Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 9

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  Marmara Sea
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
In this study, monthly heavy metal concentrations in the whole-body tissue of Patella caerulea (Mediterranean limpets), a bioindicator species living in the coastal zone of the Gulf of Izmit (Marmara Sea), were examined for the first time. The mean metal concentrations in Patella caerulea (mg kg−1 dw) were 2.01–5.74 Cd, 2.45–12.90 Cu, 0.74–1.95 Pb, 21.12–109.57 Zn, 16.31–154.67 Ni, and 1120.67–3086.00 Fe. Cd levels in all months and Pb levels in October and November were found to be above the safe limits set by international organizations. The estimated daily intakes and estimated weekly intakes determined for each heavy metal were below the acceptable daily intakes and provisional tolerable weekly intakes. However, the target hazard quotient and total target hazard quotient values calculated for Cd, Ni, and Fe were found to be higher than 1. The carcinogenic risk value was also found to be high.
EN
It is becoming increasingly important to monitor zoobenthic biodiversity in seas that are under industrial and anthropogenic pollution pressure, such as the Black Sea and the Marmara Sea. This study covers crustacean species in the Turkish waters of the Black Sea and the Marmara Sea, both of which are closed systems. Sampling was carried out in July–August 2019 and yielded 32 crustacean species from the Black Sea and 77 species from the Marmara Sea. In the Marmara Sea, two species [Kupellonura mediterranea and Leucon (Macrauloleucon) siphonatus] represent new records for the Turkish waters, and 12 species [Cirolana cranchii, Cumella (Cumella) pygmaea, Cyathura carinata, Cymodoce truncata, Eurydice pulchra, Gammaropsis sophiae, Harpinia truncata, Iphinoe serrata, Iphinoe trispinosa, Liocarcinus pusillus, Nebalia strausi and Synchelidium maculatum] are new to the Marmara Sea. The following species: Gammaropsis palmata, Pontocrates arenarius, and Synchelidium haplocheles are new records for the Black Sea. The order Amphipoda dominated in both seas in terms of the number of species and the number of individuals.
EN
The aim of this study is to determine the optimum location for an oil spill response center in the Marmara Sea. The analytic hierarchy process (AHP) and technique for the order of preference by similarity to ideal solution (TOPSIS) method as the most preferred multi-criteria decision-making (MCDM) technique were used. The results reveal that the LOC criterion and PRA sub-criterion have the highest effects on the optimal location selection of the oil spill response center. According to the results, the most suitable location for the oil spill response center in the region is Izmit Bay Entrance. This location has been proposed for the response headquarters to manage the whole operation with the assistance of auxiliary installations in the area. In this study, only technical and operational variables are taken into account, but political and administrative criteria are excluded.
EN
The benthopelagic oilfish Ruvettus pretiosus Cocco, 1833 was recorded for the first time from the Marmara Sea coast in Turkey. In addition, this is the third record of the species from the Turkish sea waters.
EN
Although marine research on anthozoans began at the end of the 1800s with some reports on the occurrence in Turkey, comprehensive knowledge about their biotic features remains limited. This study is the first detailed diversity assessment of scleractinian corals inhabiting the Turkish waters. The surveys conducted on rocky habitats between 2011 and 2014 around the Dardanelles and Marmara Sea provided the distributional data of nine corals, five of which (Caryophyllia inornata, Paracyathus pulchellus, Polycyathus muellerae, Phyllangia mouchezii, Leptopsammia pruvoti) were recorded for the first time from the above- mentioned regions. During the surveys carried out at 200 stations down to 50 m depth, a total of 1072 scuba dives were made and the ecological features of habitats, physical characteristics of coral species and an updated list of corals as a contribution to the scleractinian fauna of Turkey were provided. The abundance rate of Polycyathus muellerae and Cladocora caespitosa in Eceabat and Dardanos regions was higher than at the other stations.
EN
High-resolution seismic survey was conducted to investigate acoustic characteristics of gassy sediments along the southern shelf of the Sea of Marmara. The acoustic turbidity zones outlined within the study area are generally below 2-9 m (2-10 ms TWT) the seafloor whilst this vertical distance varies between 9 and 21 m (10-25 ms TWT) for acoustic blanket type reflections. The gassy sediments cover an area of sea floor of about 45, 110, and 75 km2 in front of Gönen River, Kocasu River, and Gemlik Bay, respectively. The gassy sediments in the center of Gemlik Bay exhibited an elliptical geometry similar to its basin while the others have deltaic forms in front of the rivers. The sea bottom and near surface sedimentary units are made-up of organic-rich sediments, mostly transported by the southern rivers. The gas observed in sediments is thought to be of biogenic origin, which may be caused by degradation of organic matter in the sediment.
EN
This study includes new records of soft corals found in the Turkish Straits System (Dardanelles) between 2013-2014. In the above-mentioned area, 50 stations were searched by scientific divers from the intertidal zone to a depth of over 45 m and the ecological characteristics with substrate differences were also recorded. A total of 47 cnidarians were examined during the surveys. Eleven anthozoan species (Aiptasia mutabilis, Alcyonium acaule, Andresia parthenopea, Calliactis parasitica, Cereus pedunculatus, Condylactis aurantiaca, Epizoanthus couchii, Maasella edwardsi, Pteroeides spinosum, Sarcodictyon roseum, Veretillum cynomorium) belonging to 4 orders are new to the Dardanelles strait, one of which is reported from the Marmara Sea. The current data contributed to the advancement of the knowledge about anthozoan species in the Turkish Seas.
EN
The aim of this study was to determine the environmental factors affecting the fauna and the distribution of benthic amphipod species occurring on the Kapıdağ Peninsula, which is located in the south of the Marmara Sea. A total of 31 amphipod species were identified during the course of this study. In both seasons, Jassa marmorata (Holmes, 1905) and Protohyale schmidtii (Heller, 1866) were the most abundant species. During the study, temperature varied between 11.0 and 17.8°C, while salinity varied between 12.5 and 18.7 PSU; values of dissolved oxygen and pH ranged from 7.2 to 11.4 mg l-1 and 7.2 to 8.5 respectively at the coastal sites where hard bottom sampling was conducted. However, with regard to other sites where soft bottom sampling was carried out, the temperature varied between 8.0 and 18.0°C, salinity between 17.7 and 29.2 PSU, while values for dissolved oxygen and pH ranged from 5.1 to 11.4 mg l-1 and 7.8 to 8.7, respectively. In addition, the study of the amphipod species distribution revealed that the number of species was higher in spring compared to autumn while the number of individuals was higher in autumn compared to spring.
EN
Benthic foraminifera (total assemblages) were studied from 30 sea-floor samples collected along a bathymetric transect on the southern shelf of the Marmara Sea from depths of 15–350 m. At each station, Kaiho’s Benthic Foraminiferal Oxygen Index (BFOI) was calculated based on species abundances using the methods outlined by Kaiho (1994). The calculated BFOI values were converted to analogue oxygen values, and calibrated to the dissolved oxygen values measured 1 m above the sea floor at each station. In the surface waters and central part of the Marmara Shelf transect, the BFOI values reproduce the measured dissolved oxygen values with a remarkable degree of accuracy. Beneath the pycnocline at depths of 30 to 75 m, the BFOI underestimated the measured oxygen values. This discrepancy is attributed to seasonally higher summer oxygen values within the chlorophyll maximum, corresponding to the position of the Mediterranean Inflow Water (MIW) present during summer. In the deeper part of the transect (below 140 m), BFOI values overestimated the measured oxygen values. This discrepancy is attributed to the presence of denser MIW that cascades down the submarine canyon beneath the Marmara ship channel during winter, ventilating the deep Marmara Sea. The BFOI accurately points out the seasonal differences in the position and depth of the MIW in the southwestern Marmara Sea. The BFOI likely reflects the longer-term oxygen values averaged over the span of many years.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.