Study of Population Structure of Microalgae in Sanandaj Dam-Iran

Algae species are a major contaminant in improving rivers and lakes because they oxygenate the water while photosynthesizing and combine elliptical and non-elliptical materials in their cells, thus purifying water pollution. They are good for determining water quality. In this study, due to the size of the lake, 5 stations were determined in the lake. Therefore, according to preliminary studies and morphology of the dam, five stations were determined in different situations. The results of the study of species composition and species diversity of phytoplankton showed identified in the Sanandaj Dam Lake 20, 1, 9, 6, 16 and 2 species were observed. Examination of phytoplankton communities during the study of the Sanandaj Dam Lake shows the predominance of Bacillariophyta group of diatoma with 20 species during the year and then the group of green algae or Chlorophyta with 16 species. The lowest frequency of species diversity in Chrysophyta and Euglenophyta groups was observed with 1 and 2 species, respectively.


Introduction
Algae are the basis of primary production in aquatic ecosystems. The onset of food production in a aquatic environment begins with these organisms and with a complex mechanism called photosynthesis. In this process, simple foods are transformed into complex organic compounds and become a single food unit. This food collection will be fed to other aquatic organisms in the next steps (consumption). Algae are very important in aquaculture because they directly affect water properties such as color, odor, taste, dissolved oxygen, and turbidity. Natural food production in breeding ponds is directly related to the growth rate of these small, microscopic plants, so that the higher the algae growth rate, the more natural the production of natural food (algae and non-algae) will be with Latter Njiru, et al., [1] and as the rate of natural food production increases, so does the growth rate of organisms under fish farming and production Anneville, et al. [2].
Rivers have been studied in other countries for a long time, but in Iran they have been young and have been studied in research centers in the country for almost two decreases. They are microalgae and Nitzschia, Naviculla and Diatoms are the most abundant in these ecosystems. Chlorophyta and Cyanophyta groups had a significant frequency after diatoms Anneville, et al. [2]. In some seasons of the year, due to the increase in nutrients in aquatic ecosystems, the entry of untreated sewage and agricultural effluents, etc. (causes algae blooms such as Cyanophyta (green-blue algae) and excessive accumulation of algae in the water surface causes saturation. Water in made from oxygen, reducing CO 2 and thus reducing photosynthesis and nitrogen fixation Rakaj [3].
Preventing photosynthesis ultimately leads to the destruction of algae and then their breakdown by bacteria and the rapid use of oxygen by bacteria leads to a decrease in the oxygen content of the water, which endangers the life of the aquatic life and causes their death Mirzajani, et al. [4].
Other adverse effects include the formation of blooms by greenblue algae and the release of toxins in the water, which in addition to fish can cause disease and death of other aquatic and domestic animals and even endanger human health (Contact or consumption of contaminated water or contaminated fish). About 25 toxic species of this phylum have been reported so far. Of course, in the case of rivers, their origin can be unknown, and the timing of their contact Moisan, et al. [5]. In the ecological study of aquatic ecosystems, algae are used as determinants of environmental change. Algae have many connections (dependencies) with their surroundings, and environmental factors affecting algae include light, inorganic materials (Nutrition) and so on. There is a strong link between light intensity and the rate of synthesis of substances in algae cells, and high light intensity increases the rate of synthesis of various compounds such as lipids and polysaccharides Richmond [6].
Algae are used in various aquatic ecosystems to assess water quality or water pollution. The compound and microalgae can be used as a complementary indicator of water trophy levels Wan Maznah, et al. [7]. The growth and proliferation of microalgae depends on the dynamics of the water, the amount of light spectrum, and the availability of food and the quality and stability of water resource around the world is important, although these resources are exposed to pollution in the catchment areas of domestic water systems Wan Maznah, et al. [7]. The development of towns and villages along rivers and beaches, and subsequently the proliferation of industrial and agricultural centers, increases the pollution burden caused by waste and water-polluting waste.
These pollutants are able to create unpredictable changes in the environment and water resources and endanger the lives of microalgae and other aquatic animals.

Materials and Methods
Field activity of this research was performed for one year from June 2015 to June 2016 at seasonal sampling intervals. Due to the size of the lake, 5 stations were determined in the lake. Therefore, according to preliminary studies and morphology of the dam, five stations were determined in different situations according to Figure   1 & 2 in the whole lake. Also, due to the depth of the station, in   The Palmer Contamination Ratio (Palmer 1968) was used to evaluate water quality.

Results
The results of the study of species composition and species  Table   3).     are related to toxic blooms and toxic states and anoxic states.
They are associated with harmful blooms in polluted waters that produce odors and unpleasant odors. Due to their short life cycle, plankton reacts rapidly to environmental changes, which is why the abundance and composition of plankton species is significant in showing the water quality in which they are observed. Not only do they strongly influence certain non-biological aspects of water quality (such as pH, color, odor, and taste), but in a scientific sense, they are part of water quality.
However, the validity or accuracy of plankton as an indicator of water quality may be limited due to their unstable nature and uncoordinated distribution. Of course, in the case of rivers, their origin can be unknown and the duration of their contact with pollutants is unknown. Is a transition Wan Maznah, et al. [7]. Based on the numbers obtained in this study, three cases of algae pollution were observed in stations 1 and 2. The amount of algae contamination in winter has been. In other samples, the contamination was relatively low. And the conditions were suitable for aquaculture. Algae species are a major contaminant in improving rivers and lakes because they oxygenate the water while photosynthesizing and combine elliptical and non-elliptical materials in their cells, thus purifying water pollution. They are good for determining water quality Lobban, et al. [10]. In the study, the pollution index of station one showed that the highest rate of pollution index was 18 with medium pollution load and in station 2; the highest rate of pollution was in winter. In stations 3 and 4, pollution was low, and in the end, station 1 had the highest level of pollution and station 4 had the lowest. But it should be noted that even a poisonous bloom can have a high risk potential. In general, due to the absence of harmful species and the presence of beneficial species, microalgae conditions are favorable for fishing in Sanandaj Dam Lake, but it should not be forgotten that in order to fish, it is necessary to monitor lake water monitoring [11][12][13][14][15][16].