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    Cardiovascular Toxicity in Daphnia magna: Heart Rate Analysis Under Exposure to Crystal Violet, Ethanol, and Formaldehyde
    (Ordu University, 2025) Karademir, Arda Sarp; Can, Melisa; Sönmez, V. Zülal; Sivri, Nüket
    Water fleas have become valuable model organisms for ecotoxicity studies due to their ease of cultivation, transparent bodies, and high sensitivity to chemical pollutants. In this study, heart rates in Daphnia magna were examined to assess basic behavioral and physiological characteristics under exposure to known toxic chemicals. Crystal violet, ethanol, and formaldehyde selected for their distinct chemical properties and documented toxicity were utilized as toxic solutions. A slow-motion, video-based method was implemented to evaluate cardiovascular performance by monitoring heart rates in water fleas. Data for important parameters like heart rates, body reactions, and heart contraction were extracted from video recordings. It was found that crystal violet increased the heart rates of Daphnia magna (489±14.19) more than ethanol (450±40.67) and formaldehyde (445±48.21). Compared to the control group, formaldehyde caused a 28.51% increase in the heart rates of daphnids, while exposure to ethanol (30.54%) and crystal violet (35.89%) resulted in a lower increase. The response of water fleas to each of the three chemicals studied was determined as a statistically significant and noticeable increase in heart rate.
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    Determination of the toxicity of different discharge waters using acute toxicity tests approved for national pollutant discharge permit in Turkey
    (Oriental Scientific Publishing Company, 2016) Sönmez, Vildan Zülal; Sivri, Nüket; Dökmeci, Ayşe Handan
    Nowadays, three methods which target the evaluation of the characteristics of ecotoxicology tests according to aquatic trophic level are well-known, approved methods. In Turkey, the toxicity dilution factor (TDF) method, approved by Turkish Water Pollution and Control Regulation, and Lebistes reticulatus the actual method name that utilizes this animal which is a high level consumer, are used in the assessment of acute toxicity levels of waste waters with different compositions. However; it is not preferred by researchers except statutory obligations due to its disadvantages in implementation. The other method Daphnia magna, which belongs to secondary trophic group, is also widely used. Vibrio fischeri which is based on bioluminescent bacteria is mostly preferred due to ability of giving fast and precise results in acute toxicity assessment tests. In this study, specific to Turkey, it is aimed to compare issues such as experimental process, time, cost, efficiency, repeatability, etc. of tests that take place in the related legislation and standards. In light of all this information, it is determined the insufficient parts about legal regulations related to toxicity in Turkey. It can be suggested that bioluminescence bacteria (V. fischeri), defined all around the world recently with its precision, optimal cost, repeatability features be used in Legal Regulations of Turkey. It is aimed to contribute to scientific literature, this study being the first on suggesting an innovative approach about acute toxicity test in Turkey.
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    Modeling The Toxicity of Textile Industry Wastewater Using Artificial Neural Networks
    (Ieee, 2017) Şamlı, Rüya; Sönmez, V. Zülal; Sivri, Nüket
    Toxicity tests are required to detect the possible effects of pollutants on organisms. This study investigates the effect of Chemical Oxygen Demand (COD), suspended solid (SS) and pH parameters on toxicity of textile industry wastewaters except for the color parameter, effect of which is well known. Fish bioassay taking place in legal regulation of Turkey was used as toxicity test. At the end of the toxicity test, various values of the parameters were predicted through Artificial Neural Networks (ANN). In addition, Artificial Neural Networks were used to calculate the effect of each parameter on toxicity (%). Accordingly, COD is the parameter which mostly affects toxicity following color parameter and SS is the parameter which has the minimum effect. It is found that results deviate at the rate of 15.41% when values of COD parameter are excluded from the model input data and the error rate becomes 5.07% when SS parameter is excluded. In this study, the effect of each input of each parameter, which is an open ecosystem, based on selected parameters is successfully predicted through Artificial Neural Networks which is a heuristic method.
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    Potential impacts of oil spill damage around the planned oil rigs at the Black Sea
    (Natl Inst Science Communication-Niscair, 2018) Başar, Ersan; Sivri, Nüket; Uğurlu, Özkan; Sönmez, Vildan Zülal
    This study uses 10 different scenarios in order to determine the risks of oil rigs which are planned to be conducted at Black Sea on coastal area or in marine environment. The Black Sea, which is among the most remarkable water basins in the world, is a unique ecosystem including endangered species and also other endemic and economic species detected by International Union for Conservation of Nature (IUCN). Only accident scenarios to be developed under variable conditions can help us to foresee such irrevocable damages against this important ecosystem. Taking stand from this point, an assessment on possible scenarios related to an area during the studies of oil exploration and oil rigs will minimize any damage on sensitive coastal system. Furthermore, 2 emergency intervention regions were determined in case of accidents.
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    QUALITY ASSESSMENT AND CHEMICAL COMPOSITION OF SURFACE WATER IN THE AKCADAG BASIN (MALATYA), TURKEY: A CASE STUDY FOR IRRIGATION AND DRINKING PURPOSES
    (Parlar Scientific Publications (P S P), 2019) Şahin, Serap Koşal; Sivri, Nüket; Şahin, Ülkü Alver; Sönmez, Vildan Zülal; Şeker, Dursun Zafer
    The quality of irrigation water has a considerable impact on what plants can be successfully grown, the productivity of these plants, and water infiltration and other soil physical conditions. Irrigated agriculture is dependent on an adequate water supply of usable quality. To avoid problems when using poor quality water supplies, there must be sound planning to ensure that the quality of water available is put to the best use. The usage of irrigation water by Polat and Silrgti Streams is one of the most important factors in respect to the intensification of agricultural activities in the Akcadag Basin. Responsible and accurate use of these factors by means of GIS is of vital importance. This study aims to visualize waters defined to be qualified to be used for irrigation or drinking purposes with the aid of GIS and to ensure the sustainable use of surface waters in the Akcadag Basin. The most common measure to assess irrigation in water is called the Sodium Adsorption Ratio (SAR). The SAR defines sodicity in terms of the relative concentration of sodium (Na) compared to the sum of calcium (Ca) and magnesium (Mg) ions in a sample. The SAR assesses the potential for infiltration problems due to a sodium imbalance in irrigation water. The highest value was found in SAR station 2 (0.473) while the lowest value (0.027) was calculated in the station 7. The selected stations should be monitored in wet and dry seasons in order to provide a more accurate interpretation of the area and to ensure proper use. It is possible to aim to protect water resources and make people reach these resources in a healthy way, to create a sustainable water management policy by means of different monitoring tools to be used for the monitoring of the area.