Physicochemical conditions and trophic levels of the Anzali Wetland

Anzali wetland is one of the most important wetlands in the southern coast of the Caspian Sea which is under the influence of the brackish water of the Caspian Sea and the freshwater rivers entering it. Therefore, it plays important role as an exclusive ecotone. Physicochemical conditions and trophic levels of the Anzali Wetland were evaluated monthly from May 2014 to May 2015. Trophic State Index (TSI) was calculated based on the evaluation of chlorophyll a, total phosphorus (TP), total nitrogen (TN) and water transparency. The results showed that the average annual amounts of total nitrogen, total phosphorus and dissolved oxygen were 1.023±0.523, 0.113±0.105 and 8.71±2.63 mgL-1, respectively. The amounts of total nitrogen were not significantly different among various research locations (P>0.05), whereas the amounts of total phosphorus were significantly different among various research locations (P