Browsing by Author "Sepil, Ahmet"

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Balık Larvaları için Alternatif Bir Canlı Yem; Bakteriyel Protein ile Zenginleştirilmiş Sirke Kurtları (Turbatrix Aceti)
(2019) Önalan, Şükrü; Sepil, Ahmet
Özellikle deniz ve süs balıkları türlerinin ticari olarak yetiştirilmesinde erken evre besleme işlemlerinin başarılması larva kayıplarını azaltmak için çok önemlidir. Bu nedenle, ilk ağız boşluğu büyüklüğünde balık larvaları için uygun canlı gıda organizmalarının üretilmesi ve kullanılması gerekmektedir. Bu konuda yaygın olarak kullanılan rotifer (Brachionus plicatilis), kolay olmayan kültür prosedürlerine sahiptir, bu nedenle alternatif canlı gıda organizmalarının değerlendirilmesi çok önemlidir. Bu çalışmada altrisayal balık larvalarının erken beslenme evresinde sirke kurdunun canlı yem olarak uygulanabilirliği denenmiştir. Diğer balık türlerinin beslenme denemelerinde kullanılandan daha küçük ağız boşluğu büyüklüğüne sahip olan Zebra balığı (Danio rerio)’nın sirke kurtlarını canlı yem olarak kabul edilebilirlikleri değerlendirilmiştir. Sirke kurtlarının beslenmesinde ise bakteriyel (Lactococcus garvieae) proteinlerin kullanımı değerlendirilmiştir.
Comparison of Predicted and Measured Levels of Organic Material Input From a Commercial Cage Farm in Western Turkey
(Western Philippines Univ, 2022) Sepil, Ahmet; Onal, Umur
In this study, two different sediment trap trials were carried out to determine the deposition rate (flux) of particulate organic materials (POM) from marine cage farms. Flux predicted using a commercial software (Meramod), measured almost two-fold higher (1,355.5 g m-2 yr- 1) in 2009 compared to that in 2008 (765.0 g m-2yr-1). Predicted levels of flux were higher than measured values in all trials and ranged between 1,251.6 g m-2 yr-1 in 2008 and 1,811.9 g m-2 yr-1 in 2009. There were also considerable differences in measured and predicted rates of flux at each station. High variations of flux in repeated measures indicated the need for strict control of farm maintenance routines during long-term trap studies. Near bottom current speeds, periodic resuspension events and the presence of wild fish assemblages were considered as major factors that may have effects in predicting the accumulation rates of POM.
Effects of Salinity on Gill Histology in Sailfin Velifera (Poecilia Velifera)
(Springer, 2024) Oguz, Ahmet R.; Sepil, Ahmet; Alkan, Zehra; Azizoglu, Burcu Ergoz; Sen, Fazil; Oguz, Elif Kaval
Fish live in aquatic areas with varying salinity from fresh water to seawater. Gills are one of the most important osmoregulatory organs for maintaining the salt-water balance. In this study, changes in the gills of velifera (Poecilia sphenops) acclimated to 20, 30, 40, and 50 ppt of saline in the laboratory were examined histologically and immunohistochemically. Mucus cells (MCs), proliferating cell nuclear antigen (PCNA), mitochondria-rich cells (MRCs), and heat shock proteins (HSP70) + cells were marked in the gill tissue, which underwent routine histological procedures, and the severity of histological alterations increase with the increase of the salinity. When the gills were examined histologically, it was determined that there was an increase in cells due to hyperplasia, especially in the primary lamellae. A rapid increase in MC and HSP70 + cell numbers was observed in the 20 and 30 ppt groups. Although PCNA + cells were present in each salinity group, they were observed in the salinity group up to 50 ppt. An increase in the number and volume of MRCs was observed with increasing salinity. Based on the histological and immunohistochemical results, it is thought that the cytological and molecular arrangements of cells in gills of sailfin velifera under different levels of salinity are essential for the regulation of ion and salt balance.
Evaluating Water Quality of Nemrut Crater Lake (bitlis) and Investigating in Terms of Larvae Ontogeny and Osmoregulator Capacity of Aphanius Mento (heckel, 1843) Is Distributed Within the Lake
(2020) Sepil, Ahmet; Şen, Fazıl
Bu çalışmada, Bitlis ili sınırları içerisinde yer alan Nemrut Krater Gölü'nün su kalitesinin belirlenmesi, suda yayılış gösteren Aphanius mento, (Heckel, 1843) türünün moleküler düzeyde identifikasyonunun sağlanması, embriyonik ve larval gelişiminin mikroskobik ve histolojik olarak incelenmesi ve farklı tuzluluk seviyelerine toleransının değerlendirilmesi amaçlanmıştır. Eylül 2018 ve Ekim 2019 tarihleri arasında gerçekleştirilen örneklemelerde suyun fiziko-kimyasal analiz sonuçlarına göre, Nemrut Krater Gölü suyunun içme, kullanma, sulama ve balıkçılık açısından uygun kalitede olduğu belirlenmiştir. Balık türüne özgü primerlerle gerçekleştirilen PCR identifikasyonunun pozitif sonuç verdiği, türün ‰ 22 tuzluluk seviyesine kadar tolerans gösterdiği ve en yüksek kan serumu osmolarite değerinin 572±7.32 mOsm/Kg olduğu tespit edilmiştir. Laboratuvar ortamında üremenin 23.96±1.16 oC sıcaklık, 8.33±0.27 pH, 952±364 µS/cm iletkenlik, 6.92±0.10 mg/L ÇO değerlerinde gerçekleştiği, 23.5 °C'de 11 günde açılan, 8-12 adet yağ damlası içeren yapışkan ve filamentli yapıdaki döllenmiş yumurtaların 1.251±0.316 mm (n:30) çapa sahip olduğu, 3.695±0.225 mm (n:20) total boya sahip yeni çıkan larvada, eksojenik beslenmenin 3. günde ve toz yeme geçişin 10. günün sonunda gerçekleştiği belirlenmiştir.
Evaluation of Global Warming Effects on Juvenile Rainbow Trout: Focus on Immunohistochemistry and Osmoregulation
(Springer, 2025) Alkan, Zehra; Karatas, Boran; Sepil, Ahmet
The negative effects of global warming also directly affect aquatic populations. Consequences such as evaporation due to chronic temperature increase, increase in salinity, and increase in stock density per unit volume are potential stress factors. While creating the trial design, an attempt was made to simulate the effects of global warming, especially on species living in salty and brackish water biotopes. In this study, changes in the gills of rainbow trout (Oncorhynchus mykiss) acclimated to 0, 20, and 38 parts per thousand of saline in the laboratory were examined histologically and immunohistochemically and blood serum osmolarity. In addition, the water temperature was changed, and experiments were carried out at 16, 19, and 22 degrees C for each salinity group in parallel with the increase in salinity. However, to simulate the decrease in water volume and intensive stocking due to the potential impact of climate change, the study was carried out using 15 fishes in low-volume aquariums (45 L). Tap water that had been kept for at least 3 days was used in the aquariums. To protect the water quality, independent aquariums with sponge filters were used, and since the aim was to keep dissolved oxygen low, no ventilation system other than the sponge filter was used. In order to minimize the deterioration in water quality during the trial, a 15% water change was performed by performing a bottom flush every 4 days and water of the same temperature and salinity was added as much as the reduced volume. In addition, since increasing stock density due to temperature increase and water decrease will cause the amount of dissolved oxygen to decrease, pure oxygen was not entered into any tank throughout the experiment, and the concentration was requested to be at a low level (7 +/- 0.13 mg/L) in all groups. The trials were terminated at the end of the 71st day. Increased serum osmolarity values were observed due to the increase in salinity, and the highest serum osmolarity value was measured at 644 mOsm/kg in the 38 parts per thousand salinity group. Differences between the groups were found to be statistically significant (p < 0.05). It was observed that the number of cells containing Na+/K+-ATPase increased depending on salinity. Also, the number of chloride cells reached the maximum level in the 38 parts per thousand salinity group. Due to increasing salt levels, an increase in mucus cells, limited onset hyperplasia, aneurysm, lamellar separation, and necrosis were observed in the gill tissue.
First Evaluation of Microplastic Pollution in the Surface Waters of the Van Bay From Van Lake, Turkey
(Taylor & Francis Ltd, 2022) Atici, Ataman Altug; Sepil, Ahmet; Sen, Fazil; Karagoz, Mustafa Hamdi
Increasing pollution of plastics smaller than 5 mm (microplastics [MPs]) in seas and oceans as well as in inland waters around the world has recently been a significant threat to water resources. In this study, MP pollution levels were investigated using a 335 mu m mesh manta trawl in November 2019 in Van Bay. Water samples were collected from 15 stations. MP particles ranged from 641424 to 1426638 per km(2) in surface waters (ranged from 2.35 to 5.09 MPs/m(3) in water columns). The most frequently observed MP type, size, shape and colour classes were fiber (40.5%), <0.1 mm (52.3%), irregular (40.8%) and blue (57.1%), respectively. The highest MP abundance was observed at 14 and 15 stations where lake current were effective. Station 6 were also under serious plastic pollution pressure beacuse it was located close to Akkopru and Kurubas Rivers that pass through the densely populated city center. The chemical structure of all examined MPs showed presence of polyethylene (60.2%), followed by polypropylene (20.4%), polyethylene terephthalate (17.2%) and poly(methyl acrylate) (2.2%). The MPs were also examined using scanning electron microscopy to understand the surface characteristics. In conclusion, our study revealed that the surface waters of Van Bay are highly contaminated with MPs.
Growth and Reproduction Properties of Endemic Capoeta Kosswigi and Barbus Ercisianus in the Delicay Stream (Van, Turkey)
(Ege Univ, Fac Fisheries, 2021) Atici, Ataman Altug; Sepil, Ahmet; Sen, Fazil; Cavus, Asude
In this study, the growth and reproductive characteristics of Capoeta kosswigi Karaman, 1969 and Barbus ercisianus Karaman, 1971, which are endemic to the Lake Van Basin, in Delicay (Van) were investigated. A total of 309 C. kosswigi and 288 B. ercisianus specimens were caught by electrofishing between April and August 2018. The fork length of C. kosswigi and B. ercisianus ranged from 3.7-26.1 cm and from 4.3-22.7 cm, and the total weights ranged from 0.6-227.4 g and from 1.2-140.0 g, respectively. The most intensive catching was in C. kosswigi population of 5.0-6.9 (27.5%) cm and 0-19.9 (67.0%) g in the groups, and 12.0-13.9 (24.7%) cm and 0-9.9 (23.3%) g groups in B. ercisianus. Condition factor was determined as 1.305 +/- 0.008 (0.798-1.886) in C. kosswigi and 1.158 +/- 0.006 (0.864-1.559) in B. ercisianus. The length-weight relationships were calculated as W = 0.01435 x L-2.952 (r(2) = 0.996) for C. kosswigi and W = 0.01276 x L-2.959 (r(2) = 0.994) for B. ercisianus. The M:F ratio was calculated as 1:0.15 in C. kosswigi and 1:0.64 in B. ercisianus. It was established that C. kosswigi attained sexual maturity when they reached to 11 cm fork length for males, 18 cm fork length for females. Maturation of B.ercisianus individuals occurred at 9 cm fork length in males and 12 cm fork length in females. The spawning in C. kosswigi was observed from 1st week of May to 2nd week of July, and in B. ercisianus from 1st week of May to 1st week of August. It may be suggested that minimum catching size must be 20 cm fork length for C. kosswigi and 15 cm fork length for B. ercisianus.
High Levels of Microplastic Ingestion by Commercial, Planktivorous Alburnus Tarichi in Lake Van, Turkey
(Taylor & Francis Ltd, 2021) Atici, Ataman Altug; Sepil, Ahmet; Sen, Fazil
Microplastic pollution of inland environments has been receiving increased publicity over the last few years. For the first time, this study reports on the presence of microplastics (0.1 mm to <5 mm) in the gastrointestinal tracts of Alburnus tarichi in Lake Van from January to April 2020. In total, 101 fishes were obtained from Citoren, Edremit, Gevas and Dagonu fisheries regions. A total of 3338 pieces of plastic, ranging from 8 to 124 samples per fish with averaging 34 +/- 13 MPs/individual, were extracted from gastrointestinal tracts of fish. The majority of the ingested particles consisted of fibres (74%), and blue coloured material was the most consumed microplastic. The polymers identified by Fourier Transform Infrared Spectroscopy (FTIR) were polyethylene and polypropylene. Consequently, this study suggested that the vast majority of A. tarichi were contaminated with microplastics and showed higher abundance in comparison with other worldwide studies so far.
A Risk Assessment on Occupational Health and Safety in Fishing Activities in Gevas District (Van, Turkiye) for Healthcare Management
(Arman Darya inc, 2023) Cengiz, Ozgur; Demir, Muhammet; Sepil, Ahmet; Seremet, Mehmet
In this study, the commercial fishing activities, which is one of the oldest professions, is categorized as the most dangerous profession both in the world and in Turkey due to the workplace and working conditions. Diseases and accident rates are high in the aforementioned occupational group. The current study was carried out by face-to-face survey method with fishermen from April 2022 to September 2022 and the "L type matrix" method to evaluate possible risk factors in fishing activities in Gevas district in terms of occupational health and safety. The important risk factors; "Having no training in occupational health and safety (OHS)", and "Fatigue from irregular and long working hours" affect on the working conditions of the fishermen. This research is the first for Gevas region and is expected to be a reference for future studies.
Van Gölü Havzası Tuzlu Sularının Su Kalitesi Özellikleri ve Ağır Metal Kirlilik İndeksinin Belirlenmesi
(2021) Sepil, Ahmet; Şen, Fazıl; Atici, Ataman Altug
Amaç: Van Gölü Havzası kapalı bir havza konumunda olup, içerisinde birçok tuzlu su kaynağı bulunmaktadır. Bu çalışmada Van Gölü Havzası içerisinde yer alan Van Gölü dışındaki diğer tuzlu su kaynaklarının özellikleri araştırılmıştır. Materyal ve Yöntem: Çalışmada 7 noktada 2019 yılında Temmuz ayı içerisinde multimetre ile ölçümler yapılmış, su örneklerinde ağır metal kirlilik indeks değerleri hesaplanmıştır. Ayrıca titrimetrik analizler ile nitrit, nitrat, amonyum azotu, fosfat, fosfor, sülfat, florür, siyanür, bulanıklık, askıda katı madde ve silisyum analizleri de gerçekleştirilmiştir. Elde edilen sonuçlar ilgili su kalite yönetmeliklerine göre değerlendirilmiştir. Araştırma Bulguları: Çalışmada sıcaklık, çözünmüş oksijen, tuzluluk, elektriksel iletkenlik ve pH ortalama değerleri sırasıyla 23.5±1.8 (13.8-27.4)°C, 11.36±1.56 (6.91-17.70) mg/L, ‰3.67±1.47 (0.71-12.16), 6452.4±2350.0 (1087.0-19730.0) μS/cm ve 9.02±0.50 (6.21-10.13) olarak ölçülmüştür. Ağır metallerden bakır, kadmiyum, kurşun ve selenyum belirlenmezken, diğer ağır metal ortalama seviyeleri Mo> Mn > Al > Zn > Fe > Cr > Co > Ni > As şeklinde olmuştur. Ağır metal kirlilik indeks ortalama değeri ise 147.4±25.2 hesaplanmıştır. Sonuç: Su örnekleri ağır metal indeksi (HPI) kalite sınıfına göre genel olarak “kullanılamaz su” sınıfında yer almıştır. Sonuçlara göre “mükemmel” sınıfta örnek noktası yer almazken, N1 “iyi” sınıfta yer alan tek nokta olmuştur. N2, N3, N4, N5, N6 ve N7 noktaları “kullanılamaz su” sınıfında yer almıştır.