Study on Cyanobacteria Population in Iranian Waters of the Caspian Sea during 2010-2011

Tahami F

Published on: 2020-05-15

Abstract

Since awareness of the cyanobacteria population of each ecosystem is important, the aim of this study is focuses on cyanobacteria population of Iranian waters of the southern Caspian Basin. The present study was conducted in southern part of Caspian Sea, Iran. All samples were taken during 2010-2011 through spring, summer, autumn and winter, in 32 stations from 8 transects (Astara, Anzali, Sefidrood, Tonekabon, Noshahr, Babolsar and BandarTurkman). In each transect 5 stations in different depths of 5 m, 10 m, 20 m, 50 m and 100 m were defined that the seasonal sampling were performed from the depth of zero (surface), 10 m, 20 m, 50 m and 100 m by Ruttner Water Sampler, and then transferred to laboratory of Caspian sea ecological institute. Then the samples transferred to laboratory of Ecological Academy, kept in cool and darkness in properly capped glass bottles. The cyanobacteria were analyzed on a “Nikon” light microscope at ×480 magnification. Algae abundance was determined using the Hydro bios counting chamber and sampled (volume 0.1 ml). The volume of each cell was then calculated by measuring its appropriate morph metric characteristics and geometric. A total of 19 species, that belong to 10 different genera, showed significantly decrease with increasing depth, especially at the depth of less than 20 m (P<0.05). The Cyanobacterial compositions were significantly changed with seasons and depths, and depth and the maximum cell abundance and biomass observed in summer. The Microscopic Cyanobacteria species were identified. (P<0.05) and Shannon index was different for different seasons.