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

Abstract

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./m3 and 180.58±149.03 mg/m3in 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./m3 and 47.07±31.96 mg/m3, 5281±5521 ind./m3 and 29.03±31.68 mg/m3 in 5m of summer and autumn seasons, respectively. Copepoda comprised more than 95 percent of marin zooplanktons in all of depths in these seasons. The most abundance and biomass were 19030±16518 ind./m3 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 marin zooplanktons in all of depths and the abundance of other groups was not considerable in zooplankton community.