تاثير شوري بر پراكنش فيتوپلانكتونهاي رودخانه جزر و مدي بهمنشير

Composition and frequency and impact of the salinity on distribution phytoplankton in the Bahmanshir tidal river

Bahmanshir River branches out of the Karoun River and empties into the Persian Gulf. This river is a tidal water body with characteristics under effects of such condition. Sea water moves ahead of the river by tidal forces and affects salinity, phytoplankton species composition and distribution. We conducted a year round study in five stations in the river and determined phytoplankton species composition and distribution. Bacillariophyceae had the highest frequency and Cyclotella, Nitzschia and Melosira genera were very frequent. Cyanophyceae was present in estuary area. Salinity caused areas of water to be dominated by Euryhaline and Stenohaline species. Some species including Nitzschia, Cyclotella< Synedra and Melosira were seen in wide range of salinity and other frequent species such as Lauedria, Coscinodiscus, Cheatocerus and Rhizosolenia were only presented in the estuary or highly saline waters. Because of high tide, some of the marine phytoplankton species were also spotted at the mouth of Bahamanshir River.