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Trend of Macronutrients Fluctuation of Waterin the Iranian Coasts of Southern Caspian Sea
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Hasan Nasrollahzadeh Saravi   , Reza Pourgholam , Fariba Vahedi , Asieh Makhlough , Ebrahim Safavi |
| , hnsaravi@yahoo.com |
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Abstract: (16068 Views) |
| This study was conducted to nutrient concentrations of water in the southern Caspian Sea waters during
four seasons at 8 transects (Astra, Anzali, Sefidrud, Tonekabon, Nowshahr, Babolsar, Amirabad and
Bandar Turkman) during 2009-2010. 480 samples were collected at different layers of water and then
analyzed based on standard methods. Annual concentration of inorganic nitrogen (DIN= NH4+, NO2-,
NO3-) has a fairly wide variation. Percentage of nitrogen components out of DIN were varied 9-98, 0.2-
28.2 and 0.0-90.0 respectively. In this study, percentage of DIN was lower than 15% and organic nitrogen
(DON) was higher than 80%. Overall, results showed that DON was recorded lower than the previous
study (2008), but NH4+, NO3- and DSi were higher than the previous sampling period. Inorganic
phosphorous (DIP) and NO2- have not changed substantially. N/P ratio of Caspian Sea has a narrow range
which order of magnificent lower than other seas. The results of the present study showed that Caspian
ecosystem was nitrogen limitation (N/P<10) before introduction of Mnemeiopsis leidyi, while it seems that
after introduction of Mnemeiopsis leidyi the system has been shifted to the phosphorous limitation
(N/P>20). |
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| Keywords: Macronutrients, Water, Iranian Coast, Caspian Sea. |
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Full-Text [PDF 119 kb]
(1915 Downloads)
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Type of Study: Research/ Original/ Regular Article |
Received: 2012/12/11 | Revised: 2012/12/12 | Accepted: 2013/09/22 | ePublished: 2013/09/22
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