Evaluation of photosynthetic products (phytoplankton) in the major estuaries of the southern Caspian Sea

Abstract

Due to various Physic and chemical factors of rivers leading to the sea, the situation seems different topography and throughput rate initial productions in the different seasons and due to various circumstances physical and chemical rivers leading to the sea, seabed topography in different situation appears to be of primary production in the eastern and western between the Caspian Sea in the season, may be altered.Identifying species and determining the distribution and biomass of the changes and how they are affected by environmental changes and we are environmentally conscious. We also compare the current situation with previous studies, we find that the number and types of plankton biomass have been what it is. During 1392 in spring, summer, autumn and winter, in a study of 8 transects of 40 stations. In each transect from Astara to the Turkmen. 5 stations at depths of 5. 10 and 20 m were selected for sampling. The total number of 182 species from seven branches Bacillariophyta, Pyrrophyta, Cyanophyta, Chlorophyta, Euglenophyta, Xantophyta and Chrysophyta phytoplankton were identified. Including 81 species of Bacillariophyta, 33 Cyanophyta, 25 Pyrrophyta, 31Chlorophyta , 9 Euglenophyta, 1 Xantophyta and Chrysophyta had 1 specie. Most of Bacillariophyta (61 species) was in Autumn and then in winter (48 species). Dominant species of Bacillariophyta were Pseudonitzschia seriata, Rhizosolenia fragilissima, Stephanodiscos sp. , Melosira varians, Nitzschia acicularis and Cyclotella menenghiniana Pyrrophyta was greatest diversity of branches in summer, autumn and winter (19 species), which includes Exuviaella cordata, Exuviaella marina, Prorocentrum praximum and Prorocentrum scutllum. In the autumn density of Cyanophyta was 285/7(± 137/1) cubic meters × 106 and biomass was 95( ± 54) mg per cubic meter) and 18 species were observed. The dominant species in this category were Oscillatoria sp., Nodularia spumigena and Oscillatoria agardhii. Most species of Chlorophyta branche in autumn and winter and summer median region with the highest density at the density of 26/2% and most of it is Binuclearia lauterbornii. Identified as the branches Euglenophyta were Trachelomonas, Euglena and Phacus that were observed in all seasons. In winter, the highest mean biomass was 9( ± 0/818) mg per cubic meter and the highest density of in summer was 0/5 ( ± 0/5) in cubic meters × 106. In winter the depth of 10 meters and surface of Babolsar, Amir Abad and Anzali, a kind of Chrysophyta and in surface of Tonekabon and Anzali a species of Xantophyta were observed that had negligible density and biomass. Studies have shown that density and biomass of Bacillariophyta were 228 (± 471) per cubic meter × 106) and 6157 ± ( 290) mg per cubic meter) respectivity and Pyrrophyta were 28/17( ± 27/14) cubic meter × 106in cubic meters) and 3349 ( ± 336) mg per cubic meter) and Cyanophyta 120/40 (± 123/87) per cubic meter × 106 per cubic meter), biomass (55 ± 57mg per cubic meter) were the branches of the dominant phytoplankton. Abundance and biomass in different seasons have been significant differences (p <0.05).