Karasu River Research Articles

Investigation of the Effects of Erzurum Province Wastewater Treatment Plant on the Karasu River Water Quality

This study was carried out to investigate the effects of the wastewater treatment plant located in the Aziziye District of Erzurum Province on the Karasu River. For this purpose, water samples were taken from 3 stations for a year between 2022-2023. The mean water temperature was measured in situ during sampling as 13.8 ˚C, the mean pH value was 7.7, the mean electrical conductivity was 403 µs/cm, and the mean dissolved oxygen value was 6 mg/l. The mean total suspended solid (TSS) amount was determined as 46.7 mg/l, the mean chemical oxygen demand (COD) concentration was 28.9 mg/l, the mean biological oxygen demand (BOD) concentration was 18.5 mg/l, the mean total nitrogen (TN) concentration was 4.47 mg/l, the mean nitrate (NO3) concentration was 5.35 mg/l, the mean nitrate nitrogen (NO3-N) concentration was 1.21 mg/l, the mean total hardness (TH) was 155 mg/l, the mean ammonium (NH4) concentration was 2.75 mg/l, and the mean ammonium nitrogen (NH4-N) concentration was 2.16 mg/L. As a result, it was determined that the Wastewater Treatment Plant positively affected some water quality parameter values of the Karasu River.

Structural alterations in scales of Capoeta capoeta (Güldenstädt, 1773) from heavy metal-contaminated river water.

Heavy metal pollution, especially in freshwater, is a serious problem for aquatic organisms and human health. In this study, the scales of Capoeta capoeta living in the Karasu River (Turkey), which is estimated to be contaminated with pollutants, especially heavy metals, were examined for structural anomalies. Two stations on the river were selected for this purpose. Fish and surface water samples were taken at the stations. The heavy metal analyses were carried out in the water and the fish tissue. Heavy metal pollution was detected in the surface water. It was also observed that some heavy metals (As, Cu, Cd, Cr, Mn, Pb, Ni, Zn) accumulate in the fish tissue. Significant structural differences were observed on the dorsal surface of the scales, such as interrupted primary radii, damaged circuli, damaged focus, damaged anterior scale margin, broken focus, deformed scale structure, scattered chromatophores, dilatation of primary radii, loss of focus, damaged annuli, symmetry shift in the lateral line canal, eroded circuli, damaged posterior scale margin, double focus, branching in the primary radii, asymmetric circuli, incomplete annuli and interrupted secondary radii in each of the fish collected from the contaminated site. Heavy metals are suspected to be responsible for the structural anomalies in the scales. Based on these observations, it can be said that fish scales can be used as an effective indicator of water quality.

Evaluating dynamic soil quality by the soil management assessment framework (SMAF) in the watershed scale in a semi-arid Mediterranean ecosystem in Turkey

Soil is an indispensable and important natural resource and it is necessary to manage and monitor soil quality with appropriate methods in order to ensure the sustainability of the soil. The aim of this study is to determine the current state of soil quality in different land uses where soil functions change. This study was carried out in the Karasu river watershed with an area of 19,178 ha where Entisols soil order is dominant, located Andırın, Kahramanmaraş. The Soil Management Assessment Framework (SMAF) method and Principal Component Analysis (PCA) was used to assess the dynamic soil quality in watershed scale. In the evaluation of soil quality, random samples were taken from a total of 360 topsoil layers (0−30) according to land use and physiography. Soil indicators such as bulk density, aggregate stability, total organic carbon, pH, electrical conductivity, available phosphorus (P), potassium (K), available water amount and water-filled pore volume were selected to create the minimum data set (MDS). The results showed that the productivity, environmental protection, waste recycling quality scores and general soil quality index of forest lands are higher than agricultural lands. According to expert opinion, general soil quality scores were found to be 0.86 in forest land, 0.78 in crop land and 0.83 in grassland, while in PCA, general soil quality scores were calculated as 0.85 in forest land, 0.79 in crop land and 0.78 in grassland. Contribution level of soil functions to management targets was observed in water relations function the most. The contribution levels of the water relations function to the productivity, environmental protection and waste recycling management targets are 0.38, 0.32 and 0.34 in forest lands, 0.42, 0.33 and 0.35 in croplands, respectively; It was showed that 0.40, 0.33 and 0.36 in grasslands. Contribution rates of productivity, environmental protection and waste recycling management targets to soil quality were 30%, 37% and 33%, respectively, in forest lands; 29%, 37% and 34% in crop lands; It has been determined as 30%, 36% and 34% in the grasslands. Negative effects such as heavy rainfall in the watershed, wrong agricultural practices (excessive fertilization and irrigation, improper tillage, and crop selection, etc.) and excessive grazing have led to soil degradation and erosion, reducing the soil function capacity of agricultural lands and meadows. In order to increase the functional capacity of the soil, a soil management approach aimed at protection, improvement and sustainability must be adopted and implemented.

The performance of Karasu Bridge following the February 6, 2023 Kahramanmaras-Turkiye earthquake sequence

The evaluation liquefaction-induced excessive ground displacements of the approach embankments of the Karasu Bridge, as surveyed following the Pazarcik M7.8 and Ekinozu-Elbistan M7.6, Kahramanmaras-Turkiye earthquakes on February 6, 2023, is presented. The Karasu Bridge, located on the Karasu River, connects the metropolitan city of Hatay and the State Hospital. The approach embankments of the bridge are underlain by layers of low to high plasticity stiff clay and liquefaction susceptible clayey and silty medium dense sand units. Specifically, the non-plastic silty sands with fines contents ranging from 21% to 42%, were evaluated as the critical (liquefied) soil units during the Pazarcik earthquake. Liquefaction triggering assessments, following the procedure outlined by Cetin et al. (2018), estimated factor of safety against liquefaction <1.0, confirming the surface manifestations of liquefaction at the site. Empirical approaches suggested by Hamada et al. (1986) and Youd et al. (2002) predicted lateral ground displacements triggered by liquefaction, averaging 137 cm and 383 cm, respectively. These values are comparable with mapped lateral displacements, which exceeded 150 cm. Volumetric settlement assessments, utilizing the method outlined by Cetin et al. (2009), predicted 14 to 26 cm, approximately one third to half of the mapped settlement values ranging from 40 to 55 cm. The discrepancy is attributed to the three-dimensional nature of site behavior and induced deviatoric strains, contributing to additional settlements beyond the volumetric component.

Investigation of Water Quality of the Karasu River in Bilecik Province in terms of Agricultural Irrigation

Together with increasing people's need for water, water needs to be monitored due to the pressure created by factors such as drought and pollution. In this study, water quality was monitored by determining 10 points on the Karasu River in Bilecik Province and it was aimed to examine the seasonal change in water quality. pH, EC, Na, K, Ca, Mg, CO3, HCO3, Cl, B, SO4, Sodium Adsorption Rate (SAR), Residual Sodium Carbonate (RSC) and %Na parameters were determined in water. And then using these parameters, quality classes were determined with the help of water quality classification systems developed by scientists such as Schofield, Wilcox, Thorne, Doneen and Soifer. The study were temporally diveded into 4 periods. They are period 1, period 2 (Spring), period 3 (Summer) and period 4 (Fall). After all, for the period 3, heavy metal pollution, especially Al, attracts attention. Except for the period 2 of point 7 and period 4 of point 9, the class of all periods and points in terms of sulphate was "Very good (class 1)". According to Schofield (1933 and 1935) systems, point 7 is in particularly bad situation in terms of EC. According to Wilcox (1948), point 7 is not suitable for irrigation in the period 2. At point 7, water pollution in period 2 has been identified as common to most classification systems. According to Christiansen et al. (1977), there is intense pollution in terms of EC and Na2CO3 parameters. According to Soifer (1987), point 2 is the cleanest point. As a result, Karasu river is not suitable for irrigation in terms of Al and B. It was understood that heavy metal pollution did not cause much of a problem in non-industrialized cities such as Bilecik. Besides, it was understood that the most common element among heavy metals was Pb in Karasu River. The SAR and RSC values of all periods, seasons and points were classified as "Very Good-Safe (C1S1)".

Gene Expression Analysis in Freshwater Mussels (Unio stevenianus) Collected from Pollutant-Associated Environment

Common pollutants found in rivers include sewage, pesticides, heavy metals, nutrients from agricultural runoff, and pathogens. The resulting pollution can alter the physiological processes of living systems and cause environmental stress in aquatic environments. The need to monitor the effects of pollution in aquatic ecosystems has been driven by environmental and human health concerns. Freshwater mussels, which play an important role in freshwater ecosystems, are constantly exposed to a wide variety of contaminants as filter feeders. The sessile nature of mussels and their relatively long life span make them useful indicator species for monitoring and assessment of water quality. The aim of this study is to determine physiological stress in Unio stevenianus living in Karasu river, whose pollution level is increasing daily, by Cox gene expression. Real-time PCR analysis using β-actin as a reference gene was used for gene expression. The expression level of the Cox gene was higher in the Zeve region than in the Arısu region. The lower level in Arısu region indicates that water quality criteria are better in this region than in Zeve region. Expression studies should be carried out in U. stevenianus by selecting different genes specific to certain pollutants.

Biological Characteristics of Siraz Fish, Capoeta kosswigi (Teleostei: Cyprinidae) and Host Relationship with Ectoparasitic Glochidia Larvae of Freshwater Mussel, Unio stevenianus (Bivalvia: Unionidae) in the Karasu River (Van, Türkiye)

Capoeta kosswigi (Karaman, 1969) and Unio stevenianus (Krynicki, 1837) are endemic species in the Karasu river, the Lake Van basin. This study was carried out to determine the biological characteristics of C. kosswigi and distribution and prevalence of U. stevenianus glochidia on this host fish. A total of 379 C. kosswigi were caught by electrofishing between March 2022 and February 2023. The maximum fork length and total weights of C. kosswigi were 29.2 cm and 421.8 g for females and 27.8 cm and 337.9 g for males. The length-weight relationships were calculated as W=0.017L2.881 (r2=0.986) for males (negative allometric growth) and W=0.016L3.001 (r2=0.953) for females (isometric growth). The Fulton condition factor was determined as 1.53±0.13 (1.23-1.99). The female:male ratio was calculated as 0.18:1.00. Additionally, a total of 12525 Unionid glochidia were detected on C. kosswigi samples in this study. Glochidia was more inclined to prefer male C. kosswigi as a host. The highest amount of glochidia was recorded in May, while the lowest in August. The amount of glochidia was statistically found the highest in the gill filaments (454.3±678.0) compared to all fins. Therefore, the native species, C. kosswigi is a suitable host for the freshwater mussel, U. stevenianus.

Antropojenik aktivitelerden etkilenen nehirden toplanan Cyprinidae familyasına ait balık türlerinin gonad sağlığı durumları

Many freshwater ecosystems are contaminated with heavy metals released by municipal wastewater, cultivation and factory wastewater. The aim of the study was to evaluate the negative impact of metal pollution on the fish reproductive system. It was performed using the gonadal histopathology, hepatosomatic index (HSI), and gonadosomatic index (GSI) of three fish species, Capoeta damascina, Squalius semae and Alburnus sellal inhabiting in Karasu River (Erzurum, Turkey) contaminated by various anthropogenic activities. The highest GSI values were determined for each sex according to the seasons, and lower GSI values were observed in polluted stations in all three species. It was observed that HSI values in fish varied significantly from station to station. In addition, an increase in ovarian and testicular lesions (degeneration in oocyte and spermatocytes, atresia, congestion, infiltration, edema, vascular hypertrophy, fibrosis) was detected in the polluted areas. The results clearly showed that the metal pollution in the river adversely affected the reproductive system of the fish species living in the river.

Structural health monitoring of sabo check dams with cosmic-ray muography

Debris dams have a crucial role in consolidation of river basins and allow erosion control, flood protection in mountainous areas. Many of these infrastructures have operated over five decades, thus structural health monitoring (SHM) of these infrastructures became timely due to their aging. Utilizing new techniques is required for inspecting a large number of dams and deciding about their reinforcement or reconstruction. In this work, we propose cosmic-ray muography as a complementary tool for the SHM of debris dams. We conducted the first muographic surveying of a sabo check dam in the Karasu River, Gunma, Japan. The average mass density image was produced with a spatial resolution of 0.5m through the dam. The comparison of density data reconstructed by muography and gamma-ray logging suggest the internal deterioration of dam in the region where cement released out from the embankment body.

Effects of Total Suspended Solids at Different Levels on the Eggs and Larvae of Endemic Fish, Tarek (Alburnus tarichi Güldenstädt, 1814) in the Karasu River (Van, Turkey)

Effects of Total Suspended Solids at Different Levels on the Eggs and Larvae of Endemic Fish, Tarek (Alburnus tarichi Güldenstädt, 1814) in the Karasu River (Van, Turkey)

Evaluation of the Trophic Status of Karasu River (Erzincan, Türkiye) by Biodiversity Indices

Bu çalışma, Karasu Nehri'ndeki fitoplankton kompozisyonunun ve biyolojik çeşitliliğinin mevsimsel ve zamansal değişimlerine odaklanmıştır. Fitoplankton ve su örnekleri Ocak 2019-Temmuz 2019 döneminde iki ayda bir 0,5-8 m derinlikten beş istasyondan toplanmıştır. Dört çeşitlilik indeksi (Shannon-Wiener, Simpson, Margalef ve Menhinick) incelenmiştir. Endeksler arasındaki ilişkiyi yorumlamak için MINITAB 15 yazılımı kullanılmıştır. Ortalama su sıcaklığı, çözünmüş oksijen, pH ve iletkenlik değerleri sırasıyla 19,43 °C, 7,9 mg/l, 8,3 ve 465 mS/cm olarak ölçülmüştür. Bu çalışmada toplam 123 fitoplankton türü tespit edilmiştir. Bu türlerden Bacillariophyta grubuna ait 106 tür, Chlorophyta grubuna ait 10 tür, Cyanobacteri grubuna ait 6 tür ve Euglenophyta grubuna ait 1 tür teşhis edilmiştir. Çalışma boyunca Shannon-Wiener, Simpson Margalef ve Menhinick çeşitlilik indeksleri sırasıyla 1,89 H´, 11,53, 5,12, 0,83 ve 1,44 olarak hesaplanmıştır. Bu çalışma sonucunda fitoplankton çeşitlilik indeks değerleri ile Karasu Nehri’nin su kalitesine bağlı ekolojik durum değerlendirilmesi bir biri ile uyumlu olmadığı tespit edilmiştir. Ancak farklı şehirler için referans koşulların geliştrilmesi endekslerin kullanılabilirliğini artırabilir. Bu nedenle bu çalışmaların devam etmesini ve yaygınlaşmasını öneriyoruz.

Karasu ırmağında (Erzurum) yayılış gösteren Chondrostoma regium'un (Teleostei: Leuciscidae) karyotipik analizleri

In this study, the karyotypic characteristics of Chondrostoma regium (Heckel, 1843) have been investigated. Fish samples were caught from the Karasu River (Euphrates River Basin) with fishing net. The live fish were transported to the laboratory and kept in aerated aquaria before the analyses. The karyotype analysis was performed in fish kidney and gill epithelium cells. It was determined that C. regium had 2n=50 chromosomes. In detail, the karyotype formula of C. regium was determined as 9 metacentric, 7 submetacentric, 1 subtelocentric and 8 telocentric chromosome pairs (18M+14SM+2ST+16T), and fundamental arm number was calculated as 82. Constitutive heterochromatin regions were determined on telomeres of the chromosomes. Nuclear orgnizer regions were detected on 21st chromosome. Karyotype symmetry/asymmetry index was calculated as 2.32. The karyotypes of gill and kidney cells were the same. No sex chromosomes were cytologically detected.

МЕЗОТРОФНЫЕ ДОЛИННЫЕ БОЛОТА НА СЕВЕРНОМ МАКРОСКЛОНЕ ЦЕНТРАЛЬНОГО КАВКАЗА

Alpine swamps, among other wetlands, are of particular interest due to their relict nature, some peculiarities of their origin, functioning and dynamics, as well as due to their poor knowledge. The object of our study was a cascade swamp complex, consisting of three communicating baths and a lake, located at different heights in the Karasu river valley, in Upper Balkaria at an altitude of about 2 thousand meters above sea level. On the basis of our field descriptions, an analysis of the relief and vegetation of the mesotrophic and lowland bogs which constitute the complex was carried out. It was revealed that the basis of the plant communities of mesophytic segments is sphagnum and three types of sedge (marsh, urchin-hairy, and spout). There are communities of subalpine meadows and forests on the slopes around the wetland complex. It is assumed that the complex has some underground supply, in addition to rain and snow supply and runoff from the neighboring mountain massif.

Evaluation of heavy metal accumulation in sediment, surface water and some plants in the Karasu Riparian Zone

ABSTRACT. This study aims to determine and compare the heavy metal concentrations in the water, sediment, and plants of the Karasu river in Erzurum, Türkiye. In this context, aluminum (Al), manganese (Mn), iron (Fe), nickel (Ni), zinc (Zn), and barium (Ba) concentrations were measured for this study. Salix excelsa (willow), Rosa canina L., Pyrus elaeagnifolia (wild pear), Malus sylvestris (wild apple), and Hippophae rhamnoides L. (sea buckthorn) plants were used as samples. Heavy metal concentrations follow the order of Al3+ &gt; Fe2+ &gt; Mn2+ &gt; Ba2+ &gt; Ni2+ &gt; Zn2+ in the sediment. Heavy metal concentrations follow the order of Al3+ &gt; Fe2+ &gt; Ba2+ &gt; Mn2+ &gt; Zn2+ &gt; Ni2+ in water. The leaf part of Salix excelsa has the highest bioconcentration factor (BCF) for Mn among plant parts. Mean BCF values were as follows: Zn2+ &gt; Mn2+ &gt; Ba2+ &gt; Ni2+ &gt; Al3+ ≈ Fe2+. In addition, the highest plant translocation factor (PTF) values were determined in Salix excelsa for Al and Fe; in Rosa canina L. for Ni and Zn; in Hippophae rhamnoides L. for Mn and in Malus sylvestris for Ba.&#x0D; &#x0D; KEY WORDS: Heavy metals accumulation, Sediment, Water, Plant, Riparian Zone&#x0D; Bull. Chem. Soc. Ethiop. 2023, 37(1), 35-45. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v37i1.4

Hydrochemical and hydrobiological researches of number reservoirs in the East Kazakhstan region

This article describes the results of an exploration of the current state of some reservoirs of the Ulan district of the East Kazakhstan region: a pond on the Karasu River 7 km upstream of the village of Privolnoye, a pond on the Karasu River 2 km upstream of the village of Mitrofanovka, a pond on the Peschanka River and a pond on the Tugulka River according to hydrochemical and hydrobiological indicators, in order to determine the status and suitability of water objects in fish breeding. Research works was carried out in 2021. Inspections of reservoirs were carried out sporadically, in connection with this, these water objects can be considered poorly studied. For the analysis of temporal changes, hydrochemical and hydrobiological samples were taken in spring, summer and autumn. The content of biogenic compounds and main ions was studied, the results obtained were compared with the values given in the Unified Classification System for Water Quality in Water Bodies, and their seasonal dynamics was also considered. The article defines the class of the reservoir by chemical composition, the category by mineralization and the class of hardness. According to the results of research, water objects are characterized by an optimal oxygen regime, slightly alkaline reaction (pH 7.2–8.7) and low salinity (310–438 mg/dm3). According to the classification of the main ions, the waters of the surveyed ponds belong to the hydrocarbonate class, the calcium group, the first type. It was determined that the concentration of biogenic compounds in 2021 does not exceed the established fishery standards. The values of the abundance and biomass of zooplankton and benthos in different seasons of research are estimated, an assessment of the trophic status of the reservoirs was given according to hydrobiological indicators and a brief physical and geographical characteristic of water objects is described. In general, the trophic class of ponds in the Ulansky district varied from very low class to high class in terms of hydrobiological indicators, which indicates a good supply of food resources. It can be noted that the maximum indicators of the development of the forage base were observed in the summer period. Based on the results of the analyzes obtained, the status and category of the studied water bodies were determined.

Water quality assessment of the Karasu River (Turkey) using various indices, multivariate statistics and APCS-MLR model

Determining the water quality status of a river and accurately identifying potential pollution sources threatening the river are pillars in effective control of pollution and sustainable water management. In this study, water quality indices, multivariate statistics and absolute principal component score-multiple linear regression (APCS-MLR) were applied to evaluate the water quality of the Karasu River, the main tributary of the Euphrates River (Turkey). For this, 19 water quality variables were monitored monthly at eight stations along the river during one year. Based on the mean dissolved oxygen (DO), electrical conductivity (EC), nitrate-nitrogen (NO3–N), orthophosphate-phosphorus (PO4–P), total phosphorus (TP), ammonium-nitrogen (NH4-N), chemical oxygen demand (COD) and total nitrogen (TN) levels, most stations of the river had “very good” water status according to surface water quality criteria. Spatial cluster analysis (CA) divided eight stations into three regions as clean region, moderate clean region and very clean region. The mean values of Nutrient Pollution Index indicated that the river was “no polluted”. Similarly, Water Quality Index and Organic Pollution Index values indicated that the river water quality was between “good” and “excellent”. A minimum water quality index (WQImin) consisted of ten crucial parameters was not significantly different with the WQI based on all the 17 parameters. Discriminant analysis (DA) results showed that water temperature (WT), EC, chlorophyll-a (Chl-a), potassium (K), calcium (Ca), NO3–N and COD are the variables responsible for temporal changes, while WT, total dissolves solids (TDS), Chl-a, K, magnesium (Mg), Ca, NH4–N and COD are the variables responsible for spatial changes in the river water quality. Principal component analysis/factor analysis (PCA/FA) identified four potential sources, including anthropogenic, natural, seasonal and phytoplankton. Source apportionment in the APCS-MLR model revealed that seasonal and anthropogenic sources contributed 35.2% and 25.5% to river water quality parameters, respectively, followed by phytoplankton (21.4%) and natural sources (17.9%).

Comparison of sequential and variational assimilation methods to improve hydrological predictions in snow dominated mountainous catchments

• Assimilation of streamflow and snow data using variational and sequential techniques in a hydrological model. • Satellite snow coverage products are assimilated together with streamflow data. • Variational techniques outperform sequential techniques in two mountainous basins. • Average relative gains in variational assimilation are 49% for streamflow and 28% for snow data. Snowmelt modeling is vital issue for proper operational flow forecasting systems but still challenging in upstream mountainous basins due to limited observations and associated uncertainties. Data assimilation is a valuable tool to improve model state estimates to improve hydrological forecast. While assimilation of snow has been increasingly implemented in research, particularly using sequential data assimilation methods, less attention has been dedicated to compare different types of assimilation techniques. This study aims at comparing the well-known Ensemble Kalman Filter (EnKF) sequential data assimilation and the less known Moving Horizon Estimation (MHE) variational assimilation. Initial conditions of the hydrological model states are improved by assimilating in-situ streamflow and remotely sensed snow covered area data into the Hydrologiska Byråns Vattenbalansavdelning (HBV) conceptual rainfall-runoff model. The study is applied to improve runoff predictions over two mountainous basins: one in the uppermost catchment of the Karasu river, in Eastern Turkey, and the second in an alpine basin located in the headwaters of the Genil River in the northern flank of the Sierra Nevada Mountain in Southern Spain. The forecast models are tested in a hindcasting condition, i.e. closed loop environment, which simulates real-time forecasting systems. The results are analyzed using forecast verification metrics. Results showed that streamflow and snow state predictions using MHE outperform the commonly used EnKF based on the continuous ranked probability score (CRPS).

The first evidence of microplastic uptake in natural freshwater mussel, Unio stevenianus from Karasu River, Turkey

Purpose Microplastic pollution is a major problem that threatens freshwater mussels as well as marine bivalves, since these filter-feeding organisms are directly exposed to microplastics in the water column. There is no study on the microplastic contamination of Unio stevenianus as a bioindicator organism. The aim of this study is to determine the microplastic contamination in U. stevenianus. Materials and methods In total, 32 U. stevenianus were obtained from three different sites from Karasu River, in October 2020. The soft tissue of each mussel was digested and filtered. The filters with microplastics were observed under a stereomicroscope. Results A total of 1,253 microplastics, ranging from 0.81 to 6.69 items/gram (mean 2.85 ± 1.27 items/g) and 13.00 to 84.73 items/individual (mean 39.15 ± 16.95 items/individual), were extracted from soft tissues of mussel for all stations. The dominant of the detected microplastics consisted of fragment (48.8%) followed by fiber (47.5%) types, and ˂0.1 mm size (44.8%), irregular shape (48.7%) and black coloured (48.8%) items were the most uptaked microplastics. Conclusion This study indicated that U. stevenianus has a lot of pollution where there are a lot of microplastics in the river.

Determination of oxidative, genotoxic, and histopathologic effects of metal pollution on the fish fauna inhabiting Karasu River, Turkey

The water quality of rivers located in areas close to major cities is deteriorating significantly due to increased pollution. The Karasu River, which passes through Erzurum city Turkey, is getting polluted day by day due to domestic and industrial wastewater. In the study, various assessments were made in three different fish species to determine the impact of possible contamination here. Capoeta capoeta, Alburnus mossulensis and Squalius cephalus were caught from four stations of the river. Micronucleus test was applied to find out genotoxic alterations, and plasma total oxidant status (TOS) and total antioxidant status (TAS) were measured to determine oxidative effects. Histological changes in fish brain were also assessed by histopathological alterations index (HAI). The highest serum TOS levels and the lowest TAS levels were detected in fish species inhabiting polluted stations. A high erythrocytic nuclear abnormality frequency and HAI values were observed in all species from the Aşkale stations. The abnormalities observed in the peripheral blood cells were micronucleus, binucleus, kidney-shaped nucleus, notched nucleus, lobed nucleus and bud nucleus. Histological damages like dilatation, congestion, vacuolization in Purkinje layer, infiltration, hyperemia, degenerations, and axonopathy were noticed in all fish brains. It was determined that histopathological changes were more common in fish species inhabiting the polluted stations. S. cephalus showed to be more sensitive to the pollution. The most important result obtained from this study is that the pollution in the river adversely affects the fish species found in the natural fauna of the river. Histopathological abnormalities, genotoxicity and increased oxidative stress detected in fish are the most important indicators of this situation.

Contribution to the trout of Euphrates River, with description of a new species, and range extension of Salmo munzuricus (Salmoniformes, Salmonidae)

In an effort to reveal the Euphrates trout taxonomy, the Karasu River, which is one of the eastern drainages of the river, was investigated and three independent populations were identified. Result revealed that two populations belonged to Salmo munzuricus, which was known only in Munzur River, while the other population belonged to an unnamed species. Salmo baliki, a new species, is described from the Murat River, a drainage of Euphrates River. It differs from Salmo species in adjacent water by the combination of the following characters: a grayish body; commonly one, rarely two pale black spots behind eye and on cheek; two to seven black spots on opercle; a few black spots on back and upper part of flank, missing on predorsal area; few to numerous large irregular-shaped red spots in median, upper and lower part of flank, surrounded by a large irregular-shaped white ring; the number of black and red spots not increasing in parallel with size; maxilla short and narrow; adipose-fin medium size, no or rarely one or two red spot its posterior edge; 107–118 lateral line scales; 24–28 scales rows between dorsal-in origin and lateral line; 18–22 scale rows between lateral line and anal–fin origin; maxilla length 7.7–9.1% SL in males, 8.2–9.6 in females. Finally, the genetic study of the Cyt b mitochondrial gene confirmed the morphological data, suggesting the separation of S. baliki from other Salmo species.