Phytoplankton population changes(fluctuations) in

urmia lake(North west of iran

 

L. Esmaeili1*;  F. Mohebbi1 ; H. Negarestan2 and  R. Ahmadi 1

l_smaili@yahoo.com

  1. Iranian Artemia Research Center, P. O. Box: 368, Urmia, Iran.
  2. Iranian Fisheries Research Organization, No. 297, West Fatemi St., Tehran, Iran.

 

Abstract: 

     Phytoplankton as Artemia food and primary producers play a critical role in Urmia Lake. Seasonal variations in physico-chemical parameters of the lake such as salinity, organic and inorganic materials and temperature induce fluctuations in phytoplankton communities. In recent years, due to reduced water inflow salinity has influenced phytoplankton composition more than other parameters. In this study phytoplankton population changes and salinity fluctuations was syudied in Urmia Lake from 2006-2007. phytoplankton were belonged to Chlorophytae, Diatoms and Cyanophytae(2). Dunaliella sp.a hypersaline tolerant alga was the most abundant species so that it composed 93% and 88.4% of Urmia Lake s total phytoplankton abundance in 2006 and 2007 respectively. Diatoms suchas Navicula, Nitzschia sp. and Synedra sp. Were the second abundant species. Other species which was observed in this study included: Closterium sp., Diatoma sp., Symbella sp., Cymatopluera sp., Gyrosigma sp., Cyclotella sp., Surirella sp., Amphora sp., Oscillatoria sp., and Anabaena sp. One-Way analysis indicated that the mean monthly abundance of phytoplankton was statistically significant(p≤0).