Multivariance analysis on the distribution of micro-macro elements and their derivates at Meriç River (Thrace Region, Turkey)

Özet

Meriç River, called international water, is one of the most important river systems in Thrace. As the river is an open ecosystem to intensive anthropogenic impacts from settlements, agricultural and industrial areas, monitoring its aquatic characteristics is very valuable in terms of maintaining its sustainable use. In particular, knowing the micro and macro element contents that play an important role on primary productivity in aquatic ecosystems will be very useful in predicting the eutrophication process. In this study some chemical analyzes (calcium, magnesium, chloride, nitrate nitrogen, nitrite nitrogen, sulphate, phosphate, cupper, iron, zinc) were carried out to determine the concentrations and distribution of some micro-macro elements and their derivates in Meriç River. Thus, it was aimed to determine the micro and macro element contents of different regions in the river, to compare the data with other studies in the region and to make suggestions on the sustainable use of the river. For this aim, samplings were done selected from eight stations located in Meriç River at Thrace region of Turkey between January and December 2011. Chemical analyzes of Ca, Mg, Cl, NO3-N, NO2-N, PO4, SO4 in water samples taken from the sampling stations by the Ruttner water sampler at monthly intervals were carried out in the laboratory using classical and spectrophotometric methods. The multivariance analysis (Bray-Curtis Cluster Index) was used to evaluate the similarities of sampling stations in terms of seasonal averages of these parameters. In order to determine the concentrations of some heavy metals (Cu, Fe and Zn), water samples taken by Ruttner sampler and sediment samples taken by Ekman grab at seasonal intervals were measured in flame atomic absorption spectrometry. The sampling stations were evaluated also statistically by using Bray-Curtis Cluster Index in terms of heavy metal contents of water and sediment. According to the result of statistical analysis, it was determined that the locations at lower Meriç River area are different from the upper area. Especially it was observed that the sampling locality after Ergene River added to Meriç River has very low quality level in terms of some chemical contents. It is thought that this may be due to the agricultural and industrial pollution load carried by the Ergene River. Therefore, it has been concluded that these locations must be evaluated in the studies of physicochemical evaluation of Meriç River.