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    A Study on Diet Composition and Feeding Habits of Sphyraena putnamae Jordan & Seale, 1905 from the Northern Arabian Sea
    (Central Fisheries Research Inst, 2025) Zohra, Kashifa; Yousuf, Farzana; Ahmed, Quratulan; Ali, Qadeer Mohammad; Bilgin, Sabri; Bat, Levent
    The food and feeding habits of the Sphyraena putnamae (n=381) ranging from 16 to 99 cm were investigated the Karachi coast, the Northern Arabian Sea, Pakistan. S. putnamae consumed various prey items, which were divided into three categories: teleosts, molluscs, and crustaceans. Molluscs and crustaceans were the second preferred food component rather than teleost. The major constituents of the teleost group on basis of their ascendancy, were identified to be (dorosomatids; sciaenids; leiognathids; platycephalids; engraulids; carangids; bregmacerotids; nemipterids; scombrids; and synodontids). The empty stomach ratio and stomach fullness index did not differ significantly between the sexes and size classes. The stomach fullness index of juvenile barracudas (16-29 cm in length) was significantly higher as compared to adults in the medium (30-55 cm) and large (56-99 cm) size groups. Additionally, an analysis of dietary preferences revealed that small (juvenile) barracudas (16-29 cm) primarily consumed crustaceans, while medium-sized individuals (30-55 cm) preferred mollusks, and large individuals (56-99 cm) favoured teleost. The present study provides detailed information on the feeding ecology of the S. putnamae, for the first time from the Pakistan coast that will be useful for understanding trophodynamics of species developing effective management and conservation measures, ensuring the species' long-term viability.
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    A study on recent variations in the population structure of European anchovy (Engraulis encrasicolus L. 1758) in the Southern Black Sea
    (Ege Üniversitesi Su Ürünleri Dergisi, 2006) Samsun, Osman; Samsun, Necati; Kalaycı, Ferhat; Bilgin, Sabri
    This research was carried out to estimate variation of stock structure anchovy ( Engraulis encrasicolus , L . 1758) (N=7487) of the in Sinop Turkish coast in the southern of the Black Sea between 2000 and 2003. The mean sex ratio was 59 % (female): 41 % (male). The b constant of weight-length relationships were 2.7101, 3.0568, 2.8946 and 2.8695 for 2000-2001, 2001-2002, 2002- 2003, and 2000-2003 fishing seasons, respectively. The result showed that fish were 0-3 years old. The von Bertalanffy growth parameter value of L ? (cm) were 16.84 cm, 18.46 cm, 18.73 cm and 18.91 cm for fishing seasons, respectively. Total (Z), natural (M), fishing (F) mortality rates and exploitation rate (E) were Z=2.07 year -1 , M=0.30 year -1 , F=1.77 year -1 , E=0.86, respectively for overall samples.
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    About the record of the black-bellied angler, Lophius budegassa Spinola, 1807, from Sinop coast in the Black Sea, Turkey
    (Cahiers De Biologie Marine, 2016) Sumer, Cetin; Bilgin, Sabri; Bektas, Serdar; Satilmis, Hasan Huseyin
    One specimen of the black-bellied angler, Lophius budegassa Spinola, 1807, was caught off Sinop (Black Sea, Turkey) on 8 February 2015 by turbot bottom set net. The specimen weighed 1926.6 g and measured 42.2 cm standard length (SL) and 51.8 cm total length (TL). The specimen sexed as a maturing male with a testicular development stage II. This work has undoubtedly enhanced our knowledge on the recent introduction of the black-bellied angler in the Black Sea.
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    Common dolphin, Delphinus delphis (Cetacean: Dolphinidae) stranding off sinop peninsula in the black sea
    (Centenary University, 2018) Duyar, Hünkar Avni; Bilgin, Sabri
    The present study summarizes information on the stranding common dolphin, Delphinus delphis, off the Sinop peninsula and also describes information on the weight-length relationships of the common dolphin in the center Black Sea, Turkey for the first time. During the research period, a total of 10 D. delphis were examined as stranding off Sinop Peninsula. It was determined that a lot of water birds species (Great cormorant) were seen as died on the sea coast during the dolphin survey. The death reasons of the common dolphin were drowned after the catching the nets and it is also suspected that death reason of common dolphins is water pollution. The length weight relationship (WLRs) of D. delphis determined as Log (W) = 2.2898 L-2.6501, r2 = 0.9959 (n = 7). It is important that standing levels of Cetaceans living in the Black Sea in terms of protection efforts. It is also important to investigate the causes of death. Focusing on these topics in subsequent studies will be important for the protection of endangered (Phocoena phocoena and Tursiops truncatus) and vulnerable (D. delphis) cetaceans in the Black Sea. © 2018, Centenary University. All rights reserved.
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    Comparison of electronic length frequency analysis (ELEFAN) for estimation of growth parameters for lollyfish, Holothuria (Holothuria) atra and sand sea cucumber, Holothuria (Thymiosycia) arenicola (Holothuroidea: Echinodermata) in the north Arabian Sea, Pakistan
    (2020) Ahmed, Quratulan; Bilgin, Sabri; Alı, Qadeer Mohammad
    To estimate the growth parameters, the non-seasonal von Bertalanffy and Hoenig seasonal von Bertalanffy models were fitted to the length frequency data of Holothuria atra and H. arenicola obtained from coastal areas of Karachi in the northern Arabian Sea, Pakistan between January and December 2014. The Hoenig seasonal von Bertalanffy growth parameters were estimated as L∞=36.1 cm total length (TL), K=0.75 year-1 for H. atra and as L∞=34.9 cm TL, K=0.70 year-1 for H. arenicola. H. atra individuals reached 73.9% of their maximum total length at the one year old. For H. arenicola it was calculated as 72.7%. Monthly mean growth rate of H. atra at the same ages was calculated higher than H. arenicola. The seasonal oscillation in growth rate for H. atra (C=0.50) was larger than it was for H. arenicola (C=0.37). The time of the year when the growth is slowest corresponded to the middle of April (WP=0.30) in H. atra and at the beginning of August (WP=0.60) in H. arenicola may be the result of the extended both reproduction and poor nutrition periods due to monsoonal effects on the marine environment. The relatively high growth rates (K>0.7 year-1) of these two species may have important implications for high survival rate, particularly in environmental condition where cause biological stress and marine confusion but may also increase their potential as a candidate species for aquaculture.
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    Decade of microplastic alteration in the southeastern black sea: An example of seahorse gastrointestinal tracts
    (Academic Press Inc Elsevier Science, 2023) Onay, Hatice; Minaz, Mert; Ak, Kubra; Er, Akif; Emanet, Muammet; Karsli, Baris; Bilgin, Sabri
    Unconscious and excessive use of plastic supports the diversity and abundance of microplastics (MPs) in marine environments. As a result of MP exposure, organisms in the marine environment are faced with adverse scenarios up to death. In this study, ten-year MP composition was investigated in gastrointestinal tracts (GITs) of low-mobility seahorses (90 individuals per period) from the Southeastern Black Sea. Seahorse GITs sampled during both 2012 and 2022 contain 102 and 135 MP items, respectively. The number of MPs per unit individual seahorse and unit seahorse weight was higher in the 2022 period. On the other hands, no significant differences were observed between the MP lengths of both periods. The majority of MPs in both sample periods were materials shorter than 1000 mu m. Of the eight found synthetic polymers, five belonged to the 2012 period, while seven were observed during the 2022 period. Additionally, the most abundant synthetic polymer for both periods is polyvinyl stearate (PVS). As a result, 43% of the total plastic material belonged to the 2012 period, while 57% was observed in the 2022 period. Considering both the diversity of polymers and the abundance of plastics, the region was adversely affected by plastic materials in the 2022 period.
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    Derleme: Karadeniz Faunasindaki Yabanci Yengeçlerle Birlikte Yengeç (Crustacea: Decapoda: Brachyura) Türlerinin Güncel Listesi
    (Bülent VEREP, 2019) Bilgin, Sabri
    ÖzetKaradeniz'de günümüze kadaryapilan çalismalarda, 7 üst familya (Eriphioidea, Grapsoidea, Majoidea,Parthenopoidea, Pilumnoidea, Portunoidea ve Xanthoidea) ve 12 familya'ya ait(Eriphiidae 1 tür, Grapsidae 1 tür,Varunidae 3 tür, Inachidae 3 tür, Parthenopidae 1 tür, Pilumnidae 2 tür,Portunidae 1 tür, Carcinidae 2 tür, Polybiidae 4 tür, Pirimelidae 2 tür,Panopeidae 2 tür ve Xanthidae 1 tür) 23 yengeç türü tespit edilmistir. 23türden dördü (Callinectes sapidus,Rhithropanopeus harrisii, Eriocheir sinensis, Hemigrapsus sanguineus ve Dyspanopeussayi) Karadeniz faunasi için yabanciyengen türleridir. Yengeç türlerinin güncel isimleri Dünya Deniz TürleriKayitlari (WoRMS 2019) esas alinarak gözden geçirilmistir. Buna göre Liocarcinus navigator (Leach, 1814) türününgenus ve tür ismi degiserek Polybius vernalis(Risso, 1827) olarak, Liocarcinusnavigator (Leach, 1814) türünün genus ismi degiserek Polybius navigator (Herbst, 1794) olarak, Macropodia aegyptia (Milne Edwards, 1834) türünün tür ismi ise M. czernjawskii (Brandt, 1880) olarakdegismistir.
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    Derleme: Karadeniz Faunasındaki Eksotik Yengeç Türleri (Crustacea: Decapoda: Brachyura) ve Güncel Fauna
    (2019) Bilgin, Sabri
    Karadeniz'de günümüze kadar yapılan çalışmalarda, 7 üst familya (Eriphioidea, Grapsoidea, Majoidea, Parthenopoidea,Pilumnoidea, Portunoidea ve Xanthoidea) ve 12 familya'ya ait (Eriphiidae 1 tür, Grapsidae 1 tür, Varunidae 3 tür, Inachidae 3 tür, Parthenopidae1 tür, Pilumnidae 2 tür, Portunidae 1 tür, Carcinidae 2 tür, Polybiidae 4 tür, Pirimelidae 2 tür, Panopeidae 2 tür ve Xanthidae 1 tür) 23 yengeçtürü tespit edilmiştir. 23 türden dördü (Callinectes sapidus (Rathbun, 1896), Rhithropanopeus harrisii (Gould, 1841), Eriocheir sinensis (MilneEdwards, 1853), Hemigrapsus sanguineus (de Haan, 1835) ve Dyspanopeus sayi (Smith, 1869)) Karadeniz faunası için eksotik türlerdir.Liocarcinus vernalis (Risso, 1816)'in genus ismi Polybius vernalis (Risso, 1827) olarak, Liocarcinus navigator (Risso, 1816)’ün genüs ismiPolybius navigator (Herbst, 1794) olarak, Macropodia aegyptia (Milne Edwards, 1834)’nın tür ismi ise M. czernjawskii (Brandt, 1880) olarakdeğişmiştir.
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    Effect of Garlic (Allium sativum L.) on the Microbiological, Chemical and Sensorial Quality of Smoked Atlantic Mackerel (Scomber scombrus Linnaeus, 1758) Stored in Vacuumed Packets at Refrigerator Temperature (+4°C)
    (Adem Yavuz Sonmez, 2019) Duyar, Hunkar Avni; Kalayci, Zafer Hakan; Bilgin, Sabri
    In this study, the effect of garlic (Allium sativum L.) on the microbiological, chemical and sensorial quality of smoked Atlantic Mackerel (Scomber scombrus Linnaeus, 1758) stored in vacuumed packets at refrigerator temperature (+4 degrees C) were investigated. The results of total volatile basic nitrogen (TVB - N) in control group (without garlic contains 10% salt) showed that the product reached the limit of consumable value on the 43rd day (TVB - N = 36.45 +/- 1.133 mg / 100 g) and on the 67th day in the garlic group (with 2% garlic contains 10% salt) (TVB - N = 35.69 +/- 1.026 mg / 100 g) (P < 0.05). It was observed that garlic group values were higher than control group in terms of sensory analysis (texture, appearance, odour and taste). However, it was determined that the value of taste did not fall below the consumable value in both groups. These results showed that the shelf life of smoked Atlantic Mackerel was 24 days longer with garlic application and the garlic supplement increased both the shelf life of the product and gave sensory appreciation to the product.
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    External Morphology and Weight - Length Relationships (WLRs) of Harbour Porpoise, Phocoena phocoena (Cetacea: Phocoenidae) in the Black Sea
    (Central Fisheries Research Inst, 2020) Bilgin, Sabri; Kose, Ozay; Yesilcicek, Tuncay
    The present study summarized information on the morphometric characteristics and weight-length relationships (WLRs) of pregnant females, non-pregnant females and males of harbour porpoise, Phocoena phocoena (Linnaeus, 1758) along the Rize coast in the Black Sea, Turkey. A total of 68 harbour porpoises (31 males, 22 non-pregnant females and 15 pregnant females) were obtained as bycatch in the turbot gill net fisheries from April 2010 to July 2011. A total of 16 external morphological characteristics of the harbour porpoises were examined by Principal Component Analysis (PCA). The PCA results clearly showed that there is sexual dimorphism mainly in the general size between non-pregnant females and males and also pregnant females and males. The greatest body length in the sample was 142.0 cm for females and 128.0 cm for males. Weight-length relationships (WLRs) of harbour porpoise showed negative allometric growth characteristics (Pauly' t test, P<0.05). The slopes of the regression lines for males, non-pregnant females and pregnant females were significantly different from the isometric growth curve slope of 3 (Pauly' t test, P<0.001). Correlation coefficient (r) was significant for both sexes (P<0.05). These results will enable researchers, fishermen and fisheries management authorities to enhance the knowledge of harbour porpoises life history and ecology.
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    Fecundity and egg size of three shrimp species, Crangon crangon, Palaemon adspersus and Palaemon elegans (Crustacea: Decapoda: Caridea), off Sinop Peninsula (Turkey) in the Black Sea
    (Turkish Journal of Zoology, 2006) Bilgin, Sabri; Samsun, Osman
    The fecundity and egg size of 3 shrimp species, Crangon crangon , Palaemon adspersus , and Palaemon elegans , were studied off Sinop Peninsula in the Black Sea. Shrimps were sampled by beam trawl with a beam length of 3 m and 10 mm codend mesh size. Mean fecundity of C. crangon females was 2297 ± 134 (range: 910-3630). Mean egg size (shortest x longest axis) at early and late embryonic development stages was 0.472 ± 0.005 mm x 0.509 ± 0.008 mm and 0.489 ± 0.003 mm x 0.627 ± 0.004 mm, respectively. Mean fecundity of female P. adspersus was 1963 ± 144 (range: 758-3710). Mean egg size (shortest x longest axis) at early and late embryonic development stages was 0.585 ± 0.005 mm x 0.739 ± 0.011 mm and 0.622 ± 0.005 mm x 0.851 ± 0.008 mm, respectively. Mean fecundity of female P. elegans was 1057 ± 88 (range: 308-2628). Mean egg size (shortest x longest axis) at early and late embryonic development stages was 0.455 ± 0.005 mm x 0.567 ± 0.007 mm and 0.479 ± 0.008 mm x 0.707 ± 0.007 mm, respectively. Fecundity of all species was positively correlated to the size of the individuals. Egg size for each species increased with increased embryonic development stages. ANOVA results showed that mean egg size was significantly different between early and late embryonic developmental stages of all shrimp species (P < 0.05).
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    Growth, reproduction and chemical composition of whiting, Merlangius merlangus euxinus (Nordman, 1840), in the Black Sea
    (Ege Univ, Fac Fisheries, 2018) Bilgin, Sabri; Bilgin, Ozlem
    In this study, studies on growth and reproduction biology and mortality rates, chemical composition of meat in terms of nutritional value were reviewed and the results presented as a whole in the scope of population dynamics of whiting fish (Merlangius merlangus euxinus) living in Black Sea. The regression equation of log (a) against b for different weight length relationships of whiting is Log (a) = -0.0013 (b) +1.735; r(2) = 0.998 (n = 6) for male and Log (a) = -0.0013 (b) +1.650; r(2) = 0.994 (n = 6) for the female. It was determined that the reproductive activity intensified during the summer months of the whiting continued throughout the year. It was determined that whiting meat protein contents is about 15.5 +/- 0.85% and fat ratio is about 1.5 +/- 0.54%. The results showed that the whiting, which grow as fast as the sex maturity, was under the fishing pressure and the fishing with bottom gill nets and mesh size of gill nets are suitable for whiting sustainable fisheries. It is appropriate that the fishing pressure applied on the whiting fish is high (E = 0.75 +/- 0,031) and the fishing mortality rate should be reduced to 50-60% levels. This can be achieved with no fishing, or less fishing of whiting at zero and one year old fish that have not reached sexual maturity.
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    Güney Doğu Karadeniz’de Beam Trol ile Avlanan Liocarcinus depurator (Crustacea: Decapod: Brachyura)’ün Üreme Biyolojisi
    (2021) Onay, Hatice; Bilgin, Sabri
    Bu çalışma Aralık 2012- Kasım 2013 ayları arasında Güney Doğu Karadeniz’de beam trol ile avlanan Liocarcinus depurator (Crustacea: Decapod: Brachyura)’ün üreme özelliklerini belirlemek amacıyla yürütülmüştür. İyidere, Merkez ve Çayeli istasyonlarından 2 m genişliğinde kirişli trol (Beam trol) kullanılarak 0-30+ metre derinliklerde örnekleme yapılmıştır. En yüksek GSI değerleri dişilerde Ağustos- Kasım aylarında, erkeklerde ise Mart ayında tespit edilmiştir. %50 cinsi olgunluk erkekler için 32,28 mm (KG) dişiler için ise 28,19 mm (KG) olarak hesaplanmıştır. Bu çalışma sonuçları L. depurator türü üzerinde yapılacak daha sonraki çalışmalar için önemli bir kaynak olacaktır.
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    Güney Doğu Karadeniz’de Beam Trol ile Avlanan Liocarcinus depurator (Crustacea: Decapoda)’ün Boya Dayalı Büyümesi
    (2022) Onay, Hatice; Bilgin, Sabri
    Bu çalışma Aralık 2012- Kasım 2013 ayları arasında Güney Doğu Karadeniz’de beam trol ile avlanan Liocarcinus depurator (Crustacea: Decapod: Brachyura) türünün mevsimsel ve mevsimsel olmayan büyüme özelliklerini belirlemek amacıyla yürütülmüştür. İyidere, Merkez ve Çayeli istasyonlarından 2 m genişliğinde kirişli trol (Beam trol) kullanılarak 0-30+ derinliklerde örnekleme yapılmıştır. Toplamda 2715 adet L. depurator (%39,4 yumurtasız dişi, %7,8 yumurtalı dişi ve %52,8 erkek) biyolojik olarak incelenmiştir. Karapas genişliği, yumurtasız dişilerde 6,8- 37,5 mm, yumurtalı dişilerde 17,3- 35,0 mm, erkek bireylerde 10,1- 51,3 mm olarak hesaplanmıştır. L. depurator türünün büyümesi mevsimsel büyüme modelinde hesaplanan Rn değeri dişi için 0,766, erkek için ise 0,676 olarak , mevsimsel olmayan büyüme modeline göre hesaplanan Rn değerinde dişi için 0,434 erkek için ise 0,597 olarak hesaplanmıştır. Büyümeeki sezonsal salınım (C) dişiler için 0,703 erkekler için 0,990 olarak hesaplanmıştır. Mevsimsel von Bertalanffy büyüme denklemi parametreleri erkek için K = 1,739 yıl-1, L∞ = 36,4 mm WP= (0) olarak, dişiler için ise K = 1,692, L∞ = 35,0 yıl-1 WP = (4,73), Φ´=(3,317) mm ve olarak belirlenmiştir. Erkek bireyler için büyümenin en yavaş olduğu zaman, Aralık ayı sonu Ocak ayı başı (WP = 0), dişi bireyler için ise Mayıs ayının ikinci haftasından sonra (WP = 4,73) olduğu tespit edilmiştir. Bu sonuçlar L. depurator türünün Karadeniz’de mevsimsel büyüme özelliği gösterdiğini ortaya koymuştur.
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    Güneydoğu Karadeniz'de (Rize kıyıları, Türkiye) Deneysel Krişli Trol ile Örneklenen Yengeç (Crustacea: Decapoda: Brachyura) ve Mollusca (Bivalvia, Gastropoda) Türleri
    (2019) Bilgin, Sabri; Onay, Hatice
    Bu çalışma, Karadeniz'in Türkiye sularında (Rize civarında) bulunan yengeç ve mollusca türlerini belirlemek amacıylayürütülmüştür. Toplamda 146 örnekleme 15 mm torba ağ gözü açıklığına sahip deneysel krişli trol ile Aralık 2012 ve Kasım 2013 tarihleriarasında aylık olarak gerçekleştirilmiştir. Çalışmada 5 familyaya ait (Portunidae, Eriphiidae, Xanthidae, Grapsidae, ve Inachidae) 7 yengeç türü(Eriphia verrucosa, Pachygrapsus marmoratus, Macropodia longirostris, Carsinus aestuarii, Liocarcinus depurator, Polybius navigator veXantho poressa) ve Bivalvia sınıfına ait 5 tür (Scapharca inaequivalvis, Mytilus galloprovincialis, Donax trunculus, Chamelea gallina, Pitarrudis), Gastropoda sınıfına ait ise 3 tür (Rapana venosa, Nassarius reticulatus, Gibbula sp.) olmak üzere toplamda 8 mollusca türübelirlenmiştir.
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    HEAVY METAL CONCENTRATIONS IN DIFFERENT MARINE ORGANISM OBTAINED FROM THE BLACK SEA, TURKEY
    (Parlar Scientific Publications (P S P), 2019) Duyar, Hunkar Avni; Bilgin, Sabri
    This study was carried out to provide information on heavy metal concentrations in the marine organisms as two fish species (Raja clavata and Trachurus trachurus), one mussel species (Mytilus galloprovincialis) and one seaweed species (Ulva lactuca). These marine species obtained from coast of Sinop province in the Black Sea. The concentrations of 23 heavy metals (Be, Na, Mg, Al, K, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Cd, Cs, Ba, Hg, Ti, Pb and U) were determined in the muscles of M. galloprovincialis and T. trachurus, in the whole U. lactuca and in the muscles, heart and liver of R. clavata. Twelve of the 23 metals (Be, Al, V, Cr, Co, Ni, Cd, Cs, Ba, Hg, Ti, Pb and U) levels were estimated very lower values between <= 0.001 - 0.08 mg/kg in the muscles, heart and liver in R. clavata. The levels of heavy metals varied significantly in tissues of R. clavata. Statistically differences were obtained for different metals among the muscles, heart and liver. The determined highest level of metals in muscles was Na, Mg, Sr, in heart K, Fe, Se and in liver Mn, Cu, Zn, As, Hg (P < 0.05). Seven of the 23 metals levels were estimated higher values K > Na > Al > Fe > Sr > Zn > Mn in U lactuca. Five of the 23 metals levels were estimated higher values K > Na > Mg > Zn > Fe in T. trachurus. Six of the 23 metals levels were estimated higher values Na > K > Mg > Al >Fe > Sr in M. galloprovincialis. The results showed that K, Na, Mg, Fe, Zn and Al were the highest levels in the muscles of M. galloprovincialis, T. trachurus and U. lactuca. Our results showed that studied marine organism contained different mean concentrations of heavy metal in whole body and tissues. The levels of heavy metals varied significantly among fish species and tissues. As expected, muscles always possessed the lowest concentrations of heavy metal levels within accepted by the international legislation limits and are safe for human consumption.
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    Incidental catches of endangered (Phocoena phocoena) and vulnerable (Delphinus delphis) cetaceans and catch composition of turbot bottom gillnet fisheries in the southeastern Black Sea, Turkey
    (Cahiers De Biologie Marine, 2018) Bilgin, Sabri; Kose, Ozay; Yesilcicek, Tuncay
    The present study summarizes information on the incidental catches of cetaceans and the catch composition of turbot bottom gillnet fisheries between March 2010 and September 2011 along the Rize coast in the southeastern Black Sea, Turkey. A total of 723 specimens (133 Scophthalmus maeoticus, 507 Raja clavata, 8 Squalus acanthias, 71 Phocoena phocoena, 4 Delphinus delphis) were recorded from 136 turbot gill net fishing operations. The 'danger index' or catch per unit effort (CPUE, individuals per km. day of netting) for cetaceans was 0.09 +/- 0.028 in 2010, 0.15 +/- 0.032 in 2011 and 0.13 +/- 0.023 overall for P. phocoena and < 0.003 overall for D. delphis. Monthly CPUE values for target S. maeoticus and non-target species R. clavata, and P. phocoena were similar in all years. An increasing CPUE trend between April and June was evident for target and non-target species in 2010 and 2011. The CPUE of P. phocoena was estimated highest in May as 0.18 +/- 0.088 in 2010 and in April as 0.26 +/- 0.086 in 2011. A similar pattern was evident for S. maeoticus and R. clavata. One-way ANOVA showed that no statistical significant difference of target and non-target species CPUE among 2010, 2011 and all data (P > 0.05). No new net damage due to cetacean interactions with the turbot gill nets was detected.
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    Is there a distinct harbor porpoise subpopulation in the Marmara Sea?
    (Taylor & Francis Ltd, 2017) Tonay, Arda M.; Yazici, Ozge; Dede, Ayhan; Bilgin, Sabri; Danyer, Erdem; Aytemiz, Isil; Maraci, Oncu
    Genetic population structure of geographically isolated endangered Black Sea harbor porpoise (Phocoena phocoena relicta) is little known in Turkish waters, especially in the Turkish Straits System (TSS- Marmara Sea, Bosphorus and Dardanelles), which connects the Black Sea and the Aegean Sea. Mitochondrial DNA sequences of 70 new individuals sampled in the Turkish Black Sea, TSS and Aegean Sea, revealed five new haplotypes from the Black Sea. The findings support the idea that harbor porpoises from the Black Sea dispersed into the Aegean through the TSS. Considering signatures of population expansion, all subpopulations showed a signature of population expansion. The network data and the Phi st calculations indicated that the Marmara Sea subpopulation was significantly differentiated from all of the other subpopulations, and supports the notion of its isolated. The finding of a potential management unit (MU) within an already heavily impacted subpopulation as a whole suggests that the individuals of P. p. relicta inhabiting the Marmara Sea require a very rigorous conservation strategy to ensure the survival of this subpopulation, represented by its unique haplotype.
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    Karadeniz'de 2013-2014 Av Sezonunda Avlanan Hamsinin (Engraulis encrasicolus) Büyümesinin ve Ölüm Oranlarının Farklı Modellerle Belirlenmesi
    (2020) Solak, Ebru; Bilgin, Sabri
    Bu çalışma, Eylül 2013 ve Nisan 2014 tarihleri arasında Doğu Karadeniz sahillerinde avcılık yapan ticari gırgırteknelerinden örneklenen hamsi balığının yaşa dayalı altı farklı büyüme modeline göre (von Bertalanffy, Gompertz, Lojistikya da Richards, Üssel, Morgan Mercer Flodin ve Weibull) büyümesi ve dört ölüm oranı modelline göre (Pauly, 1980; Djabalivd., 1993; Alagaraja, 1984 ve Srinath, 1998) ölüm oranının belirlenmesi amacıyla yürütülmüştür. Toplamda 5486 balıkörneklenmiş ve 1265 balığın yaş tayini yapılmıştır. Dişilerin ortalama boyu erkeklerden daha büyük hesaplanmıştır (P <0,05). Erkekler için Weibull (AIC = 2593,5; L∞ = 19,6 cm ve K = 0,031 yıl-1) ve Morgan Mercer Flodin (AIC = 2593,8; L∞ =17,0 cm ve K = 0,108 yıl-1), dişi için ise von Bertalanffy (AIC = 5725,42; L∞ = 11,1 cm ve K = 2,064 yıl-1) ve Üssel (AIC =5725,4; L∞ = 11,1 cm ve K = 2,065 yıl-1) büyüme modellerinin en uygun modeller olduğu belirlenmiştir. Av eğrisi yönteminegöre hesaplanan dişilerin toplam ölüm katsayısı (Z = 3,5 yıl-1) erkeklerden (Z = 3,3 yıl-1) daha büyük hesaplanmıştır. Dişi veerkek bireyler için hesaplanan doğal ölüm oranı (M) en düşük Djabali vd. (1993) modelinde, en yüksek ise Srinat (1998)modelinde hesaplanmıştır. Farklı büyüme modeli parametreleri kullanılarak hesaplanan doğal ölüm oranları ve M verilerikullanılarak hesaplanan işletme oranı (E) değerleri 2014-2015 av sezonunda hamsi stokunun optimum değerden (E = 0,5)daha yüksek bir derecede işletildiğini yani av baskısı altında olduğunu göstermiştir.
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    Öğe
    Karadeniz’ de (Sinop-İnceburun) ticari dip trolü ile avlanabilir balık biyokütle ve yoğunluk dağılımları
    (2010) Gönener, Sedat; Bilgin, Sabri
    Şubat - Nisan 2007 ve Ocak - Nisan 2008 tarihleri arasındaki av döneminde gerçekleştirilen bu çalışmada her trol çekiminde ortalama 0.13590.0013 km 2 olmak üzere toplam 80.07 km 2 lik alan taranmıştır. Sinop-İnceburun bölgesinde yapılan alan çalışmasında mezgit (Gadus mer-langus euxinus), barbunya (Mullus barbatus ponticus), kalkan (Psetta maxima maeotica), iskorpit (Scorpaena porcus), tirsi (Alosa sp.), izmarit (Spicara maena), istavrit (Trachurus mediterraneus), mahmuzlu camgöz (Squalus acanthias), dikenli vatoz (Raja clavata) ve kaya balıklarının (Gobius sp.) yıllık, aylık ve günlük av miktarları belirlenerek türlerin avlanabilir biyokütleleri ve bölgedeki stok büyüklükleri incelenmiştir. 2007 ve 2008 yılı olmak üzere her iki av sezonu için ayrı yapılan araştırmada elde edilen bulgulara göre avlama bölgesinde orta-lama 619.44 13.71 kg/km 2 mezgit; 22.451.20 kg/km 2 barbunya; 40.781.11 kg/km 2 kalkan; 0.750.11 kg/km 2 iskorpit; 7.260.82 kg/km 2 tirsi; 2.980.24 kg/km 2 izmarit; 1.100.38 kg/km 2 istavrit; 13.053.00 kg/km 2 mahmuzlu camgöz; 2.420.36 kg/km 2 dikenli vatoz ve 1.300.18 kg/km2 kayabalığı bulunmaktadır. 2007-2008 yılı av sezonlarında avlama böl-gesindeki ortalama stok büyüklükleri mezgit için 451.599.89 ton; barbunya 15.960.81 ton; kalkan 30.050.83 ton; iskorpit 0.550.77 ton; tirsi 5.070.52 ton; izmarit 2.190.17 ton; is-tavrit 0.810.27 ton, mahmuzlu camgöz 9.542.30 ton; dikenli vatoz 1.600.24 ton; kayabalığı 0.970.12 ton olarak belirlenmiştir.