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Öğe Biomonitoring of Trace Metals in the Keban Dam Reservoir (Turkey) Using Mussels (Unio elongatulus eucirrus) and Crayfish (Astacus leptodactylus)(Humana Press Inc, 2018) Varol, Memet; Sunbul, Muhammet RasitFreshwater mussels and crayfish are commonly used as biomonitors of trace metals. In the present study, the concentrations of ten metals were determined in mussels (Unio elongatulus eucirrus) and crayfish (Astacus leptodactylus) collected from the Keban Dam Reservoir in Turkey. The significant spatial differences in concentrations of studied metals except As in mussels were not found. However, Co, Cr, Cu, and Zn concentrations in mussels and As, Co, Cu, Fe, Pb, and Zn concentrations in crayfish showed significant seasonal differences. As, Cd, and Mn levels in mussels were about nine times higher than those in crayfish. The concentrations of Cd, Cr, Cu, Pb, Zn, and inorganic As in crayfish and mussels were lower than maximum permissible levels. When compared with other biomonitoring studies using mussels and crayfish, high concentrations of As, Cd, Co, Cr, and Ni in mussels and Cr and Ni in crayfish were observed due to lithogenic sources and anthropogenic activities in the basin. Bioconcentration factor values of Fe, Mn, Cd, and Zn in mussels and Zn, Cu, Fe, and Co in crayfish were > 1000, which indicates that both U. e. eucirrus and A. leptodactylus have potential to bioaccumulate these metals. Therefore, attention should be paid to mussels and crayfish from ecological and human health perspective, because they are potential vectors of metals to higher trophic levels.Öğe Biomonitoring of Trace Metals in the Keban Dam Reservoir (Turkey) Using Mussels (Unio elongatulus eucirrus) and Crayfish (Astacus leptodactylus) (vol 185, pg 216, 2018)(Humana Press Inc, 2018) Varol, Memet; Sunbul, Muhammet RasitThe original version of this article contained mistakes: the units mg/kg(-1) and mu g/kg(-1) found on tables 1, 2, 4, 5 and 6 should be mg kg(-1) and mu g kg(-1), respectively.Öğe Biotic and abiotic controls on CO2 partial pressure and CO2 emission in the Tigris River, Turkey(Elsevier, 2017) Varol, Memet; Li, SiyueRivers act not only as vectors from the terrestrial biosphere to the ocean but also as significant sources of CO2 to the atmosphere, which plays a key role in the global carbon cycle. In this study, dissolved inorganic carbon (DIC) and carbon dioxide partial pressure (pCO(2)) in the Tigris River were investigated. The alkalinity concentrations of the Tigris River ranged from 1718 to 4995 mu q/L with an average of 3064 mu q/L (median: 2877 mu eq/L), 23 times the global median value of 1256 mu eq/L Higher alkalinity values occurred in autumn and winter months that were due to carbonate rock weathering, pCO(2) values varied from 95.6 to 16,001.8 mu atm with a total average of 1277 +/- 1883 mu atm. >80% of samples had pCO(2) above atmospheric equilibrium (390 mu atm). The highest levels of pCO(2) occurred at stations Diyarbakir, Bismil and Cizre, which are categorized as polluted stations. The lowest levels of pCO(2) generally occurred in the wet season (October-April) due to dilution effect of rainfall. The estimated water-to-air CO2 degassing flux from the Tigris River was around 39 mol/m(2)/y. Thus, 0.15 Tg C/y as CO2 released from the river to the atmosphere, about 0.6 fold the riverine DIC flux (0.25 Tg C/y). Correlative analyses demonstrated that population density and air temperature increased pCO(2), while slope degree decreased pCO(2). pCO(2) also had positive correlations with COD, NH4-N, PO4-P, SO4, Cl, phytoplankton abundance and number of phytoplankton taxa, while negative correlations with DO saturation and pH. (C) 2016 Elsevier B.V. All rights reserved.Öğe Comparison of heavy metal levels of farmed and escaped farmed rainbow trout and health risk assessment associated with their consumption(Springer Heidelberg, 2017) Varol, Memet; Sunbul, Muhammet RasitIn this study, levels of ten metals (arsenic, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, and zinc) in muscles of farmed and escaped farmed rainbow trout (Oncorhynchus mykiss) in the Keban Dam Reservoir (Turkey) were determined. Also, human health risks associated with their consumption were assessed. Of ten metals, only Co and Fe levels in escaped rainbow trout were significantly higher than those in farmed rainbow trout. The metal levels in farmed and escaped rainbow trout were below the maximum permissible limits. The estimated daily intake (EDI) of each metal in both farmed and escaped farmed rainbow trout was much lower than the respective tolerable daily intake (TDI). The target hazard quotient (THQ) values for individual metal and the total THQ values for combined metals were lower than 1 in both farmed and escaped rainbow trout, indicating no health risk for humans. The cancer risk (CR) values estimated for inorganic As in both farmed and escaped rainbow trout indicated low carcinogenic risk to the consumers. According to the maximum allowable monthly consumption limits (CRmm), adults may safely consume 24 meals of farmed rainbow trout per month or 39 meals of escaped rainbow trout per month, with minimal adverse carcinogenic and non-carcinogenic health effects. This study revealed that the risk from consuming farmed and escaped farmed rainbow trout in the Keban Dam Reservoir due to these trace elements is minimal.Öğe Dicle Nehri’nin Planktonik Alg Florası(İnönü Üniversitesi Su Ürünleri Fakültesi, Temel Bilimler Bölümü,Malatya, Türkiye, 2014) Şen, Bülent; Varol, MemetÖz: Bu çalışma, Dicle Nehri'nin fitoplankton kompozisyonundaki değişimlerini ortaya koymak için Şubat 2008-Ocak 2009 tarihleri arasında 7 istasyonda aylık olarak yürütülmüştür. Bacillariophyta, Chlorophyta, Cyanophyta, Euglenophyta, Chrysophyta, Pyrrophyta, Cryptophyta, Xantophyta ve Rhodophyta divizyolarına mensup 390 takson teşhis edilmiştir. Tür çeşitliliği bakımından fitoplanktonun en zengin gruplarını, toplam takson sayısının %39.23'ünü kapsayan Bacillariophyta, %32.05'ini kapsayan Chlorophyta ve %18.46'sını kapsayan Cyanophyta divizyoları oluşturmuştur. Bacillariophyta divizyosundan Achnanthes minutissima var. minutissima, Amphora ovalis, Cocconeis pediculus, Cymbella affinis, Diatoma vulgaris, Encyonema silesiacum, Gomphonema angustatum, Gomphonema olivaceum, Gomphonema parvulum, Gomphonema vibrio var. intricatum, Navicula capitatoradiata, Navicula cryptonella, Navicula trivialis, Nitzschia fonticola, Nitzschia palea, Reimeria sinuata, Rhoicosphenia abbreviata ve Ulnaria ulna; Chlorophyta divizyosundan Cladophora glomerata, Eudorina elegans, Mougeotia sp., Oedogonium sp., Pediastrum boryanum, Spirogyra sp., Stigeoclonium lubricum, Ulothrix tenerrima ve Ulothrix tenuissima; Cyanophyta divizyosundan Oscillatoria subbrevis, Phormidium formosum, Phormidium limosum, Planktolyngbya limnetica, Planktothrix agardhii ve Pseudanabaena limnetica; Pyrrophyta divizyosundan Ceratium hirundinella ve Peridinium cinctum; Euglenophyta divizyosundan Euglena oxyuris ve Euglena sp.; Rhodophyta divizyosundan Audouinella hermannii Dicle Nehri'nde yaygın bulunan türler olarak teşhis edilmiştirÖğe Dissolved heavy metal concentrations of the Kralkizi, Dicle and Batman dam reservoirs in the Tigris River basin, Turkey(Pergamon-Elsevier Science Ltd, 2013) Varol, MemetWater samples were collected at monthly intervals during 1 year of monitoring from Kralkizi, Dicle and Batman dam reservoirs in the Tigris River basin to assess the concentrations of dissolved heavy metals and to determine their spatial and seasonal variations. The results indicated that dissolved heavy metal concentrations in the reservoirs were very low, reflecting the natural background levels. The lowest total metal concentrations in the three dam reservoirs were detected at sampling sites close to the dam wall. However, the highest total concentrations were observed at sites, which are located at the entrance of the streams to the reservoirs. Fe, Cr and Ni were the most abundant elements in the reservoirs, whereas Cd and As were the less abundant. The mean concentrations of dissolved metals in the dam reservoirs never exceeded the maximum permitted concentrations established by EC (European Community), WHO and USEPA drinking water quality guidelines. All heavy metals showed significant seasonal variations. As, Cd, Cr, Cu, Fe, Ni and Pb displayed higher values in the dry season, while higher values for Zn in the wet season. Cluster analysis grouped all ten sampling sites into three clusters. Clusters 1 and 2, and cluster 3 corresponded to relatively low polluted and moderate polluted regions, respectively. PCA/FA demonstrated the dissolved metals in the dam reservoirs controlled by natural sources. (C) 2013 Elsevier Ltd. All rights reserved.Öğe External morphological variations and temporal distribution of the dinoflagellate Ceratium hirundinella in two dam reservoirs in the Tigris River basin (Turkey)(Tubitak Scientific & Technological Research Council Turkey, 2016) Varol, MemetSeasonal distribution, abundance, and external morphological changes of Ceratium hirundinella in the Kralkizi and Dicle dam reservoirs on the Tigris River were investigated during 1 year (February 2008 to January 2009). This species was present in both dam reservoirs during all 4 seasons. The highest mean density of C. hirundinella in Kralkizi Dam Reservoir was recorded in December, while in Dicle Dam Reservoir it was highest in June. C. hirundinella cells had a fourth horn in both dam reservoirs during the study period, and morphologically they showed the highest relative standard deviation in the fourth horn. In addition, a new fifth horn occurred on some cells, always between the antapical and postequatorial horns. Total length, length of antapical horn, and length of the fourth horn of C. hirundinella displayed significant seasonal variations (P < 0.05). The total cell length showed significant correlations with the length of the apical horn and the length of the antapical horn.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 Heavy metal and arsenic concentrations in rainbow trout (Oncorhynchus mykiss) farmed in a dam reservoir on the Firat (Euphrates) River: Risk-based consumption advisories(Elsevier, 2017) Varol, Memet; Kaya, Gulderen Kurt; Alp, AlperThe concentrations of ten metals in rainbow trout (Oncorhynchus mykiss) farmed in the Karakaya Dam Reservoir (Turkey) on the Firat River were determined. The metal concentrations in rainbow trout did not exceed the maximum permissible levels. Biomagnification factors (BMF) of ten metals were <1, indicating that these metals were not biomagnified. The estimated daily intake (EDI) of each metal was much lower than the respective tolerable daily intake (TDI). The target hazard quotient (THQ) for individual metal and total THQ for combined metals were lower than 1, indicating no health risk for consumers due to the intake of either individual metal or combined metals. The cancer risk (CR) value for toxic inorganic As was below 10-6, indicating no carcinogenic risk. According to the calculated maximum allowable consumption rates (CR.), an adult may safely consume 28 meals of rainbow trout from the dam reservoir per month with no adverse carcinogenic and non carcinogenic health effects. According to these results, the consumption of rainbow trout farmed in this dam reservoir is completely safe for human health. (C) 2017 Elsevier B.V. All rights reserved.Öğe Multiple approaches to assess human health risks from carcinogenic and non-carcinogenic metals via consumption of five fish species froma large reservoir in Turkey(Elsevier, 2018) Varol, Memet; Sunbul, Muhammet RasitKeban Dam Reservoir (KDR), located on the Euphrates River (Turkey), is an internationally important reservoir. In this study, levels of ten metals in 220 muscle samples of five fish species (mangar, common carp, Tigris scraper, Euphrates barbell and trout barb) taken from 11 sampling sites in the KDR were determined and compared with the results of previous studies carried out in other countries and Turkey. In addition, multiple approaches were used to assess human health risks from fish consumption. The significant spatial differences in concentrations of studied metals except As and Ni in Euphrates barbell were not found. However, concentrations of all metals except Cd showed significant seasonal differences. The concentrations of ten metals in fish species were lower than or comparable to those in fish species from other freshwater bodies. The metal concentrations in all fish species were found below the maximum permissible concentrations. No health risks of studied heavy metals on human were found by daily fish intake. The target hazard quotient (THQ) and total THQ values were below 1, which suggests there are no significant non-carcinogenic health risks for fish consumers. The cancer risk values calculated for inorganic arsenic in all fish species except Euphrates barbell did not exceed the 10-6 threshold. The allowable number of fish meals per month can be categorized as safe fish consumption. The results of this study revealed that the consumption of the examined fish species does not pose a significant risk to human health. (C) 2018 Elsevier B.V. All rights reserved.Öğe New records and rare taxa for the freshwater algae of Turkey from the Tatar Dam Reservoir (Elazig)(Tubitak Scientific & Technological Research Council Turkey, 2018) Varol, Memet; Blanco, Saul; Alpaslan, Kenan; Karakaya, GokhanRecently, the number of algological studies in Turkish inland waters has increased remarkably. However, taxonomic and floristic studies on algae in the Euphrates basin are still scarce. This study contributes new information to the knowledge of the Turkish freshwater algal flora. Phytoplankton samples were collected from the Tatar Dam Reservoir in the Euphrates Basin between January 2016 and December 2016. Two taxa were recorded for first time and 14 rare taxa for the freshwater algae of Turkey were identified in this study. The new records belong to the phylum Bacillariophyta, whereas taxa considered as rare belong to the phyla Chlorophyta, Cyanobacteria, Rhodophyta, Charophyta, Euglenophyta, and Bacillariophyta. The morphology and taxonomy of these taxa are briefly described in the paper and original light microscopy illustrations are provided.Öğe New Records of Euglenophyceae for Turkish Freshwater Algae(Central Fisheries Research Inst, 2016) Varol, Memet; Sen, BulentPhytoplankton samples were collected from four different water bodies in the Tigris River basin in 2008. Nine Euglenophyceae taxa at specific and infraspecific level are reported for the first time on Turkish freshwater algal flora. New records come from six sampling sites in the study area. These taxa consist of one Euglena Ehrenberg (E. sociabilis), two Strombomonas Deflandre (S. planctonica and S. pascheriana), four Trachelomonas Ehrenberg (T. nigra, T. aspera, T. borodiniana and T. scabra var. labiata) and two Phacus Dujardin (P. inflexus and P. ovalis). Identification keys and general information on the morphology and taxonomy of the species are briefly described in this paper, with original illustrations.Öğe Organochlorine pesticide, antibiotic and heavy metal residues in mussel, crayfish and fish species from a reservoir on the Euphrates River, Turkey(Elsevier Sci Ltd, 2017) Varol, Memet; Sunbul, Muhammet RasitThis study investigated the residues of 19 organochlorine pesticides, 37 antibiotics and 5 heavy metals in biota samples (one mussel species, one crayfish species, six wild fish species and one farmed fish species) from the Keban Dam Reservoir on the Euphrates River, Turkey. Among monitored OCPs, only p,p'-DDE was detected in biota samples. It was found only in mussel, fish muscle and fish gill samples. The highest concentration of p,p'-DDE (0.032 mg/kg ww) was determined in the gill of common carp, which was found to be below the maximum residue limit (MRL). Only sulfadimethoxine was detected among antibiotics in biota samples. Its maximum concentration (0.0044 mg/kg ww) did not exceed the MRL of 0.1 mg/kg. Sulfadimethoxine was found only in muscle and gill of common carp collected from site S6, where there are many rainbow trout cage farms. However, no detectable residue of sulfadimethoxine was found in farmed rainbow trout. The highest concentrations of As, Cd and Pb were detected in mussels, while the highest concentrations Cu and Zn were determined in crayfish. Metal concentrations in biota samples did not exceed the maximum permissible levels. According to these results, the consumption of biota samples from the Keban Dam Reservoir is safe for human health. (C) 2017 Elsevier Ltd. All rights reserved.Öğe Sürgü'deki (Malatya) alabalık işletmelerinin su kalitesi yönünden incelenmesi ve işletmelerin çıkış sularının sürgü çayı üzerine etkisi(2015) Gökot, Bülent; Balcı, Mustafa; Varol, Memet[Abstract Not Available]Öğe Trace Metal Levels in Rainbow Trout (Oncorhynchus mykiss) Cultured in Net Cages in a Reservoir and Evaluation of Human Health Risks from Consumption(Springernature, 2018) Varol, Memet; Kaya, Gulderen Kurt; Alp, Sumru Anik; Sunbul, Muhammet RasitAlthough fish consumption has positive health effects, metals accumulated in fish can cause human health risks. In this study, the levels of ten metals in rainbow trout (Oncorhynchus mykiss) farmed in the Keban Dam Reservoir, which has the biggest rainbow trout production capacity in Turkey, were determined and compared with the maximum permissible levels (MPLs). Also, human health risks associated with rainbow trout consumption were assessed. The metal concentrations in rainbow trout were found below the MPLs. The estimated daily intake of each metal was much lower than the respective tolerable daily intake. The target hazard quotient (THQ) for individual metal and total THQ for combined metals did not exceed 1, indicating no health risk for consumers. The cancer risk (CR) value for inorganic arsenic was within the acceptable lifetime risk range of 10(-6) and 10(-4). For carcinogenic and non-carcinogenic effects, the maximum allowable fish consumption rates were high enough to ensure the human health. According to these results, the consumption of rainbow trout farmed in the Keban Dam Reservoir does not pose a risk on human health.
