtensional strands, we suggest that the biogenic CH4 emissions found along strike-slip segments, showing a relatively low gas background noise and a potential to increase during seismic events, are more suitable to study relationships between gas expulsion and the earthquake cycle. [ABSTRACT FROM AUTHOR]

Abstract: An overview is given of mass wasting features along the slopes of the Sea of Marmara, Turkey, based on new data and previously published information. The Sea of Marmara is characterized by active tectonics along the North Anatolian Fault and by eustatic sea level changes controlling the connections both to the Mediterranean and Black Sea (i.e. lacustrine and marine conditions during sea-level low and high stands, respectively). High resolution bathymetric data, subsurface echo-sounder and seismic reflection profiling, seafloor visual observations, as well as stratigraphic analysis of sediment cores have been used to identify, map and date submarine slope failures and mass wasting deposits. Gravity mass movements are widespread on the steep slopes of the Sea of Marmara, and range from small scale slope failures, mainly located within the canyons, to wider unstable areas (20 to 80km2). The largest mass wasting features, i.e. the Tuzla, Ganos and Yalova complexes, have been analyzed in connection with crustal deformation. These gravitational gliding masses are probably induced by the transtensional deformation within the crust. Moreover, age determination of landslides and debris flows indicate that they were more frequent during the last transgressive phase, when the rate of terrigenous sediments supplied by the canyons to the deep basin was higher. We discuss these results taking into account activity, pre-conditioning and trigger mechanisms for slope instability with respect to tectonics and paleo-environmental changes induced by sea-level oscillations. [Copyright &y& Elsevier]

During September 2008 and February 2009, the NR/V Alliance extensively sampled the waters of the Sea of Marmara within the framework of the Turkish Straits System (TSS) experiment coordinated by the NATO Undersea Research Centre. The observational effort provided an opportunity to set up realistic numerical experiments for modeling the observed variability of the Marmara Sea upper layer circulation at mesoscale resolution over the entire basin during the trial period, complementing relevant features and forcing factors revealed by numerical model results with information acquired from in situ and remote sensing datasets. Numerical model solutions from realistic runs using the Regional Ocean Modeling System (ROMS) produce a general circulation in the Sea of Marmara that is consistent with previous knowledge of the circulation drawn from past hydrographic measurements, with a westward meandering current associated with a recurrent large anticyclone. Additional idealized numerical experiments illuminate the role various dynamics play in determining the Sea of Marmara circulation and pycnocline structure. Both the wind curl and the strait flows are found to strongly influence the strength and location of the main mesoscale features. Large displacements of the pycnocline depth were observed during the sea trials. These displacements can be interpreted as storm-driven upwelling/downwelling dynamics associated with northeasterly winds; however, lateral advection associated with flow from the Straits also played a role in some displacements. [ABSTRACT FROM AUTHOR]

This paper deals with annelids (Oligochaeta and Polychaeta) collected in the Sea of Marmara between 2006 and 2010 at depths from 0 to 66 m. A total of five oligochaete and 198 polychaete species were found. Five polychaete species, namely Prosphaerosyllis marmarae sp. nov., Levinsenia demiri sp. nov., Levinsenia kosswigi sp. nov., Levinsenia marmarensis sp. nov. and Levinsenia tribranchiata sp. nov. are new to science, and five oligochaete and 84 polychaete species are new to the fauna of the Sea of Marmara. A list of species found in the region and their maximum densities are presented at depth intervals. The present material includes six alien polychaete species, Paraprionospio coora, Polydora cornuta, Prionospio (Minuspio) pulchra, Pseudopolydora paucibranchiata, Chaetozone corona and Metasychis gotoi, of which the latter four species were new records for the region. [ABSTRACT FROM AUTHOR]

The connection of Marmara Sea and Black Sea with global ocean and between themselves are established via the Çanakkale and Istanbul straits. Because of the shallow sill depths of these straits, these connections were interrupted in during the late glacial period (LGM). As a result of these important paleoceanographic events, Marmara and Black Seas experienced significant sedimentological, biological and chemical changes. Despite the high scientific interest and large number of previous studies, the timing and nature of the interruptions and reconnections of the two basins with each other and with the world ocean are still matters of debate. This debate has stemmed from mainly the following shortcomings of the previous studies: a) confinement of the study in one basin, b) selection of unsuitable core locations, and/or c) use of inadequate sampling resolution and proxies. To overcome these difficulties, we analyzed organic (Corg) and inorganic carbon (total carbonate:Tkarb) and determined sedimentation rates for the different climatic stages in four chronostratig-raphically well dated cores (two each) from the Black Sea and Sea of Marmara. As identified by the previous studies, three units are present in the Black Sea Cores GC-19 and SL-12 covering the period from the LGM to present. The uppermost unit is the Coccolith Unit that consists of microlaminated gray green mud containing alternations of coccolith-rich and clay-organic matter rich lamina. The unit started depositing when coccolit-hophore Emiliania huxleyi invaded the basin at 2720 a (calib.) BP and the present-day oceanographic conditions were established. The underlying unit is Sapropel Unit that consists of laminated dark gray mud with high (up to 21 wt %) Corg. The Lutit Unit deposited under lacustrine conditions that consists of gray clayey mud. The lake /marine transition is characterized by high total carbonate content (up to 80 wt %) in the Black Sea (C1 carbonate) and dated 9.3 ka (calib.) BP. The Sea of Marmara cores contain two lithostrati-graphic units deposited in the last 20 ka. The upper unit (Unit 1) is a green marine mud that includes a dark olive green Sapropel with more than 1.5 % Corg. The lower unit (Unit 2) is banded gray mud that was deposited under lacustrine conditions. The lacustrine / marine transition occurred 14.7 ka BP. Unit 2 includes a rhyodacitic ash layer that is defined as the Y-2 ash-layer of Santorini origin, dated 22 ka (calib.) BP. Sedimentological and geochemical (Corg and Tkarb) analysis, together with the changes in the sedimentation rates in the cores show that the Black Sea and Sea of Marmara were disconnected to each other during the LGM but connected during the post-glacial Heinrich 1 (H1, 17.9-16.5 ka BP), Red Clay Layer (RL; 16.2-14.8 ka BP) and Younger Dryas (YD, 12.9-11.9 ka BP) cold periods when large inputs of freshwater and sediment occurred to the Black Sea and Marmara basins by the west and northwest European rivers, leading to one-way connection between the two basins. In between the post-glacial cold periods during the early Holocene (11.9-9.3 ka BP) and Bølling-Allerød (14.8-12.9 ka BP), carbonate-rich C2 and C3 units, predominantly of calcite composition, were deposited with low sedimentation rates respectively. During these carbonate depositional periods relatively warm and dry conditions with low water levels prevailed in the Black Sea and the Sea of Marmara, and no connection existed between the two basins. Another carbonate depositional event, this time predominantly of aragonite composition, took place in the Sea of Marmara and the Black Sea as during the lake/marine transition. The carbonate beds are dated 14.5-12.9 ka BP in the Sea of Marmara and 8.6-7.6 ka BP in Black Sea (C1); the event in the Sea of Marmara partly overlapping with the Bolling/Allerod (B/A). The carbonate deposition in both the basins took place as a result of mixing of lacustrine and marine waters leading to carbonate overstaturation. Sapropels were deposited in the Black Sea and in the Sea of Marmara Sea during 11.5-7.0 and 7.8-2.7 ka BP, respectively, when the Mediterranean waters poured sequentially into the lacustrine Sea of Marmara and Black Sea. Arrival of marine waters pushed up the nutrient rich deep waters up into the photic zone, thereby initiating high primary productivity and lead to water stratification, preconditioning the basins for the sapropel formation. The sapropel de-position was interrupted in the Sea of Marmara during YD and 8.2 ka BP cold periods as a result of increased deep water ventilation. [ABSTRACT FROM AUTHOR]

The Mw 7.4, August 17, 1999 İzmit earthquake ruptured a ~100-km-long onshore section of the North Anatolian Fault (NAF) in the eastern Marmara region, causing the loss of more than 20,000 people and extensive destruction. The western termination and total length of the earthquake rupture is still a matter of debate because the surface rupture goes of shore in the Gulf of İzmit after displaying a coseismic displacement of ~5 m. Such a considerable slip implies that the fault rupture must definitely continue some distance westward on the sea floor, but where exactly it terminated is difficult to determine. h is issue is critical for determining the size of the Marmara seismic gap, south of Istanbul. Therefore, to explore the fault scarps associated with the 1999 rupture on the sea floor, we have studied ultra-high resolution bathymetry (0.5 m resolution) acquired with a remotely operated submersible during the MARMARASCARPS cruise, an innovative approach which proved to be useful in seeking earthquake surface deformation on the sea floor. The analysis of microbathymetry suggests that the 1999 İzmit earthquake rupture extended westward at least to 29.38°E longitude about 10 km west of the Hersek Delta in the Gulf of İzmit. It is clearly expressed as a sharp fault break with a 50 cm apparent throw across the bottom of a submarine canyon. Further west, a pronounced and linear fault rupture zone was observed, along with fresh enéchelon cumulative fault scarps. We infer that the seismic break continues westwards, reaching a total length of ~145 km at around 29.24°E longitude, consistent with the 1999 rupture deduced from SAR interferometry. It appears to stop at the entrance of the Çinarcik Basin where a normal faulting component prevails. We suggest that fault complexity at the junction between dominant strike-slip faulting along the Izmit fault and signii cant normal faulting in the Çinarcik Basin may act as a barrier to rupture propagation of large earthquakes. [ABSTRACT FROM AUTHOR]

Abstract: An extensive rescue excavation has been conducted in the ancient harbor of İstanbul (Yenikapı) by the Sea of Marmara, revealing a depositional sequence displaying clear evidence of transgression and coastal progradation during the Holocene. The basal layer of this sequence lies at 6m below the present sea level and contains remains of a Neolithic settlement known to have been present in the area, indicating that the sea level at ~8–9cal ka BP was lower than 6m below present. Sea level advanced to its maximum at ~6.8–7cal ka BP, drowning Lykos Stream and forming an inlet at its mouth. After ~3cal ka BP, coastal progradation became evident. Subsequent construction of the Byzantine Harbor (Theodosius; 4th century AD) created a restricted small basin and accumulation of fine-grained sediments. The sedimentation rate was increased due to coastal progradation and anthropogenic factors during the deposition of coarse-grained sediments at the upper parts of the sequence (7th–9th centuries AD). The harbor was probably abandoned after the 11th century AD by filling up with Lykos Stream detritus and continued seaward migration of the coastline. [Copyright &y& Elsevier]

The destructive earthquake that struck near the Gulf of Izmit along the North Anatolian fault in Northwest Turkey on August 17, 1999, not only generated a local tsunami that was destructive at Golcuk and other coastal cities in the eastern portion of the enclosed Sea of Marmara, but was also responsible for extensive damage from collateral hazards such as subsidence, landslides, ground liquefaction, soil amplifications, compaction and underwater slumping of unconsolidated sediments. This disaster brought attention in the need to identify in this highly populated region, local conditions that enhance earthquake intensities, tsunami run-up and other collateral disaster impacts. The focus of the present study is to illustrate briefly how standardized remote sensing techniques and GIS-methods can help detect areas that are potentially vulnerable, so that disaster mitigation strategies can be implemented more effectively. Apparently, local site conditions exacerbate earthquake intensities and collateral disaster destruction in the Marmara Sea region. However, using remote sensing data, the causal factors can be determined systematically. With proper evaluation of satellite imageries and digital topographic data, specific geomorphologic/topographic settings that enhance disaster impacts can be identified. With a systematic GIS approach - based on Digital Elevation Model (DEM) data - geomorphometric parameters that influence the local site conditions can be determined. Digital elevation data, such as SRTM (Shuttle Radar Topography Mission, with 90m spatial resolution) and ASTER-data with 30m resolution, interpolated up to 15 m) is readily available. Areas with thesteepest slopes can be identified from slope gradient maps. Areas with highest curvatures susceptible to landslides can be identified from curvature maps. Coastal areas below the 10 m elevation susceptible to tsunami inundation can be clearly delineated. Height level maps can also help locate topographic depressions, filled with recently formed sediments, which are often linked with higher groundwater tables. Such areas are particularly susceptible to higher earthquake intensities and damage. The sum of risk GIS factors increases the susceptibility of local soils in amplifying seismic ground motions. Areas most susceptible to higher earthquake impacts can be identified using a systematic GIS approach, the weighted-overlay method implemented in ArcGIS. Finally, the data obtained by remote sensing can be converted into Google Earth-kml-format and become available at no cost, to raise public disaster awareness and preparedness in the Sea of Marmara region. [ABSTRACT FROM AUTHOR]

We report on the recent captures of the bramble shark, Echinorhinus brucus, from the Sea of Marmara, Turkey. A short description is given. Based on available data, current status of the species in the Sea of Marmara is discussed. [ABSTRACT FROM AUTHOR]

Abstract: The reflection and refraction seismic data collected during the SEISMARMARA Leg 1 survey in the Sea of Marmara provide detailed imaging of sedimentary record and fault activity with deep penetration into its basement. First, a detailed analysis of pre-stack depth-migrated seismic lines crossing the Central Basin enable us to discuss the space and time relations of the large and smaller nested basins of the inner depression, as well as the diversity of style and rate of activity of motion at the diverse basin border faults. Second, forward modeling of OBS refraction arrival times reveals the effect of compaction on the sedimentary pile whereas its layering imaged by MCS as seismic reflectors rather recorded the tectonic evolution. Another major result of the refraction modeling is the identification of the crystalline basement. The latter is imaged about 1 or 2km deeper than the base of the layered sedimentary sequence imaged on the coincident MCS profiles. This basement exhibits sharp topography across the Central High, the Kumburgaz Basin and the eastern tip of the Cinarcik–North Imrali Basin in an unexpected way with respect to the sea-bottom depressions. We furthermore imaged several large tilted basement blocks, which separate the deep basins as between the Cinarcik and Imrali basins. Despite the varying width of the NMT and the sizes of the tilted blocks, we propose that the imaged finite deformation results from a similar process of partitioning deformation over more than one or even two faults across the NMT that may have changed activity with time and space. [Copyright &y& Elsevier]

The composition and abundance of phytoplankton and the corresponding environmental conditions were investigated during a mucilage event (October 2007-February 2008) in the Sea of Marmara. The mucilage producers Gonyaulax fragilis, Skeletonema costatum, and Cylindrotheca closterium were identified as abundant species. Thallassiosira rotula was also identified in large numbers. The maximum number of G. fragilis was observed at 83,600 cells L-1 in November 2007 during the first sampling occasion on the surface layer of Izmit Bay, and T. rotula was the most abundant diatom species, with 131,040 cells L-1 in the same period. G. fragilis was recorded at 96,250 cells L-1 in the dense mucilagecontaining water samples collected from Degirmendere (Izmit Bay) in January 2008, and C. closteriumwas the dominant (161,250 cells L-1) diatom species in the same sample. Species diversity values (H'log2) increased from November to February, displaying maximum values of 2.5-3.5 in February at almost all stations (depths of 0.5 and 10 m), caused by the balanced increase of diatom species and their individual numbers in the total phytoplankton abundance. The surface layer waters of Izmit Bay exhibited severely low nitrogen to phosphorus ratio (N:P) values (0.1-14.4) compared to the Redfield ratio (16), which could be supported by the fact that the limiting nutrient for the Sea of Marmara is nitrogen. Even though there is a lack of data from before the mucilage period, the data obtained during the lifespan of the event indicated that a mixture of several phytoplankton species might have played a key role in the mucilage formation. The high organic carbon content of the mucilage (24% org-C) and the surrounding waters support the possibility that the event could have been related to organically rich cellular exudates of phytoplankton. [ABSTRACT FROM AUTHOR]

Four species of copepod, Caligus bonito Wilson, 1905 (Caligidae), Clavellisa scombri Kurz, 1877 (Lernaeopodidae), Pandarus bicolor Leach, 1816 (Pandaridae) and Anchistrotos laqueus Leigh-Sharpe, 1935 (Bomolochidae) were reported from Coryphaena hippurus Linnaeus, 1758, Scomber scombrus Linnaeus, 1758, Mustelus mustelus Linnaeus, 1758 and Serranus hepatus Linnaeus, 1758. These parasites were recorded for the first time in the Aegean Sea and the Sea of Marmara. [ABSTRACT FROM AUTHOR]

The North Anatolian Fault crosses the Sea of Marmara from east to west. Tectonic features of the Sea of Marmara were studied using multi-channel deep seismic reflection data. The northern branch of the North Anatolian Fault is active as a right lateral strike-slip fault zone and indicates both negative and positive flower structures. The North Anatolian Fault splays into two faults at the Sea of Marmara as a northern branch and north segment of the southern branch. The northern branch named the Main Marmara Fault extends in a complicated manner from the north of the Kapıdağı Peninsula to westward in the Sea of Marmara. The north segment of southern branch extends between the Gemlik and Bandırma gulfs in the south of the Sea of Marmara. In addition, uplift areas arose by compression and a push-up style in between the Kapıdağı Peninsula and the Main Marmara Fault. The North Anatolian Fault is characterized by a negative flower structure in basins and push-up style in uplift areas in the Sea of Marmara. An uplift area arose between the north segment of the southern branch and the northern branch of the North Anatolian Fault. The north segment of the southern branch of the North Anatolian Fault is a strike-slip fault and displays a pull-apart style in the seismic reflection data. [ABSTRACT FROM AUTHOR]

Istanbul is the most important city of Turkey in the view of economical, social and cultural aspects. Because of the active faults in the Sea of Marmara, there is always an expectation of an important earthquake that will be harmful for the city and also for the other big cities that are located around the Sea of Marmara such as Bursa, İzmit, Tekirdağ and Yalova. In addition to the earthquake, a tsunami which occurs in the Sea of Marmara can also be a very destructive hazard for Istanbul and other cities around the Sea of Marmara. There are many tsunamis that happened in the Sea of Marmara in the history. The main reason of these tsunamis is the slumps and the landslides that were triggered by an earthquake. One of the most important reasons of the tsunamis on the earth is the submarine landslides. Movement at the sea bottom stirs the above water mass. This causes tsunami waves and these waves damage the coastal areas seriously. The aim of this study is to find the maximum wave heights of possible tsunamis around Tuzla coasts using different scenarios. A submarine landslide that may be occurred after an earthquake or because of any other reason in the Sea of Marmara at the region near to northeast Marmara coasts is taken as the reason of the tsunami in the simulations that are performed in the study. As the solution method, one hybrid method was developed. The main objective of this method is to combine an analytical solution presenting near-field tsunami amplitudes above the submarine mass failure with a numerical solution indicating the tsunami amplitudes in the coastal regions. An analytical model that is frequently used in the literature was applied to find the amplitudes of tsunami waves at the surface of Sea of Marmara above the submarine landslide region. These tsunami waves will be directly affected from the water depth of the Sea of Marmara. It will be also affected by the shore profile when traveling to the coasts. Because of this reason, a computational fluid dynamics model which is based on finite elements method is used in the regions that are very close to the coasts. The model solves the Navier-Stokes equations. Analytical and numerical models were used together in this study. The analytical model is used from the submarine up to sea surface and the numerical model is used for modeling of the movement of the tsunami waves at the sea surfaces. In the border of two models the outputs of analytical model is used as the inputs of numerical model that means the initial and boundary conditions of numerical model is obtained from the analytical model.… [ABSTRACT FROM AUTHOR]

Abstract: The sedimentary sequence discovered at archaeological excavations in ancient Theodosius Harbour at İstanbul contains the records of sea level, environmental changes and the cultural history of the region. The cobbles at the base of the sequence include archaeological remnants of Neolithic culture that settled in the area between 8.4 and 7.3 14C ka BP, and are located at 6 m below the present sea level. The sediments representing a coastal environment indicate that the area was used as a harbour from AD 4th to at least the 11th century and were filled by the sediments derived from Lykos Stream after 11th century. [Copyright &y& Elsevier]

Rose shrimp is one of the important commercial shrimp species in the Marmara Sea. Data from the coastline between Silivri/Istanbul and Tekirdağ during 1987-1988 are presented in this paper. Sampling was performed with shrimp beam trawling. Catch composition and stocks were investigated. In 1987 the carapax length varied between 85 mm and 346 mm. Maximum length class was 186 mm. In 1988 the carapax length varied between 85mm and 306 mm. The maximum length class was 126 mm. As by-catch, 24 fish species and 20 invertebrate species were caught. [ABSTRACT FROM AUTHOR]

Abstract: Chirp sub-bottom profiling, multibeam bathymetric mapping and a combination of faunal and isotopic analysis of molluscs and foraminifera in sediment cores on the northern shelf of the Sea of Marmara (SoM) provide evidence of sea-level excursions, water exchanges between the adjacent Mediterranean and Black Seas, and oscillating salinity over the last 160ka bp. During the marine isotope stages MIS-2, MIS-3, MIS-4 and MIS-6 the SoM disconnected from the Mediterranean Sea and evolved into a lake. During MIS-1, MIS-5 and MIS-7, the SoM reconnected and became salty once again. Sapropels formed shortly after each invasion of Mediterranean saltwater observed in our cores. Concurrent suboxic–dysoxic conditions prevailed over quite shallow substrates on the shelf. Ancient shorelines are pervasive at −85m on the northern shelf and in the region of Prince Islands coincident with the elevation of the modern bedrock sill in the Çanakkale (Dardanelles) Strait. At times when global (eustatic) sea level dropped below this sill, the surface of the SoM stabilized at its outlet and freshened. Thus this particular shoreline is interpreted as the edge of the most recent SoM lake that existed from about 75ka bp to 12ka bp. The freshening is observed in very light (−6‰) values of δ 18O measured on freshwater molluscs and the complete absence of foraminifera. Two brief lacustrine episodes during MIS-5 suggest that the level of the Çanakkale outlet might have been as shallow as −50m in the past, a likelihood supported by submerged terraces along its margins bounding the modern central channel and the presence of an euryhaline biofacies in Unit L4.1 corresponding to MIS-5b. δ 18O profiles and carbon-14 dating show that salinification of the SoM and the blossoming of bioherms evolved rapidly after the latest connection with the Mediterranean at 12ka bp. However, freshening proceeded more slowly once the connection was severed. [Copyright &y& Elsevier]

Abstract: In this paper the aim is to investigate whether there are differences between the dispersion and non-dispersion solutions on tsunami propagation. For this purpose, two numerical models of tsunami propagation are compared. One of these numerical models is a nondispersive model that uses Saint Venant equations and the other is a dispersive model that uses Boussinesq equations. The tsunamis resulting from a submarine mass failure (SMF) which is settled at the bottom of the north eastern Sea of Marmara are examined. An analytical solution considering wave dispersion is developed for obtaining near-field tsunami amplitudes above the submarine mass failure. Numerical modeling is used at the sea surface from the common boundary called as liquid boundary with incident waves up to the coastal regions to get the tsunami amplitudes. The output of the analytical model is taken as the disturbances for the numerical method. In the numerical solutions TELEMAC-2D software system is used for both dispersive and nondispersive modeling. The results of the dispersive and nondispersive models are compared to each other. Both temporal and spatial differences in the amplitudes and wave shapes are examined. The obtained results demonstrate that there are no noticeable differences between the dispersion and non-dispersion solutions except some special cases and some special landslide velocities. [Copyright &y& Elsevier]

Abstract: Gas hydrates and gas bubbles were collected during the MARNAUT cruise (May–June 2007) in the Sea of Marmara along the North Anatolian Fault system, Turkey. Gas hydrates were sampled in the western part of the Sea of Marmara (on the Western High), and three gas-bubble samples were recovered on the Western High, the Central High (center part of the Sea of Marmara) and in the Çinarcik Basin (eastern part of the Sea of Marmara). Methane is the major component of hydrates (66.1%), but heavier gases such as C2, C3, and i-C4 are also present in relatively high concentration. The methane contained within gas hydrate is clearly thermogenic as evidenced by a low C1/C2 +C3 ratio of 3.3, and carbon and hydrogen isotopic data (δ 13CCH4 of −44.1‰ PDB and δDCH4 of −219‰ SMOW). A similar signature is found for the associated gas bubbles (C1/C2 +C3 ratio of 24.4, δ 13CCH4 of −44.4‰ PDB) which have the same composition as natural gas from K. Marmara-af field. Gas bubbles from Central High show also a thermogenic origin as evidenced by a C1/C2 +C3 ratio of 137, and carbon and hydrogen isotopic data (δ 13CCH4 of −44.4‰ PDB and δDCH4 of −210‰ SMOW), whereas those from the Çinarcik Basin have a primarily microbial origin (C1/C2 +C3 ratio of 16,600, δ 13CCH4 of −64.1‰ PDB). UV-Raman spectroscopy reveals structure II for gas hydrates, with CH4 trapped in the small (512) and large (51264) cages, and with C2H6, C3H8 and i-C4H10 trapped in the large cages. Hydrate composition is in good agreement with equilibrium calculations, which confirm the genetic link between the gas hydrate and gas bubbles at Western High and the K.Marmara-af offshore gas field located north of the Western High. We calculate the characteristics of the hydrate stability zone at Western High and in the Çinarcik Basin using the CSM-GEM computer program. The base of the structure II hydrate stability field is at about 100 m depth below the seafloor at the Western High site, whereas in the Çinarcik Basin, P–T conditions at the seafloor correspond to the uppermost range for structure I hydrate formation from microbial gas. [Copyright &y& Elsevier]

Abstract: We investigated Gemlik Bay of the Marmara Sea with an extensive high-resolution shallow seismic survey to locate and map active traces of the southern strand of the North Anatolian Fault (NAF). The southern strand splits from the main trace of the North Anatolian Fault about 80 km southeast of İzmit and extends as a continuous trace to the west for about 140 km to Gemlik Bay where it enters the Sea of Marmara. The seismic profiles reveal many faults that offset the Quaternary deposits. We interpret that four major fault zones play a significant role in shaping Gemlik Bay, the Gemlik, Kocadere–Mudanya, Gençali and Armutlu Faults, and propose that these faults are responsible for the formation of two prominent morphological features in the bay, namely Burgaz Depression and Gemlik Rise which are a pull-apart basin and a push-up structure, respectively. Closely spaced profiles to interpret the fault patterns and complex kinematics, therefore, are shown to be necessary in such areas. Besides active fault traces along the profiles, we also observed mass movements along the southern shore, offshore Mudanya–Zeytinbağı and Kurşunlu in the study area. Although no destructive earthquakes were experienced in the region recently the mass movements observed on the seafloor indicate remarkable past activity along the southern strand of the North Anatolian Fault which is overshadowed by the northern strand in 20th century from seismicity point of view. [Copyright &y& Elsevier]