Effect Of The Caspian Sea Water On Chracteristics Of Southern Lagoon And Bay
Anzali Lagoon and Gorgan Bay are two important inland water bodies in the Southern boundary of the Caspian Sea, in the north of Iran. In this paper water exchange phenomenon and physical and chemical properties of seawater along connecting channels between Gorgan Bay and Anzali Lagoon with the Caspian Sea were evaluated. The research is based on field collecting data on 12 sampling stations during warm and cold seasons. Measurements were performed by a portable CTD Ocean Seven 316 probe using local vessels. The parameters ranges in the warm and cold seasons were different. Based on data, water temperature in vertical direction changed between 27.5-25 centigrade in June and it ranged between 9.3-7.5 centigrade in February. In general, concentrations of dissolved oxygen along connecting transect was increased from lagoon side to seaside in warm and cold seasons. Furthermore, levels of saturated and dissolved oxygen in cold seasons (10-12 ppm) were more than those (6-8 ppm) in warm seasons. Mean values of water salinity in cold season were less than that in warm season in the connecting channel. Variations of salinity were around 12 psu in warm season while salinity values in cold season observed about 7.5 psu. According to high correlation between seawater density and temperature in the Bay and Lagoon connecting channels as well as the Caspian Sea, vertical structures of water density and temperature were in agreement.
Keywords: Caspian Sea, Anzali Lagoon, Gorgan Bay, Water Characteristics.