【摘要】 采用气相色谱-电子捕获检测器(GC-ECD)内标法定量测定了南极乔治王岛世袭栖息地海鸟(棕贼鸥、灰贼鸥、巨海燕、白眉企鹅)卵样中持久性有机氯污染物多氯联苯(PCBs)和有机氯农药(OCPs)残留量,研究探讨南极海洋食物链顶级生物体有机毒物积累水平探讨其环境意义。结果显示,卵样中有机毒物积累水平依次为:多氯联苯>滴滴涕>氯代苯>六六六。贼鸥卵样多氯联苯含量范围在91.9~515.5ng/g,滴滴涕56.6~304.4ng/g,氯代苯6.5~70.5ng/g,六六六<0.5~2.0ng/g;企鹅卵样多氯联苯含量范围在0.4~0.9ng/g,滴滴涕2.4~10.3ng/g,氯代苯6.0~10.2ng/g,六六六0.1~0.4ng/g;巨海燕卵样多氯联苯含量范围在38.1~81.7ng/g,滴滴涕12.7~53.7ng/g,氯代苯4.2~8.8ng/g,六六六0.5~1.5ng/g。研究结果还显示,不同种类海鸟卵样检出多氯联苯和有机氯农药均以七氯、六氯联苯、滴滴涕同系物(P,P′-DDE)和氯代苯化合物为主体。贼鸥、巨海燕卵样检出9种多氯联苯同系物(大小依次为PCB-180>PCB-153>PCB-194>PCB-138>PCB-118>PCB-170>PCB-101>PCB163>PCB-149)。贼鸥卵样七氯、六氯取代物的多氯联苯同系物含量在17.5~205.5ng/g占其总多氯联苯的62%;巨海燕卵样在14.5~30.5ng/g,占其总多氯联苯的69%;企鹅卵样检出5种多氯联苯同系物相对积蓄较低,其卵样之间变化相对稳定。对不同种类海鸟卵样的有机污染物数据进行统计分析,结果显示不同鸟种有机毒物积累水平的差异取决于不同鸟种的生态习性,如活动范围、迁徒距离、觅食习性以及巢址选择等,最主要是海鸟在海洋生态食物链中的位置,其食谱的宽窄,同时表明海鸟体内PCBs和OCPs积累通过食物链逐级加强的结果。有机毒物最高积累水平出现在棕贼鸥卵样中,灰贼鸥和巨海燕次之,企鹅最低。因为贼鸥不仅食性杂食谱宽,而且贼鸥与企鹅及其他小型海鸟之间存在着一定的捕食与被捕食的关系。南极海鸟卵样多氯联苯和有机氯农药的检出,是全球性有机氯污染又一新的重要证据。南极海鸟卵样中有机毒物的检出,揭示了人造有机污染物在南极鸟类代间转移的存在,它们在南大洋生态系统中的消除将会需要较长的时间过程,表明人类活动对南极生物圈与南极海洋环境的持久影响,南极是全球唯一无污染地区的价值正在丧失。更多还原

【Abstract】 Residue levels of polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs) in eggs of seabirds (Brown Skua Catharacta lonnbergi, South Polar Skua Catharacta maccormicki, Giant Petrel Macronectes giganteus and Gentoo Penguin Pygoscelis papua) breeding on King George Island, Antarctica, were measured using a gas chromatography-electron capture detector (GC-ECD) to determine accumulated organochlorine levels in taxa at the top of the marine food chain, and to consider their environmental significance. The results show that bio-magnification in levels of anthropogenic chemicals is taking place in the eggs of Antarctic seabirds and total concentrations can be arranged as ΣPCB>DDT>ΣHCB (hexachlorobenzene)>HCH (hexachlorocyclohexane). The concentration ranges of ΣPCB, DDT, ΣHCB and HCH in the eggs of skuas were 91.9～515.5ng/g, 56.6～304.4ng/g, 6.5～70.5ng/g and 0.5～2.0ng/g respectively; in the eggs of penguins ranges were 0.4～0.9ng/g, 2.4～10.3ng/g, 6.0～10.2ng/g and 0.1～0.4ng/g; and in Giant Petrel eggs they were 38.1～81.7ng/g, 12.7～53.7ng/g, 4.2～8.8ng/g and 0.5～1.5ng/g respectively. The results also indicate that PCB-180, PCB-153 and P,P′-DDE and HCB were the main components of the residues. Nine PCB congeners were found in the eggs of the skua and Giant Petrel (arranged as PCB-180>PCB-153>PCB-194>PCB-138>PCB-118>PCB-170>PCB-101>PCB-163>PCB-149); the concentration of PCB-180 and PCB-153 in the skua and Giant Petrel eggs were 17.5～205.5ng/g and 14.5～30.5ng/g, accounting for 62% and 69% of the ΣPCB respectively. Five PCBs were detected in the penguin eggs, in which HCB and P,P′-DDE concentrations were relatively higher. The original polluter data in seabirds eggs are studied by using statistical analysis. The result shows the differences in the mean accumulated organochlorines reflected the ecological habits of the seabirds, such as nesting areas, extent of movement in non-breeding periods, foraging areas and foraging methods, and the species’ positioning and interrelationships within the marine food chain. Importantly, the results show that an accumulation of PCBs and OCPs occurs progressively in the food chain. Thus the highest residue levels of PCBs were found in the eggs of the Brown Skua, while the lowest levels were in the penguins. Skuas have a wide-ranging diet, which also includes eggs and chicks of penguins, and this may be a factor in the bioaccumulation reported here. It is considered that, even without additional burdens, it would take a long time to eliminate this contamination in the Southern Ocean because of the transfer of these pollutants from one generation to the next.更多还原