فهرست مطالب rasul ghorbani

Wetlands are a critical part of our natural environment and they can reduce the impacts of floods, absorb pollutants and improve water quality. This survey was conducted at 7 stations in three international wetlands Alagol, Almagol and Ajigol wetlands between February 2017 and November 2018. Results showed that water quality characteristics are somewhat in good conditions but amount of phosphates, was more than standard in summer at Alagol and in Autumn and winter at Ajigol. In this study, 57 different species (25 Bacillariophta, 12 Chlorophta, 9 Cyanobacteria, 5 Pyrophyta, 3 Euglenophyta and 2 Xanthophyta and Carophyta) were identified. Bacillariophyta was dominant in all seasons, however Cyanophyta in Alagol and Ajigol wetlands and Pyrophyta in Ajigol were dominant in summer. In the study of water quality index (WQI), it was observed thatexcept in summer and autumn in Ajigol wetland in other seasons of the studied wetlands were in good quality. It seems that the Atrak river as the main source of water supply for these wetlands, is the place where high amounts of agricultural and rural effluents are received, which practically enter these wetlands, appropriate management and corrective measures should be taken.

Estimation of initial production capacity is one of the important principles of water resources assessment and management. Due to the size, depth and different positions of wetlands (inlet area, middle and near the dam base) of some physicochemical parameters of water, plankton (phytoplankton and zooplankton), macrobenthos and fish from 3 stations, in Alagol wetland, 2 stations in Ajigol wetland and 2 stations in Almagol wetland were sampled for one year from winter 2016 to autumn 2017. Comparison of the three wetlands, the results showed that in all seasons, the highest biomass per hectare was observed that phytophagus fish and zoophagus fish in Ajigol is much higher than the other two wetlands. Regarding benthic fish biomass, most biomass was observed in spring, summer and winter in Almagol wetland and in autumn in Ajigol wetland. The highest abundance in all three wetlands is related to Gambusia and in excluding Gambusia fish, the highest abundance in Alagol wetland is related to crucian carp, in Ajigol capoeta and common carp and in Almagol, crucian carp and in relative weight, phytophaguus and crucian carp were the dominant fish. Also, catfish are found only in Alagol lagoon. It seems that the role of releasing benthic fish such as common carp should be considered more and invasive fish should be controlled.

Dynamic energy Budget (DEB) theory describes the rate of energy absorb by living organisms and use it for body protection, growth, and reproduction. The present study was performed on Alburnoides eichwaldii in Zarrin-Gol and Kaboudwal rivers (Golestan province). The results showed that the DEB growth model in the two rivers and the allocation of energy fraction for body maintenance (κ) was more than 0.9, which indicates the high growth rate and short lifespan of this species. Maximum surface specific-area assimilation rate {pAm}  in Kabudwal river fish is about three times that of Zarringol River. Somatic maintenance based on body volume, pM  for Zarringol River is about 3 times and the maximum reserve density[Em]  is about 5 times less than Kabudwal. In Addition, maturity at birth EHb , In Zarringol river was less than Kabudwal and maturity at the time of reproduction EHp  in Zarringol river was more than Kabudwal but its size was bigger at maturity in Kabudwal river. On the other hand, the higher energy conductivity ϑ in A. eichwaldii in Zarringol River was due to its low energy density, and this fish in Zarringol River needs less energy to somatic maintenance. The DEB standard model is superior to other models in that it is able to provide quantitative and measurable descriptions for the aspects of individual and population metabolism of animals.

Proof of species existence in different regions can be useful for studying the migration pattern of the species. The use of non-invasive methods such as eDNA can be very effective in tracking and dispersing and improving the management of water resources and species. In this study, 15 water samples were taken from different areas of the southern Caspian Sea basin. Amino-modified silica-coated magnetic nanoparticles were used to separate DNA from water. In this study, for the first time, the amino magnet method was used to separate environmental DNA from a water sample. DNA of three water samples were properly extracted ,from the water output of Oncorhynchus mykiss farm in Tajan river  in Sari, water samples from salmon cages in Nowshahr and water samples from around Caspian salmon farming cages in Tonekabon were properly examined. The results showed that sample No. 1 was located in the rainbow trout clad and samples No. 2 and 3 were located in the Caspian Sea salmon clad, indicating that the species were properly isolated with amino silicate magnetic nanoparticles and their presence in the aqueous body was confirmed by environmental DNA.

The fish's primary immune system in epidermis produces the mucosal layer as a surplus mechanism to cover the surface of the fish's body against infections. In addition to its physical functions such as reducing water friction and protecting against abrasion, it contains biologically active constituents, which is the first line of defense against pathogens. During the past years, the antimicrobial activity of various fish mucus has been studied. Due to the lack of information on sturgeon, in the present study, some properties of proteins in the epidermal mucus (Huso huso) as one of the native species of the southern coast of the Caspian Sea were evaluated. In this study, mucus was directly collected from fish surface in three different weight classes (0.4 , 4 and 40 kg) and some properties such as total protein concentration, chromatogram (RP-HPLC) and molecular mass profile of mucus proteins in three weight classes were compared. Antimicrobial activity of mucus was evaluated by disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The crude samples of different weights showed no significant difference in protein concentration (1.02 ± 0.03, 1.04 ± 0.01, 1.07 ± 0.02 µg/µl, respectively) but HPLC fraction No.4 in the third weight (40kg) showed a significant higher concentration in comparison to others (α=0.05). SDS-PAGE results revealed that the mucus samples contain peptides and proteins ranging from 5 kDa to 245 kDa with no considerable differences. All chromatograms showed similar numbers of fractions at similar retention time while the area percentage of fractions underwent significant differences in fractions 2, 4 and 9 (α=0.05). Disk diffusion showed the same antibacterial activity against A. hydrophila while group 1 (0.4 kg) had a significantly lower inhibition zone against S. iniae. All the samples possessed the same antimicrobial activity in MIC and MBC assays (MIC48=MBC48=25 µg). The current study revealed that all selected weight groups had the same properties in HPLC chromatogram and SDS-PAGE. Comparison of antimicrobial activity in MIC and MBC tests showed no significant difference between groups while in the disk diffusion test, there were significant differences in the antibacterial activity of weight groups exposed to S.iniaei, which could refer to the test competency. In conclusion, it can be claimed that in terms of protection (non-specific immunity), the first weight group (i.e. ≈ 0.4 kg) reached an evolutionary level as well as higher weights did (i.e. ≈ 4 and 40 kg).

The main of this study was to trac the local migration of common carp in the southern  of Caspian Sea by comparing the  composition of essential and non-essential amino acids in muscle tissue. Therefore, 26 samples of Common carp from the nets of  beach sein cooprative companies was evaluated on the southern shores of the Caspian Sea in the fishing areas of Golestan, Mazandaran and Gilan provinces and control samples from Sijwal (Golestan) and Shahid Rajaei (Sari) zones reproduction centers was prepared. Fish sampeling held in 2017 and 2018. Protein extraction was performed by Isoelectric Solubilization/Precipitation point. Total amino acids were analysed by high-performance liquid chromatography (HPLC). The results showed that the samples of the three provinces were separated in terms of amino acid composition and there are probably three carp populations in the western, central and eastern parts of the Caspian Sea, but migration with short distances takes place in the border part of the three provinces. Comparison of amino acid levels in males and females showed that in most cases in males it was more than females but it was not significant. Also,very high levels of lysine in muscle tissue of Golestan province and its proximity to breeding centers can confirm the role of artificial reproduction in the reconstruction of carp stocks in Golestan province. The results of some tests indicated the proximity of Gilan and Golestan fish groups, which could be due to human intervention in the transfer of finger fish to the two provinces.

The objective of the present study was to determine the effects of fish aggregation device (FAD) deployment on biodiversity, catch composition and length frequency distribution in the Qeshm Island handline fishery. Two FADs were deployed in the Qeshm Island. Four biodiversity indices including Margalef, Shannon-Weaver, Simpson and Pielou and also catch composition and length frequency distribution were calculated and compared between FAD and non-FAD area among spring and fall seasons. Comparing catch composition between FAD and non-FAD area by simper analysis showed that Scomberoides commersonnianus, Acanthopagrus latus, Scomberomorus commerson, Argyrops spinifer, Nemipterus japonicas and Caranx sexfasciatus were responsible for 78.03 dissimilarity. However, Comparing catch composition between spring and fall seasons indicate that A. spinifer, C. sexfasciatus, Netuma thalassina, S. commerson N, japonicas and Pomadasys kaakan were responsible for 82.77 dissimilarity. Length frequency distribution of all species (except P. kaakan) was differed significantly between FAD and non-FAD area (P<0.05). All of the biodiversity indices were lower significantly around the FAD area (P<0.05). But no significant difference was found in biodiversity indices between spring and fall seasons (P>0.05). In other mean, limited species comprise the catch dominantly. Quantifying biodiversity on the basis of diversity indices is essential both for sustainable development policies and for addressing ecological issues, such as the relationship between biodiversity and ecosystem functions.

In this study, the ability of Spirulina platensis microalgae in dairy wastewater treatment and nutrient removal associated with biomass production was evaluated. Therefore, two concentrations of Spirulina platensis (0/05 and 0/1 g/L) were cultured in three dilutions (25, 50, 75%) of dairy wastewater and the efficiency of nutrient removal and biomass production was evaluated with six treatments in three replications. Nutrient and biomass values ​​were measured on every other day. The results showed that both factors of different concentrations of algae and different dilutions of wastewater had an important role in nutrient absorption and biomass production. The highest percentages of nitrate, phosphate, ammonia removal (99/85, 82/60, 99/83%) and maximum amount of biomass (1/690±0/01 g/l) in 25% dilution and concentration of 0/1 g/l microalgae was obtained. In this research, by decreasing percentage of dilution of dairy industry wastewater and increasing amount of nutrients available in microalgae and also by increasing the initial concentration of injectable microalgae in the wastewater, more nutrients were removed, and the nitrate and ammonia levels were almost 100% eliminated and the amount of biomass increased. As a result, according to the results, Spirulina platensis microalgae has a high performance in removing nutrients (nitrate, phosphate, ammonia) from dairy industry wastewater and can be considered for dairy industry wastewater treatment.

Determining morphological characteristics of exotic species is one of the important aspects to ecological studies that can be used in ecosystem management. In this research, some morphological characteristics of three-spined stickleback Gasterosteus aculeatus Linnaeus, 1758 in Gorgan-rud and Qarah-su River estuaries are surveyed. 147 specimens were collected using beach-seine with 0.5 cm mesh from February 2014 to April 2014. Samples were being biometry and age determination was done by otolith. Results showed that maximum age were 2+ and 3+ in male and female, respectively. The maximum length and weight were observed 7.62 cm and 7.43 gr and 6.93 cm and 4.43 gr in female genus in Gorgan-rud and Qarah-Su River estuaries, respectively. The growth model was positive allo-metric in female and male in Gorgan-Rud and Qarah-su Rivers. It was indicated body height and width, distance between initial dorsal fin and anal fin, eye diameter, distance between snout to end of dorsal fin and pectoral fin length showed more importance in distinguishing two populations from Gorgan-rud and Qarah-Su River estuaries. Also, it was observed macroscopic Corynoso mastrumasum in inner organs. It seems, the three-spined stickleback, exotic fish, may seriously dangerous for growth and survival of other fish species in the Caspian Sea basin due to the host of this parasite and transmission in the food cycle.

Development planners and policy makers mention tourism as the main pillar of development and in this regard, tourism with principled planning and identification of advantages and limitations can play an effective role in urban and rural development, national development and diversification of the national economy and thus economic development of cities. In this regard, the present study examines and evaluates the effects of tourism on the economic development of Erbil. The statistical population of the study includes 80 experts and tourism industry experts in Ardabil. According to the objectives of the research, the three components of economic justice, economic stability and economic welfare were used in the form of 23 items. The questionnaire was designed with closed-ended questions in the form of Likert scale (very high, high, medium, low and very low). LISREL and SPSS software were used to analyze the data. The results of data analysis showed that the highest factor load among the indicators of economic justice dimension is the average annual household income (factor load 0.81), among the indicators of economic stability factor is the rapid growth of the commercial services sector (factor load 0.87) and Among the indicators of economic welfare, the item of increasing the number of service and welfare centers (factor load 0.87) is assigned. In other words, these indicators have been most affected by tourism. Among the three dimensions, the economic welfare dimension with a coefficient of 0.94, the economic stability dimension with a coefficient of 0.90 and the economic justice dimension with a coefficient of 0.85 had the most impact on tourism, respectively.

The present study aimed to isolate and detect essential amino acids (EAAs) in muscle tissue of common carp (Cyprinus carpio). Fish contains the highest protein content. Three pieces of common carp were collected from gillnets found on beaches of the southern Caspian Sea. Biometrics of collected samples were determined. Target tissue (muscle) of the fish was isolated and kept in nitrogen tanks at -196°C. Dissolution/deposition techniques were used to extract protein from the fish flesh at the isoelectric point, proteins were hydrolyzed into amino acids, and thin layer chromatography (TLC) was used to isolate essential amino acids in the laboratory. Commercial TLC silica gel 60 F₂₅₄ plates (made by Merck, Germany) were used as the stationary phase and butane/acetic acid/water as the mobile phase. Ninhydrin reagent was used to detect amino acids. Quantitative amino acid analysis was carried out and the retention factor (Rf) was calculated. TLC results showed that all EEAs (Arginine, Histidine, Phenylalanine, Isoleucine, Threonine, Valine, Leucine, Methionine and Lysine) were present in muscle tissue of common carp. Tryptophan was totally destroyed with acid hydrolysis and not detected in the analysis. Analysis of 17 essential and nonessential amino acids showed that the highest EAA content of fish flesh belonged to Lysine, Glutamic acid and the lowest content belong to Aspartic acid and Methionine. Since human body cannot synthesize EAAs, common carp should be included in human diet because it is a general source of nutritional components that contribute to growth, energy production, muscle building and treatment of many diseases.

Four streams with different sizes were selected for studying the effects of environmental factors on fish assemblages using indirect (Detrended Correspondence Analysis, DCA) and direct (Redundancy Analysis, RDA) gradient analysis in Golestan province. DCA of presence-absence and relative abundance data showed well gradient and linear model of species variability. In the within-site RDA, environmental factors explained 74.8 % variability for presence–absence data and 77.5% for the relative abundance data. Evaluation of two first axis of RDA showed that first axis has a high correlation with habitat characteristics and second axis correlated with channel morphology attributes. Based on RDA diagrams, Paracobitis malapterura and Capoeta capoeta gracilis presented in Zaringol and Tilabad Streams and had a high correlation with percent of in-stream vegetation and percent of cobble in first axis and low flow mean depth and low flow width in second axis. While Alburnoides bipunctatus and Neogobius fluviatilis had high correlation with percent of snag, pool and sand within streams. It should be stated that factors such as the size of the catchment, hydrographical and geomorphological characteristics, and land use change the morphology and stream habitats, and ultimately lead to the removal of some species in adjacent streams.

Ongoing ecological study of the Caspian Sea, in particular distribution, identifying the species composition and regional variations, seems to be necessary before any study. In order to, in present study, the replacement of benthic groups in the Gorgan Bay and southeastern basin of the Caspian Sea (Golestan province) was studied and compared with the results obtained in previous studies. The results of the study of benthoses showed that the polychaete worms, oligochaete worms, nematodes, chironomidae worms, bivalvias and amphipoda crustaceans constitute the main benthic founa of the ecosystem. These results indicate a very inadequate quality status in the studied areas. The results of the comparison with other previous studies also showed that factors such as the input of organic and inorganic pollutants, inappropriate disposal of wastes, the closure of the main channels of the Caspian Sea and the lack of ventilation of the ecosystem, the construction of inappropriate fishing facilities and etc. caused the hypertrophy conditions and a significant reduction in density and diversity of benthoses in these areas.

Aquaculture is one of the human activities in which uncontrolled development has negative effects on the environment and biomonitoring can be used to explore it. In this study, the environmental impacts of shrimp farms effluents on macroinvertebrate communities in Gomishan Wetland were investigated. Sampling was performed from six stations monthly for one year and five biological indices were used to investigate the quality status. The results showed that the average density of macroinvertebrate communities was 31934 individual/m2 and the most frequent family was Pyrgulidae. The maximum density among stations was observed in Gorganrood River mouth station. The comparison of density in different months showed that in the first three months of the year, the it was higher than the others; Then, the frequency decreased in summer. Along with the depletion of shrimp farms effluents into the Gomishan Wetland in August, the average abundance of macroinvertebrates increased, but it reduced again in the last four months of the year. The Margalf and Shannon-Weiner indices in different months and stations indicated pollution in this wetland. By calculating the Simpson index, it was found that by increasing the pollution, along with the reduction of water volume, the distribution of macroinvertebrates became more uniform. Pielou index with the mean of 0.4 showed no significant differences between different stations and months. Also, the study of distribution index confirmed the clumped distribution. The water quality in Gomishan Wetland was undesirable, indicating the necessity of effective management policies to improve the water quality in this international wetland.

Sepia pharaonis and Trichiurus lepturus are two species target catch of Bottom Trawl. These two species because of the value of export and money are very important economically. This study Biomass and the mean Catch per Unit of Area (CPUA) Sepia pharaonis and Trichiurus lepturus of Bottom Trawl fisheryfrom Oman Sea (Sistan and Balochestan province coastal waters) were investigated. Data were collected in one research cruise by using R/V Ferdows-1 during September and October 2016. The study area was stratified into 5 strata (M to Q) and 4 Substratum covering the depths of 10-20, 20-30, 30-50 and 50-100 m in the Oman Sea. A total of 92 stations were randomly selected and the biomass and CPUA were estimated by swept area method. Result indicated that maximum and minimum the mean CPUA of Sepia pharaonis was 894.0 Kg.nm-2 and 64.1 Kg.nm-2 in the region M and Q respectively. Maximum and minimum the mean CPUA of Trichiurus lepturus was 2485.3 Kg.nm-2 and 49.9 Kg.nm-2 in the region N and Q respectively. Maximum and minimum biomass of Sepia pharaonis was estimated 240.3 tons and 46.6 ton in the region P and Q respectively. Maximum and minimum biomass of Trichiurus lepturus was estimated 899.3 ton and 21.7 tons in the region N and M respectively. Also maximum and minimum the mean CPUA and biomass of Sepia pharaonis and Trichiurus lepturus were obtained in depth of 50-100 m and 10-20 m respectively. Result this study is useful for management of these two species resources from of Oman Sea.

The percent study was carried out to determine the impact of Sturgeon pen culture activities on the water quality from August 2015 to July 2016 in Gorgan Gulf. The study was done at 3 pen culture sites in Ashoradeh Island, Bandar Tourkman. Sturgeons with averaged weight of 21.00 ±12.28 kg /pen and 25.00 ±21.66 Pieces /pen were taken from sea respectively. Total input feed were recorded during the experiment in this study. 5 sampling stations with 3 repetitions were selected which were in distance 0, 5, 25, 50 and 100 m from pen sites. Physico – chemical factors of water were evaluated. Results of season variations of Physico – chemical factors of water showed that, there were no significant differences between SD, Turbidity, Chol a and Cyano biomass, P and PO4-3 (p>0.05). However, there were significant differences between BOD5, COD, TDS, NO2-, TAN and TDS (p<0.05). At the sampling station far from the pen, TDS and Clα and biomass value was found to decrease and turbidity value was found to increase. The maximum amount of Chol a, BOD5, COD, NO2- and TAN were in the station which was 25 m far from the pen sites which showed a significant differences with the other stations (p<0.05). The results also proved that feeding can cause increase, though not significant in P and PO4-3 values around the pen. However, there was significant difference between stations. These results indicate that the pen culture had maximum effect on water quality in distance 5 m far from the pen sites.

Nowadays, the environmental impact of fish culture on water quality and benthic macroinvertebrates is known as pollution water. Therefore the studies were carried out to determinate of distribution, abundance and biomass value macro invertebrate around Sturgeon pen culture in Gorgan Gulf. Seasonal samplings were carried out from August 2015 to July 2016. The study was done at 5 stations in 3 transects, where three pen culture were active. Stations were in distance 0, 5, 25, 50 and 100 m far from pen. Benthos was collected using a van Veen grab (20*25 cm). Density, abundance percent and biomass were calculated for groups. Totally, 11 genus's and 10 families belong to 3 phyla as Mollusks, Arthropods and Annelids were identified. The results showed, there were the maximum abundance percent belong to Pyrgulidae (Hydrobiidae) and Cochliopidae with 33.83% and 26.05% and the minimum abundance percent belong to Gammaridae with 0.05% respectively. However, the maximum abundance belongs to Pyrgohydrobia sp., from Pyrgulidae with 3410 n/m2. The results showed, there were the maximum and minimum abundance in autumn and spring with 3263n and 2044n respectively. So, there were the maximum and minimum abundance of benthic in 3 and 1 stations with 2469 n and 1821 n respectively. Finally, there were no significant difference on abundance and biomass macroinvertebrate around Sturgeon pen culture in Gorgan Gulf (p>0.05).

In order to come up with the sustainable fishing pattern of longtail tuna, there was a need to the gillnet mesh size designed to allows immature fishes escape and provide an opportunity for them to spawn at least once. In this review original gillnet mesh size (140 mm stretched), 114 and 132 mm mesh size nets were examined. The percentage of immature species in 140, 132 and 140 mm nets were 97%, 84% and 78% respectively. The linear relationships between fork length and head (in pre gill), gill, body (in first dorsal fin) and second dorsal fin perimeters were (HP=0.48FL+0.83), (GP=0.51FL+2.35), (BP=0.60FL+0.87) and (SDP=0.49FL+3.89) respectively. There was significant coefficient between linear equations and perimeter in first dorsal fin was maximum body perimeter. The elastic ratio were 24% in first dorsal fin and 19% in head and gill. The optimum standard gillnet mesh size based on relationship between fork length - body and length at first maturity was 170 mm stretched.

The aim of this study was to determine the influence of environmental parameters on
the abundance of monkey goby Neogobius pallasi. A total of 526 and 163 individuals of monkey goby specimens were caught by electro-shocker in the Kaboodval and Shirabad Streams, respectively. The ranges of total length of the specimens in Kaboodval and Shirabad Streams were respectively 22-137.55 mm and 32.64-137.97 mm. All the specimens of both streams belonged to the 5th age group (0+4). The morphological, hydrological, biological and physicochemical parameters were investigated in both streams. The results showed that the hydrological parameters and vegetation coverage in the Kaboodval Stream and also, water velocity and depth in the Shirabad Stream had significant relationship with the monkey goby abundances (P

The use of Silver nanoparticles (with a size less than 100 nm), especially in the field of health is widely developed. Daphnia has wide application in pollution studies of aquatic ecosystems due to the simplicity the top to reproduce and sensitive to environmental. The aim of this study was to determine the lethal toxicity (LC50 96h) silver nanoparticles on Daphnia magna adult. Samples of D.magna were prepared from fish farms in the Gonbad region and reared in the laboratory under controlled conditions (temperature 20±1°C; 16h:8h light:dark; dissolved oxygen, 8.80mg/liter; pH 8; total hardness, 293 mg/liter; salinity to 1.86 ppt). Then in order to purification of a daphnia, three consecutive generations were prepared. Acute toxicity test (LC50) was achieved at four different concentrations (0.25, 0.5, 1 and 2 parts per million) along with control and three replications and mortality in periods of 24, 48, 72 and 96 hours were measured. In this study, L C5048h for silver nanoparticles was estimated 0.416 part per million (ppm) on D.magna. Overall, it seems that silver nanoparticles show high toxicity for D.magna and significant increase by increasing the concentration and exposure time.

Nitrification rate of biofilters is influenced by ammonia concentration and levels of ammonia vary in response to feeding time. On the other hand, existence and activity of different groups of bacteria can be expected in the biofilters. Hence in this research, nitrification dynamic of biofilters during day hours and also rules of different biofilteration process (nitrification, denitrification and anamox) in aerobic biofilters of Common carp recirculating aquaculture system were surveyed. To conduct of this research 12 pilot recirculating aquaculture systems with barley straw, wood chip, sponge and PVC pure pipe based biofilters were designed. After activation of biofilters, nitrification rates measured at day 46 and 61 in 4 hour interval and via sampling of granules from biofilters at day 62, nitrification, denitrification and anamox process were surveyed. Results indicated that nitrification rates were different during day hours, as so peak rates observed in related to feeding time. Nitrification rates in batch culture of granules were greater than maximum rates obtained for biofilters established in recirculating aquaculture systems and these granules showed not only nitrification but also denitrification and relatively anamox activities. In conclude by modifying the management of biobilters all biofilteration process of inorganic nitrogen wastes can be useful.

The purpose of the present study was to find the sub-lethal effects of Diazinon and Endosulfan on olfactory responses in Persian sturgeon fingerlings (Acipenser persicus). The fingerlings used in this study were in the range of 7-9 g in weight and 10-13cm in length. For qualitative and quantitative study of environmental effects on behavioral responses, the amino acids glycine and alanine (At the concentration of 0.001 mol per liter as of olfactory stimuli) and Daphnia extract (positive control) and tap water (negative control) each with five replicates were used. Olfactory responses of juveniles in tap water and the sub-lethal concentration (LC10 and 0.1LC50) of the diazinon and endosulfan, after 24, 48 and 96 hours, were evaluated. The average percentage of olfactory responses to olfactory stimuli in both concentrations of LC10 and 0.1LC50 of diazinon with increasing concentration and time compare to the control was decreased. The concentration of 0.1LC50 endosulfan, Showed a greater reduction in the percentage of the average responses of olfaction compare to control. The results suggest that environmental factors are affecting olfactory responses in the Persian sturgeon.

Biofilter is one of key components of recirculating aquaculture system (RAS) that affect initial investment, executing cast and success or unsuccess of system. Hence in this research, performance of barley straw, wood chip, sponge (as cheap and available media) and PVC pure pipe (to compare) based biofilters was surveyed in Common carp recirculating aquaculture system. To conduct this research 12 pilot recirculating aquaculture systems designed and 50 common carp individuals (mean weight: 4/8 g) were stocked in each system. After activation period (about 1 month), waste removal efficiency of biofilters and growth performance of Common carp were surveyed. Results indicated that sponge based biofilters had the best performance. Barley straw and wood chip based biofilters showed acceptable waste removal efficiency, while PVC pure pipe biofilters had poor performance. The highest feeding and growth performance of fish were observed in systems involved barley straw based biofilter. In conclusion barley straw, wood chip and sponge because of having low cast, being available, having relatively high specific surface area and showing acceptable waste removal efficiency, can be used in RAS and semi reuse systems.

According to the importance of the surface water resources in terms of food production for society, and in order to sustainable development we should manage them consciously, In addition to protecting water resources provide suitable habitat for aquatic species. In the past the most Iranian coastal rivers of the Caspian Sea were the normal amplification of Ruitilus frisii kutum, but nowadays for several reasons only some of these rivers are the main areas of spring migration of fishes in Iranian coastal water of Caspian Sea. So this study was done with the purpose of assessing variation of some physico-chemical factor in major estuaries of the southern coastal water of the Caspian Sea and to identify the most appropriate river to release Ruitilus frisii kutum juveniles; So the most important environmental factor affecting the release of juveniles using the Delphi method and preference degree of factors using the AHP method was determined. So the rivers were assessed using Multi Criteria Decision method; so in multisubject compensatory decision models of grading and scoring subgroups, a simple weighted method and to reach a general consensus the mean ranks method was used. The results showed that all estuaries of rivers in the view of physicochemical Factors are subject to large variations. And results showed that Gorganrud, Tajan and Sefidrud are most polluted rivers and Cheshmehkileh, Khalehsara and Khoshkrud are best rivers for releasing of Ruitilus frisii kutum in among the studied rivers southern Caspian Sea.