Physico-chemical parameters and aquatic investigation in Tajan River and identification of effects on destroytion its

This project was carried out for one year in 1994-1995. Tajan River originated from Alborz Mountain and passes from sari city, and then entered into Caspian Sea. In this study 14 physical and chemical factors surveyed. This survey demonstrated that water quality in milk factory and kilka factory was more than standard. With utilization of water in agriculture period and dry of river, caused to increasing of chloride, total hardness, Ca^++, Mg^++ in estuary. This issue obtained to mixture of fresh water and saline water in estuary. In the survey of the river phytoplankton, 92 species identified that belong to 41 genus and five phyla. The Chrysophyta has more variation and density. Zoo plankton of river included in Protozoa, Rotaria, Cladocera and Copepoda, also the meroplankton such as Lamellibanchiate and Cirripedia observed. The high species variation is relative to protozoa but copepoda has high density and biomass. The five classes of zoobenthos observed in Tajan river such as Bivalvia, Crustacea, Arachnoids, Oligochaeta and insecta. The insecta class has six order and 22 families that Diptera order from insecta class has high variation. The river fishes are belonging to 23 species, 18 genus and eight families. The highest variation observed in station 4 in estuary that 17 species identified in this area. Ths seasonal stations situated in tributary river, station 5 (Zarem rood) has high variation and station 7 (Khormabad river) has important for salmo truta fario habitat

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