فهرست مطالب fariba madadi

The aim of this study was to investigate the changes in the structure of the plankton community in the southwestern Caspian Sea and its relationship with the reduction of Rutilus frisii and Chelon auratus catches. The current study was conducted seasonally in the coasts of Guilan provience from 2020 to 2021. A total number of 48 genera and species of phytoplanktons were identified. Tthe findings showed that the non-native species Pseudo-nitzschia seriata from chrophyta and the toxic species Nodularia spumigena from cyanobacteria formed the highest density. The increase of water temperature and nutrition and the decrease of wind speed were directly related to the bloom of phytoplanktons, especially cyanobacteria in the Caspian Sea, which caused the third bloom of N. spumigena in Anzali shores in July 2021. The results showed an increase in the abundance of phytoplankton by more than 7-folds compared to 1996. The highest abundance of phytoplankton was observed in Anzali shores in 5 m depth. The pattern of phytoplankton abundance and the abundance of R. frisii and C. auratus juveniles were similar to each other.  The food eaten by C. auratus and R. frisii juveniles showed that these fish species fed on phytoplankton detritus. Probably the reduction of Cerastoderma glucaum biomass, illegal fishing with gillnet, the quality and quantity of R. frisii release by Iranian fisheries, and the lack of restoration of the rivers where the natural reproduction occurs are the factors affecting the reduction of the R. frisii catch in recent years.

About 30 species of commercial fish have been caught in the seawater of Guilan province annually and the most important species is Kutum (Rutilus frisii). The aim of this study was to determine the feeding indices, food spectrum, and dominant food items of fingerlings kutum under the investigation of feeding habits of kutum and grey mullets on the coasts of Guilan province. The fish were captured with a seine net with 6 mm mesh size from winter 2020 to autumn 2021 in the coastal areas of Talesh, Anzali, Kiashahr, and Chaboksar. The results on R. frisii with body weight 0.31-14.5 (3.64±2.8)g, total length 34.3-120 (68.3±19.0) mm and ages 0+ and 1+ years showed that the relative length of intestine is 0.59-1.16 (0.78±0.10). Vacuity index was calculated at 0, 0, 5, 0 and 1% in spring, summer, autumn, and winter seasons and the total of the year, respectively, and the mean fullness intensity was 372±267, 360±151, 230±173, 581±689 and 365±302 in spring until winter and total of the year, respectively, which showed significant differences (F=9.10, p<0.05). Detritus, filamentous algae, 26 genera of phytoplankton, 2 types of zooplankton and 13 types of benthic animals and as well as eggs and larvae of fish were observed in the gastrointestinal tract of kutum fingerlings with a frequency of presence 10, 73, 62, 5, 86 and 2 percent of all studied specimens, respectively. The phytoplanktonic genera of Cyclotella, Navicula and Nitzschia were observed in 60%, 52%, and 47% respectively, and gammaridae among the benthic animals had the most frequency in 68% of the fish. In general, according to the feeding indices, feed diversity, and dominance of feed items, kutum fingerlings are a benthic feeders and euryphagous with a good fullness intensity on Guilan coasts.

Neor Lake in Ardabil Province was ecologically degraded recently and the invasive fish Prussian carp (Carassius gibelio) has been dominated. In 2017, the biological study of this species carried out in order to control of its population in the lake. Fish samples were caught by different equipment; Gill-net, Cast-net and purse seine. The average weight of fish was seasonally varied between 59.76±36.25, 54.72±42.85, 102.66±26.32 g while the average length of fish was ranged between 146.20±36.51, 133.40±38.20, 174.41±13.04 mm. The age of fishes was about 2 or 6 years. Intestine length was varied between 2.8±0.28, 2.88±0.34, 3.19±0.34 mm and the condition factor was calculated 1.67±0.28, 1.85±0.16, 1.90±0.15. Feeding intensity was calculated 250.34±136.91, 165.11±64.11, 163.45±86.99. The Prussian carp feed mostly on detritus. Six phytoplankton and four zooplankton phylum were identified in their guts which Bacillariophyta and Rotatoria were dominant respectively. From their gut contents were identified 44 phytoplankton genus and 10 zooplankton genus that Synedra and Rotaria were dominant respectively. The range of length and weight of C.gibelio showed the unfavorable environmental conditions for feeding and living of this fish in Neor Lake. The range of length and weight of carp showed the unfavorable environmental conditions for feeding and living of this fish in Lake Inver.

This study focused on phytoplankton structure and compared with previously study at the 5 stations between 2017 and 2019 in the Chitgar Lake. This study identified 37 phytoplankton taxa comprised of Diatoms (12 genus), Chlorophyta (10 genus), Cyanophyta (8 genus), dinoflagellates (3 genus), chrysophytes (1 genus) and Euglenophyta (3 genus) in the lake. The finding showed, the Diatom abundance dominate (average of 8700000 ± 7900000 cells.l-1) in the lake. The annual average phytoplankton abundance was calculated as 13400000, with the maximum value recorded in March 2018 (23000000 ± 8500000 cell. l-1). The results showed that the abundance of phytoplankton increased (more than 5-fold). Chlorophyll a, 0.5 μg / L was recorded in this study, which was 5 times more than in 2013-14. Phacus, Trachelomonas and Euglena genera from Euglenophyta phylum were first observed in lake, the presence of Euglenophyta indicating increased lake contamination trend. The abundance and species diversity of green-blue algae decreased after release of silver carp in the lake in June 2019. The abundance of Oscillatoria increased from 800,000 cell. l-1 in September 2018 to 200,000 cell. l-1 in June 2019. The decrease in cyanophyta abundance has prevented the unpleasant odor and prevented the increase of insects in the environment around the lake, preventing aquatic mortality and increasing trend of tourists.

Women's participation in various social activities is considered part of their social rights, but there are many cultural and social barriers. Women's participation in sports is very important because of its impact on public health. The aim of this study was to investigate the relationship between vandalism and women's participation in selected sports activities.

After initial coordination with the national authorities, monitoring of sporting sports, and determining the statistical population of female athletes in each field who have valid sports insurance and are among the official statistics of each federation were selected as statistical population. In this research, using the analysis of the obtained data and using a combination of quantitative and qualitative methods, it was used as a mixed research method.

For the descriptive and variable statistical descriptive statistics, the questionnaire was extracted using specific questions of the questionnaire and along with the use of score scores, and the confirmatory factor analysis method was also used. For vandalism, the decoration was normal. The variance percentage is 18.983 and the result of dividing the chi-square index by the degree of freedom is 1.86.

The more attention is paid to the motivation of the company in sports sports, the lower the vandalism spirit. The intensity of the relationship between these two variables (-0.402) is evaluated at low and negative levels. The correlation diagram between the two variables confirms this result.

Zooplankton is one of the best foods with high quality for transfer energy in the food web, they are as biological pump which transfer Co2 from surface layers to the deep waters for fishes. The zooplankton species changed striking after ctenophores invasion in 2001 and during two decades. This study performed seasonal at 4 stations (5, 10, 20 and 50 m depths) in the coasts of Anzali in the Caspian Sea, during 1996 and 2001-2013. A total of 71 zooplankton taxa were identified in the southwestern Caspian Sea. The fifty six of them were holoplankton taxa and fifteen were meroplankton taxa. In zooplankton taxa, 14 genera and species were belonged Rotatoria taxa indicated the influence of the Anzali wetland and river inflows. The funding showed, many of zooplankton native species disappeared between 2001 and 2013, while meroplankton groups as Nematoda, Olighcheata and Polycheata were increased in the sea. Climate changes, man-made and alien species could play on the zooplankton species variations in the southwestern Caspian Sea.