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The phenomenon of cyanobacterial bloom, among other things, is chronic and periodic pollution, which is mainly caused by phosphorus and nitrogen, as well as high temperatures and direct sunlight. To carry out this experiment, in order to obtain blooming cyanobacteria in the warm water pond fish, water samples were taken from 5 farms and after purification, mass culture of 4 species of cyanobacteria that had the highest density was prepared. Then kaolin with a concentration of 0.5 g/liter and separately with two sizes of 50 and 100 micrometers was added to the pure culture of any cyanobacteria species using a 1-meter column. The amount of reduction of cyanobacteria was checked by counting by Neubauer chamber at 0, 3, 9 and 24 hours after adding to it. The results showed the decrease in the number of cyanobacteria Chroococcus sp. For kaolin with two sizes of 100 and 50 micrometers, it was 24.4 and 39%, respectively. This rate was 25.8 and 15.5% for the cyanobacterium Gloeocapsa sp. Also, for cyanobacterium Oscillatoria sp., 23.5 and 35.3% were calculated and finally for cyanobacterium Microcystis sp., 29.4 and 33.3% were calculated. The results of this research showed that the separate use of two sizes of kaolin, 100 and 50 micrometers, is effective for the immediate control of cyanobacterial bloom, and also, comparing the two sizes of kaolin, kaolinite with the size of 50 micrometers had better operation. [ABSTRACT FROM AUTHOR]

This study was designed to determine the effect of rainbow trout culture in floating cage on the distribution and structure of Phytoplankton community in the Abbas Abad area, southern basin of the Caspian Sea. For this purpose, water and phytoplankton samples were collected by a distances of 5, 50, 100 and 1000 m from the cage culture during December 2014 (pre cage), March and April (production period) and August 2015 (post cage). The results of physicochemical factors of water showed that most of the measured parameters had significant differences only among different sampling periods (P<0.05). In this study, 42 taxa of phytoplankton belonging to five phyla (with the dominance of Bacillariophyta) were identified. The results showed that the abundance of most dominant phytoplankton samples had a significant difference during different periods (P<0.05), but this significant difference between different stations was observed for few species studied only. Also, the results of determining the effect of environmental factors using CCA test on the Bacillariophyta abundance showed a minor impact and a positive correlation with turbidity and total nitrogen, While the effect of temperature and ammonium on its abundance was negative. It seems that the rainbow trout cage culture in the Abbas Abad region had a minor impact on water quality factors and nutrients concentration probably due to short duration of cage culture activity and high velocity currents, but no remarkable effect on phytoplankton structure in the vicinity of fish cages, so that the observed changes were more associated with seasonal fluctuant. [ABSTRACT FROM AUTHOR]

Background and Objectives: Land degradation and soil erosion are critical global problems due to their adverse effects on agricultural productivity, the environment, and their impact on food security and quality of life. In recent years, the study of the effect of soil microorganisms on soil degradation in dry areas and saline soil on various components of soil stability and stabilization has attracted the attention of many researchers. In the present research, it has tried to present new biological solutions and methods in compliance with the standards for curbing land degradation based on surface inoculation of soil-borne cyanobacteria on the surface of saline and alkaline soil. This research was done based on the natural conditions of the soil in the field under study and the evaluation of the potential effect of the inoculation of local soil cyanobacteria on the stability and stabilization of the saline and sodium soil surface using image processing. Materials and Methods: In this regard, the biologically studied soil was prepared from saline and erosion-sensitive lands from the Incheh Borun region in Golestan Province, Iran. Then, the most suitable cyanobacteria in the mother soil were identified, selected, purified, and propagated in two different soil salinities with two repetitions on prepared plots with dimensions of one in one in the study area. In order to maximize the effect of cyanobacteria in the soil environment, after 60 days of inoculation of cyanobacteria on the soil surface, in order to process the image with MATLAB software with different algorithms, the surface of the plots was photographed. Results: The results obtained from visual observation showed that the morphometry of soil surface in soil with low and high salinity, the surface of the soil treated with cyanobacteria was less swollen, and soil particles were mixed than the surface of the control treatment. According to the results obtained from the software, the value of the standard deviation of the pixels and the entropy of the images obtained from the image processing showed in the treatments with a lower salinity level compared to the treatments with a higher salinity level. The mean value of the standard deviation of the pixels of the images in the treatment inoculated with cyanobacteria has decreased by 37.36% and 14.55%, respectively, compared to the control treatment significantly (P<0.01). In addition, the mean entropy of the images in the treatment inoculated with cyanobacteria decreased by 9.18% and 3.04%, respectively, compared to the control treatment in a non-significant manner (P>0.01). Conclusion: According to the results, it can be said that the inoculation of cyanobacteria on the surface of saline soil can be considered to increase stabilization and reduce the degradation of soil grains on the soil surface. The results of the present study can be therefore considered as a bioengineering approach for soil stabilization in saline watersheds, which ultimately provides the basis for water, food, and environmental security. [ABSTRACT FROM AUTHOR]

The life cycle of barnacles usually consists of two stages: the free-swimming larval stage and the stationary stage. Their larval stage has 6 stages. Considering that plant essential oils showed anti-algae properties in previous studies, in this study, the toxicity of this essential oil was investigated on different stages of barnacle larvae of A. amphitrite species. Because they should not have a negative effect on the food chain. Also, in order to evaluate the toxicity effects of Z. multiflora essential oil on barnacle larvae as a study model. This test was performed based on the determination of LC50 in a 24-hour period on different stages of barnacle larvae, in such a way that in 24-well plates of each stock, 6 concentrations of 50, 25, 12.5, 6.25, 3.125, 1.5 μg/ml was prepared, then 1 ml of sea water and 10 barnacle larvae were added to each well and the number of dead and alive was checked by loupe. The obtained results showed that the LC50-14.198 μg/ml in the (VI(stage of and the LC50-36.91 μg/ml in the)II(stage have a significant difference. Also, this plant essential oil showed a toxic effect on barnacle larvae at concentrations higher than 20 g/ml. But in general, the use of this herbal essential oil has significant biological activity due to having carvacrol as the main component of the essential oil. Also, by having different compounds such as phenolic, terpenoids and alkaloids, it can be a pioneer in the development of practical and bio-compatible with eco-management goals in low concentrations. [ABSTRACT FROM AUTHOR]

In this study, the relationship between dissolved oxygen reduction in the Gulf of Oman and changes in effective factors such as temperature and thermal stratification, exchanges with nearby water bodies, biological activities, chlorophyll-a concentration, and primary production was studied. The data used in this research were extracted from the measurement data available on global sites such as the World Ocean Atlas and SeaWiFS and MODIS satellite images. Comparing the average annual DO profiles in the Gulf of Oman showed a decrease in the upper 1000 m layer in 2010 compared to 1960. The DO reduction in the surface mixed layer was 0.4 mg/l and reached 3.7 mg/l at 100 m depth. At depths more than 100 m, the amount of change decreased and reached 0.1 mg/l at 1000 m. Due to the deoxygenation, the thickness of the surface layer with DO˃2 mg/l decreased from 150 m to 80 m. The results demonstrated that the drop in DO in the surface mixed layer was consistent with the decrease in gas solubility caused by the temperature increment in this layer. Regarding the severe reduction of DO in the layer below the surface mixed layer, it was shown that the strengthening of thermal vertical stratification and intensification of thermocline (0.01°C/m increase in thermal gradient) were the most important factors. [ABSTRACT FROM AUTHOR]

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 that except 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. [ABSTRACT FROM AUTHOR]

Cyanobacterial blooms cause huge and irreparable financial losses to fish farmers every year. One of the most effective methods for managing water cyanobacterial bloom is biological control by adding pathogenic agents to break down cyanobacterial cells. Therefore, this study investigated the possibility of using Pseudomonas putida bacteria to control the bloom of cyanobacteria Chroococcus sp., Oscillatoria sp., Microcystis sp. and Gloeocapsa sp., isolated from fish Culture ponds was done in the laboratory. The results of this study showed that Pseudomonas putida bacteria have a significant effect on controlling all 4 cyanobacterial species. So, for the cyanobacterium Chroococcus sp. In the experimental group containing 106 CFU/ml of Pseudomonas putida bacteria, there was a moderate 80.7% reduction and also in the group containing 104 CFU/ml of this bacterium, there was 63.1% reduction compared to the control group models on the 10th day. Also, for the cyanobacterium Oscillatoria sp. at the 10th day, 78.9% reduction occurred in 104 CFU/ml and 87.7% in 106 CFU/ml. Next, for the cyanobacterium Microcystis sp. On the tenth day, there was 61.7 percent decrease in the group containing 104 CFU/ml and 70.5 percent decrease in the group containing 106 CFU/ml of Pseudomonas putida bacteria. Finally for the cyanobacterium Gloeocapsa sp. A decrease of 72.3% was observed in the experimental group containing 104 CFU/ml and an 83% decrease in the group containing 106 CFU/ml. Although the control group show an increase of 37-78 percent (P<0.05). The results of this research showed that the bacterium Pseudomonas putida has a high efficiency in controlling the bloom of cyanobacteria. [ABSTRACT FROM AUTHOR]

Wetlands, as fragile water sources, are constantly affected by climate change and human activities. Recently, human intervention and the reduction of surface water in the catchment area of Lake Urmia have altered the microflora and physicochemical parameters of the wetlands, which need to be investigated. Results showed that phytoplankton populations of Darga-Sangi wetland consisted of Chlorophyta (2 classes, 10 families, and 22 genera), Cyanobacteriata (1 classes, 3 families, and 4 genera), Streptophyta (1 classes, 2 families, and 2 genera), Ochrophyta (2 classes, 2 families, and 2 genera), and Basillariophyta (4 orders, 6 families, and 10 genera). In addition, pH value, Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) were investigated. The highest amount of BOD5 of Darga-Sangi wetland was estimated to be between 78 and 98 mg/l, while the highest amount of COD was 159 and 198 mg/l during the summer season. The results indicate that the high influx of organic and mineral substances into the wetland has affected its enrichment which resulted in blooming of microalgae and hence, rising ecological concerns. The bacterial load in this wetland puts it in an unfavorable condition, which can be dangerous for native and migratory organisms. [ABSTRACT FROM AUTHOR]

The aim of the present study was to identify the phytoplankton species which producing domoic acid and okadaic acid toxins in coastal waters of Banar Abbas city, and to determine the concentration of domoic acid and okadaic acid toxins in water and shellfish samples.Water sampling was performed in winter 2015 and summer 2016 from coastal areas overlooking the discharge of municipal and industrial effluents. Shellfish were collected from the coasts of Bandar Abbas and Bandar-e- Lengeh. Phytoplankton toxins were measured by kit method and instrumental analysis based on ELIZA method.Pseudonitzschia delicatissima, Pseudo-nitzschia pungens and Pseudo-nitzschia seriata were identified in the production of domoic acid, while Dinophysis caudate and Prorocentrum Lima were recorded as okadaic acid producers in the coastal waters of Bandar Abbas. Water-soluble okadaic acid showed significantly higher concentrations than domoic acid. Instudied shellfish samples (Circenita callipyga, Barbatia candida, Telescopium telescopiumandThalessa savignyi), the measured concentrations of okadaic acid ranged from 59.8 ± 2.38 to 121.96 ± 28.25 μg / kg. This value for domoic acid was from 0.85 to 83.59 ± 38.72 μg / kg.Compared to the guideline values, the observed concentrations of okadaic acid and domoic acid toxins in the studied shellfish were lower than the allowable level. But this value was recorded for the water-soluble domoic acid above the allowable value, which requires continuous monitoring to achieve the quantitative and qualitative pattern of phytoplankton toxins in order to support the safety of the marine ecosystem users in Hormozgan province. [ABSTRACT FROM AUTHOR]

A 3D current and water level forecasting system is developed for the whole Persian Gulf in this study, in order to offer a reasonable response for the needs to provide a better understanding of coastal and gulf-scale hydrodynamic processes in this important body of water. There are a couple of research attempts published during the past decades on the hydrodynamics and circulation of the Persian Gulf; however, most of them were concentrated on the coastal and relatively shallow water areas and presented reasonable results. Hence, this study aims to improve model performance in deep water areas while the accuracy of tidal and wind-driven current parameters in shallow water results is acceptable. The most important driving forces, including tides and surface winds, are taken into consideration in simulations, in order to provide relatively accurate estimations of hydrodynamic parameters in the Persian Gulf. For water level and current three-dimensional simulations, FVCOM numerical open-source model is applied and run for some time periods in which field observations are available for both current specifications and water levels in the Persian Gulf. The open boundary data are adopted from OTPS global model and the input wind field data are applied from WRF wind modeling over the whole body of water. The model results were calibrated for a number of parameters selected in an extensive sensitivity analysis program and optimum values are selected for the under-study parameters. A comprehensive set of field measurements is collected, whose main objective is to provide sufficient and reliable input data for current simulations in the Persian Gulf in both deep and shallow areas. The collected survey parameters are mainly focused on: vertical profiling of current speed and direction; mid‐depth current speed and direction measurements; tidal (water level) measurements; and wind measurements. The data covers a wide range of spatial distribution in the Persian Gulf, including near-shore and offshore areas as well as a wide range of water depth values. In this study, the obtained water level and current model results are verified against collected field observations, both in shallow and deep water areas and near-shore and offshore regions. Consequently, the optimum settings for obtaining accurate model results in both shallow and deep water areas are reported. The results of this research are of great help to understand the hydrodynamics of the Persian Gulf and provide a basis for more accurate estimations of forecasted current and water level parameters over the study area. [ABSTRACT FROM AUTHOR]

Background: Marine neurotoxins as of Marine biotoxins are natural toxins that produced mainly by dinoflagellates, diatoms and several species of invertebrates and fish. Marine poisoning results from the ingestion of marine animals contain these toxins and causes considerable adverse effects. Materials and methods: This review provides some facts about the structures of marine neurotoxins, their molecular target and pharmacology, analytical methods for their detection and quantitation, diagnosis and laboratory testing, clinical manifestations, as well as prevention and treatment, if were obtainable. Furthermore, we focus on marine poisoning and various associated neurological syndromes like ciguatera, tetrodotoxin poisoning, and paralytic shellfish poisoning, after ingestion of the common marine toxins. Results: A number of neurotoxins that prescribed according to their potency (LD50) are: Maitotoxin, Ciguatoxins and Palytoxin, Tetrodotoxin and Saxitoxin, Brevetoxins, Azaspiracid, Yessotoxin, Cooliatoxin, Domoic acid and Conotoxins, Respectively. The primary target of most marine neurotoxins is voltage gated sodium channels and the resulting block of ion conductance through these channels. Moreover, these compounds interact with voltage-gated potassium and calcium channels and modulate the flux of stated ions into many cell types. As well, the target recognized for palytoxin is the Na+-K+/ATPase. Conclusion: Results of reviewed studies revealed that, the Ciguatera is the commonest syndrome of marine poisoning, but is rarely lethal. Puffer fish poisoning results from the ingestion of fish containing tetrodotoxin and paralytic shellfish poisoning are less common, but have a higher fatality rate than ciguatera. Despite their high toxicity, no much research has been done on some of the toxins, like maitotoxin. In addition, there have remained unknown the pharmacological effects, mechanism of action and molecular target of some toxins such as Cooliatoxin and Ostreotoxins, Which could be the subject of the research in Future, or perhaps a new generation of drugs. [ABSTRACT FROM AUTHOR]