Study On The Transmitting Characteristics Of Marine Microplastics Along The Food Chain

Marine plastic garbage and microplastics(<5 mm)have become a global environmental pollution problem and have been listed as the second largest scientific issue in the field of environmental and ecological science research by the United Nations Environment Assembly.They are widely detected in the marine environment and easily ingested by organisms and enter the food chain.They have potential health hazards to the marine ecosystem and human health.Based on the establishment of an economical and efficient plastic non-destructive microplastic extraction method,this study studied the microplastic occurrence characteristics of wild aquatic organisms in Liaodong Bay,and revealed the differences between microplastics in different species and trophic levels,and explored the transmission characteristics and rules of microplastics along food chain.The main research results are as follows:(1)The digestion efficiency of 10%KOH,30%H₂O₂,protease K,RIPA tissue lysate+protease K for 7 tissues such as muscle,stomach,intestine and gill of silver carp was compared and analyzed.Ten plastics were treated with the above schemes respectively.The quality,morphology,size and spectral characteristics before and after digestion were compared.The digestion efficiency of 10%KOH solution for all tissues was stable compared.For co mmon plastics without damage,the recovery of micro-plastics with large particles(3-5 mm)and small particles(200-1000?m)is100%and 88.89%-100%,which can be used as the reco mmended method to extract micro-plastics from biological tissues.(2)39 kinds of polymer plastics were detected in 8 invertebrate species in Liaodong Bay(Nereis succinea,Mactra veneriformis,Sinonovacula constricta(Lamarck),Neverita didyma,Rapana venosa(Valenciennes),Octopus ocellatus,Oratosquilla oratoria,Portunus trituberculatus.Among them,there are 22kinds of single-component polymers,10 kinds of two-component copolymers,and 7kinds of multi-component polymers or more.The main plastics were PET(24.74%),PE(24.40%),PP(8.93%),and PVAL(7.90%),with an average abundance of 1.31±1.38n/ind(0.25±0.40 n/g ww)and a detection rate of 65.0±14.0%,And microplastics are mainly fiber(35%-88%),and the fiber length is mainly distributed in the range of200-2000?m.(3)35 polymer plastics were detected in 6 species of vertebrates(Synechogobius ommaturus,Lateolabrax maculatus Mc Clelland,Liza haematochelia(Temminck et Schlegel),Pseudosciaena polyactis Bleeker,Cynoglossus semilaevis Gunther and Phoca largha)in Liaodong Bay,including 25 single-component polymers and two-component polymers.There are 7 kinds of copolymers and 3 kinds of polymers with three components and above.The main materials of the five fish species are PE(20.85%),PP(18.15%)and PET(15.83%).There was no significant difference in the intake abundance of fish gastrointestinal microplastics,and the gastrointestinal microplastic intake abundance was significantly higher than that of gills.The average abundance of individual fish(gastrointestinal and gill)was 3.41±2.37 n/ind,and the average abundance of gastrointestinal and gill was 2.30±1.91 n/ind(0.36±0.30 n/g ww)and 1.11±1.20 n/ind(0.30±0.32 n/g ww).Harbor seals are mainly made of PET(35.09%),PP(19.30%),and PAN/PAA(10.53%)in six types of tissues:stomach,anterior small intestine,posterior small intestine,large intestine,liver,and kidney.The abundance range of microplastics It is 0.1-0.48 n/g ww.The average detection rate of microplastics in six vertebrates was 95.78±5.44%,and the fibrous microplastics(36.17%-59.65%)were mainly distributed in the range of 200-2000?m.(4)Microplastics have a biomagnification effect from invertebrates to vertebrates.The biomagnification factor(BMF)of the average intake abundance of individual and unit mass of microplastics is 1.29 and 1.28,respectively.According to the 15N stable isotope method,the nutritional level of organisms is estimated.The abundance of individual microplastics produces a biological amplification effect in the food web.The trophic magnification factors(TMF)is 1.73.The average intake of individuals and the trophic level(TL)There is a positive correlation,but there is no obvious correlation between the abundance of microplastics per unit mass and nutritional level.