The Properties And The Relationship Of Microplastic Pollution In Mussels And That In Their Living Water In China

Microplastics can be produced by crushing or other processes in the ocean.Because of their stable chemical properties,microplastics can exist in the marine environment for hundreds of years.Nowadays,microplastic pollution is increasingly becoming a severe environmental concern worldwide.Microplastics have been found in many marine organisms due to the plastic pollution within marine environments.Many exposure experiments have also shown that marine organisms suffer from microplastics they ingest.However,the relationship between microplastics in organisms and that in their living environment is still poorly understood.Besides,there are few exposure experiments using microplastics with environmental characteristics.In this paper,all the above problems are studied,and the main conclusions are as follows:We investigated microplastic pollution including adundance,size,type and chemical compositon in the water and the mussels(Mytilus edulis,Perna viridis)at 25 sites along the coastal waters of China.Microplastics varied from 0.9 to 4.6 items/g in mussels and from 0.68-6.44 items/L in water.A positive linear correlation was observed between the abundance of microplastics in the surrounding water and in the mussels(p<0.05).It proved that mussels can be used as indicator organisms for the detection of environmental microplastic pollution.Fibers were the dominant microplastics.The most common composition of microplastics was polyester.There are size differences of microplastics between mussels and surrounding waters(p<0.001).Micropalstics in smaller sizes are more likely to be ingested by mussels.According to the results of the investigation of marine environmental,exposure experiments were carried out using microplastics with environmental characteristics including size,shape and chemical composition.From our experiment,the higest shape of microplastic in mussels was the fiber,and the higest composition was the polyester,which was consistent with our field investigation.The size distribution in exposure experiment also showed the same results as field investigation.However,the relative abundance in exposure experiment didn't match the results in field investigation.Therefore,we suggest to select microplastics with environmental characteristics instead of with environmental concentrations for the indoor exposure experiment.In order to describe the characteristics of microplastics more intuitively and to analyze the correlation of integrated characteristics of microplastics in the water and mussels,we tried to establish the environmental characteristic spectrum library of microplastics.Based on genetic evolution tree and clustering,we established the spectrum library by R language.According to the comparison between mussels and water,the pairwise comparisons with a correlation over 0.5 composited 69.30%,which indicated a general good correlation of microplastics between mussles and their surrounding waters.It proved that multi-characteristics of microplastics of mussles can accurately reflect the microplastic pollution in water,which further indicated that mussles could be used as an indicator for microplastic pollution.Through the above researches and discussions,they can proved that mussels can be used as indicators of marine microplastics pollution,not only from the perspective of abundance,but also from the perspective of comprehensive characteristics of microplastics,such as size,shape,color and chemical composition.The exposure experiments using microplastics with environmental characteristics can simulate the field to some extent,such as the size distribution,which showed the same patterns with the field.However,how to simulate and explain the phenomenon of the field need further exploration.