نشریه آبزیان دریای خزر
سال دوم شماره 3 (زمستان 1396)

The aim of current study is effective water quality parameters of Aras River using principal component analysis (PCA) from 2015 to 2016. Samples were collected at four seasons and analyzed using standard methods (titration and spectrophotometer instruments). In this study, thirteen parameters such as water temperature, DO, BOD5, COD, TDS, Turbidity, TA, CO2, pH, DIP, NH4/N, NO2/N and NO3/Nwere analyzed. Results showed that based on PCA test, six parameters were involved in the first component (with variance of 34%) and DO and COD contained high loading factor which there were selected as the main parameters of the first component. Also, in the second component (with 23% variance), the parameters of carbon dioxide and pH, in the third component (with 16% variance), the parameters of BOD5 and NO2- and in the fourth component (with 12% variance), the TA were contributed. This study showed that the PCA test is a suitable and effective method for determining the effective water quality parameters and also dominance source of various contaminations.

The aim of this study was to evaluate the antioxidant properties of alcoholic extracted of chlorella vulgaris algae and spirulina platensis. Three concentrations of 200, 400 and 600 μg/ml of ethanolic extracts of algae were evaluated using DPPH (1,1-diphenyl-2- picrylhydrazyl) radical scavenging activity and ferric reducing antioxidant power (FRAP) tests. The results showed that concentration increased for each algae was accompanied by an increasing in antioxidant activity, so that at 600 μg/ml concentration, DPPH and FRAP values for spirulina were 77.12%, 0.46 and for Chlorella 73.27% and 0.43 at 700, respectively. In terms of the antioxidant power of the algae and the side effects of synthetic antioxidants (carcinogens), it is suggested that algae extracts can be used as an alternatives to synthetic antioxidants (by supplementary tests) in a variety of foods.

In this project (April 2013- March 2014), microbial indicators of fecal contamination of water contains total coliform, fecal coliform, fecal streptococcus and fish pathogen bacteria in seawater were investigated. Monthly sampling was conducted at surface layers of different stations in 5 and 10m depths. Analysis monthly showed that the range of the average total bacteria in different months of the study fluctuated 12.29 ×104 ± 94.73×104CFU / 100ml in November 2013, 1300 ±17.70×102 CFU / 100ml in April 2014. Mean total coliform were recorded 1.8 ×102 ± 1.48 CFU / 100ml October, 16 ± 16 2013 CFU / 100ml in April 2014. The mean fecal coliform was recorded 40 ± 33 CFU / 100ml in October 2013, 5.5 ± 4.7CFU / 100ml in April 2014 and mean fecal streptococci in different months of 11.1 ± 8.8CFU / 100 ml in October 2013 1.8 ± 1.7CFU / 100 ml in April 2014. Most of the isolated pathogenic bacteria in water sample contained Pseudomonas, Vibrio, Aeromonas and Escherichia coli. According to the results, the number of indicator bacteria was more than standard value of drinking water in most stations. On the other hand heterotrophic bacteria population is also relatively high, which indicates low water quality. The presence of these bacteria increases the growth and reproduction of pathogenic and zoonotic bacteria and, as a result, the health of aquatic and human beings is compromised. Therefore, in order to reduce the indicator and the heterotrophic bacteria, the input of pollutants in the Caspian Sea to the rivers should be reduced and wastewater and wastewater after treatment should be discharged into the river in accordance with environmental standards.

Today’s, Algae have many uses in the world. In many countries, algae constitute a major part of the economy and algae provide large quantities of the exports. The green micro-algae of Dunaliella and its various species are highly regarded by biotechnology researchers. In this study, the effects of iron nanoparticles solution (0.1 gr/lit concentration) on growth rate of Dunaliella salina evaluated in 3 treatments with different volumes of nanoparticles solution (0.75, 7.5 and 75ml). The cells density was monitored for 12 days and once in 2 days in different treatments and 3 replicates. Based on the results, the maximum cell growths (25.0× 105 cells/ml) were observed in in third treatment (75 ml of nanoparticles solution) and the minimum growth (10.8× 105 cells/ml) was in control treatment. The mean of cell density in second treatment (7.5 ml of nanoparticles solution) was not significantly different with control treatment in 6th and 8th days (p>0/05). However, there were significance difference in other days (P<0/05). The cell density showed significant difference (p<0/05) between first and third treatments (0.75 and 75 ml of nanoparticles solution) at level 95% for 12 days. Also growth rate and specific growth factor indicated that Dunaliella salina increased in third treatment and that other treatments had more growth than control treatment.

This research was carried out in two seasons of summer and autumn in 2014. Fish sampling was done using a 2.3kW electrofishing in 7 stations. The purpose of this study was to investigate the effects of sand and gravel harvesting on abundance and variation of Shannon Wiener Index of Haraz River community. The results showed that the species diversity increased from the upstream (0.55) to the downstream (2.83) of the river and there was a significant difference in Shannon wiener index at different stations (p<0.05). The results of the survey on fish populations in the Haraz river showed that rainbow trout (Onchorhyncus mykiss) had the predominant fish population in the upstream of the river, in which could be a food competitor for the indigenous species of brown trout (Salmo fario) which led to a decrease in the populations of brown trout and its absence in catch and sampling was in the main stream of the river. Also, the catches from the cyprinidae were of a lower variety and density than the past, so that no specimens were collected from the species of fish Barbus spp. groups, and other species such as Squalius cephalus, Capoeta capoeta, Alburnoides eichwaldii, and brown trout (S. fario) has a very low abundance, which could be due to fish aquaculture, the increased activity of the sand and gravel extraction, the lack of attention to the installation of filtration apparatus for rocks washing, increasing the water turbidity and its effect on the eggs and larvae of fish.

Rivers have been addressed as one of main resources of water supply for different consumptions including agriculture, drinking and industry. Therefore, with regard to recent droughts, also rural and urban development, monitoring the quality of these resources is considered as an important function in the context of environmental management. Havigh River is one of the most important river in Guilan province and on its way crossing agricultural areas in country and villages collect the pollutants and eventually to the Caspian Sea. The aim of this study was to evaluate coliforms and fecal coliform in the Havigh River in Gilan Province. Study of microbial contamination was performed over a one year period and seasonal sampling was performed. The contamination rate was studied by counting total coliforms (MPN) method. The stations studied were selected from the upstream, middle and estuary regions and sampling was carried out from the water surface and sediment of the river. The results showed that the highest amount of pollution was in estuarine (surface water and sediment) station. Totally, the contaminations average surface water include: the highest amount of coliform contamination was 85.83 numbers in 100 cubic centimeters and the highest amount of fecal coliform contamination was 21.66 numbers in 100 cubic centimeters and sediment include: the highest amount of coliform contamination was 106.83 numbers in 100 cubic centimeters and the highest amount of fecal coliform contamination was 35.83 numbers in 100 cubic centimeters in summer season. Sediment in summer time in this season , but weather increases , the temperature of the environment and as a result the growth of bacteria will be more. Because they need to receive more stuffs and there is more competition. Also the most pollution was considered in the estuary area, because of calm flowing of water and passing through city and agricultural centers, and by entering these damages into the rivers .also garbage house emptying and use of chemical fertilizer and lands the amount of pollution in comparison with other parts of the rivers with rapid flowing of water, has been apparently reached a high level.