Yazar "Arslan İhsanoğlu, Mukadder" seçeneğine göre listele

Listeleniyor 1 - 7 / 7
  • Küçük Resim
    Öğe
    Age, Growth and Reproduction of the Thornback ray, Raja clavata (Linnaeus, 1758) in the Waters Off Gökçeada (the Northern Aegean Sea)
    (Springer Science and Business Media Deutschland GmbH, 2023) Yığın, Cahide Çiğdem; Cabbar, Koray; İşmen, Ali; Daban, İsmail Burak; Arslan İhsanoğlu, Mukadder
    In this study, the age, growth, maturity, and reproductive biology parameters of 262 Raja clavata, which were collected monthly from commercial trawlers off Gökçeada between February 2019 and February 2020, were estimated. The individuals comprise of 55.7% females and 44.3% males. The length of the females ranged between 23-84.2 cm (Disc width: 13.5-55.8 cm) and 11.2-74 cm (Disc width: 8-48.9 cm) for males. For age determination, age readings were performed on the vertebrae of 255 Raja clavata specimens (43.5% female, 56.4% male). The calculated von Bertalanffy growth parameters were estimated to be L∞= 93.04 cm, K=0.17 years-1, to=0.48 years for males, and L∞=102.46 cm, K=0.16 years-1, t0 =0.72 years for females. The minimum and maximum ages of the thornback rays ranged from 1 to 10 years. The first sexual maturity length of the population was measured to be L50 =57.7 cm in males, and L50 =66.1 cm in females.
  • Küçük Resim
    Öğe
    Analysis of Demersal Fish Fauna off the Sea of Marmara, Turkey
    (Çanakkale Onsekiz Mart Üniversitesi, 2021) Daban, İsmail Burak; İşmen, Ali; Şirin, Murat; Yığın, Cahide Çiğdem; Arslan İhsanoğlu, Mukadder
    Demersal fish fauna of the Sea of Marmara, Turkey was determined by bottom trawl surveys between March 2017-December 2018 at 34 stations with the monthly samplings. During the study, a total of 61 teleost and 12 cartilaginous fish species belonging to 42 families were sampled. The target, bycatch and discard rates of CPUE were determined as 13.40%, 69.64% and 16.95%, respectively. In total, 53.9% of the CPUE was stemmed from Trachurus trachurus. Mustelus mustelus, Raja clavata, Merluccius merluccius and Merlangius merlangius had the highest CPUE with a mean of 77.63, 71.86, 71.72 and 72.68 kg/km2, respectively. The highest biodiversity was observed in the southwestern part of the Marmara Sea. With increasing depth, the species number of the teleost fish decreased, whereas the species number of the cartilaginous fish increased. The mean CPUE values of the economical demersal fish species were lower in comparison to those reported from other regions in Turkey. Evidence suggests fish stocks with shallower distribution is under heavier threat against fishing pressure. Since commercial trawling is banned in the Sea of Marmara, beam trawl fishery can be considered as the major threat to demersal fish stocks in the region.
  • Küçük Resim
    Öğe
    Length-Weight and Otolith Morphometry Relationships of Hoplostethus mediterraneus Cuvier, 1829 from the Saros Bay, Northern Aegean Sea
    (Springer Int Publ Ag, 2025) İşmen, Ali; Yığın, Cahide Ciğdem; Öz, Melike İdil; Arslan İhsanoğlu, Mukadder
    The relationship between total length (TL) and total weight (TW) and the morphometric relationships of the otolith between total length and otolith length (OL), total length and otolith weight (OW) and otolith length and otolith weight of Hoplostethus mediterraneus were examined in Saros Bay, North Aegean Sea, T & uuml;rkiye. The samples were collected with commercial trawls in Saros Bay from September 2006 to September 2008. A total of 970 specimens were caught at depths of 100-500 m. The average value of fish length was 11.86 +/- 0.14 cm (4.0-22.1 cm), and weight 32.2 +/- 1.0 g (0.83-148.75 g). Otolith size was measured with a minimum of 4.31 mm and a maximum of 12.88 mm. The relationships between TL and TW, OW and OL, OL and TL, OW and TL and OW and OL were determined as TW = 0.010*TL3.10 (r2 = 0.99), OW = 0.0004*OL2.64 (r2 = 0.99), OL = 0.055*TL + 0.564 (r2 = 0.98), OW = 0.0002*TL2.38 (r2 = 0.98), and OW = 0.0004*OL2.64 (r2 = 0.99). The high correlation coefficients (r(2) values) demonstrate the reliability of the established equations, offering a robust framework for estimating the size and weight of this species based on otolith measurements. This study provides crucial insights into the growth patterns and morphometric relationships of Hoplostethus mediterraneus, which can be used to enhance fishery management and conservation efforts in Saros Bay.
  • Küçük Resim
    Öğe
    Marmara denizi'nde parapenaeus longirostris (Lucas, 1846)'in populasyon yapısı, bolluk ve av oranlarının zamansal-alansal değişimleri
    (Çanakkale Onsekiz Mart Üniversitesi, Lisansüstü Eğitim Enstitüsü, 2017) Arslan İhsanoğlu, Mukadder; İşmen, Ali
    In this study, temporal and spatial changes of catch per unit effort (CPUE-kg/h), stock amount (biomass-kg/km2), population structure of Parapenaeus longirostris, and current situation of the stocks, effects of beam trawl were determined in the Sea of Marmara. Samples were obtained by beam trawls monthly between October 2011-July 2014 and population parameters; size distributions, length-weight relationships, condition factor, growth-mortality parameters and sex rates were determined. The catch per unit effort value (CPUE) and abundance index of deep water pink shrimp were found 8,5 kg/h and 1545 N/h in the Sea of Marmara. The highest CPUE values were estimated region 2 (10,1 kg/h) and region 6 (15,1 kg/h). The lowest value was in region 5 (3,4 kg/h). According to depth contours, catch per unit effort values were determined as 8.8 kg/h in 50-100 m, 7 kg/h in ≥100 m. Biomass of the species was found 354 kg/km2 in the Sea of Marmara. The maximum value of biomass were in Tekirdag and Silivri and the lowest value was in the Yalova. 36288 individuals were measured, total length (TL), carapace length (CL) and weight (g) values were found as 34-175 mm (107 mm), 8-41 mm (22.6 mm), 0,2-28,9g (6,1g), respectively. Carapace length-weight relationship was calculated as W=0.0022*CL2.52. Growth parameters were determined as L∞=199,5 mm, k=0,47, t0=-0,5 in total length, L∞=36,8 mm, k=0,37, t0=-0.69 y in carapace length. Total mortality, natural mortality, fishing mortality and exploitation rates were found 1,60, 0,61, 0,99 and 0,62, respectively. Male-female ratio was found as 1:1,3.
  • Küçük Resim
    Öğe
    Population Structure, Age, Growth and Reproduction Biology of Piper Gurnard, Trigla lyra (Linnaeus, 1758) in the Sea of Marmara, Turkey
    (Springer Int Publ Ag, 2024) Şirin, Murat; Daban, İsmail Burak; Arslan İhsanoğlu, Mukadder; İşmen, Ali; Yığın, Cahide Çiğdem
    This study describes the biomass, age, growth, mortality and reproduction biology of piper gurnard, Trigla lyra. Individuals were obtained with monthly trawl surveys between March 2017 and December 2018 from 34 stations located in the Sea of Marmara, Turkey. Mean Catch per unit effort (CPUE-kg/h) and stock amounts (biomass kg/km(2)) were calculated as 0,62 kg/h and 8,54 kg/km(2), respectively. The age interval was determined as between I and VIII. Von Bertalanffy growth parameters were determined as L infinity = 59.92 cm, K = 0.21 per year and t0 = -0.36 for females and L infinity = 78.53 cm, K = 0.13 per year and t0 = -0.41 for males. The total mortality (Z) was determined as 0.55 t(-1). The natural mortality (M) and fishing mortality (F) were estimated as 0.36 t(-1) and 0.19 t(-1). The exploitation rate was determined as 0.35 t(-1). The length at first maturity (L50) was calculated as 32.7 cm TL for females and 25.2 cm TL for males. The spawning period of T.lyra was determined between December and April and peaked in March.
  • Küçük Resim
    Öğe
    Reproductive biology of Penaeus kerathurus (Forskal, 1775) (Decapoda: Penaeidae) in the Sea of Marmara, Turkey
    (De Gruyter Open Ltd, 2021) Arslan İhsanoğlu, Mukadder; Daban, İsmail Burak; İşmen, Ali; Cabbar, Koray; Yığın, Cahide Çiǧdem
    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.
  • Küçük Resim
    Öğe
    Some biological aspects of White seabream, Diplodus sargus (Linnaeus, 1758) from the northeastern Aegean Sea, Turkiye
    (Ege Univ, Fac Fisheries, 2024) Daban, İsmail Burak; İşmen, Ali; Arslan İhsanoğlu, Mukadder; Daban, İsmail Burak
    In the study, the age, growth, mortality parameters and length-weight relationship parameters of Diplodus sargus (white seabream) collected by a small-scale fisherman between August 2020 and July 2021 along the northeastern coast of Aegean Sea (Turkiye coast), were investigated. D. sargus had a range of total length and weight from 14.3 cm to 36.7 cm and from 50.5 g to 836.5 g, respectively. The length-weight relationships (LWRs) were calculated as W=0.02368*L-2.881 for females, W = 0.01847*L-2.959 for males and W = 0.01989*TL2.936 for both sexes. Using data from fish scales, the maximum age was determined to be 11 years. von Bertalanffy growth parameters have been calculated as follows L-infinity=39.01 cm TL, K=0.13 year(-1), and t(0)= -2.58 year for both sexes combined. Total (T), natural (N) and fishing (F) mortalities were defined as Z: 0.83 year-1, M: 0.33 year(-1) and F: 0.50 year(-1) for both sexes combined. The exploitation rate (E) was calculated as 0.70, 0.44 and 0.60 for females, males and combined, respectively.