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Öğe Accumulation of trace elements in muscle, gill and liver of fish species (Capoeta umbla and Luciobarbus mystaceus) in the Tigris River (Turkey), and health risk assessment(Academic Press Inc Elsevier Science, 2020) Varol, Memet; Kacar, Emel; Akin, Hulya KaradedeTwo fish species (Capoeta umbla and Luciobarbus mystaceus) were collected from the Tigris River (Turkey), and tissues (gill, muscle and liver) of fish samples were analyzed for Cd, As, Mn, Cr, Cu, Co and Ni using the inductively coupled plasma-tandem mass spectrometry. Significant differences were present between fish species in regard to trace element (TE) concentrations in muscle for Mn, in liver for Cu, Cd and Mn, and in gill for As, Co, Cu and Cd (p < 0.05). Liver had the highest total TE concentration, followed by gill and muscle. Significant negative correlations were recorded between fish size (length and weight) and TE concentrations in the tissues. Both fish species showed no gender differences in TE accumulation in muscle, gill and liver (p > 0.05). The estimated daily intakes for all TEs were much lower than the tolerable daily intakes. The target hazard quotient (THQ) and total THQ values of all TEs did not exceed 1, which means that non-carcinogenic health effects are not expected for the consumers. Arsenic carcinogenic risk values were within acceptable range. Mean Cd concentrations in muscle tissue of both fish species exceeded the maximum permissible limit set by the European Commission Regulation, while mean concentrations of As, Cr and Cu were below the legislated limits.Öğe Assesment of Water Pollution in the Tigris River in Diyarbakir, Turkey(Iwa Publishing, 2010) Varol, Memet; Gokot, Blent; Bekleyen, AyselDiyarbakir is the biggest city and the largest urban settlement in the Tigris Basin in Turkey. It has been gradually developing and growing thanks to the Southeastern Anatolia Project (GAP), and is one of the most important centers of industry, agriculture and animal husbandry in the Tigris Basin. The Tigris River is an important water source for the city, and it serves for irrigation, fishing, recreation and receiving wastewater. With the development of industry, agriculture and the growth of urban population, its pollution has become a serious problem. Pollution from domestic, industrial and agricultural activities has led to deterioration of water quality. In this context, the aim of the present study is to identify point sources of pollution and to assess the surface water quality of the Tigris River in the study area by monitoring physicochemical parameters. Diyarbakir produced a negative impact on the Tigris River water quality, particularly after the WWTP discharge. Concentrations of chemical oxygen demand, organic nitrogen, total nitrogen and total phosphorus increased markedly downstream of Diyarbakir WWTP discharge point. During the summer, the extent of organic pollution was so serious in the stations, downstream of WWTP, that dissolved oxygen became almost absent from the river water. The metal concentrations of all water samples were mostly below or close to the maximum permitted concentration for protection of aquatic life and drinking water.Öğe Dicle nehri ile Kralkızı, Dicle ve Batman baraj göllerinin fiziko-kimyasal özellikleri, fito ve zooplanktonu üzerine bir araştırma(2009) Varol, Memet; Gökot, Bülent; Şen, Bülent; Bekleyen, Aysel[Abstract Not Available]Öğe Dissolved heavy metals in the Tigris River (Turkey): spatial and temporal variations(Springer Heidelberg, 2013) Varol, Memet; Gokot, Bulent; Bekleyen, AyselMultivariate statistical techniques, such as analysis of variance, cluster analysis (CA), correlation analysis, principal component analysis (PCA), and factor analysis (FA), were applied to determine the spatial and temporal variations of dissolved heavy metals in the Tigris River at 7 different sites spread over the river stretch of about 500 km during the period of February 2008 to January 2009. The results indicated that Fe, Cr, and Ni were the most abundant elements in the river water, whereas Cd and As were the less abundant. Cu, Fe, Ni, and Zn showed significant spatial variations, reflecting the influence of anthropogenic activities. The lowest total concentration of heavy metals was found at site 2 downstream of the Dicle Dam due to clean water from the dam. The concentrations of most metals were found lower when compared with results of previous studies due to reduction of the activity of the copper mine plant and the construction of two dams on the river. The lowest total concentrations were determined in February due to high precipitation and snow melts. Hierarchical agglomerative CA classified all the sampling sites into three main groups of spatial similarities. Clusters 1 (Maden and Bismil), 2 (Cizre), and 3 (Egil, DiyarbakA +/- r, Batman, and Hasankeyf) corresponded to moderate polluted and relatively low polluted regions, respectively. PCA/FA, CA, and correlation analysis suggest that Cu, Ni, and Zn are controlled by anthropogenic sources.Öğe First Record of the Genus Phyllodiaptomus Kiefer (Copepoda, Calanoida, Diaptomidae) from Turkey(Central Fisheries Research Inst, 2017) Bekleyen, Aysel; Gokot, Bulent; Varol, MemetThe genus Phyllodiaptomus Kiefer, 1936 is reported from Turkey for the first time. Phyllodiaptomus sp. collected from the Batman Dam Reservoir in Southeastern Turkey was observed only between May and November 2008. The female and male specimens are illustrated in detail. Phyllodiaptomus sp. is closely related to P. blanci (Guerne & Richard) and P. irakiensis Khalaf, from which it differs in several characteristics that are discussed. The present new record extends the known distribution of the genus Phyllodiaptomus to Turkey being a natural bridge between Europe and Asia.Öğe First Record of the Order Choanoflagellida in Turkey(Central Fisheries Research Inst, 2011) Varol, Memet; Bekleyen, Aysel; Sen, Bulent; Gokot, BulentWe report the first record of the order Choanoflagellida in the waters of Turkey. The choanoflagellate Salpingoeca amphoridium James-Clark was found in plankton net samples in November and December 2008, and January 2009 from the Batman Dam Lake, the Batman Stream and Hasankeyf sampling site of the Tigris River. Salpingoeca amphoridium was found attached to planktonic diatom Aulacoseria granulata (Ehrenberg) Simonsen.Öğe Geochemistry of the Tigris River basin, Turkey: Spatial and seasonal variations of major ion compositions and their controlling factors(Pergamon-Elsevier Science Ltd, 2013) Varol, Memet; Gokot, Bulent; Bekleyen, Aysel; Sen, BulentA total of 204 water samples were collected from 17 sites in four different water bodies in the Tigris River basin during the period from February 2008 to January 2009. Major ions (Ca2+, Mg2+, Na+, K+, HCO3-, SO42-, Cl-, NO3- and SiO2), water temperature, pH, EC and TDS were determined, and consequently analysis of variance, correlation analysis, cluster analysis, factor analysis and principal component analysis were performed to explore their spatial and seasonal variations, quantify the geochemical and anthropogenic processes and identify factors influencing the ionic concentrations. The results indicated that waters in the Tigris River basin are mildly alkaline with high concentrations of Ca2+ and HCO3-, which in total account for approximately 78% of the total ionic budgets. All parameters studied in the Tigris River showed significant spatial variations, while EC, TDS, Cl-, SO42-, Na+, Ca2+, Mg2+ and HCO3- had significant spatial variations in the dam reservoirs. In the Tigris River, EC, TDS, SiO2, Ca2+ and Mg2+ displayed higher values in months of the dry season, while higher values for pH, NO3-, Cl-, SO42-, Na+, K+ and HCO3- in months of the wet season. In the dam reservoirs, all parameters studied except pH showed higher values in months of the wet season. The major ion chemistry of Tigris River basin is mainly controlled by rock weathering with HCO3- and Ca2+ dominating the major ion composition because of the abundance of carbonate rocks in the basin. A comparison with WHO standards for drinking water indicates that the basin has high-water quality. (C) 2013 Elsevier Ltd and INQUA. All rights reserved.Öğe Hydrochemistry, water quality and health risk assessment of streams in Bismil plain, an important agricultural area in southeast Türkiye(Elsevier Ltd., 2023) Çankaya, Şihap; Varol, Memet; Bekleyen, AyselIn this study, the water quality of Ambar, Kuruçay, Pamuk and Salat streams, which are the important tributaries of the Tigris River in the Bismil Plain (Diyarbakır, Türkiye) was assessed using 19 physicochemical parameters. Except for a few exceptions, all parameters in the water samples taken from the streams were below the drinking water limit values. Kuruçay Stream had significantly higher TOC, Na+, NO3−, NO2−, Cl− and SO42− levels and lower DO levels than other streams (p < 0.05) due to sewage water discharges, animal manure storage areas near the stream and irrigation return flows. In all streams, Ca–HCO3 was dominant water type. Gibbs diagram indicated that rock weathering is the major factor controlling the hydrochemistry of the streams. According to the results of water quality index (WQI), all sampling stations of Ambar, Pamuk and Salat streams and K1 station of Kuruçay Stream had “good” quality water for drinking purposes, while K2 station of Kuruçay Stream had “poor” quality water. Irrigation indices (permeability index, sodium percentage, magnesium hazard, residual sodium carbonate, Kelley's ratio, sodium adsorption ratio and potential salinity) revealed that all water samples taken from the streams were suitable for irrigation. The water samples from Ambar, Pamuk and Salat streams were in the C2S1 (medium salinity and low alkalinity) category, while the samples from Kuruçay Stream were in the C2S1 and C3S1 (high salinity and low alkalinity) categories. Both hazard quotient and hazard index values of NO3–N, NO2–N and F− for children and adults were found below 1, indicating that adverse health effects are not expected from exposure to these contaminants via water ingestion and dermal contact. The findings of this study showed that the water quality status of Kuruçay Stream is worse as it receives large amounts of irrigation return flows compared to other streams.Öğe A new record of the freshwater jellyfish Craspeducusta sowerbii Lankester, 1880 (Hydrozoa) in Southeastern Anatolia (Turkey)(Science Press, 2011) Bekleyen, Aysel; Varol, Memet; Gokot, BulentWe report the first record of the invasive freshwater jellyfish Craspedacusta sowerbii Lankester in Kralkizi Dam Lake, Southeastern Anatolia, Turkey. The medusa was found only in August, 2008 when average surface water temperatures were 26.9 degrees C.Öğe Spatial and temporal variations in surface water quality of the dam reservoirs in the Tigris River basin, Turkey(Elsevier, 2012) Varol, Memet; Gokot, Bulent; Bekleyen, Aysel; Sen, BulentMultivariate statistical techniques, such as cluster analysis (CA), principal component analysis (PCA), factor analysis (FA) and discriminant analysis (DA), were applied to evaluate the temporal/spatial variations of water quality data sets for Kralkizi, Dicle and Batman dam reservoirs in the Tigris River basin, obtained during 1 year (2008-2009) of monitoring. This study highlights the usefulness of multivariate statistical techniques for the evaluation and interpretation of complex water quality data sets, apportionment of pollution sources/factors and the design of a monitoring network for the effective management of water resources. Hierarchical CA grouped 12 months into two clusters (wet and dry seasons) and classified ten monitoring sites into four clusters based on similarities in the water quality characteristics. PCA/FA identified five factors in the data structure that explained 80% of the total variance of the data set. The PCA/FA grouped the selected parameters according to common features to help evaluate the influence of each group on the overall variation in water quality. Discriminant analysis showed better results for data reduction and pattern recognition during both spatial and temporal analysis. Temporal DA revealed nine parameters (water temperature, dissolved oxygen, total alkalinity, total hardness, nitrate nitrogen, ammonia nitrogen, total phosphorus, chloride and calcium), affording 100% correct assignations. Spatial DA revealed eight parameters (water temperature, pH, dissolved oxygen, electrical conductivity, nitrate nitrogen, orthophosphate phosphorus, sodium and total suspended solids), affording 92.5% correct assignations. Therefore, DA allowed a reduction in the dimensionality of the large data set and indicated a few significant parameters responsible for large variations in water quality that could reduce the number of sampling parameters. (C) 2011 Elsevier B.V. All rights reserved.
