Yazar "Partal, Nurbanu" seçeneğine göre listele

Listeleniyor 1 - 13 / 13
  • [ X ]
    Öğe
    An invasive species, Carassius gibelio, alters the native fish community through trophic niche competition
    (Springer Basel Ag, 2019) Yalçın Özdilek, Şükran; Partal, Nurbanu; Jones, Roger I.
    Carbon and nitrogen stable isotope analyses were used to determine isotopic niche width of the invasive fish species Carassius gibelio to help assess the niche overlap and potential impact of this species on the native fish fauna in the Karamenderes River, northwest Turkey. C. gibelio had the highest niche area of the coexisting species. The greatest overlap of isotopic niche was between C. gibelio and Mugil cephalus in the river mouth. The freshwater species displayed similar patterns when taking into consideration their relative abundance and isotopic overlap. While C. gibelio is likely to outcompete some species at some localities, the species was found co-occurring with others by maximum tolerable overlap degree and apparently utilised vacant niche space at some stations. Overall our results indicate that C. gibelio has extensive niche overlap with the native fish species making it a strong competitor, and because of its high abundance and high niche width this invasive species represents a serious threat to the native fish fauna, particularly in the river mouth.
  • [ X ]
    Öğe
    Bayramiç Baraj Gölü ve gölü besleyen iki kolda yaşayan alburnus istanbulensis populasyonlarının biyoekolojik özelliklerinin belirlenmesi
    (Çanakkale Onsekiz Mart Üniversitesi, 2019) Partal, Nurbanu; Yalçın Özdilek, Şükran
    Bu çalışmada Karamenderes akarsuyunun iki yukarı kolu ve bu akarsuyun üzerinde bulunan Bayramiç baraj gölündeki tatlı su balıklarının dağılım ve bollukları belirlenmiştir. Akarsu balıkları arasından hem akarsu hem baraj gölünde yaşayan, her iki ekosistemde de nispeten bol bulunan türler arasından yerli ve endemik Alburnus istanbulensis populasyonu seçilmiş ve bu türün Bayramiç Baraj Gölü ve gölü besleyen iki koldaki biyoekolojik özellikleri ele alınmıştır. Çalışmada A. istanbulensis bireylerinin boy, ağırlık ve yaş kompozisyonu, boy-ağırlık ve yaş-boy ilişkisi, kondisyon faktörü, %GSI değeri, eşey oranları, %IRI, beslenme özelliği ve şiddeti, trofik seviyeleri, izotopik niş genişlikleri, ortamdaki besinlerin diyete katkıları belirlenmiştir. Alburnus istanbulensis türünün diğer türlerle olan ilişkileri belirlenirken istasyonlara göre besin ağları ve türler arasındaki niş çakışmaları kararlı izotop analizleri (SIA) sonuçlarına göre değerlendirilmiştir. Örneklemeler boyunca Barbus oligolepis, Cobitis fahirae, Gobio kovatschevi ve Rhodeus amarus, sadece akarsularda, Carassius gibelio, Cyprinus carpio, Siluris glanis ve Aterina boyeri sadece baraj gölünde, Esox lucius ve Squalius cii türleri hem akarsu hem de baraj gölünde yakalanmıştır. Toplamda 354 adet A. istanbulensis bireyi üzerinde değerlendirme yapılmıştır. Alburnus istanbulensis bireylerinin tüm istasyonlarda boy dağılım 9,9±3,5 cm (3,1–17 cm), ağırlık dağılımı 14,19±11,97 g (0,27–53,5 g) ve yaş dağılımı 0+-V yaş olarak belirlenmiştir. Boy-ağırlık ilişki denklemi Çalıoba istasyonunda W=0,0072L3,1476, Mollahasanlar istasyonunda W=0,0078L3,1228 ve Bayramiç Baraj Gölü'nde W=0,0111L2,9821 olarak belirlenmiştir. Yaş-boy ilişkisinde Von Bertalanffy denklemi tüm bireylerde Lt=19,36(1-e-0,2514(t+0,1146)) olarak belirlenmiştir. Kondisyon faktörü 0,56-1,88 arasında değişmektedir. Ortalama %GSI değerleri dişilerde en yüksek Temmuz 2016 ayında Bayramiç Baraj Gölü'nde (4,57±1,94) erkeklerde ise Nisan 2017 ayında Çalıoba istasyonunda (4,56±2,0) tespit edilmiştir. Çalıoba istasyonunda bulunan bireylerin %25'inin dişi, %74'ünün erkek ve %1'inin juvenil, Mollahasanlar istasyonunda %14'ünün dişi, %29'unun erkek ve %57'sinin juvenil, Bayramiç Baraj Gölü'nde ise %25'inin dişi ve %75'inin erkek bireylerden oluştuğu belirlenmiştir. Sindirim kanalı içeriklerinin %IRI değerleri istasyon ve mevsimlere göre farklılık göstermekle birlikte, A. istanbulensis bireyleri ağırlıklı olarak makroomurgasız ile beslenmekte, beslenme özelliği bakımından karnivor özellik göstermektedir. SIAR sonuçlarına göre akarsuda bentik, baraj gölünde seston ve perifiton besinlerinin diyete katkılarının yüksek olduğu belirlenmiştir. %IRI ve SIA verilerine göre trofik seviyeler sırasıyla ortalama 2,83 ± 0,39 ve 2,92 ± 0,60 olarak belirlenmiştir. Alburnus istanbulensis bireylerinin niş genişlikleri %IRI ve SIA verilerine göre sırasıyla ortalama 0,31±0,1 ve 4,44±2,3 olarak belirlenmiştir. Genel olarak A. istanbulensis x S. cii, C. gibelio x C. carpio, A. istanbulensis x E. lucius, A. boyeri x E. lucius ve A. boyeri x A. istanbulensis türleri arasında çeşitli mevsim ve istasyonlarda niş çakışmaları olduğu görülmüştür.
  • [ X ]
    Öğe
    Climate change effects on abundance and distribution of the European eel in Türkiye
    (Wiley, 2024) Mestav, Burcu; Ozdilek, Suekran Yalcin; Acar, Zahide; Gokkaya, Kemal; Partal, Nurbanu
    Spatial and temporal distribution of European eel (Anguilla anguilla) during 1967-2020 was used to model European eel distribution in response to climate variability. Modeling integrated predictions from two distinct models for inferences. First, modeling of the relationship between temperature and precipitation and European eel catch values using multiple time-series regression analyses showed that climate variables contributed to eel distribution in T & uuml;rkiye. Eel catch became restricted to western and southern coasts of T & uuml;rkiye and total catch decreased between 1967 and 2020. From 1967 to 2020, favorable climatic conditions for European eels in T & uuml;rkiye were characterized by moderate temperatures. Furthermore, projections for 2050 and 2070 suggested that suitable habitat would be lost in T & uuml;rkiye. Our findings underscore the urgent need for immediate and widespread implementation of effective conservation policies to mitigate threats to European eel in T & uuml;rkiye and globally.
  • [ X ]
    Öğe
    Feeding ecology of invasive Carassius gibelio (Bloch, 1782) in Karamenderes Stream, Turkey
    (Ege Üniversitesi, 2017) Partal, Nurbanu; Özdilek, Şükran Yalçın
    Karamenderes River, which is located in Biga Peninsula, originates from Kazdağı and Ağı Dağı and flows into Çanakkale Strait in Kumkale meadows. Distribution and feeding ecology of Carassius gibelio (Bloch, 1782) in the Karamenderes River were investigated. A total of 252 specimens have been collected by electrofishing and using cast net, fyke net and gill net from 14 stations along Karamenderes River in three seasons (Summer 2012, Autumn 2012 and Spring 2013). The fork length, weight and gut length of specimens were measured. The gut contents of each specimens were analyzed and the food organisms were identified to lower possible taxon. C. gibelio specimens were caught only the lower part of the Bayramiç Dam. This species is omnivore and feed on mostly algae. The highest diversity in diet were in Sarımsaklı station in Summer (2.55) and the lowest diversity was in Kumkale station in Summer (0.70). Among the food organisms Heterokontophyta and Amphipods have a high the relative importance index values [TR] Carassius gibelio (Bloch, 1782)’nun Biga Yarımadası’nda Kazdağı ile Ağı Dağı’ndan doğan ve Kumkale ovasından Çanakkale Boğazı’na dökülen Karamenderes Çayı’ndaki beslenme ekolojisi araştırılmıştır. Yaz 2012, Sonbahar 2012 ve İlkbahar 2013 olmak üzere üç mevsimde toplam 14 istasyonda yapılan örneklemelerde, serpme, elektroşoker, çeşitli göz açıklığındaki solungaç ağları kullanılarak 251 adet birey yakalanmıştır. Her bireyin çatal boy, ağırlık ve sindirim kanalı uzunluğu ölçülmüş, pullarından yararlanılarak yaş tayinleri yapılmış, sindirim kanalı içerikleri incelenmiştir. Sindirim kanalından çıkan besin organizmaları muhtemel en düşük taksona kadar tanımlanmıştır. Bireylerin beslenme şiddeti, sindirim kanalı içerikleri iki farklı yöntemle değerlendirilmiştir. C. gibelio bireylerinin omnivor olduğu ve çoğunlukla alglerle beslendiği belirlenmiştir. Sindirim kanalı içeriğinde besin çeşitliliği en yüksek yaz mevsiminde Sarımsaklı istasyonunda (2,55) en düşük çeşitlilik de yaz mevsiminde, Kumkale istasyonunda (0,70) görülmüştür. Sindirim kanalından çıkan besin organizmaları arasında Heterokontophyta ve Amphipoda üyelerinin önem indeksleri yüksektir.
  • [ X ]
    Öğe
    How does a reservoir affect the fish assemblage structure in a Mediterranean River (Turkey)?
    (Wiley, 2022) Yalçın Özdilek, Şükran; Partal, Nurbanu; Mestav, Burcu
    Most rivers around the Mediterranean region, regardless of size, are interrupted by human induced barriers. Although various studies have been conducted to investigate the impacts of reservoirs on undisrupted freshwater biota, what kind of effects they exert on the distribution of freshwater fish assemblages with respect to the presence of invasive species remains to be answered. To attend to this research need, the Karamenderes River, which is disrupted by the Bayramic Reservoir, was selected as the research site. Relying on the river continuum concept (RCC), we hypothesized that fish assemblages in a given river would demonstrate a gradual downstream change unless the river is interrupted by any reservoir. The ad hoc unweighted pair group method with arithmetic means (UPGMA) agglomerative hierarchical cluster analyses revealed 11 fish assemblages 100 km down the studied river, which is characterized by four environmental gradients. Besides, co-occurrence network analyses were performed to gain a better understanding of the constructs of the observed fish assemblages. The analyses yielded two distinct clusters along the river and showed that the Bayramic Reservoir had no decisive part in the spatial clustering of these fish assemblages. The migratory species Anguilla anguilla was found only in and around the river mouth area. The co-occurrence network analyses indicated that the freshwater, estuarine and introduced species were observable in distinct groups. It is notable that the non-native Cyprinus carpio and invasive Carassius gibelio were determined in the native freshwater fish species module. The research evidenced that the reservoir had a triple effect, that is, a migration barrier to migratory fish species, a donor facilitating invasion, and a cause of homogenization of river fish assemblages along the river. The results suggest that the impact of the reservoir should be assessed in view of multiple nested model and fish passageways and controlling invasive species are two contradictory problems as far as the impacts of reservoirs are concerned. Therefore, river management should be performed in a way to allow the native migratory species to migrate freely while preventing the introduced species from moving upstream or downstream to preserve and promote rivers' heterogeneity.
  • Küçük Resim
    Öğe
    Interactions of invasive pumpkinseed with a riverine endemic fish indicate trophic overlap but minimal consequences for somatic growth and condition
    (EDP Sciences, 2023) Karakuş, Uğur; Tarkan, Ali Serhan; Yalçın-Özdilek, Şükran; Top-Karakuş, Nildeniz; Partal, Nurbanu; Britton, John Robert
    The North American invasive fish pumpkinseed Lepomis gibbosus has been associated with some detrimental ecological consequences in some parts of its invasive range. Here, we tested the trophic interactions of pumpkinseed with the endemic stream fish Aegean chub Squalius fellowesii ('chub') in a Mediterranean-type water course in SW Anatolia, Turkey, using a bulk stable isotope approach (d13C, d15N). Seven sampling sites were able to be grouped as chub in pumpkinseed presence (n=2) and absence (n=3), and pumpkinseed in chub absence (n=2). Across these groups, stable isotope metrics revealed that chub trophic (isotopic) niche size was similar in pumpkinseed presence/absence, but pumpkinseed had a larger niche in chub presence. In sites where they are co-habited, their niches showed some convergence, but with no apparent consequences for their growth or body condition, suggesting there were minimal ecological consequences of this sharing of food resources. These results suggest that the trophic consequences of this riverine invasion of pumpkinseed on this endemic chub was minimal.
  • [ X ]
    Öğe
    Karamenderes Çayı'nda istilacı bir tür olan Carassius gibelio (Bloch, 1782) taksonunun dağılımı ve beslenme ekolojisi
    (Çanakkale Onsekiz Mart Üniversitesi, 2014) Partal, Nurbanu; Yalçın Özdilek, Şükran
    Carassius gibelio (Bloch, 1782) türünün Biga Yarımadası'nda Kazdağı ile Ağı Dağı'ndan doğan ve Kumkale ovasından Çanakkale Boğazı'na dökülen Karamenderes Çayı'ndaki dağılımı ve beslenme ekolojisi araştırılmıştır. Yaz 2012, Sonbahar 2012 ve İlkbahar 2013 olmak üzere üç mevsimde toplam 14 istasyonda yapılan örneklemelerde, serpme, elektroşoker, çeşitli göz açıklığındaki solungaç ağları kullanılarak 251 adet birey yakalanmıştır. Her bireyin çatal boy, ağırlık ve sindirim kanalı uzunluğu, ölçülmüş, pullarından yararlanılarak yaş tayinleri yapılmış, sindirim kanalı içerikleri incelenmiştir. Sindirim kanalından çıkan besin organizmaları muhtemel en düşük taksona kadar tanımlanmıştır. C. gibelio ve birlikte bulunan diğer balık türlerinin CPUE (birim çaba başına düşen av miktarı) değerleri ve nisbi bolluk değerleri hesaplanmıştır. Bireylerin beslenme şiddeti, kondisyon faktörü, beslenmenin üreme ile ilişkisini değerlendirebilmek amacıyla GSI (Gonadosomatik indeks) değerleri hesaplanmıştır. C. gibelio bireylerine Bayramiç Barajı'nın alt kısmında bulunan istasyonlarda rastlanılmıştır. C. gibelio bireylerinin omnivor olduğu ve çoğunlukla alglerle beslendiği belirlenmiştir. Sindirim kanalı içeriğinde besin çeşitliliği en yüksek yaz mevsiminde Sarımsaklı istasyonda (2,55) ve 0+ yaş grubunda (2,51), en düşük çeşitlilik de yaz mevsiminde, Kumkale istasyonda (0,70) ve 3 ile 3+ yaş grubunda (1,80) görülmüştür. Sindirim kanalından çıkan besin organizmaları arasında Heterokontophyta ve Amphipoda üyelerinin önem indeksleri yüksektir. Anahtar sözcükler: Ekoloji, Akarsu, Balık, Çe?itlilik, Çanakkale
  • [ X ]
    Öğe
    Karamenderes Çayı'nda istilacı Carassius gibelio (Bloch, 1782) türünün beslenme ekolojisi
    (2017) Partal, Nurbanu; Özdilek, Şükra Yalçın
    Carassius gibelio (Bloch, 1782)'nun Biga Yarımadası'nda Kazdağı ile Ağı Dağı'ndan doğan ve Kumkale ovasından Çanakkale Boğazı'na dökülen Karamenderes Çayı'ndaki beslenme ekolojisi araştırılmıştır. Yaz 2012, Sonbahar 2012 ve İlkbahar 2013 olmak üzere üç mevsimde toplam 14 istasyonda yapılan örneklemelerde, serpme, elektroşoker, çeşitli göz açıklığındaki solungaç ağları kullanılarak 251 adet birey yakalanmıştır. Her bireyin çatal boy, ağırlık ve sindirim kanalı uzunluğu ölçülmüş, pullarından yararlanılarak yaş tayinleri yapılmış, sindirim kanalı içerikleri incelenmiştir. Sindirim kanalından çıkan besin organizmaları muhtemel en düşük taksona kadar tanımlanmıştır. Bireylerin beslenme şiddeti, sindirim kanalı içerikleri iki farklı yöntemle değerlendirilmiştir. C. gibelio bireylerinin omnivor olduğu ve çoğunlukla alglerle beslendiği belirlenmiştir. Sindirim kanalı içeriğinde besin çeşitliliği en yüksek yaz mevsiminde Sarımsaklı istasyonunda (2,55) en düşük çeşitlilik de yaz mevsiminde, Kumkale istasyonunda (0,70) görülmüştür. Sindirim kanalından çıkan besin organizmaları arasında Heterokontophyta ve Amphipoda üyelerinin önem indeksleri yüksektir.
  • [ X ]
    Öğe
    Length-Weight Relationship, Condition Factor, and Gonadosomatic Index of Endemic Alburnus istanbulensis (Battalgil, 1941) in Two Different Habitats: Karamenderes River and Bayramiç Reservoir (Çanakkale, Turkey)
    (İstanbul Üniversitesi, 2022) Partal, Nurbanu; Özdilek, Şükran Yalçın
    Objective: The first aim of this study is to describe the length, weight, condition factor, and GSI of Alburnus istanbulensis (Battalgil, 1941) in two different connected habitats (stream habitat and reservoir lake) in Karamenderes River, Çanakkale. The second aim is to state the growth type of this species in the sampled habitat using the length-weight relationship (LWR) model.Materials and Methods: The sampling areas are Bayramiç Reservoir and two tributaries on Karamenderes River, which feed the reservoir. Sampling was conducted between May 2016 and June 2017, and depending on the habitat types, different gears were used in the samplings. W=aLb equation was used to calculate the length-weight relationship, K=100×W/L3 equation for the condition factor, and GSI=WG×100/W equation for the gonadosomatic index.Results: The results showed that the mean fork length of specimens in reservoir and stream habitats were 11.86±1.83 cm and 7.69±3.56 cm, respectively, and body weight of the specimens in the reservoir and stream habitats were 19.28±8.99 g and 8.17±10.82 g, respectively. The condition factor was higher in the reservoir habitat and GSI values were higher in the stream habitats. The growth for all the specimens was positive allometric (b=3.13), whereas in the reservoir habitat the growth was isometric (b=2.99) and in the stream habitat the growth was positive allometric (b=3.12).Conclusions: Determining the biological characteristics of an endemic species makes an important contribution to the conservation of the species. In the Çanakkale region, data on LWR, growth, condition, and GSI values were not available with the valid name of the species. Therefore, this study is important in terms of presenting new data in the Çanakkale region with the valid name of the species. The findings of this study indicate that the A. istanbulensis species exhibited habitat-dependent differences in LWR, growth, and condition.
  • [ X ]
    Öğe
    Length-weight relationships and condition factors of three fish species in the Karamenderes Stream (Çanakkale, Türkiye)
    (İstanbul Üniversitesi, 2022) Özdilek, Şükran Yalçın; Partal, Nurbanu
    Objective: The aim of this study is to determine the length-weight relationships and condition factors of two native freshwater fish species and the invasive Carassius gibelio in the Karamenderes Stream (Çanakkale, Türkiye). Materials and Methods: Fish specimens were caught monthly from August 2007 to July 2008 using cast nets in Karamenderes Stream’s Pınarbaşı location. The length-weight relationship was calculated according to W = aLb and the Fulton’s condition factor was calculated according to K = 100*W/L3 equations. Results: The b (slope) values of the length-weight relationships are 3.026, 3.201, and 3.255, respectively, for Barbus oligolepis, Squalius cii, and C. gibelio. The growth was isometric in B. oligolepis and positive allometric in C. gibelio and S. cii. The Fulton’s condition factor varied between 0.51 and 2.08 in C. gibelio, 0.76 and 1.25 in B. oligolepis, and 0.59 and 1.44 in S. cii specimens. Conclusion: This study is the first report that presents the length-weight relationship of two native species, B. oligolepis and S. cii, in the presence of invasive C. gibelio. The length and weight distribution pattern through the year indicated that there was seasonality in the utilization of this section of the stream by juvenile and adult stages of three species. The lowest condition factor and b value in B. oligolepis led us to the conclusion that the competitive exclusion risk of this species. The effect of invasive C. gibelio on the natives should be further researched focusing on species interactions. From the fact that there are limited data on the length-weight relationship and biology of B. oligolepis and S. cii, there is a need for further research.
  • [ X ]
    Öğe
    Ontogenetic Diet Shift of Invasive Gibel Carp (Carassius gibelio, Bloch 1782) in Karamenderes River (Turkey)
    (2019) Partal, Nurbanu; Yalçın Özdilek, Şükran
    The ontogenetic diet shift of invasive Carassius gibelio (Bloch, 1782) wasinvestigated in Karamenderes River, Turkey. The fieldwork was performedduring summer 2012, autumn 2012 and spring 2013. The fishes were caught byelectrofishing and using gill nets. Nine fork length groups were used in order toassess the ontogenetic diet shift. The gut contents were assessed by the index ofrelative importance that was calculated from the frequency of occurrence,numerical abundance, and volumetric analyses. The most abundant length groupsof C. gibelio were 18-20 cm, 6-8 cm, and 27-29 cm length groups during summer2012, autumn 2012 and spring 2013, respectively. The feeding intensity was thelowest in the length groups of 15-17 cm during summer 2012, in 3-5 cm lengthgroup in autumn 2012 and in 24-26 cm length group in spring. Seasonal variationswere observed in the ontogenetic diet shift of C. gibelio. Large specimensconsumed more animal materials during summer and more algae in autumn. Therewas not any significant niche overlap recorded between small and large specimensexcept summer. Any niche overlap between small and large specimens might beadvantageous for the establishment success of invasive Gibel carp inKaramenderes River.
  • [ X ]
    Öğe
    The Gut Contents of the Squalius cii in a Permanently Interrupted River System, the Karamenderes River
    (Natural and Engineering Science, 2022) Partal, Nurbanu; Yalçın Özdilek, Şükran
    The goal of this study was to determine the temporal and spatial distribution of the gut contents of Squalius cii specimens in a permanently interrupted Karamenderes River. The specimens were sampled at seven distinct locations along the Karamenderes River in summer 2012, autumn 2012, and spring 2013. The gut contents of a total of 157 specimens were examined. The data on the identified food organisms were quantified as the percentage of the index of relative importance (IRI%), niche breadth (BA), trophic level (TL), feeding intensity (Vacuity Index, VI), and food diversity (H’). In all seasons, the examined specimens were found to mostly feed on the members of the Insecta family in the river's upper section and on Bacillariophyceae and macrophytes in the lower section. The feeding intensity was found to be the highest in spring 2013, while the food diversity was realized to exhibit the highest value (2.21) at the Karaköy 1 site in summer 2012. The niche breadth of the examined specimens varied between 0.01 and 0.73, whereas their trophic levels ranged between 2.01 and 3.48. The S. cii specimens were fed on high-quality foods in the upper section of the dam. © 2022, Natural and Engineering Science. All rights reserved.
  • [ X ]
    Öğe
    Trophic Interactions of Two Ponto-Caspian Gobies in the Turkish Part of Their Native Range
    (Central Fisheries Research Inst, 2018) Tarkan, Ali Serhan; Karakus, Ugur; Tepekoy, Erdi Gokhan; Top, Nildeniz; Yalçın Özdilek, Şükran; Partal, Nurbanu; Britton, John Robert
    Several Ponto-Caspian gobiids have expanded from their native distribution ranges to Europe and North America. As knowledge on their bio-ecological features in their native range is still limited, the trophic ecology of monkey goby Neogobius fluviatilis and Western tubenose goby Proterorhinus semilunaris was studied in three natural lakes in the Marmara Region of NW Turkey using the stable isotopes of delta C-13 and delta N-15. In two of the lakes, the trophic niches ( as the isotopic niche) of the gobies were highly divergent with co-existing native fishes, with no overlap. Moreover, mixing models suggests considerable inter-specific dietary differences. In all lakes, the trophic niches of gobies were never significantly larger than those of coexisting fishes. These results suggest that when introduced outside of their natural range, the gobies might integrate into new fish communities via exploiting resources that are underexploited by native fishes or will initially share resources with these species before their niches diverge, perhaps through competitive displacement.