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All living creatures in nature are constantly exposed to ionising radiation, which is emitted from natural and artificial radiation sources. For this reason, it is important to monitor the levels of radioactivity in living spaces and visited areas. In this study, natural (238U, 232Th, 40K) and artificial (137Cs) radioactivity concentrations in sediment samples taken from Borçka Black Lake located on the Nature Park in Artvin province were determined using a high purity germanium detector (HPGe). It was determined that 238U, 232Th, 40K and 137Cs radioisotope concentrations in the sediment samples varied between 8.73 and 26.45, 7.01 and 22.98, 289.92 and 578.98, and 6.26 and 70.96 Bq kg−1, respectively. Mean radioactivity concentrations were found to be 14.99 ± 0.89 Bq kg−1 for 238U, 13.85 ± 1.10 Bq kg−1 for 232Th, 473.67 ± 14.21 Bq kg−1 for 40K and 35.06 ± 0.96 Bq kg−1 for 137Cs. In order to evaluate the radiological hazards, radium equivalent activity, external hazard index, absorbed dose rate in the air, the annual effective dose rate and excess life time cancer risk were calculated and compared with the values recommended by international organisations. As a result, it has been shown with this study that the radioactivity caused by the examined radioisotopes will not pose any health risk for the visitors of Borçka Black Lake. [ABSTRACT FROM AUTHOR]

Lakes can be monitored using benthic diatoms as proposed by Water Framework Directive. In recent years, in addition to the indices developed for rivers, the indices developed for lakes have been also used. The relationship between environmental parameters and diatom assemblages was investigated monthly to understand temporal and spatial changes in diatom community structure, and to specify the ecological status of the three lakes between May 2015 and April 2016. Based on the Redundancy Analysis (RDA) result, main environmental parameters (orthophosphate, total phosphorus, specific conductance, soluble silica, water transparency, nitrate-nitrogen, and pH) strongly affected the temporal and spatial distribution of diatom assemblages. Shannon diversity index, evenness, and species richness were measured, however, they were not effective in explaining the water quality. The ecological status assessment of the lakes was also performed by using Trophic Index Turkey (TIT), Trophic Diatom Index for Lakes (TDIL), and Specific Pollution Sensitivity Index (IPS). Based on the results of three indices, TIT gave more consistent results with environmental parameters and indicator species and is more sensitive to changes in the trophic status of lakes over time. According to TIT, Lake Little Akgöl had a poor ecological condition, while the water qualities of Lake Taşkısığı and Lake Poyrazlar were determined as moderate. Due to the sensitivity of the changes in the diatom community structure with the effect of environmental parameters during one year, TIT is an effective tool to assist in the ecological assessment of three natural lakes within the borders of Sakarya province in the north of Turkey. [ABSTRACT FROM AUTHOR]

Paleolimnological assessment of Ladik Lake (N Turkey) using diatoms was carried out along a 62 cm-long sediment core recovered from the southeastern part of the lake. The chronology of the sediments was established by 137Cs - 210Pb dating. Accordingly, three major chronostratigraphical diatom assemblage zones (DAZ) were defined by the CONISS (constrained cluster analysis) program. The oldest assemblage, DAZ C (AD 1925-1958), was dominated by Ulnaria ulna (Nitzsch) Compère, Cocconeis placentula Ehrenb. and Cocconeis pediculus Ehrenb. taxon. In DAZ B (AD 1958-1986), in addition to Ulnaria ulna species that dominated through the whole core, Epithemia spp. occasionally dominated the assemblage in this zone. Ulnaria ulna and Pantocsekiella ocellata (Pant.) K.T. Kiss & Ács predominated since the beginning of DAZ A (AD 1986-2006). After the first regime of the lake with dystrophic character, the diatom community underwent a significant shift, with decreased abundance of periphytic diatom samples. The improvement of the regulator in 1986 resulted in a larger water level increase that affected the lake ecology, causing a shift from a diverse periphytic diatom to planktonic diatom assemblage. Based on our monitoring it can be inferred that the limnological regime shifts in Ladik Lake during the 20th century are of anthropogenic origin, rather than being due to climatic changes. [ABSTRACT FROM AUTHOR]

Water availability in lakes must be studied in order to better manage ecosystems within lake basins and meet economic development needs. Despite being Iran's largest lake, Lake Urmia's water level and surface area have declined dramatically over the past two decades. During the same period, Lake Van in Turkey maintained a relatively stable water level and surface area. As a result, comparing factors related to water level and surface area in these lakes, which have similar geographical and climate conditions but different management policies, can be an appropriate way to identify the causes of water declines in Lake Urmia. Comparing these variables may help explain observed differences in lake behavior between 2000 and 2016. Hydrometric and climatic parameters, as well as the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Water Index (NDWI), were used to achieve this goal. Changes in precipitation, temperature, and evapotranspiration in both lakes show essentially identical trends, but this is not a convincing explanation for Lake Urmia's water surface changes. The results revealed that dam construction and water diversion projects, the expansion of irrigated agriculture, and the lake's shallow depth in most parts were the primary causes of Lake Urmia's shrinkage compared to Lake Van. [ABSTRACT FROM AUTHOR]

The composition and abundance of solid waste and the effect of COVID-19 measures were studied in an inland water ecosystem in Turkey. Solid waste items were collected annually for 5 years from 2017 to 2021 from seven stations located in Borçka Dam Lake (B1–B4) and Murgul Stream (M1–M3) in the Artvin Province. The highest densities by number and weight were recorded at M3 in 2020 (5.72 items/m2) and M1 in 2020 (0.39 kg/m2), respectively. However, no significant difference in density was recorded (p < 0.05) between the years. Plastic was the most abundant waste material by number of items in all the stations with a percentage contribution varying between 25.47 and 88.89%. There was a considerable increase in medical items during the COVID-19 pandemic in 2020–2021. Nonmetric multidimensional scaling (NMDS) and ANOSIM results revealed visually and statistically significant differences in solid waste composition between the years and stations. The dissimilarity between the years was driven by plastic and medical waste. The main sources of solid waste were river transportation (22.93%), improper disposal (20.74%), aquaculture activities (16.42%), and recreational and tourism activities (14.72%). The results of our study can be a baseline for transportation models, local administrations, and non-governmental organizations. Besides, the current waste management measures in Turkey are not effective in preventing waste accumulation in inland aquatic systems such as the Borçka Dam Lake and Murgul Stream. Furthermore, these findings indicate that the COVID-19 pandemic influenced solid waste composition and increased its abundance in the study area. [ABSTRACT FROM AUTHOR]

The current status and annotated checklist of fresh- and brackish-water amphipod species inhabiting the inland waters (streams, lakes, ponds, lagoons, subterranean waters, etc.) of Turkey is presented. Totally, 171 papers, 3 books, 3 book chapters, 5 conference papers, 2 projects, 3 PhD and 3 MSc thesis were examined in the present study. As the result of the previous records, 201 taxa comprising 121 amphipods (16 families, 31 genera), 27 isopods (9 families, 13 genera), 9 mysids (1 family, 5 genera), 4 tanaids (3 families, 4 genera) and 40 decapods (16 families, 18 genera) were compiled. All the previously recorded localities of each taxon were listed in detail. The endemic taxa and the doubtful records were indicated and discussed. Twenty maps showing the distribution of reported species were also presented. [ABSTRACT FROM AUTHOR]

Although planktonic algae are a basic component of freshwater ecosystems, studies on their diversity and species distribution are still not in satisfactory numbers. This study aims to contribute to Turkish freshwater algal flora particularly with the new records reported. A total of 158 Charophyta taxa were determined in the study conducted from 2017 to 2019 in 25 river basins of Turkey. In this study, while the highest Charophyta taxon was found in Sakarya and Batı Akdeniz basins with 50 and 42 taxa, respectively, Burdur basin was the only basin where we did not find the Charophyta species. The highest Charophyta diversity was observed in Girdev Lake (Batı Akdeniz basin) and Işık Dağı Karagöl Lake (Sakarya basin) among the lakes of Turkey’s 25 river basins. Thirty-one of these Charophyta taxa represent new records for the freshwater algal flora of Turkey. Of these, 13 species are commonly distributed, while 18 species have rare distribution areas. Morphology, ecology, and distribution of each taxon were also discussed in details. [ABSTRACT FROM AUTHOR]

In the present study, adopting of citizen science approach for monitoring water quality of a lake (Uzungöl, Turkey) was investigated. The study consisted of selection of sampling points and water quality parameters, training of volunteers, sampling and analysis by volunteers, and development of a mobile application for data collection and storage. In the scope of the study, four measurement points around the lake were selected and elementary school students were trained both theoretically and practically to collect water quality data. During the project (June-December, 2018), volunteers collected water samples and measured temperature, pH, nitrate, and phosphate with the given test kits. The mobile application was developed using open source code and used to collect and store the volunteer data. According to the volunteer data, temperature values were between 8.5 and 15.5 °C, pH values were between 2 and 8.5, nitrate values were between 0.5 and 2.5 mg/L, and phosphate values were between 0.5 and 5 mg/L in the lake. Most of the pH and temperature results were compatible with field measurements done by research group during field visits. The motivation of the volunteers and mobile application development were the achievements of the project. Low number of the data and its reliability were the main limitations. Therefore, this study showed that citizen science has both capabilities and constraints for collection of water quality data, however; outstanding potential of citizen science is obvious. [ABSTRACT FROM AUTHOR]

In this study, a total of 248 moss samples were collected from 25 stations as a result of the field studies carried out in the Acarlar Lake Longoz Forests during the different vegetation periods of 2016 and 2017. According to the identification studies of the collected samples, 23 families, 58 genera and a total of 93 taxa belonging to these genera were determined. Of the determined taxa, 29 are new records for Sakarya province bryophyte flora and 6 taxa are new records for A2 square. Also, registered from this region; Atrichum crispum, Pseudephemerum nitidum and Dicranella staphylina are also important species for bryophyte flora of Turkey. [ABSTRACT FROM AUTHOR]

Artificial neural networks offer a viable route in assessing and understanding the presence and concentration of heavy metals that can cause dangerous complications in the wider context of water quality prediction for the sustainability of the ecosystem. In order to estimate the heavy metal concentrations in Iznik Lake, which is an important water source for the surrounding communities, characterization data were taken from five different water sources flowing into the lake between 2015 and 2021. These characterization results were evaluated with IBM SPSS Statistics 23 software, with the addition of the lake water quality system. For this purpose, seven distinct physicochemical parameters were measured and monitored in Karasu, Kırandere, Olukdere and Sölöz water sources flowing into the lake, to serve as input data. Concentration levels of 15 distinct heavy metals in Karsak Stream originating from the lake were as the output. Specifically, Sn for Karasu (0.999), Sb for Kırandere (1.000), Cr for Olukdere (1.000) and Pb and Se for Sölöz (0.995) indicate parameter estimation R 2 coefficients close to 1.000. Sn stands out as the common heavy metal parameter with best estimation prospects. Given the importance of the independent variable in estimating heavy metal pollution, conductivity, COD, COD and temperature stood out as the most effective parameters for Karasu, Olukdere, Kırandere and Sölöz, respectively. The ANN model emerges as a good prediction tool that can be used effectively in determining the heavy metal pollution in the lake as part of the efforts to protect the water budget of Lake Iznik and to eliminate the existing pollution., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This study reports on the Sinanpaşa Basin, a typical example of the Miocene tectonic intracontinental grabens formed in West Anatolia, Turkey. The study reconstructs the paleoenvironmental and paleogeographic history of the graben based on a detailed sedimentological analysis of basin-fill deposits exposed mainly near the graben's northern and southern margins. The sedimentary paleoenvironments in the graben range from basin-margin alluvial fan systems and basin-axis fluvial distributary system to an intrabasinal shallow lake environment surrounded by peat-forming mires, changing from carbonate to more clayey, episodically evaporitic, and shifting its shorelines considerably. The spatial distribution and stratigraphic stacking of these paleoenvironments indicate the main controlling role of climatic changes and an asymmetrical "see-saw" tectonic subsidence of the graben floor. An important component of the sedimentation in the graben was volcanism, which probably commenced in the late Early Miocene and was related to the development of a local stratovolcano. Volcanic products - accumulated mainly at the graben's northern margin - include variously welded pyroclastic airfall and ground-surge tephra, vent-derived volcanic fluidization breccias, autoclastic lava flow breccias, and water-bearing lahars. The volcanic deposits made the intrabasinal lake struggle for accommodation space within the graben, while the ash tephra and related hydrothermal activity had a major impact on the lake water chemistry. B- and U-bearing evaporites formed episodically in drying lake areas, reaching economic thicknesses in several adjacent sister grabens. The Sinanpaşa Basin is a representative example of the Miocene tectonic grabens of West Anatolia, and its sedimentation model suggested by the present study may serve as a tentative reference case for the region's numerous sister grabens, helping to understand their sedimentation conditions, environmental changes, and lithostratigraphic facies organization. [ABSTRACT FROM AUTHOR]

Examining the enduring alterations in microplastic (MP) concentrations within fish in inland waters is of utmost importance in understanding the historical trajectory of plastic waste and formulating consequential predictions regarding upcoming pollution levels. This study includes the collection of fish samples from 22 different river basins in Türkiye and all Squalius species distributed in Türkiye, covering the years 2004–2018, and examined the presence of MP in museum specimens' gastrointestinal tracts (GITs). 331 specimens were examined, and microplastic was observed in 20.8% (69). A mean value of 0.27 ± 0.19 MP per individual was observed, resulting in a cumulative score of 91 MP. Most observed MPs were composed of fiber, representing 79.1% of the total. The polymer types identified were mostly polyethylene (PE) at 38.5% and polyethylene terephthalate (PET) at 29.7%. The black color was prominent among MPs, and MP length ranged between 101 and 4963 μm. The analysis revealed no statistically significant difference in the mean MP values across different years and basins. There is no substantial correlation between the abundance of MP and the sizes of fish, population density, or quantities of plastic production. The data indicate that MP has persistently acted as a contaminant in freshwater ecosystems over an extended period. It is projected that the laundering of synthetic textiles serves as the primary contributor to MP contamination in freshwater bodies. Our results offer significant baseline data on the pervasive issue of MP pollution in the freshwater environment. These findings enable us to gain profound insights into the current state of MP contamination in fish residing in lotic systems while empowering us to make accurate predictions about its future trajectory. [Display omitted] • Squalius species taken from 22 river basins from Türkiye were examined. • Microplastics (MP) was detected in 20.8% (69) of the specimens. • The most observed MPs had the following features: fiber, PE, black and <1000 μm. • Changing of MPs based on years and basins was not significant. • No significant relationship was between MP abundance and population/plastic production in Türkiye. [ABSTRACT FROM AUTHOR]

Abstract The debate in historical geomorphological studies about the causes of erosion in regions such as the Mediterranean has been long-standing. The relative roles of climate change and human impacts can be difficult to disentangle in the absence of highly resolved chronologies. Here we reconstruct the erosion history of a small lake catchment in central Anatolia, located on the edge of one of the Mediterranean's most iconic badland landscapes in Cappadocia. Because these lake sediments are annually laminated, precisely dating clastic inwash layers and calculating recurrence intervals and flux rates is possible. Lake cores have been analysed for μXRF elemental geochemistry and via thin sections, along with proxies for hydroclimate (oxygen isotopes) and land cover (pollen). Peaks in titanium, along with other detrital elements, and changes in clastic layers indicate increased sediment influx into Nar Lake between 9300 and 8000 cal BP (ceramic Neolithic, when obsidian mining took place nearby) and again, more importantly, during the last 2500 years (Iron Age to modern), the latter exhibiting three phases of enhanced catchment erosion. Multiproxy comparisons show that these phases were related primarily to periods of increased human impact on vegetation and soils around the lake. Most sediment influx has been in the form of turbidites, linked to the presence of a fan delta at the lake edge, although this store does not appear to have significantly delayed sediment delivery from eroding hillslopes to the lake bed. The marked increase in detrital influx during the late Holocene implies that badland development in the lake catchment is recent and largely anthropogenic, rather than ancient and of climatic causation, and probably involving stream capture. The record also shows that sediment influx diminished markedly at times when human land use disintensified, which in turn indicates that hillslope degradation is reversible with appropriate land management. [ABSTRACT FROM AUTHOR]

The brackish Bafa Lake located in the southwestern part of Turkey is under stress because of both natural and untreated wastewater effluents. The purpose of this research is to determine spatiotemporal distributions of some physicochemical variables in water column (temperature, salinity, pH, conductivity, dissolved oxygen, NH-N, NO-N, NO-N, oPO-P, TPO-P, chlorophyll- a, total suspended solids) and sediment (TN, TC, TOC, TP) and their relationships at coastal stations. In the water column, nitrate and phosphate concentrations showed seasonal variations with high values recorded in winter period. Ammonium was determined as a main source of TIN component. During summer period, a large amount of total phosphorus was found as dissolved organic form. However, in the winter period, inorganic phosphate levels increased at sampling stations. N limitation was a common feature throughout the lake where P-limitation was only observed in summer period. The total phosphorus levels which showed hypereutrophic condition at the western part of the lake changed between 1.55 and 4.99 μM and did not remain in the range for uncontaminated condition. In the lake sediment, a strong relationship was found between TOC and TC levels. Generally, the mean TOC concentrations constitute small amount of TC values in the sampling stations. The results also indicated that a strong correlation exists between TOC and TN values, and TN was greatly regulated by organic sources. In the lake, TOC:TN ratios changed between 5 and 13; the ratio greater than 10 could be an indicator of algal and land plant sources mixing as an organic matter. [ABSTRACT FROM AUTHOR]

This paper studies the radionuclide (137Cs, 226Ra, 232Th, 40K) activity concentrations and gross radioactivities in waters and sediments of Lake Van, which is the third largest closed lake (with no natural or artificial outlet) within the Earth. The physico-chemical parameters were measured and evaluated in the lake waters. The mean gross α activities in surface, middle and bottom waters are 0.04, 0.03 and 0.03 Bq/L, respectively, and in the same order, the mean gross β activities are 0.30, 0.23 and 0.33 Bq/L, respectively. In sediment samples, the mean activity concentrations were measured as 1.98 Bq/g for gross-α, 3.46 Bq/g for gross-β, 48.3 Bq/kg for 226Ra, 32.0 Bq/kg for 232Th, 540.1 Bq/kg for 40K and 25.9 Bq/kg for 137Cs. The radiation hazard parameters values based on the measured activities were calculated and Ra eq values are lower than the world average value in all samples, while D out and AED values are relatively high in some sediment samples. • Lake Van is the third largest closed soda lake and the third largest terminal lake (by volume) in the world. • Physico-chemical parameters (pH, T, EC, TDS, S, OS, DO, turbidity) were measured in the lake waters. • The mean gross alpha and beta radioactivities are 0.031 Bq/L and 0.286 Bq/L in water and are 1.981 Bq/g and 3.461 Bq/g in sediment, respectively. • The mean activities 226Ra, 232Th, 40K radionuclides in sediment samples are 48.25, 31.96 and 540.06 Bq/kg, respectively. • Ra eq values calculated in deep sediments are lower than 370 Bq/kg, while D out and AED values are slightly higher than the world average limits. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that projected climate change will likely enhance nitrogen (N) and phosphorus (P) loss from farms and farmland, with the potential to worsen freshwater eutrophication. Here, we investigate the relative importance of the climate and land use drivers of nutrient loss in nine study catchments in Europe and a neighboring country (Turkey), ranging in area from 50 to 12,000 km2. The aim was to quantify whether planned large-scale, land use change aimed at N and P loss reduction would be effective given projected climate change. To this end, catchment-scale biophysical models were applied within a common framework to quantify the integrated effects of projected changes in climate, land use (including wastewater inputs), N deposition, and water use on river and lake water quantity and quality for the mid-21st century. The proposed land use changes were derived from catchment stakeholder workshops, and the assessment quantified changes in mean annual N and P concentrations and loads. At most of the sites, the projected effects of climate change alone on nutrient concentrations and loads were small, whilst land use changes had a larger effect and were of sufficient magnitude that, overall, a move to more environmentally focused farming achieved a reduction in N and P concentrations and loads despite projected climate change. However, at Beyşehir lake in Turkey, increased temperatures and lower precipitation reduced water flows considerably, making climate change, rather than more intensive nutrient usage, the greatest threat to the freshwater ecosystem. Individual site responses did however vary and were dependent on the balance of diffuse and point source inputs. Simulated lake chlorophyll-a changes were not generally proportional to changes in nutrient loading. Further work is required to accurately simulate the flow and water quality extremes and determine how reductions in freshwater N and P translate into an aquatic ecosystem response. [ABSTRACT FROM AUTHOR]

Previously determined biological and physico-chemical properties of Lake Manyas are employed in modelling the sensitivity of water quality and ecosystem integrity to the (a) water residence time and (b) nutrient inputs from anthropogenic sources. In that context, simple ecological conceptual models are simulated for predicting changes in the aquatic ecosystem with respect to these driving variables. Results yield thresholds where major changes in system behaviour are expected. Based on model predictions, recommendations for the restoration of water quality and ecosystem integrity are made. [ABSTRACT FROM AUTHOR]

The genus Phaenopsectra Kieffer, 1921 found in Turkey is new based of larva stage of Phaenopsectra flavipes (Meigen, 1818) was found for the first time in KeçI Lake (Gerede - Bolu, Turkey). The morphological, biological and ecological properties and distribution of the larva are explained in the article. [ABSTRACT FROM AUTHOR]

Gross α and gross β activities and U concentrations were determined in 18 surface water samples collected from Van Lake. The instrumentations used to count the gross α and gross β activities and to determine the U concentrations were α/β counter of the multi-detector low background system (PIC-MPC-9604) and Inductively Coupled Plasma-Mass Spectrometry (Thermo Scientific Element 2), respectively. Concentrations ranging from 0.001 to 0.021 Bq L and from 0.111 to 2.794 Bq L were observed for the gross α and β activities in surface waters, respectively. For all samples the gross β activities were higher than the corresponding gross α activities. The results indicated that the gross α radioactive contamination in water samples was lower than recommended values for the guideline of drinking waters and most of the gross β activities in water samples were higher than those in the same procedure. The U concentrations ranged from 74.49 to 113.2 μg L in surface waters. The obtained results have showed that U concentrations are higher than guideline values for uranium. [ABSTRACT FROM AUTHOR]

Radioactive particle movement analysis in any environment gives valuable information about the effects of the concerned environment on the particle and the transportation phenomenon. In this study, the spatio-temporal point cumulative semivariogram (STPCSV) approach is proposed for the analysis of the spatio-temporal changes in the radioactive particle movement within a surface water body. This methodology is applied to the 210Pb radioactive isotope measurements at 44 stations, which are determined beforehand in order to characterize the Keban Dam water environment on the Euphrates River in the southeastern part of Turkey. It considers the contributions coming from all the stations and provides information about the spatio-temporal behavior of 210Pb in the water environment. After having identified the radii of influences at each station it is possible to draw maps for further interpretations. In order to see holistically the spatial changes of the radioisotope after 1st, 3rd and 5th hours, the radius of influence maps are prepared and interpreted accordingly. [Copyright &y& Elsevier]

Copyright of Review of Hydrobiology is the property of NK Yayincilik Egitim Hizmetleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Omerli reservoir is located on the northeastern side of the Istanbul City. It is one of the most important sources of drinking water with a surface area of 23.1 km2 and a volume of 220 × 106 m3 in the Marmara Region. Water quality characteristics of the lake investigated from May 2002 to April 2003 enabled us to identify the effect of waste loads on water quality of Omerli Lake. The following parameters were measured in the lake water: temperature (16.1°C), conductivity (250 μS/cm), secchi disk depth (1.9 m), dissolved oxygen (DO) (9.36 mg/L), nutrients [ortho-phosphate (78.9 μg/L), nitrate + nitrite (707.5 μg/L) and ammonia-nitrogen (264 μg/L)], chlorophyll a (9.43 μg/L), total organic carbon (3.33 mg/L), total suspended solids (4.54 mg/L), total poly aromatic hydrocarbon (t-PAH) (0.69 μg/L) and copper (24.5 μg/L). T-PAH (16.5 mg/g-dry-w), Cu (96.5 μg/g-dry-w), organic carbon (org-C) (2.0%) and N (0.44%) were determined in the surface sediment. The values of chlorophyll a and DO in the upper layer were relatively high and low secchi disk depths indicates eutrophic state. There are five channels discharging water, including waste water, into the lake. All channels were sampled during six occasions in order to cover variations between seasons. The following parameters were measured: total organic carbon, total phosphorus, total kjeldahl nitrogen, ammonia and total suspended solids with the flow rates. The Göçbeyli stream has the highest flow into the lake (1.5 × 108 m3/year) but most of the nutrients were discharged from the Paşaköy channel. It is accounting for 81% of ammonia and 80% of total phosphorus into the lake. Three scenarios were run using AQUATOX model: (1) all existing inflows are discharging into the lake (present situation); (2) none is discharging; (3) all are discharging except the Paşaköy channel. The first scenario produced concentrations consistent with measurements in the lake. In all stations, a phytoplankton peak value was predicted during November and December 2002, and January 2003. In the second scenario, as expected, a significant decrease in the concentrations was predicted. In the third scenario, a small improvement in the water quality was obtained. To significantly improve the state of the lake, instead of entering Paşaköy channel, wastewater should bypass the lake. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study is to determine the radioactivity levels as a baseline for further studies and to obtain the distribution patterns of radioactivity in lake surface water around Izmir/Turkey. In this study, surface water samples were collected from three lakes around Izmir–Turkey. Surface water samples were analyzed for pH, mV conductivity and alkalinity content. The gross alpha/beta and uranium concentrations were investigated in the collected lake water samples. Mean gross alpha and gross beta activity concentrations in the surface water were found to be between (0.03 and 2.62)Bql−1 for Karagol Lake, (0.75 and 2.35)Bql−1 for Golcuk Lake, (0.03 and 1.77)Bql−1 for Cakalbogaz Lake, respectively. Uranium concentration varied between (0.05 and 900)μgl−1 for Karagol Lake, (0.05 and 0.95)μgl−1 for Golcuk Lake and (3.33 and 10)μgl−1 for Cakalbogaz Lake. Radioactivity contour maps were produced and their data were evaluated statistically. [Copyright &y& Elsevier]

Some ecological requirements of aquatic Coleoptera species were studied in a natural lake. Water beetle samples, collected in 2007 from the National Park Sahara-Karagöl belonging to the families Helophoridae, Hydrophilidae, Hydrochidae, and Dytiscidae were identified and listed. Both physical (conductivity and temperature) and chemical (pH, dissolved oxygen, total dissolved solids, hardness, organic matter, chloride, phosphate, and some metal ions) parameters of the inhabited water were measured. [ABSTRACT FROM AUTHOR]

The theoretical basis of the proposed technique is the cumulative variation of 137Cs measurements’ squared-differences between a reference and other sites. The change of the cumulative squared-differences with distance from the reference site is referred to as the point cumulative semivariogram (PCSV), which provides appropriate measure of cumulative similarity. Inspection of individual experimental PCSV provides local interpretation about the 137Cs radioactivity concentration around each site, whereas collective inspections provide possibility for grouping similar sites and hence identifying homogeneous sub-areas within the study area. It is also possible to prepare 137Cs radioactivity concentration maps based on pre-specified distances in each experimental PCSV, which lead to similarity levels. Such maps provide appreciation of 137Cs radioactivity concentration regional dependence in Keban Dam Lake, Turkey. Apart from the individual PCSV interpretations, the whole lake is divided into four distinctive classes. [ABSTRACT FROM AUTHOR]

In Turkish art a lot of fertile works on architectural and handmade crafts are done. Hand-carved which belongs to those arts includes ıne part of decorative art. To inrease the durability of hand-carved ornaments, a transparent wax called "lake" is used. In this study a Mevlevî Koran Stand with "lake" on wooden hand-carved ornament is studied. It is a unique example of Turkish handmade crafts seeing in motifs and compositions. It is also important to show the fully developed arts of Seljuks wooden art. [ABSTRACT FROM AUTHOR]

To identify the mollusk fauna of Lake Sapanca (Turkey), samples were collected monthly from 5 stations between September 2000 and August 2001. The mollusk fauna of the lake consists of a total of 16 species, 12 of which belong to Gastropoda: Theodoxus fluviatilis, Viviparus acerosus costae, Esperiana accicularis situssineri, Esperiana esperi, Bithynia tentaculata, Lithoglyphus naticoides, Borysthenia naticina, Galba truncatula, Radix labiata, Lymnaee stagnalis, Planorbis planorbis, and Oxyloma elegans, and 4 to Bivalvia: Unio pictorum, Dreissena polymorpha, Anadonta cygnea, and Sphaerium lacustre. Furthermore, temperature, dissolved oxygen, pH, turbidity, and depth of each sample were measured at the sampling sites. [ABSTRACT FROM AUTHOR]

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Lake Ýznik, which is under the threat of pollution, has been subject to a very limited number of studies in terms of its fish fauna, and therefore the species living in the lake are not well known yet. It was demonstrated that 19 fish species inhabit Lake Ýznik: Alburnus alburnus (Linnaeus, 1758), Alburnus chalcoides (Güldenstadt, 1772), Barbus tauricus escherichi Steindachner, 1897, Capoeta tinca (Heckel, 1843), Carassius gibelio (Bloch, 1782), Cyprinus carpio Linnaeus, 1758, Leuciscus cephalus (Linnaeus, 1758), Rutilus frisii (Nordmann, 1840), Rutilus rutilus (Linnaeus, 1758), Vimba vimba (Linnaeus, 1758), Tinca tinca (Linnaeus, 1758), Cobitis vardarensis Karaman, 1928, Nemacheilus angorae Steindachner, 1897, Silurus glanis Linnaeus, 1758, Atherina boyeri Risso, 1810, Gambusia holbrooki Girard, 1859, Gasterosteus aculeatus Linnaeus, 1758, Salaria fluviatilis (Asso, 1801) and Proterorhinus marmoratus (Pallas, 1814). B. t. escherichi, C. tinca, C. gibelio, T. tinca and G. holbrooki were recorded for the first time from the lake. The diagnostic characteristics of these 5 species and Rutilus rutilus were studied and are given in detail. [ABSTRACT FROM AUTHOR]

The distribution of some heavy metals in three different organs of mullet, Liza abu, and catfish, Silurus triostegus, from Atatu¨rk Dam Lake located on Euphrates (Turkey) was studied. Co and Mo concentrations were below limits of detection in all fish organs, whereas Ni was also below limits in organs of mullet. The metal accumulation in the liver and gill of L. abu and S. triostegus was found to be quite high in comparison with the muscle. In general, the concentrations are similar to those previously observed on other fish studied in Atatu¨rk Dam Lake and lower than those determined in Tigris River. The analysed metals (Co, Cu, Fe, Mn, Mo, Ni and Zn) were found in fish muscle at mean concentrations under the permissible limits proposed by FAO. [Copyright &y& Elsevier]