Toxic Effects Of BDE-47on Two Marine Copepods

In this paper, BDE-47was chosen as the research object pollutants, andEurytemora pacifica and Tigriopus japonicas were used for experimental study. Anexperiment was aimed to the ingestion, metabolism (oxygen consumption rate andammonia excretion rate), reproduction and development, antioxidant defense systemand DNA alkaline unwinding of BDE-47in E. pacifica and T. japonicas respectivelyunder static exposure with different concentrations. The goal is to research the toxiceffect and mechanisms of BDE-47to these two copepods. It provided the basic data todevelop the biological monitoring and ecological risk assessment (ERA) of PBDEs inthe marine environment. This paper can be divided into four parts:1、The acute toxicity of BDE-47on E. pacifica and T. japonicas was studied by themethods of acute toxicity test. The results of two copepods indicated that the96h-LC50values were57ug/L for E. pacifica and851ug/L for T. japonicas. It wasshown that BDE-47has higher toxicity to E. pacifica than T. japonicas.2、The study was conducted to determine the effects of BDE-47on ingestion rate,filtering rate, oxygen consumption rate and ammonia excretion rate of the twocopepods respectively. It turned out that the effects of these two copepods aboutenergy ingestion and metabolism could product different influences. BDE-47couldaffect the feeding of two copepods with a dose related effect. It could always promotethe feeding of E. pacifica in a moderate concentration, while the feeding of T.japonicas was declined in a high concentration. The variation tendency of ammoniaexcretion rate on E. pacifica as well as T. japonicas were both increased at first, andthen decreased. It seemed that BDE-47could promote the ammonia excretion rate ofthese two copepods under the different degree. The oxygen consumption rate of T.japonicas presented similar tendency to the ammonia excretion rate thatabove-mentioned, while the trend of oxygen consumption rate on E. pacifica wasrestrained obviously in high concentration. The energy intake and metabolism of T.japonicas was apparently higher than E. pacifica as a whole. 3、The experiment has conducted on the antioxidant response and DNA damage ofBDE-47on E. pacifica and T. japonicas respectively. The activities of SOD, GST,GPx, the content of GSH and MDA and the degree of DNA alkaline unwinding wereselected as the sublethal endpoints. The results of96h exposure showed that in E.pacifica, the activities of SOD was restrained throughout the experiment; the activitiesof GST and the content of MDA were very sensitive to BDE-47, since low levelexposure could cause distinct promotion; the variation trend of GSH and GPx weremore complicated than other endpoints. Its tendency curve was increased at first andthen decreased at low level, and at high level it was on the contrary; the degree ofDNA alkaline unwinding was always inferior to control groups, and steady declinedin0-36h, then the downtrend was not obviously. The studies about T. japonicas’96hexposure indicated that, the activities of SOD and GSH were both very sensitive toBDE-47, since the activities of SOD were inhibited first, then induced and inhibited atlast in the96h; the activities of GST was more sensitive at high level, since itsactivities was no significant difference at low level; the activities of GPx wasinhibited first then induced, and the content of MDA was quite the opposite; Thedegree of DNA alkaline unwinding was also lower than the control groups, andincreased at first and then decreased with the time.4、It was studied about development and reproductive of T. japonicas with the toxiceffect of BDE-47. The development time was prolonged from nauplius to adult in amoderate concentration. Contrast wih the control groups, the survival rates were bothdecreased at10d and24d in a high level of BDE-47.The number of nauplius wasdecreased obviously. The sex ratio was declined in a high concentration.