Mohammad Ali Afraei Bandpei - Assistant Professor, Caspian Sea Ecology Research Center, Iranian Fisheries, Science Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), Sari, Iran
Hassan Nasrollahzadeh Saravi - Associated Professor, Caspian Sea Ecology Research Center, Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), Sari, Iran
Nima Pourang - Associated Professor, Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran

This research is part of the study of biotic, abiotic and environmental pollutants in the range of fish breeding cages in the southern Caspian Sea (Mazandaran-Keralabad coastal) during the years 2011-2011. Sampling was seasonally, at a depth of 20 meters (cage deployment) and at three stations. The purpose of this study was to investigate the abundance and biomass of the zooplankton in different stations. The results showed that 6 species belonging to 4 families were identified. Acartia tonsa (Acartidae) was dominated over other species at different stations and seasons, especially at station 1, in which could be due to cage establishment, alien species, high adaptability in various ecosystems and the availability of food items depends. The study of abundance and biomass at different stations showed that the highest density recorded 14708 ind.m-3 an average (±SD), (1337 ± 2007ind.m-3) and maximum biomass was 128.1 mg .m-3 with mean (±SD), (11.6 ± 22 mg.m-3) in station 1, respectively. The lowest density and biomass was recorded in station 3 where it was selected as the control station. Significant difference in abundance and biomass in different stations was found (p <0.05). Therefore, in order to obtain more accurate information, further research is required.

Abundance, Biomass, Zooplankton, Cage culture, Caspian Sea, Iran