Study On The Enrichment Of Organochlorine And Bromide Of The Narrow-ridged Finless Porpoise In The East China Sea

In recent years,the persistent organic pollutants(POPs),such as polychlorinated biphenyls(PCBs)and polybrominated diphenyl ethers(PBDEs),have become a hot spot in the research of organisms.A variety of toxicity of these persistent organic pollutants have been reported to organisms.These POPs can deposit in marine environment with atmospheric circulation and water circulation.With migration and bioconcentration they will accumulate in the top predator through food chain in the marine environment.Therefore,besides commercial harvesting,fishery bycatch and habitat degradation,the exposure of POPs in the marine environment has become another serious anthropogenic threat to the survival and the sustainability of cetacean populations in the past decades.The present project aims to reveal the accumulation profile of representative PCBs and PBDEs accumulated in finless porpoises(Neophocaena asiaeorientalis)through detecting 7 PCBs homologues and 11 PBDEs homologues as well as new flame retardant alternatives BTBPE and TBB;to have a comprehensive risk assessment for finless porpoises.In the study,PCBs and PBDEs had a certain accumulation in the finless porpoises.However,the concentrations of BTBPE and TBB in flame retardant substitutes is low.The concentrations of ?7PCBs(wet weight)of all samples in the blubber were 17.43-1866.78 ng/g and the average concentrations was 379.79 ng/g.The result showed that the concentration PCB138 was the highest among the homologues of PCBs,followed by PCB101,153 and 180.Where PCB138 accounted for about 36%of the total PCBs.Through correlation analysis we had found that the accumulation concentration of PCBs had correlation with biological effects,such as body length,sex,tissues and reproductive process of the finless porpoise.Contrary to accumulation profile feature of male finless porpoise,the accumulation of organic pollutants in female porpoise decreases with the increasing length of the body.Besides,the accumulation of pollutants in male finless porpoise is generally higher than that of female.Therefore,we did do further research on the mother and calf dolphin of the PCBs accumulation profile.The result showed that there is a certain biological transfer phenomenon between the mother and calf dolphin,and the transfer rate can reach 16.86 per cent which revealed the reasons for the decreasing of organic pollutants in female adult dolphin to some extent.The concentrations of ?11PBDEs(wet weight)of all samples in the blubber were 8.38-75.53 ng/g and the average concentrations is 33.83 ng/g.However,the concentration of BTBPE do not reach the detection limit(<0.588 ng/g).The concentration of TBB was lower,and the highest concentration was lower than 4 ng/g.Among the homologues of PBDEs,the concentration BDE47 was the highest,followed by BDE154?BDE100 and BDE99.Where BDE47 accounted for about 36.45%of the total PBDEs.Through correlation analysis we had found that the accumulation of organic pollutants in female porpoise decreases with the increasing length of the body.Besides,the accumulation of pollutants in male finless porpoise is generally higher than that of female.Among the 19 species food resources of ridge finless porpoise,the maximum concentration of PCBs was 420.37 mg kg-1 in the Tapertail anchovy(coilia mystus),which was below the maximum allowable exposure dose(MACTRV),1006 mg kg-1.In addition,the RQ value of the risk entropy(RQ)is less than 1.Therefore,we determined that the bioaccumulation of PCBs in finless porpoise of Nantong has not yet been toxic to it.For PBDEs risk assessment,the reference value for the health effects of PBDEs on marine mammals was of 1500 ng/g.However,in our research,the maximum enrichment value of PBDEs in finless porpoise was 75.53ng/g.Therefore,we speculate that the bioaccumulation of PBDEs in narrow ridge finless porpoise is not yet harmful to its health.