Study of Zooplankton Species Structure and Dominance in Anzali International Wetland

Anzali International wetland is one of the most important places for various organisms such as fishes. Zooplankton are the first consumers in the ecosystem, and they are perfect food for the larvae of fishes. The present study conducted monthly during January 2012 to December 2013 in 9 different stations with zooplankton population and chemical characteristics analysis such as water temperature ranged from 10°C - 22°C, pH determined alkaline nature of the wetland ranged from 7.05 to 9.47, dissolved oxygen was recorded in the range of 3.36 mg/l to 10.51 mg/l, nitrate was ranged between 0.48 - 4.36 mg/l, total phosphates was between 0.15 - 0.67 mg/l, salinity was recorded between 220 - 692 mg/l, TDS was determined between 246 - 1971 mg/l, BOD and COD was also recorded 2 - 36 mg/l and 4 - 74 mg/l respectively. Total 61 zooplankton species were found belonging to 4 groups: Protozoa (22 sp.), Rotatoria (29 sp.), Copepoda (5 sp.) and Cladocera (4 sp.). Rotatoria were found dominating other groups of zooplankton. Kruskal Wallis test showed that there was significant difference between density of zooplankton in different stations, months and seasons (P ≤ 0.05) and significant differences were found between densities of different zooplankton phylum (P ≤ 0.05). The water body is continuously receiving domestic discharge leading to large amount of nutrient inputs and high amount of phosphate and nitrate in the water body indicates that water is eutrophic in nature.