A preliminary study was carried out to understand Gorgan-Bay ecosystem as a whole and determine environmental factors affecting it. Gorgan-Bay with an area of 400 Km2 is situated in the south-eastern part of the Caspian Sea. There have been four canaLs connecting the Bay to the sea. now reducet to only one. Average pH is found to 83 and there is no difference in total Alkalinity, total Hardness and pH of the Bay compared 10 the Caspian Sea. Water temperature ranges from 5 'c to 30'c in a year. The bottom is covered with Marine alluvial and colluvial sediments with the organic materials originating from dead plants and non-skeletal parts of marine oysters. Pollution Sources include urban/Industrial sewage and pesticides. During the study 8 genus of Zooplanktons and 16 genus Phytopelanktons were identified with the abundance ranging from 71,000 to 12,915,000 per cubic meter. Identified fishes include natural and artificially produced Cyprinus carpio, Aspius aspiuc, Rutilus rutilus.....
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