The current study was performed to investigate the protective effects of dietary Haematococcus pluvialis (H. pluvialis) on the oxidative stress induced by arsenic in rainbow trout (Oncorhynchus mykiss). The fish (20.70 ± 0.09 g) were fed with H. pluvialis at the levels of 0.28, 0.56, and 1.12 g 100 g-1 diet for 60 days. Then, each group was divided into two subgroups. In one of the subgroups, fish were exposed to arsenic challenge at a level of 9.1 mg/L. The other subset was used as the negative control. After the 96 h of toxicity test, protein and lipid oxidative levels, antioxidant-relevant gene expression as well as several chemical factors, including pH and peroxide value and moisture content, were evaluated in the fillet samples. Results showed that feeding with H. pluvialis decreased the levels of pH, peroxide value, as well as protein and lipid oxidation levels in treatment groups. Besides, the expression of antioxidant genes was significantly increased in the groups administrated with H. pluvialis. Based on the results of this study, feeding H. pluvialis attenuated the oxidative stress induced by arsenic in rainbow trout fillet through improving the antioxidant defense system.As a new type of pollutant, microplastics are of emerging widespread concern, while amount of research done in freshwater environments and organisms is litter compared to that in marine. Following this reality, the categories of MPs in two economic freshwater fish at 25 sites from 11 cities in the north and west rivers of Guangdong province were documented. Here, 76 individuals belong Oreochromis niloticus and Cirrhinus molitorella were investigated and microplastics were found in the GITs of 43.4% and gills of 25%. The average abundances of microplastics have significant difference between Oreochromis niloticus (0.015 items/ g) and Cirrhinus molitorella (0.031 items/g), while no difference by individual (~1.9 items). The plastics were dominated by white in color (61%), fragment in shape (67%), and lass than 1 mm in size (74%). The spatial distribution of microplastics revealed that there are significant differences between different cities in average abundances, and the highest average abundances of MPs were found in Zhanjiang city (4.25 items/individual) and Guangzhou city (0.044 items/g), respectively. Our results fully proved that the microplastics was widely ingested by wild fish species and suggested that the abundance and distribution of microplastics are positively related with the development of economy, tourism, industry, agriculture, and fishery.Toxicity monitoring of environmental pollutants especially petroleum hydrocarbons as priority pollutants is an important environmental issue. This study addresses a rapid, sensitive and cost effective method for the detection of total petroleum hydrocarbons (TPHs) using Aliivibrio fischeri bioluminescence inhibition bioassay. At the first step, the optimum conditions including time, pH and temperature for growth of A. fischeri were determined. Then, two methods were used to evaluate the toxicity of petroleum compounds. In the first method, short-term (15 min) and long-term (16 h) toxicity assays were performed. In the second method luminescence kinetics of A. fischeri was investigated during 24 h. The results demonstrated the most appropriate time for the bacterial growth occurred 16 h after inoculation and optimum temperature and pH were found 25 °C and 7, respectively. Short-term and long-term toxicity did not indicate any toxicity for various concentrations of TPHs (30, 50, 110, 160, 220 mg/L). Considering the luminescence kinetics of A. fischeri the long-term assay was introduced as 6 h. The half maximal effective concentration (EC50) was achieved 1.77 mg/L of TPHs. It is concluded that the luminescence kinetics of A. Proteasome inhibitor fischeri can be a valuable approach for assessing toxicity of TPHs in aquatic environments.Duckweed (Landoltia punctata) is an ideal species to restore cadmium (Cd)-polluted waters due to its fast growth and easy harvesting. To understand its tolerance and detoxification mechanism, the Cd stress responses, subcellular Cd distribution and chemically bound Cd forms (especially protein-bound Cd) were surveyed in this study. L. punctata, a potential Cd bioremediation plant, was cultured hydroponically with Cd concentrations of 0.0, 0.5, 2.0, and 5.0 mg L-1 for 5 days. The results showed that the Cd content in L. punctata increased significantly as the Cd content increased. The majority of Cd was localized in the soluble fraction (23-55%) and the cell wall fraction (21-54%), and only 14-23% of Cd was located in cell organelles. Analysis of the Cd chemical forms demonstrated that the largest portion of Cd was found in 1 M NaCl extracts, followed by d-H2O and 2% HAc extracts, indicating that Cd was mainly bound to different proteins. Albumin- and globulin-bound Cd forms were predominant, together accounting for over 80% of the total protein-bound Cd in L. punctata. These results indicate that cell wall immobilization and vacuolar dissociation of Cd are possible primary strategies for Cd biosorption and detoxification in L. punctata, which occur mainly through chemical forms changes, especially the binding of Cd to proteins.Oil spills have an important threat to the ecological security and human health, for example the important oil field and coastal wetland Yellow River Delta is facing the dual problems of oil pollution and salinization. Therefore, the purpose of this study was to analyze the changes of soil microbial community and physicochemical properties, including pH value, total organic carbon (TOC), total petroleum hydrocarbons (TPHs) and electrical conductivity under the combined effect of petroleum and salinization. The soil properties results showed that the petroleum addition promoted the increase of TOC from 2.31 ± 0.59 mg/kg to 7.04 ± 0.42 mg/kg (r > 0.95, P 0.95), but it had no direct effect on other soil properties. It was found that the nitrate reducing bacteria Halorhodospiraceae with potential petroleum degradation ability and the anaerobic bacteria Lactobacilliceae appeared after adding crude oil. The salt tolerant bacteria Halobacilli and the stone oil degrading bacteria Immundisolidcharacter appeared in the high salt and low salt environments respectively.