The study of diversity, distribution and abundance of zooplankton in the southern of Caspian Sea

This survey was carried out in 8 lines of southern area of Caspian sea consisting of Astara, Anzali, Sefid roud, Tonekabon, Noshahr, Babolsar, Amirabad and Torkman in depths of 5, 10, 20, 50 and 100m in 4 seasons (spring, summer, autumn and winter) of the year 2008. The goal of this survey was identification of different species, distribution, density and Biomass of the zooplankton community in different regions and also their frequency in the different layers and depths and the population fluctuations in whole of year. The most abundance and biomass of the zooplanktons were 28005±24212 ind./m^3 and 180.58±149.03 mg/m^3 in 5 min spring and they were reduced gradually to depths. Copepoda comprised between 9 to 16 percent, Rotatoria comprised between 5 to 13 percent and Lamellibranchiata larvae comprised between 27 to 70 percent of marin zooplanktons. The most abundance and biomass were 11746±7921 ind./m^3 and 47.07±31.96 mg/m3, 5281±5521 ind./m^3 and 29.03±31.68 mg/m^3 in 5m of summer and autumn seasons, respectively. Copepoda comprised more than 95 percent of marine zooplanktons in all of depths in these seasons. The most abundance and biomass were 19030±16518 ind./m^3 and 198.99±217.23 mg/m3 in 5 m in winter. Copepoda comprised between 17 to 49 percent and Rotatoria comprised between 32 to 70 percent of marine zooplanktons in all of depths and the abundance of other groups was not considerable in zooplankton community

The study abundance, distribution and diversity of zooplankton in the southern of Caspian Sea

This survey was carried out by R/V Guilan ship with a conical plankton net of 100 micron mesh by vertical hauls at different stations and depths of 5, 10, 20, 50 and 100m in 4 seasons of 2010. In this study, 16 species formed the zooplankton community including 4 species of Copepoda, 4 species of Rotatoria, 2 species of Protozoa and 4 species of Cladocera from Holoplanktons and 2 species of Balanus sp and Lamellibranchiata larvae from Meroplanktons. The annual results revealed that the mean abundance of zooplankton were 5477±5815 ind/m^3 and 5131±7908 ind/m^3 in spring and winter respectively which were more than other seasons but the maximum biomass (64/58±124/61mg/m^3 ) was in winter that was affected by Rotatoria. The maximum mean abundance and biomass of Copepoda were in summer that were 2830±2342 ind/m^3 and 22/52±21/78 mg/m^3 ,respectively and the abundance decreased gradually since autumn and reached the least in winter but increased since spring. The mean maximum abundance of Cladocera (115 ±142 ind/m^3) was in spring but it decreased gradually, so it reached to less than 3 ind/m^3 in summer. The Protozoa constituted the least community and biomass of zooplankton in southern area of Caspian Sea. The zooplankton community also was affected by Meroplanktons including Cirripedia and Lamellibranchiata Larvae in spring and the Rotatoria contributed highly in zooplankton community in winter with the mean abundance and biomass of 2604±5876 ind/m^3 and 50/71±115/33 mg/m^3 respectively.Other than Copepoda, other planktonic groups contributed lowly in zooplankton community. It was observed the reduction trend in abundance from surface depths to deeper depths in whole of the year. There were 75% of zooplankton community in stations with 5 to 20m depth and 25% of community in stations with 50 to 100m depth in spring, and also 74% in stations with 5 to 20m depth and 26% in stations with 50 to 100m depth in summer, 73% in stations with 5 to 20m depth and 27% in stations with 50 to 100m depth in autumn and 85% in stations with 5 to 20m depth and 15% in stations with 50 to 100m depth in winter. In analysis of different area of southern basin of Caspian sea the maximum abundance was observed in west in spring, summer and winter which were 7514±8115 ind/m^3, 3909±2609 ind/m^3 and 8129±11587 ind/m^3, respectively. There was 2283±2134 ind/m^3 in center area in autumn. The annual statistical analysis revealed that, there was significant difference in total zooplankton community between sampling stations, depths and layers in whole of the year

The study of abundance and dynamic zooplankton in the Southern of Caspian Sea

The Caspian Sea is the largest lake, both by its area and volume. Zooplankton are very important in the food web since many animals eat them. The Sampling was done in 4 transacts in Anzali, Tonekaboun, Noushahr and Amirabad at 3 different depths including 5, 10 and 20 m. Sampling was carried out in four seasons of spring, summer, autumn and winter in 2013. The annual changes of zooplankton was between 392±113 ind./ m^3 in autumn (Amirabad) to 8065±11735 ind./m^3 in winter (Amirabad). The lowest density of zooplankton in the spring was 2207 ind./ m^3 in Anzali. The density of zooplankton in Tonekabon and Amirabad was 2.0 and 2.8 fold more than other transects respectively. The results showed that the abundance of zooplankton in summer was between 1964±470 ind./m^3 (Amirabad) to 5706±6088 ind./m^3 (Tonekabon). The biomass was 30.02, 52.22, 22.98 and 18.31 in Anzali, Tonekabon, noshahr and Amirabad respectively. The abundance of zooplankton in the autumn reached the lowest value. The lowest value was 392 ±113 ind./m^3 and 3.71±0.19 mg/m^3 (Amirabad) and highest value was 2280 ±1435 ind./ m3 and 20.23±14.50 5mg/m^3 (Anzali). The highest density was observed in Amirabad (8065 ind./m^3) and Anzali (8061 ind./m^3) in winter. The aim of this study was diversity, distribution, density and biomass of zooplankton in the southern of Caspian Sea