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In recent years the incidence of algal blooms caused by Nodularia to become one of the serious problems and is threated life of aquatic organisms in the southern Caspian Sea. Nodularia is a Blue-green algae (cyanobacteria group) and due to production of nodularin toxin is importance. In this study, the first, three species of Pseudomonas including aeruginosa, putida and fluorescens were isolated from Tajan river estuary and identified using biochemical tests and compared to standard species. The trend of Nodularia spumigena biomass (log 5) and pseudomonas species (log 7 and 8) were examined in 30 treatments for 10 days in aquarium scale. Parameters such as chlorophyll a, dissolved oxygen, phosphate and nitrate were tested at different time the same time. The results showed that the decline trend of nodularia in aeruginosa and mixed species treatments were better than other treatments and log 8 of bacterium was also more inhibitory effect than to log 7. Similar results were observed in double layer on agar medium and latter treatments had algaecide effect on nodularia. However, putida and fluorescens treatments had algaestatic properties. Concentration of chlorophyll a, dissolved oxygen and nitrate in all treatments, especially aeruginosa and mixed bacteria have been often decreased (p

The water quality provides the valuable information about the available resources for human usage. The reservoirs are the important resources of surface water which could be considered as an appropriate water resource for irrigation, drinking water and also fish culturing. The Shahid Rajaei Reservoir- Sari is an important reservoir in Iran, which conducted to study on its water quality in this survey. In this study, some of the physicochemical parameters and Chlorophyl- a of Shahid Rajaei reservoir were measured at 4 stations (Shirin Roud branch, Sefid Roud branch, the crossing point of branches, near the tower) during six sampling months (June, July, August, September, November and February) in 2012-2013. The water quality and trophic status of reservoir calculated based on some reference values and the modified Carlson formula. The results showed that the mean (±Standard Error) of temperature, dissolved oxygen, pH, phosohate, amonium and nitrate concentrations and Chlorophyl a were 21.35 (±1.30) ºC, 10.48 (±0.37), 8.54 (±0.04), 0.050 (±0.004), 0.036 (±0.004), 0.75 (±0.03) mg/l and 18.00 (±7.23) mg/m^3 , respectively. In the present study, temperature between surface and deep layer was stratified in June and July, which the stratification was registerd 0.47 and 0.69 °C decreases with increasing of each meter depth in 15 to 30 meter culumn. But, these changes for each increasing meter of water depth were 0.2 to 0.26 °C in August and September, respectively, and finally was close to zero in November. In the warm months (July, August and September) with the formation of thermal stratification in the reservoir was formed oxygen stratification, but in the cold season (November and February), with vertical mixing of water oxygen and percent saturation of the reservoir was nearly homogeneous. The results showed that the European authorities (OECD) trophic status varied between mezotrophic to hypertrophic during the sampling period at all stations. The comparison with the values listed in the references of Iranian dams based on transparency and chlorophyll variables showed similar results. However, phosphorus variable (due to limited for phytoplankton) was not showing the true conditions of trophic status. As a conlusion, trophic status of Shahid Rajaei dam based on Carlson trophic index (TSI) was obtained oligotrophic (May and October), mezotrophic (February) and eutrophic (August and September) condintion during diferent months. Therefore, water management of the reservoir was more attention during warm months.

This study was conducted to determine phosphorous and nitrogen species at the surface sediment in the southern Caspian Sea (Mazandaran Coast, Kelarabad). Surface sediments samples were collected at three stations from autumn of 2011 to winter of 2012. All samples were prepared by digesting and extracting processes and then phosphorous and nitrogen species concentrations determined using spectroscopy instrument. Results of this study showed that annual mean of Loosely-P, Fe-P, Al-P, Bioava.-P, Ca-P, TIP, Rese.-P and TP was obtained as 5.06±0.33, 55.11±2.52, 42.38±3.74, 102.52±5.68, 172.91±7.12, 275±9.12, 333.30±28.52 and 608±52 µg/g.dw, respectively. The results also showed that inorganic phophorous was less than organic phophorous during different seasons, however, mean percentage of residue-P containing organic compounds and non-degradable compounds was more than 50 percent. Percentage of Ca-P was higher than 60, whereas Bioava.-P was less than 40 percent. In addition, Fe-P and Loosely-P attained the maximum and minimum values, respectively, among the bioavailable phophorous. The order of different forms of phosphorous were recorded as Org-P>Ca-P>FeP>Al-P>Loosely-P. Annual mean of NH4/N, NO2/N, NO3/N, TIN, TON and TN were observed as 4.23±0.50, 0.06±0.01, 0.74±0.12, 5.02±0.53, 2.48±0.63 and 7.53±0.51 µg/g.dw, respectively. Annual percentage of TIN was two folds than TON and concentration of NH4/N was also four times than NO3/N. As a conclusion, the results revealed that main causes of Bioava.-P adsorption and desorption were temperature, Eh and pH. Also, the form of NH4+/N was of a high percentage because of anaerobic condition in the sediments. According to the high ratios of nitrogen/phosphorous of sediments to nitrogen and phosphorous of bottom water, it finds that released of those from the sediments to water will be happened with high rates. Therefore, it is expected that the establishment of fish farming cages should be carried out with more precautionary approaches which not leads to increased algae bloom.

This study was conducted to determine physico-chemical characteristics of water and their spatial and temporal fluctuations in the Mazandaran coastal of Caspian Sea in 6 months, four seasons at 4 transects (Tonekabon, Nowshahr, Babolsar, Amirabad) during 2012-2013. 72 samples were collected at surface layer of water in 5, 15 and 30m depths. Then the sampls analyzed based on standard methods. Results showed that the mean of water and air temperature were 19.46±0.85 and 20.25±0.78◦C, respectively. Minimum and maximum of water temperature were recorded in winter (7.00) and summer time (28.10). Mean of salinity was 12.35±0.13 ppt. The maximum salinity was recorded in summer and minimum in winter in all transects. Mean of transparency (SD) in the present study was 2.63±0.18m. The mean of pH was observed 8.51±0.02 which was higher than the previous sampling periods. The mean of DO was observed 6.00±0.07 ml/l during sampling period. Annual concentration of dissolved inorganic nitrogen (DIN= NH4 +, NO2-, NO3-) has a fairly wide variation in different months and transects. Percentage of nitrogen components out of DIN were varied 6-53, 0.14-26.0 and 37.0-94.0 respectively. In this study, percentage of DIN was lower than 15% and dissolved organic nitrogen (DON) was higher than 80%. Mean of annual dissolved inorganic phosphorous (DIP) and organic phosphorous were 0.58± 0.04 and 0.48± 0.02 µM, respectively. DIP and DOP percentages recorded 54 and 46 respectively. Mean annual of dissolved silicon (DSi) obtained 9.5± 0.2 µM. Based on the results, the system was in phosphorus limitation during spring and summer but it shifted to nitrogen limitation in autumn and winter. Phytoplankton development was not limited by DSi at any seasons.

At the present study, the environmental pollutants such as organochlorine pesticides (OCPs), heavy metals (during three seasons) and surfactants (during four seasons) were done 2009 to 2010 that located in Mangol Dam with longitude and latitude 52° 22' 49" N and 43° 15' 43" E, respectively. The aims of this study were to determine the seasonal pollutants matters in water samples of under-groundwater and surface water in 12 stations and the results are as follow: The maximum residues fluctuations of OCPs were determined in between all water samples such as aldrin and endrin about 1.51 and 2.85 µg/l, respectively. The mean concentration of aldrin and endrin about 0.66 ± 0.59 and 0.71 ± 1.07 µg/l, respectively were determined. The maximum seasonal concentration of OCPs were detected in fall, winter and spring for such as endosulfan sulfate, γ-BHC, heptachlor, endrin aldehyde compounds about 2.85, 0.34, 0.14 and 0.14µg/l, respectively. The maximum seasonal percentage range of OCPs were detected in fall, winter and spring in water samples such as endosulfan sulfate, DDD and β-BHC were 42, 25 and 25 %, respectively. The maximum seasonal concentrations of Zn and Fe elements were detected in spring about 1.12 and 8.22 µg/l, respectively. Also for Hg in spring was determined about 17.2 mg/l. The mean concentration of Zn, Fe and Hg in water sampled were 0.23±1.01 and 1.21±2.00 µg/l, respectively and 4.65±6.38 mg/l. The maximum seasonal percentage range of heavy metals were detected in fall, winter and spring in water samples such as Ni, Zn and Fe were 66, 83 and72%, respectively. The maximum seasonal concentrations of heavy metal were detected in Sorkhroud and Polechelave stations during fall, winter and spring for only Fe about 1.48, 3.3 and 8.22 µg/l, respectively. The maximum concentration of linear alkyl benzene sulfonate (LAS) in last month of summer was 971µg/l. The mean concentration of surfactant during fall, winter, spring and summer was 418.62±52.16 µg/l. The maximum seasonal percentage range of surfactant uring fall, winter, spring and summer in all stations of sampling were 76, 76, 100 and 100 %, respectively.