Investigation of zooplankton distribution in Ashoradeh coastal in Gorgan Bay

Ongoing ecological study of the Caspian Sea, in particular identifying the distribution and species composition, density and biomass, seasonal and regional variations in zooplankton seems to be necessary before any study. The aim of this study was carried out the distribution of zooplankton in Ashuradeh Island to distances of 50, 500 and 1000 meters from the coast using plankton net with 100 microns in spring and summer in 2017 in Gorgan Bay. The result showed that distributions of zooplankton in 3 stations was shown a significant difference (p˂0.05). Totally, 470.23±50.34 m2 belong to 11 species and 4 major groups (Protozoa, Rotifera, Balanidae Copepoda) and the others were identified. The zooplankton density (m2): Copepoda in summer (158.9±40.02 m2) and in spring (102.3±31.2 m2), Rotifera in summer (72.8±25.5 m2) and in spring (8.4±3.1 m2) and Balanidae in summer (48±17.18 m2). Copepoda had the highest abundance was found Copepoda of 56% and Protozoa with the lowest abundance 4%. In general, the distribution and density of zooplankton groups were higher in the summer than in spring (p˂0.05). In general, in beach pier at a distance of 50 meters from the coast in the total of two seasons was observed the highest number of species and at a distance of 1000 meters with the least number of species

Keywords:

Zooplankton , Distribution , Beach pier , Gorgan Bay