Yazarlar
- Akpinar, Adem(4)
- Avci, Utku(2)
- Kömürcü, Murat Ihsan(2)
- Akar, Bulent(1)
- Akar, Bülent(1)
- Akpınar, Adem(1)
- Aktas, Gulten(1)
- Bekircan, Çağrı(1)
- Bingölbali, Bilal(1)
- Güney, Aysegul(1)
- Hoskan, Nihan(1)
- Kandemir, Raif(1)
- Kankal, Murat(1)
- Kayıkçı, Emine Tanır(1)
- Kurnaz, Muammer(1)
- Kömü rcü, Murat Ihsan(1)
- Kömür, Mehmet Aydin(1)
- Kömürcü, Murat I.hsan(1)
- Tur, Huseyin(1)
- Yavuzdoğan, Ahmet(1)
- Yüksek, Ömer(1)
- van Vledder, Gerbrant Ph.(1)
- Özger, Mehmet(1)
- Özkan, Korhan(1)
- Özölçer, Ismail Hakki(1)
- Şan, Murat(1)
Yayınlar
- Derleme MakaleYalnız künye2026Marine microsporidia: Hidden diversity, aquatic emergence and zoonotic risks
Bekircan, Çağrı; Kurnaz, Muammer
Marine Microsporidia represent an increasingly important but historically underestimated group of aquatic intracellular parasites. Although traditionally associated with invertebrates and fishes, recent molecular and environmental studies have revealed extensive hidden diversity across marine ecosystems together with unexpected phylogenetic links between aquatic and human-associated lineages. This review synthesizes five decades of research (1975–2025) concerning the biology, evolution, taxonomy, host–pathogen interactions, ecological diversity, and zoonotic significance of marine Microsporidia. Particular emphasis is placed on members of the Enterocytozoonidae, including Enterocytozoon hepatopenaei, Nucleospora spp., and Desmozoon lepeophtherii, which represent major threats to aquaculture sustainability and may contribute to cross-environmental transmission pathways. Environmental DNA studies further indicate that marine microsporidian diversity is substantially underestimated by morphology-based approaches. However, current evidence for zoonotic transmission remains largely indirect, resting chiefly on phylogenetic relatedness, shared genotypes across hosts and environmental (eDNA) detection; direct, seafood-borne human infection has not yet been demonstrated. Current evidence suggests that aquaculture intensification, climate-driven environmental change, and expanding seafood trade may facilitate the emergence and dissemination of zoonotic microsporidian lineages. Integrating marine Microsporidia into One Health surveillance frameworks is therefore increasingly important for both ecosystem and public health management.
- MakaleYayıncıda açık erişim2026New Records for the Algal Flora of Türkiye from Blanket Bogs of the Eastern Black Sea Region
Akar, Bülent; Avci, Utku
Blanket bogs are ombrotrophic peatlands where water is mainly supplied by precipitation. This study reports new algal records from blanket bogs in Türkiye, contributing to the knowledge of Türkiye’s freshwater algal flora. Algal samples were collected from five different blanket bogs located in the Eastern Black Sea Region of Türkiye. Samples were obtained on a monthly basis during selected months, May, July, and September in 2021, May and September in 2022, and July in 2023. A total of 50 taxa belonging to 19 genera were identified: Scytonema (1), Cavinula (1), Kobayasiella (1), Netrium (4), Closterium (3), Actinotaenium (5), Cosmarium (3), Euastrum (3), Micrasterias (2), Spondylosium (1), Staurastrum (15), Staurodesmus (2), Tetmemorus (2), Microspora (1), Characium (1), Desmodesmus (1), Trachelomonas (2), Calycimonas (1), and Opisthoaulax (1). Calycimonas and Opisthoaulax are reported as new genera for the freshwater algal flora of Türkiye. The identified taxa were predominantly observed in acidic, oligotrophic and low-conductivity waters, thereby indicating the distinctive ecological characteristics and conservation value of alpine blanket peat bogs.
- MakaleAçık Erişim2024Diatom Communities in the Littoral Sediments of the Robert Island's Lakes, South Shetland Islands, Antarctica
Akar, Bulent; Güney, Aysegul; Özkan, Korhan; Avci, Utku; Kandemir, Raif
The study area is situated at Robert Island, which is located in the South Shetland Islands in the northwest of the Antarctic Peninsula. The diatom samples were taken as part of the Turkish Antarctic Expedition (TAE-II) which took place between March and April 2018. The samples were collected from the surface of sediments (c. 5 cm) at a depth of approximately 20 cm, 50-100 cm from the littoral zones of an inland glacial lake (L1) and three coastal lakes (L2, L3 and L4) situated on glacier-free area on Robert Island. The main objective of this study was to reveal the diversity and the abundance of diatom communities in the littoral sediments of the lakes on Robert Island. The lakes were shallow and oligotrophic freshwater lakes, although the coastal lagoons had a high conductivity and nutrient concentration. Twenty-six diatom taxa belonging to Achnanthes (1), Fragilaria (1), Frustulia (1), Gomphonema (1), Halamphora (1), Hantzschia (1), Hippodonta (1), Humidophila (2), Luticola (3), Melosira (1), Nitzschia (4), Pinnularia (3), Planothidium (2), Psammothidium (2), Stauroneis (1) and Stephanopterobia (1) were identified in the samples from these lakes. The coastal lake L2 showed the highest richness of diatom communities among the in studied lakes, with 21 identified taxa.
- MakaleYalnız künye2021Geo-spatial multi-criteria evaluation of wave energy exploitation in a semi-enclosed sea
Şan, Murat; Akpınar, Adem; Bingölbali, Bilal; Kankal, Murat
The present study aims to determine priority areas for installation of wave energy converters (WECs) in a semi-enclosed sea using a multi-criteria, spatial, decision-making analysis based on geographical information systems (GIS). The study also suggests a new methodology for determination of suitable areas for WECs taking into consideration different extreme wave conditions, intra-annual variation of wave conditions, and operational range of wave conditions by the WECs. A case study over a distance of 1140 km along the coast in the southwest Black Sea is presented. In the multi-criteria analysis, areas with environmental, economic, technical and social constraints are excluded. Ocean depth, distance to ports, shore, power line, and sub-station, wave climate, and sea-floor geology are all evaluated for their impact on the system implementation and weighted according to their relevance. Thus, the final suitability index (SI) map is produced and spatial statistical significance of the suitable areas is checked using hotspot analysis. Based on this, Kırklareli coastal area and the area between İğneada Cape and Kıyıköy village are determined as primary priority areas. The sustainability parameters with different weights proposed in this study do not differentiate priority areas but affect the SI scores.
- MakaleAçık Erişim2020Ege Denizi Bağıl Deniz Seviyesi Değişimlerinde Kapula Fonksiyonları İle Trend Analizleri
Kayıkçı, Emine Tanır; Yavuzdoğan, Ahmet
İklim değişikliği başta olmak üzere birçok nedenden dolayı global ölçekte deniz seviyesinde meydana gelen artışlar, kıyı ekosistemlerinietkilemekte ve kıyı yerleşimlerini tehdit etmektedir. Jeodezik açıdan uzun dönemli deniz seviyesi gözlemleri düşey kontrol ağlarınındatumunun belirlenmesi açısından önemlidir. İstatistik, ekonomi, aktüerya analizi, meteoroloji, hidroloji gibi birçok alanda farklıdeğişkenler arasındaki ilişkileri araştırmak için kullanılan Kapula fonksiyonları değişkenlerin ve hatalarının dağılımındanetkilenmeyen, lineer ve lineer olmayan ilişkileri yansıtan, lokal bağımlılıkları da gösterebilen korelasyon yapısıyla lineer korelasyonkatsayısına göre oldukça elverişli bir korelasyon yapısı sunabilmektedir. Bu çalışmada, Ege Denizi kıyısında bulunan 5 mareografistasyonundan elde edilen 1990-2008 yılları arasında aylık deniz seviyesi ve deniz yüzey sıcaklığı ortalamaları verileri ile kıyılardakiuzun dönemli bağıl deniz seviyesi değişimleri ve bu değişimlerin deniz yüzey sıcaklığı ile ilişkisi Kapula Fonksiyonları ile incelenmiştir.Bu çalışma kapsamında ilk defa sunulan kapula temelli trend analiz yöntemi ile deniz seviyesi ve deniz yüzey sıcaklığı zaman serilerindetrend analizleri gerçekleştirilerek elde edilen trendler regresyon modelleri ile karşılaştırılmıştır. Ege denizinde 1990-1998 yıllarıarasında deniz seviyesinin oldukça hızlı bir şekilde arttığı, 1999-2008 yılları arasında ise deniz seviyesinin düştüğü görülmüştür. 1990-1998 yılları arasında deniz seviyelerindeki artışın deniz yüzey sıcaklıklarındaki sıcaklık artışlarından kaynaklandığı, 1999-2008 yıllarıarasındaki deniz seviyesindeki azalmaların da deniz yüzey sıcaklıklarındaki soğumalardan kaynaklandığı değerlendirilmiştir.
- MakaleYalnız künye2015Tectonic evolution of the northern shelf of the Marmara Sea (Turkey): interpretation of seismic and bathymetric data
Tur, Huseyin; Hoskan, Nihan; Aktas, Gulten
This study is based on the geological interpretation of 250 km2 of multibeam bathymetric data coupled with 300 km of seismic profiles recorded on the northern shelf of the Marmara Sea offshore Büyükçekmece and Küçükçekmece Lagoons. The sea bottom morphology has a highly chaotic structure at the exit of the Büyükçekmece and Küçükçekmece lagoons. This chaotic surface structure is controlled by a basin-ridge system lying in the NE–SW direction at the exit of the Büyükçekmece Lagoon and by a relatively deep entrance observed at the exit of the Küçükçekmece Lagoon. In addition, the linear submarine slope parallel to the shoreline between the Istanbul Strait and the Küçükçekmece Lagoon is an important morphological structure of this area. The Istanbul Strait’s canyon on the northern shelf of the Marmara Sea and the elevated submarine plain west of this canyon are other important morphological structures observed at the sea bottom. The geologic interpretation of seismic profiles has allowed us to distinguish two seismo-stratigraphic units. The lower one is separated from the overlying units by a seismic sequence having a seismic facies from chaotic to parallel and the top represented by a high amplitude seismic reflector. Since these units get close to the sea bottom rising landwards, they are inferred to be the seaward continuation of the Oligocene–Upper Miocene units widely exposed on land. The upper unit, overlying the acoustic basement, whose parallel internal reflections onlap and downlap on the top of the acoustic basement, is interpreted as a Quaternary basin fill. Two groups of faults have been identified on seismic profiles and identified based on their characteristics in the study area. The first group consists of dip-slip faults trending NNE–SSW. These faults border the western slope of the Bosporus and the NNE–SSW trending basins offshore of the Büyükçekmece Lagoon. The second group of faults consists of NW–SE oriented strike-slip faults. These faults have created the linearities in the same direction at the sea bottom. As the result of comparison of these NW–SE-faults to the North Anatolian Fault Zone (NAFZ), this group of faults is likely to have a relation with the NAFZ. Therefore, it is considered that the mentioned faults may be reactivated in the region due to the stress created by the NAFZ.
- MakaleYalnız künye2013Prediction of offshore bar-shape parameters resulted by cross-shore sediment transport using neural network
Kömü rcü, Murat Ihsan; Kömür, Mehmet Aydin; Akpinar, Adem; Özölçer, Ismail Hakki; Yüksek, Ömer
In order to understand the features of coastal zone and to utilize the coastal areas, it is necessary to determine the sediment movement and the resulting transport. Waves, topographic features, and material properties are known as the most important factors affecting the sediment movement and coastal profiles. In this study, by taking into consideration of wave height and period (H0, T), bed slope (m) and sediment diameter (d50), cross-shore sediment movement was studied in a physical model and various bar-shape parameters of the resultant erosion type profile were determined. Using 80 experimental data which are obtained from physical model studies, a neural network (NN) has been calibrated to predict bar-shape parameters of beach profiles. A sensitivity analysis was firstly carried out to decide data of training and test sets. Four different models, in which the rates of their training and testing set data were 80% and 20%, 70% and 30%, 60% and 40%, 50% and 50% were constituted and their performances were compared. It was determined that the model, in which the rate of its training and testing set data was 80% and 20%, respectively, has the best results. Therefore, a total of 64 experimental data were used as training set and the remainders of the experimental data were used as a testing set for the model. The performance of the NN model was compared with the regression equations developed in a previous study and the equations cited in literature indicating better performance over the equations.
- MakaleYalnız künye2013Assessment of wave energy resource of the Black Sea based on 15-year numerical hindcast data
Akpinar, Adem; Kömürcü, Murat I.hsan
In this study, the existence and variability of wave energy resource potential of the Black Sea based on 15-year hindcast data is described in detail. The hindcasts of wave parameters were carried out by using the third generation wave prediction model (Simulated WAves Nearshore - SWAN), which is one of the most popular numerical wave models and has been widely used for estimating ocean waves. The model was forced with the ECMWF ERA Interim wind fields and applied with a spatial resolution of about 0.0167°. ×. 0.0167° and a model time step of 6. h to resolve efficiently offshore and nearshore wave conditions. The results were presented in the form of charts of the spatial distribution of significant wave height and wave power, on a monthly, seasonal and annual basis. Annual energy was calculated in the study region with the hindcast data set covering 15. years (1995-2009). The areas with the highest wave energy resource were determined and the south west coasts of the Black Sea are suggested as the best site for the installation of a wave farm. It was determined the western parts of the Black Sea (especially the south-west) are exposed to energetic waves more than the eastern parts.
- MakaleYalnız künye2012Wave energy potential along the south-east coasts of the Black Sea
Akpinar, Adem; Kömürcü, Murat Ihsan
This study aims to assess and characterize wave energy resource along the southeastern coasts of the Black Sea. For this purpose, wave energy potential was investigated at a total of 7 study points in this area. The potential for energy generation was assessed based on six-hourly data from a third generation wave model (SWAN) covering the period 1995-2009. The results were validated with buoy measurements and wave energy and power was calculated with the numerical hindcast data. For characterization of wave energy potential, average annual and seasonal variations of the wave power in this area was firstly investigated. Second, wave energy development indexes and the probabilities of exceedance of wave power at the study points were determined. Third, wave energy resource in different ranges of significant wave heights and zero-crossing periods were characterized. Finally, It was found that annual wave energy of all points except Sinop point, whose annual wave energy is 10 MWh/m, is approximately 6 MWh/m and the bulk of annual wave energy occurs for significant wave heights between 0.5 and 2 m and periods between 2 and 5 s.
- MakaleYalnız künye2012Evaluation of the numerical wave model (SWAN) for wave simulation in the Black Sea
Akpinar, Adem; van Vledder, Gerbrant Ph.; Kömürcü, Murat Ihsan; Özger, Mehmet
This study summaries the implementation of the SWAN model forced by the ECMWF ERA Interim dataset reanalyzed 10 m winds over the Black Sea which will be used to study the wind-wave climate and wave energy potential in the region, and its verification. The SWAN model results were compared with directional buoy measurements at three locations along the north and south coasts of the Black Sea, parametric model results based on the JONSWAP growth relations, and the results of previous studies. The SWAN model has been applied in a third generation and non-stationary mode with spherical coordinates. The linear and exponential growth from wind input, depth-induced wave breaking, bottom friction, whitecapping, four-wave (for deep water) and triad-wave (for shallow water) nonlinear interactions have been activated in the simulations. The results of this study indicate that agreement between simulated and observed wave parameters is satisfactory and it is slightly more accurate than the results of the previous studies. However, it still has lower estimates for the maximum values of both wave parameters. These lower estimates are probably due to too low wind speeds in the applied ECMWF wind fields, which is probably caused by orographic effects, and due to the relatively course resolution in time and space of the ECMWF (ERA-Interim) wind fields for the Black Sea. (C) 2012 Elsevier Ltd. All rights reserved.
