$ # ! % ! " ! 3752 # &#! $#' "#!" & # "$# "#! " "#" #!" '" !!#" #)62= =<4= =4-6< %-:-8 1 Recep Tayyip Erdogan University, Vocational School of Technical Science, Department of Fisheries, 53100 Rize, Turkey 2 Recep Tayyip Erdogan University, Faculty of Fisheries, 53100 Rize, Turkey "#!# The purpose of this study is to determine the physico-chemical properties (temperature, pH, dis- solved oxygen, electrical conductivity, suspended solid, nitrite nitrogen, nitrate nitrogen, orthophos- phate and sulphate) within the water quality of 8 dif- ferent streams flowing into the South eastern Black Sea coast. The water samples were collected monthly from April 2016 to March 2017 at a speci- fied point at which the Melet, Aksu, Değirmendere, İyidere, Salarha, Büyükdere, Fırtına and Hopa streams flow into the sea. The physical parameters of the water samples were measured using a portable multi water quality meter (HQ40D), and analysed the chemical parameters using a spectrophotometer (HACH-LANGE-DR3900). The Gravimetric method was used to obtain suspended solids matter (SPM). The analysis results were compared with na- tional and international quality standards and regula- tions for drinking as well as non-drinkable water. The annual means of parameters for all streams featured in this study were 14.22±0.525 (4-26.1) °C in terms of temperature, 7.62±0.059 (6.1-9.1) in terms of pH, 158.63±8.837 (40-420) µS/cm in terms of electrical conductivity, and 10.38±0.132 (7.29- 14.63) mg/L in terms of dissolved oxygen. On the other hand, the amount of suspended solid matter (SPM) was 68.36 ± 8.791 (0.3-604.1) mg/L, nitrite nitrogen was 0.016±0.005 (0.001-0.53) mg NO2- N/L, nitrate nitrogen was 0.340 ± 0.026 (0-1.5) mg NO3-N/L, orthophosphate phosphorus levels were 0.388±0.064 (0.02-4.29) mg o-PO4-P/L, and the level of sulphate concentration was 10.458±0.949 (0-48) mg SO4/L. When the findings are evaluated according to national and international standards, all of the streams have a Class I water quality standard accord- ing to other parameters with the exception of ortho- phosphate phosphorus. For orthophosphate phos- phorus levels, the Değirmendere and İyidere streams were determined to be Class IV, whilst the remaining streams were determined to be Class II in terms of water quality. '&!" Water quality, South Eastern Black Sea, Stream, Water Pollution #!$# The primary water arteries feeding into the seas are surface and groundwater sources. It is inevitable that these sources are affected by atmospheric and terrestrial surface cover, as well as anthropogenic ac- tivities stretching from high elevation to sea level. Each water basin has its own characteristic geo- chemical features. On the other hand, each water ba- sin has different land use, forest cover, rural and ur- ban settlements, and industrial activities. Therefore, the water quality of streams especially surface wa- ters that change more rapidly than underground wa- ters should be monitored periodically. The quality of water that we can express as physical, chemical, and biological properties of wa- ter shows the health of the water ecosystem and wa- ter suitability for human consumption (drinking, ir- rigation, and industrial use) [1]. In this context, water pollution remains an important problem for human health and the environment [2]. Natural processes such as climate change and erosion, urbanization, chemical leaks, industrial and agricultural waste, and the degradation of water quality due to dam construction lead to the pollution of underground and surface water resources, the de- struction of ecosystem balance, and other forms of pollution [3]. It is known that water quality is an im- portant influence of human intervention [4]. World- wide water quality deterioration is due to the many anthropogenic activities that release pollutants into the environment, thus negatively affecting ecosys- tems in the water [5]. Although streams are the most important fresh- water source for humans, they are contaminated by the multitude of human activities that affect their physico-chemical characteristics and microbiologi- cal quality [6]. The Eastern Black Sea region in the north east of Turkey has two water basins. These include the water basin of Eastern Black Sea and Çoruh. The Eastern Black Sea, with an annual average of 14.90