Assessment of the Water Quality of the Anzali International Wetland using Qualitative Indices

Wetlands are valuable ecosystems that have a variety of functions to protect biodiversity, natural values, economic and social values. The importance of wetlands, especially in arid and semi-arid regions such as Iran, is higher. Wetlands can reduce the effects of climate change in different ways. Hence, the degradation of wetlands will intensify the climate change impacts. At the moment, the Anzali international wetland is under the impact of environmental stresses and pollutants such as the entry of the industrial, agricultural, and urban effluents, the presence of non-native species, changes in the purpose of usage, and eutrophication. Therefore, the need to study the spatial and temporal variations of pollutants using qualitative indicators is one of the most important factors in water quality studies. In this study, due to the importance of the Anzali wetland and its environmental impact on sustainable development, an ecosystem quality survey was conducted using the data from seasonal sampling which took place in the year 1393 at 10 stations using NSFWQIa, NSFWQIm, and OWQI qualitative indices. Based on the results of the various indices, most stations are categorized in having middle to very bad levels. During the summer season, the most polluted stations according to the NSFWQIm, NSFWQIa, and OWQI indices were Nokhale, East of wetlands, and Pirbazar, respectively. The variance analysis showed a significant difference (p