An Investigation Of Ecotoxicity Of Water Quality Based On Main Fishes In The Reservoir Area

BackgroundThe typical reservoir A in XXX city is a small and medium-sized reservoir with functions of water storage,irrigation,flood control and power generation.There are various incidents affecting water quality safety in the typical reservoir A,which have aroused wide attention from all walks of the society.Therefore,it has great significance to monitor the water environment quality of the typical reservoir A and grasp the current situation of water environment quality for the decision-making of water environment restoration.Chemical analysis methods are generally used in water environment monitoring,however,by which,only the types and contents of pollutants in the water can be detected,the potential toxic effects of water environment pollutants in the surrounding ecological environment,aquatic organisms and residents’ health can not be characterized.At present,biological monitoring is widely used in the toxicity evaluation of the water environment.Due to bio-markers have many characteristics:specificity,operability,early warning,universality and stability,the introduction of them in water environmental biological monitoring can reflect the degree of water pollution and evaluate the ecological risk of water environment.As fishes are directly contact with environmental water,and also as important members of the food chains and food web in the water environment,they can make response to the changes of water quality in the water environment timely.In particular,fishes can make early sensitive response to relatively low concentrations of water environmental pollutants.Therefore,fish is often selected as the monitoring objects in water quality monitoring.ObjectiveIn this study,I have collected five kinds of main fish in the typical reservoir A(including Labeo Rohita,Cirrhinus Molitorella,Red Tilapia,Oreochromis Niloticus,and Carassius Auratus)and the same fishes species in clean water source(the typical reservoir B)were collected as the control one.By comparing the genotoxicity and oxidative damage,the ecotoxicity status of water in the typical reservoir A was evaluated.MethodsAccording to the topography of the typical reservoir A,six sampling points were set up to collect fishes samples.The fishes in the upper reaches of the typical reservoir B were selected as the control one,and fishes of the same five species were collected.The fish blood cells were collected from the laboratory for micronucleus test and alkaline single cell gel electrophoresis assay.Compared with the control group,the micronucleus rate and DNA damage of the fish blood cells were analyzed.The superoxide dismutase activity,glutathione contents and malondialdehyde contents were measured in the liver,kidney,brain and gill of fish collected in the laboratory.The oxidative damage of fish was analyzed by comparing with the control group.Results1.During the spot investigation of the typical reservoir A,it was found that there were a lot of plastics,chemical fiber bags and other domestic garbage around the reservoir and in the bottom of the river,and the basic environmental sanitation needs to be improved.2.In micronucleus test and alkaline single cell gel electrophoresis assay,it was found that the blood cell micronucleus rate and DNA damage degree of fish samples in the typical reservoir A were significantly higher than those of the control group.It shows that Labeo Rohita was the most sensitive species to chromosome damage and DNA damage effects.3.By measuring the superoxide dismutase activity,glutathione contents and malondialdehyde contents,it can be found that there were significant differences in three indexes between the typical reservoir A and the control,that is,the fish lived in the typical reservoir A showed obvious oxidative damage effects.Conclusion1.The basic environmental sanitation of the typical reservoir A in XXX city needs to be improved;2.Water quality of the typical reservoir A in XXX city has obvious DNA damage and chromosome damage effects on fish in reservoir area;3.Water quality of the typical reservoir A in XXX city has obvious oxidative damage effects on fish in reservoir area;As a strategic drinking water source,the water quality status of the typical reservoir A in XXX city needs to be attached great importance by relevant departments,and the water quality restoration project should be put on the agenda.