عنوان مقاله [English]
Esteel wetland with 138 ha extent is one of the conserved regions in Guilan Province. This study was carried out from spring 2008 to winter 2009 in order to recognize phytoplankton species of Esteel wetland and their diversity, density, abundance, and seasonal changes. According to geographical situation of Esteel wetland, 13 stations were spotted. Sampling was done with tube (P.V.C. pipe) in the middle of each season by noticing the depth of wetland. Physicochemical properties of water such as temperature, dissolved oxygen, pH, nitrite, nitrate, ammonium, phosphate, and EC in 5 stations were measured in each sampling. In this study, totally 10 phyla and 42 genus of phytoplankton were identified. From these, 6 genus belong to Cyanophyta, 17 genus belong to Chlorophyta, 1 genus belongs to Chrysophyta, 8 genus belong to Bacillariophyta, 4 genus belong to Euglenaophyta, 1 genus belongs to Heterokontophyta, 1 genus belongs to Cryptophyta, 1 genus belongs to Phyrrophyta, 2 genus belong to Charophyta, and 1 genus belongs to Cyanobacteria phylum. The average annual density of phytoplankton in this lagoon was 12387 cell/ml1-. Cyanophyta with the density of 283274 cell/ml1- and the abundance of 93.34% and Cyanobacteria with the density of 3 cell/ml1- and the abundance of 0.001%, respectively had the most and the least annual phytoplanktonic density and abundance that had significant differences (P<0.05) with other phyla. Seasonal changes of these planktons also showed that summer with 10 phylum and 25 genus of phytoplankton and autumn with 5 phylum and 10 genus phytoplankton had the most and the least diversity, respectively. Also summer with the density of 46801 cell/ml1- and winter with the density of 14 cell/ml1- had the most and the least annual density of phytoplankton which had significant difference (P<0.05) with other seasons.