Seasonal distribution of epiphytic algae on natural and artificial substrates and the relationship between their biomass and water physico-chemical properties in Anzali Lagoon

We studied epiphytic algae in Anzali Lagoon in Guilan Province from September 2000 to August 2001. The algae were removed from natural and artificial substrates and their biomass were determined using Sedgwick - Rafter Cell and Olympus microscope. Species of bacillariophyceae were the most abundant with increased density of chlorophyceae in spring and cyanophyceae in summer. Also euglenophyceae algae showed a slight increase in summer. Direct correlation between algal biomass and environmental factors such as temperature, total phosphorous, total nitrogen and nitrate were seen. Also, a reverse relationship between epiphytic algal biomass and increased activity of macrophyte was detected. It is suggested that the excretion of allelopathic substances from macrophyte algae inhibits growth of epiphytes.