نتایج جستجو برای: river and lake
تعداد نتایج: 16861317 فیلتر نتایج به سال:
urmia lake is the largest lake in the country which during recent years faces a dramatic reduction in the water level. many reasons such as climate change, continuous droughts, development of cultivation and land use changes as well as construction of dams were mentioned, but the provided reasons have less been well documented by scientific evidences. this study is an attempt to investigate the...
Nonlinear models of ecosystem dynamics that incorporate positive feedbacks and multiple, internally reinforced states have considerable explanatory power. However, linear models may be adequate, particularly if ecosystem behaviour is primarily controlled by external processes. In lake ecosystems, internal (mainly biotic) processes are thought to have major impacts on system behaviour, whereas i...
The Balkans are known to have a high level of biodiversity and endemism. No less than 15 taxa have been recorded in salmonids of the Salmo genus. Among them, the Prespa trout is found in only four river systems flowing into Lake Macro Prespa, three in the Former Yugoslav Republic of Macedonia and one in Greece. This is the first comprehensive survey of all streams located within the Macro Presp...
Leuciscus persidis as Iranian endemic fish in Kaftar lake and its headwaters (Mesopotamian subregion, Kor-Neiriz basin and Shadkam river) has been infected with a species of Dactylogyrus sphyrna. Comparison of collected parasites with Euro-Asian subregion showed that the similarity of them is more than their differences, although a little difference between them was observed. In this paper also...
a fish species prefer a particular habitat where provides its biological requirements, hence, understanding their habitat use and preferences are crucial for their effective management and protection. this study was conducted to assess the habitat use and selection patterns of alburnoides namaki , an endemic fish in jajroud river, namak lake basin, iran. the river was sampled at 18 equally spac...
The aim of this study was to compare some biochemical blood parameters of rainbow trout (Oncorhynchus mykiss) living in running or still waters. Some biochemical parameters of rainbow trout were examined, and the results were evaluated between sampling locations and according to seasonal changes. Healthy adult rainbow trout were caught from six different locations on the Bahçelik Dam Lake and t...
The subject of the study is to analysis pattern of Mahabad River channel. This area is located on the south of Uromia Lake. Rapid changing of its channels pattern is an important characteristics which the evaluation of these characteristics is necessary to any hmplementation of development projects. For this purpose, the morphological changes of river channel were recognized by the areal photog...
Local adaptation towards divergent ecological conditions often results in genetic differentiation and adaptive phenotypic divergence. To illuminate the ecological distinctiveness of the schizothoracine fish, we studied a Gymnocypris species complex consisting of three morphs distributed across four bodies of water (the Yellow River, Lake Qinghai, the Ganzi River and Lake Keluke) in the Northeas...
Numerous waterborne outbreaks of giardiasis have occurred since 1965, yet little or no information has been reported on the viability of Giardia cysts in different aquatic environments. We have studied the viability of Giardia muris cysts suspended in lake, river, and tap water, while also monitoring water temperature, dissolved oxygen, pH, and other water quality parameters. Fecal pellets cont...
Conservation of water quality is inherently tied to watershed management. Efforts to proect Lake Baikal have increasingly focused on the Selenge River, a major tributary, with more than half its watershed area in Mongolia. Placer gold mining in Mongolia has the potential to load total suspended sediment (TSS), and total phosphorus (TP) into Lake Baikal and destroy spawning areas for the endange...
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