Diatom community in Bandar Anzali and Sefid Rood area of the southern basin of the Caspian Sea in 2021

Subject Areas : New Technologies in Aquaculture Development

Fatemehsadat Tahami ¹ (Academical research of Ecology of Caspian Sea- Sari- Iran)

Received: 2023-10-01 Accepted : 2023-10-01 Published : 2023-05-22

Keywords: Density, biomass, Caspian Sea, Keywords: Phytoplankton,

Abstract :

The coastal areas of the Caspian Sea are a natural evolved ecosystem and since it is the last recipient of land and sea pollutants, it is therefore constantly exposed to various threats.On the other hand, the condition of the shores of the Caspian Sea has undergone unfavorable changes due to the introduction of man-made pollutants, and if this water area is misused, it will lead to serious environmental problems.This research was conducted in the southern shores of the Caspian Sea in order to investigate diatoms as the dominant group of phytoplankton in the Caspian Sea as the primary producers of aquatic ecosystems in the year 2021and in this research, first sampling was done by Rutner in two half lines perpendicular to the coast (transect) in Bandar Anzali and Sefid Rood at depths of less than 30 meters and more than 30 meters. In this study, a total of 19 species from the 10 genera Actinocyclus, Chaetoceros, Cocconeis, Coscinodiscu Cyclotella, Navicula, Nitzschia, Pseudonitzschia, Thalassionema, Thalassiosira from the Diatom phylum were observed and the highest density was at a depth of less than 30 meters in Sefid Rood at the rate of 43600000 numbers per cubic meter, and the lowest density belongs to the depths of more than 30 meters, and in both stations, the layer above 30 meters had more density. Due to different physical and chemical reasons of each region, there have been different differences in terms of population and mass of diatoms in terms of depth and station and different layers of water.