ali akbar hedayati

Since aquaculture is directly related to human food and water resources, we need to use new techniques to realize sustainable aquaculture. One proposed solution to achieve sustainable aquaculture is to increase the density and improve the diet of farmed fish. The present study investigates the effect of coenzyme Q10 (CoQ10) in the diet on the growth, carcass composition, and ammonia stress of rainbow trout Juveniles. To this end, fish were fed diets containing zero, 0.1, 0.5, and 1% CoQ10 levels for two months. At the end of the breeding period, growth and hematology indicators were calculated, and the carcass composition was analyzed. Ammonia stress was induced at a concentration of 0.6 mg/liter at the end of the study. The findings reveal that adding 1% CoQ10 to the diet before stress leads to increased growth, reduced carcass fat, and increased white blood cell count (p<0.05). Additionally, after ammonia stress, CoQ10 creates resistance in fish, resulting in significantly reduced losses (p<0.05). In general, it can be concluded that CoQ10 can be effectively used in aquaculture to increase growth and improve the ability to tolerate stressful conditions, particularly those caused by an increase in ammonia levels. Furthermore, CoQ10 can be utilized during dense and ultra-dense breeding to enhance growth and increase tolerance to stressful conditions, such as an increase in ammonia levels. As a result, CoQ10 can be used in breeding farms to significantly reduce losses by preventing damage to blood cells and maintaining the oxygenation process.

The use of dietary supplements plays an essential role in enhancing fish consumer safety. On the other hand, the presence of nanoparticles affects the physiological status of fish and decreases their immune function. Therefore, the use of safety stimuli such as molasses may be necessary. The present study was performed to assess the hematological indices of molasses-fed common carp (Cyprinus carpio) exposed to titanium nanoparticles. Accordingly, 250 fish with a mean weight of 20±0.62 g was divided and fed for 42 days in four treatments, diet without molasses (treatment 1), diet containing 0.5% molasses (treatment 2), 1% molasses (treatment 3) and 2% molasses (treatment 4). At the end of the feeding period, each group received 50% lethal concentration of nano-titanium for 14 days. Blood samples were taken to measure blood levels at the end of the experiment. The results of the present study showed that with increasing molasses diet, the number of white blood cells significantly increased and also in the molasses treatments exposed to nano-titanium, there was also a significant increase in the number of white blood cells. Red blood cells, hematocrit and hemoglobin increased in molasses-fed diets and this trend was increased with increasing molasses concentration in diets and was significantly different from control group (p<0.05). The conclusion of this study showed that blood monocyte levels decreased in nano-titanium and molasses combination treatments. So, molasses in combination with nano-titanium has been able to improve undesirable lesions. Also, the number of blood lymphocytes in nano-titanium and molasses combination treatments increased, which means molasses in combination with nano-titanium could improve the reduction effect of nano-titanium.

Fish epidermal mucus protein extraction for bioassay-guided screening is challenging and variable. In this study, four different protein extraction methods, including acetone, trichloroacetic acid (TCA)-acetone, methanol, and solid-phase extraction (SPE), were investigated to study their efficiency in ultrafiltration and to obtain the appropriate peaks in HPLC to measure biological activities. The presented data shows that the solid phase extraction method is better than the other three tested methods in quantity (total protein yield) and quality (protein profile observed in SDS-PAGE) of proteins and peptides from the epidermal mucus of Caspian monkey goby. On the other hand, due to the epidermal mucus hydrophobic nature, all three extraction methods including acetone, (TCA)-acetone and methanol led to the irreversible proteins aggregation, makes ultrafiltration, HPLC, and consequently bioactivity screening impossible. In this study, the highest amount of protein (4.676 μg/ml) (P<0.01) and the best protein profile (13 bands) were related to solid phase extraction. Also, this method simultaneously leads to the extraction, concentration, and initial purification of the samples and therefore improves the efficiency ultrafiltration and HPLC. Thus, we introduce this method for the isolation of active proteins and peptides from various complex biological samples, including fish epidermal mucus.

The filtration rate is one of the physiological indices in bivalves that indicates the degree of the effectiveness of the filtration function in exposure to contaminants. In this study, the changes in filtration rate of Dressina poly morpha were investigated after 7 and 14 days of exposure to silver nanoparticles. Bivalves were removed from the natural environment and transferred to the laboratory. The distribution of nanoparticles in water tanks was tested with the DLS device. Bivalves were exposed to concentrations of 0.25, 2.5 and 25 ppm of nanoparticles for 14 days. The results showed the highest filtration rate for the control group (96 ± 47.74 ml min-1 g-1DW). On day 7, the highest filtration rate was observed in the first treatment (88.58 ± 64.38 ml min-1 g-1DW) and the lowest filtration rate was observed in treatment 3 (47.67 ± 11.81) ml min-1 g-1DW), no significant difference was observed in the filtration rate betwen first treatment and control (P >0.05), but the filtration rate in the third treatment was significantly (P <0.05) lower than that of the other treatments and the control group. Moreover, the filtration rate on day 14 showed similar differences to day 7, but more significant. Therefore, it can be concluded that filtration rate changes are a good indicator for nanoparticles contamination.

The rapid and continuous development of shrimp farming has probably led to a series of harmful developments for the environment and human health. The destruction of mangrove forests, the blooming of harmful algae in coastal waters and shrimp breeding ponds, the introduction of non-native species, the depletion of aquatic resources and the reduction of water quality are among the most important environmental problems. The widespread and unlimited use of antibiotics to prevent bacterial infections in the shrimp farming industry, especially in developing countries, has played a role in this regard. On the other hand, the use of large amounts of antibiotics that should be mixed with shrimp food also lead to some problems for human health and increases the chance of remaining antibiotics in meat and shrimp products. Therefore, it seems that global efforts are needed to promote a more rational use of preventive antibiotics in aquaculture. Because the evidence shows that this unlimited use is harmful to fish, animals, human health and the environment. It is suggested to plan according to the principles of sustainable use of the environment for various economic activities, including the construction of shrimp farms, and monitoring efforts are usually needed to predict possible effects. Aquaculture effluent monitoring is part of the assessments needed to understand environmental impacts, which may include measurements of water quality, nutrient concentrations, organic matter outputs, chemicals, and residual bacteria that affect product quality.

Phenol is one of the hydrocarbons identified as a priority pollutant by the US Environmental Protection Agency (EPA). Phenol and its derivatives have wide applications in a variety of industries and is known as an important pollutant in industrial wastewater. As conventional phenol removal methods are often expensive, there is a need for a low cost and environmentally friendly method to remove this pollutant. The purpose of this study is to examine the removal of phenol from aqueous solutions using chitosan nanoparticles. We experimented phenol removal in batch system with absorbent dose (0.01- 0.4 g/l), pH (3-8), contact time (5-120 min), phenol concentration (5-50 mg /l) and temperature (15-40°C). Based on the results, the optimal levels of concentration, pH and adsorbent dose were 50 mg/L, 4 and 0.05 g/L as parameters for use in subsequent steps. After 35 minutes, the absorption system was in equilibrium and then there was no significant change in the phenol absorption, and after 60 minutes, the absorption rate decreased. Removal efficiency of phenol at 35°C demonstrated its highest amount. According to the findings, due to the characteristics such as degradability, regeneration ability, low cost, and acceptable adsorption efficiency, chitosan nanoparticles could be used to remove phenol from water contaminated with oil compounds.

The present study was performed to evaluate the protective effect of molasses pretreatment on the liver index of common carp (Cyprinus carpio) in exposure to copper oxide and titanium nanoparticles. Therefore, 250 juveniles of common carp for 42 days in four categories, rations without molasses (treatment 1), diets containing 0.5% molasses (treatment 2), diets containing 1% molasses (treatment 3) and diets Containing 2% molasses (treatment 4) were divided. Then, 50% of the lethal concentrations of copper and titanium oxide nanoparticles were added to each group for fourteen days. Histological studies of fish exposed to molasses and oxidomes and titanium nanoparticles showed structural abnormalities in liver tissue such as hemorrhage, fattening, and macrophage accumulation. So that these changes were very different compared to the tissues of the control group. The final conclusion of the present study showed that nano-titanium and nano-copper treatment resulted in tissue damage in carp liver; Although pathological complication was also observed in the combined treatments of the mentioned nanoparticles and molasses, but the severity of injuries decreased with increasing molasses concentration.

Zinc is one of the heavy metals in aquatic ecosystems. Currently, nanotechnology has made significant progress in various industries, in the present study, the toxicity of nano-zinc oxide on the blood indices of Capoeta capoeta gracilis (Capoeta) was investigated.

This research was conducted with concentrations of 0, 5, 20, 100 and 400 mg/L of nano-zinc oxide (Nano-ZnO) for 14 days on 70 Capoeta with a mean weight of 20±5 grams. After the experiment, blood samples were taken from the Capoeta and various blood indices were measured including leukocytes, lymphocytes, neutrophils, eosinophils, erythrocytes, hemoglobin, hematocrit, MCV, MCH and MCHC.  

All blood erythrocyte indices in Capoeta showed significant changes, but leukocyte indices did not change. Also, with the increase of nano-zinc oxide in different treatments, the number of red blood cells, hemoglobin and hematocrit decreased and the number of white blood cells increased in Capoeta.  

With rising the concentration of nano-zinc oxide, the level of hematological adverse effects increased and the concentration of 100 mg/l has the most adverse effects in Capoeta. Nano-zinc oxide causes anemia and disrupts Capoeta's immune system, which may be due to its destructive effects on hematopoietic organs such as the liver and kidney.

The aim of this study was to investigate the sub-lethal effects Lead Chloride (PbCl2) on blood indices, liver enzymes, cytochrome P450 gene expression in common carp. For this purpose, Fish with a mean weight of 7 33±0.33 g were prepared and divided into 3 treatments and a control group and exposed to effective concentrations (0.05, 0.15, 0.25 mg / l) of sublethal toxicity for a period of 14 days. At the end of the experiment, sampling was done randomly. The results showed that the level of AST and ALT enzymes significantly decreased compared to the control group (P<0.05) whileThe level of ALP increased significantly (P<0.05). The results of hematology test showed that the level of white blood cells, hematocrit and hemoglobin did not change significantly with increasing the concentration of lead chloride compared to the control group; but they had a slight upward trend compared to the control group (P <0.05). Also, the amount of red blood cells, monocytes, total protein and serum immunoglobulin decreased significantly compared to the control group (P <0.05). Levels of lymphocytes, basophils and total mucus protein increased significantly compared to the control group (P <0.05). Mucus lysozyme had a slight decreasing trend compared to the control group but had no significant effect (P <0.05). The expression of P450 gene in liver and gills increased significantly compared to the control group (P> 0.05). In this study, the relative expression of cytochrome P450 gene in liver tissue was significantly higher than gill tissue (P <0.05). In general, it was found that lead chloride has destructive effects on the liver of common carp.

Awareness and recognition of institutional aspects of water resources management, notably like, the important role of civic supervision and participation in water resources management, well observed in the history of sustainable management of surface and groundwater resources in Iranian civilization. International experience also explains the transition from supply-oriented to reforming consumption patterns and a focus on institutional funds as economic schools evolve over time. Despite significant experiences in integrated water resources management, there is yet serious challenges that insist on of massive projects- with devastating inefficiency in the demand side - which focus is on supply-oriented in our country. Transformation of water between basins is considered as such projects, which not only might impose considerable costs on the country but also have far-reaching consequences afterward may go far beyond technical issues and have ecological and even social subsequences. Unfortunately, the bitter experiences of such an approach regarding the cultural rift between the people of Khuzestan, Chaharmahal and Bakhtiari and Isfahan provinces can be seen. In this study in order to indicate such proportions, first, we explained the theoretical foundations related to sustainable development from the perspective of "separation" components. The components include "social welfare", "economic growth", "reduction of dependence on basic resources", and "reduction of environmental consequences". Failure to pay attention to any of these components poses serious challenges for the sustainability of socio-ecological systems. Therefore, the documents related to the deterioration of the four components in the implementation of the water transfer plan from the Caspian Basin to Semnan were explained with objective examples. In terms of social welfare, the loss of some jobs, including the livelihoods of local fishermen, disrupting social stability and creating social tensions, threatening food security and economically valuable aquatic organisms, damaging the livelihoods of farmers and fishermen in the region, as well as endangering health must be considered seriously. Other examples of inconsistency of the plan with sustainable development principles, in terms of environmental consequences, include damage to the marine ecosystem. Upstream theoretical principles, with regard to the potential environmental and ecological potential effects that are very complex and irreversible, cannot justify any such kind of projects and its specific environmental consequences in the region. Therefore, certainly there must be more efficient alternatives than such a large and unbearable plan to consider regarding the Inadequate and insufficient demand management in the drinking, agricultural and industrial sectors in the destination basin. Accordingly, as an alternative approach, it is suggested to consider other management measures that firstly, lacks socio-ecological-environmental consequences secondly, do not put additional pressure on basic resources, and thirdly are in line with sustainable development to ensure the sustainability and survival of socio-ecological systems at source and destination. It should be noted that the implementation of such projects, in addition to the above, also causes serious problems for the management of water resources in the destination area.

In this study, the effect of different levels of the amino acid methionine on some growth factors, mucosal immunity and antibacterial properties of mucus in Rutilus frisii kutum was investigated. Therefore, first 420 juvenile Rutilus frisi katum with an average weight of 1.24± 0/02 g were prepared, then 35 fish were randomly distributed in 12 tanks with four treatments and three replications. They were then fed at doses of 0, 2/5, 5 and 10 mg / kg methionine for 60 days, respectively. The results of this study showed that different levels of methionine had no effect on whitefish growth indices, so that there was no significant difference between treatments containing different levels of methionine in terms of different growth indices. The highest lysozyme activity was observed at 5% level, and the amounts of alkaline phosphatase and mucus-soluble protein were observed at 10% level. The results showed that the highest antibacterial activity was related to the levels of 5 and 10% of the amino acid methionine. According to the results, it can be said that 5 and 10% levels of the amino acid methionine can be effective in improving the activity of some digestive enzymes (lysozyme, alkaline phosphatase), soluble proteins and antibacterial activity in the study species. Achieving more complete and accurate results requires more research in this area.

Due to the emergence of nanotechnology and insufficient knowledge of the potential dangers of these particles on the one hand and the beneficial effects of probiotics on aquatic animals on the other hand, in this study the effect of emerging nano-silver contaminants with bacterial probiotic Lactobacillus as a dietary supplement Some liver indicators in common carp were discussed. The fish were subjected to 6 experimental treatments and after 42 days of feeding with probiotics based on lethal toxicity test and sub-lethal according to OECD standard method, they were exposed to nanosilver for 4 and 10 days, respectively, with adaptation. At the end of the lethal toxicity test, liver tissue samples were extracted from the fish and hepatic histopathology indices were evaluated. Nano-silver alone caused structural abnormalities including deformation and necrosis, bleeding, swelling and dehydration, as well as lateralization of the nucleus in the liver. Probiotics alone drastically reduced the amount of these side effects. Also, the combined use of probiotics and nanosilver, although associated with increased bleeding, stimulated nonspecific immunity in common carp and improved other liver complications.

Sediment monitoring in aquatic environments is very important due to long-term exposure of various pollutants. This study was conducted to monitor the pollution of some heavy metals (Cd, Cu, Fe, Pb and Zn) in the surface sediments of Anzali wetland.

For this purpose, sediment samples were collected from east, west and central parts of the wetland in different seasons of 2020. Heavy metals contamination zoning for sediments in the study area was performed using Arc GIS 10.7

The results showed that the highest level of contaminants were obtained in the western part of the wetland. The average concentrations of heavy metals in the sediments were related to Cu (18.47), Zn (74.15), Cd (0.67), Pb (12.05) and Fe (1.97) mg. kg-1 in the western part. The pattern of changes of studied metals was in conformity with Cd 0.05) between Pb, Cu and Zn. According to the zoning map of the parts located in the middle of the center to the west of the wetland, higher amounts of metals have been deposited in its sediments.

In general, various human activities and the development of industries and the existence of agricultural lands in the area of Anzali Wetland and incoming rivers can be considered as factors affecting pollution. Therefore, with continuous biological and ecological monitoring of the wetland, it is possible to estimate the amount of heavy metals and the share of each in the wetland. Also, management in order to protect and monitor the wetland seems necessary.

The aim of this study was to investigate the effect of different prebiotic levels of oyster mushroom (Pleurotus ostreatus) on hematological indices of Nil tilapia exposed to silver nitrate. For this purpose, 120 juveniles of tilapia were fed with diet containing 0 (treatment 1, control), 0.05 (treatment 2), 0.1 (treatment 3) and 0.2% (treatment 4) prebiotic oyster mushroom) for 42 days. Then, 0.5ppm of silver nitrate was added to each group for 16 days. Before and after exposing to silver nitrate, fish blood indices were evaluated. Prebiotics alone had no significant effect on RBC, MCV, hematocrit and hemoglobin (P<0.05). But, treatments fed with prebiotics and exposure to silver nitrate toxin showed an increase in WBC, MCHC (in 0.1 and 0.2 treatments), MCH indices compared to the control group. According to the results, oral prebiotics stimulated nonspecific immunity in tilapia and using mushroom prebiotics reduced the destructive effects of the silver nitrate toxin on blood indices. In conclusion, levels of 0.1 and 0.2% of prebiotic oyster mushroom in treatments which exposed to 0.5ppm silver nitrate toxin could improve the blood factor status of tilapia.

Small plastic particles are known as emerging pollutants and this has led to the development of studies in this field. Todays, many studies have examined the effects of microplastics on living organisms and aquatic organisms, but fewer studies have been conducted on the effects of nanoplastic on organisms; However, there is still no comprehensive information on the effects of these substances on living organisms and humans. The aim of this study was to investigate the hematological and biochemical responses of common carp in exposure to polystyrene nanoplastic. 84 common carp with an average weight of 30±5.1 were distributed in 4 food treatments (control with basic food and without nanoplastic, treatments containing 0.1, 0.5 and 1 ml of nanoplastic sprayed emulsion styrene on diet for 28 days. At the end of the experimental period, serum samples were collected to investigate some biochemical and hematological indices. Different concentrations of nano polystyrene plastic despite the increasing trend, red blood cell count, hemoglobin, hematocrit, MCV, MCH, MCHC, lymphocyte count, neutrophil, monocyte, basophil and eosinophil and serum biochemical indices, such as albumin, albumin. Serum had no significant effect (P> 0.05), but the level of white blood cells and glucose at a concentration of 1 ml (highest concentration) was significantly higher than the control group (P <0.05). Finally, higher concentrations of polystyrene nanoplastic are likely to increase stress and inflammatory responses in common carp.

Golden barb, Carasobarbus luteus (Heckel, 1843), belongs to the Barbus genus and is one of the freshwater species of Iran and native to Shadegan wetland. Some biological characteristics of Carasobarbus luteus were studied in Shadegan Wetland. Monthly samples were collected from five stations; Doragh (Mahshahr), Rogabe, Khorosy, Salmane and Atish from April 2013 to Mars 2014. 1608 specimens (276 males and 1332 females) were collected and measured. Results showed Mean±s.d length values for the male and female were calculated as 161±28(110-222), 174±38(95-280) mm respectively and mean±s.d weight values were 60±31(15-175), 80±39(15-370)g respectively. The length-weight relation were calculated as W=0.00003L2.83 (R2=0.84) for males, and W=0.0001L2.80 (R2= 0.86) for female; that determined negative allometeric model. The mean values of condition factor (K) were 1.77± 0.14 in males and 0.78± 0.27 for females and have no significant different (P>0.05). The spawning peak was determined in April, and length at maturity (LM), consume per biomass (Q/B) and production per biomass (P/B) were calculated for males and females as below LM=152, 139 mm; P/B= 0.71, 0.52 and Q/B=15.41, 12.37 respectively.

Concerns about the negative effects of microplastics on human health have led to increasing attention to the occurrence of microplastics in the aquatic environments. Recent studies have focus from the marine environment to inland waters, particularly the spatio-temporal distribution of microplastics in rivers. Qarasu basin, leading to Gorgan Bay, is the site of many permanent rivers and the levels of microplastic pollution in those rivers are unknown. This study was conducted along 8 different rivers in 2020. Some 9 fish species were identified and the presence of microplastics was confirmed in 87% of fish. The prevalence of microplastic particles among species were Chelon spp.> Carassius gibelio> Gambusia holbrooki> Rutilus rutilus> Neogobius melanostomus> Cyprinus carpio = Vimba persa> Rutilus caspicus> Barbus cyri. The highest type, color and size of fish microplastics were fiber, black, 0.5-0.1mm, respectively. In conclusion the rivers of Qarasu basin have been polluted by microplastics not only in developed areas with intense human activity but also in upstream areas, which can be considered as a source of pollution in Gorgan bay.

The emergence of newly released nanoparticles in water results in stress response of fishes, which ultimately affects the physiological state and reduces the immune function of fishes. Therefore, it seems the use of immune stimulants such as molasses is very necessary. In this study 250 common carp were exposed to molasses in four groups, with no molasses (treatment 1), diet containing 0.5% molasses (treatment 2), 1% molasses (treatment 3) and diet containing 2% molasses (Treatment 4) for 42 days. Each group were exposed to 50% of lethal concentration of nano-iron for 14 days. Then, various indices such as soluble protein, alkaline phosphatase, lysozyme and immunoglobulin were measured in mucus. Results showed that total experimental treatments had a significant effect on mucus immune parameters (P<0.05), so these indices were affected by treatments fed with molasses increased with the increase of molasses concentration, in the treatment of nano-iron and in the treatment of nano-iron and molasses, the amount of this indicator increased significantly. The overall conclusion of this study shows that molasses, iron nanoparticles, molasses and iron compound increased the mucosal immune parameters.

One of the most common methods for removing pollutants from aqueous solutions is adsorption. Currently, research on cheap adsorbents with high potential for removing pollutants is economically important. In this study, the efficiency of nano-chitosan was investigated for toluene removal from aqueous solutions by adsorption method in a laboratory scale. The effect of different pH parameters, initial concentrations of toluene, absorbent dose and contact time were investigated. Toluene concentration values ​​were analyzed by UV-Vis Array spectrophotometer Model Photonix Ar 2015 at 206 nm. The results showed that the amount of toluene adsorption increased with increasing pH, increasing the dose of adsorbent and increasing the contact time by inverse ratio and increasing the concentration of direct ratio. According to the results, the optimal amount of toluene adsorption at pH=5, concentration of 70 mg /L, absorbent dose of 0.01 g L, and contact time of 5 minutes were determined. The results of this study showed that nano-chitosan adsorbent has high efficiency in toluene adsorption from aqueous solutions.

Principles of green chemistry in the production of products to reduce and eliminate environmental pollutants can introduce products such as nano-gels as environmentally friendly and biodegradable adsorbents. Freshwater supply is one of the most important goals in improving the infrastructure of aquaculture and industry due to repeated droughts. For this reason, wastewater treatment and reuse can be a suitable way to meet the country's water needs. The purpose of this research was to use herbal nano-gels from agricultural waste (bagasse) to remove phosphate from wastewater treatment. First, the bagasse nano gels were prepared by a mechanical and a top-down mechanism. Optimal values were calculated for each parameter. The optimum amount of dosage, pH, concentration, time was determined 0.2 g, 0.3 g for nano-gel, 5, 100 mg/l, 30 minutes. According to the equations, the adsorption isotherm was the most consistent with the Langmuir model and Temkin and Pseudo-second-order. The results showed that bagasse nano-hydrogels can remove phosphate by less than 0.5 mg/l.

Due to the increasing use of nano-materials, especially nano silver because of the anti-bacterial inevitable is used in various industries, it will entry into the ecosystems, so in this study, the toxic response of nano silver on goldfish was studied.
Material and

To determine the toxicity of nano-silver, O.E.C.D standard method number 203 was used. Mortality recorded was daily basis over a period of 96 hours and after records, to determine the lethal toxicity in the 24, 48, 72 and 96 hours, probit software was used. Finally, the maximum allowable concentration and degree of toxicity was found.

During the period of 24 to 96 hours with increasing concentrations of nano silver, mortality of fish was increased. The mortality rate at concentrations of 0, 0.01, 0.1, 0.5, 1, 2.5 and 5 mg after 24 hours were 0,0,0,0, 4, 11 and 21 respectively, in concentrations of 0, 0.01, 0.1, 0.5, 1, 2.5 and 5 mg after 96 hours, mortality rates were 0,0,0, 10, 21, 21 and 21, respectively. Based on these results, the lethal concentration (LC50) of nano silver on goldfish in time 24, 48, 72 and 96 hours were obtained 2.31 and 1.48 and 0.995 and 0.53 ppm respectively.

In general, the results show that the toxicity of silver nano is very high during the finger period and its side effects should not be ignored with the increasing spread of this substance. It is also necessary to compare the results with silver ions when evaluating the toxic effects of nano-silver.

Awareness on spatial dispersion of heavy metals allows for planning of appropriate environmental policies. This study aims to monitor the pollution of heavy metals in Anzali International Wetland using GIS and spatial statistics. Sampling of water was done at 10 stations in 2014. The spatial distribution, density, zoning and distribution pattern were used in GIS for interpolation method, kernel function, Moron test, and hot spots index. The zoning maps derived from the density estimates indicated an increase in lead and nickel concentrations from west to east of Anzali Wetland. Based on the moron test and the GI* index, spatial correlation and spherical distribution pattern of heavy metals cluster indicate the accumulation and proximity of high density contaminated areas adjacent to each other. Accordingly, the highest hot spot of cadmium and nickel belongs to the northern parts of the wetland (under the bridge of Anzali port), zinc and lead were in the eastern part, and form the high cluster pattern, it could conclude that in these regions, heavy metal have been shown the positive self-correlation pattern.

The presence of emerging nanoparticle contaminants in aquatic environments reduces the safety performance of aquatic animals, so the use of safety stimuli is essential. The aim of the present study was to investigate the effect of different prebiotic levels of oyster mushrooms (Pleurotus ostreatus) on tissue damage in the liver and gills of tilapia exposed to silver nanoparticles. For this purpose, 120 juveniles of Tilapia (Oreochromis niloticus) In 4 experimental groups with 3 replications including treatment 1 as a control (fed with food without probiotics), treatment 2, fed with food containing 0.05% probiotics, treatment 3, fed Were fed with food containing 0.1% prebiotics and treatment 4, fed with food containing 0.2% prebiotics and cultured for 42 days, then silver nanoparticles with a concentration of p5 ppm for 16 days. 0. was added to the culture medium of each of the treatments. At the end of the course, the fish were anesthetized with clove anesthetic solution (220 mg / L) and their liver and gill tissues were isolated for histological studies. Treatments exposed to silver nanoparticles showed extensive complications in gill tissue as well as severe injuries and bile stasis in liver tissue. However, the use of oyster mushroom prebiotics was able to reduce the destructive effects of silver nanoparticles on these tissue complications. Treatment of 0.2% with oyster mushroom prebiotics in the diet can have the best protective effect on tissue damage in the liver and gills of tilapia exposed to silver nanoparticles with a concentration of 0.5 ppm.

Today, many satellites over land cover and land water produce high-quality images of different uses. The conditions for access to these images are such that it can be used for several years to study the phenomena of aquatic ecosystems, such as wetlands, and at the same time identify their changes. Length- The temporal and spatial distribution pattern of primary production is useful for studying global climate change. In this study, using Landsat images from 1985 to 2017 and their initial processing, the average initial production (based on O.E.C.D) for Choghakhor International Wetland was determined. The results show that the wetland is in terms of chlorophyll-a and secchi disk depth (SDD) in the middle of mesotrophic and towards eutrophication.

Gorgan Bay and the southeastern coasts of the Caspian Sea in the Golestan Province are important biological and fisheries areas., while in recent years, they have been heavily contaminated. In present study, the dynamic of fishes, using stable nitrogen and carbon isotopes was evaluated to determine the diet and its trophic status, which can accurately chart the ecosystemchr('39')s biological conditions. Accordingly, in September-October 2015 at 5 ecological stations, sampling of prephytones, macrophytes, macro invertebrates and fish, were taken and dominant species were subjected to isotope analyzes using the EA-IRMS device. The results of the nitrogen-15 and carbon-13 isotopes indicate an imbalance in ecosystem conditions that alters the diet of the organisms and reduces the efficiency of the food web. The main factors of pressure on the ecosystem, the closure of the main channels of the sea to the bay, the entry of various pollutants into the ecosystem and weak physiography of Gorgan Bay, were determined.