南极生物粪对汞的生物放大作用  

Biomagnification of Hg in antarctic scats

作　　者：尹雪斌[1] 孙立广[1] 刘晓东[1] 朱仁斌[1] 

机构地区：[1]中国科学技术大学极地环境研究室,合肥230026

出　　处：《生态学报》2004年第3期630-634,共5页Acta Ecologica Sinica

基　　金：国家自然科学基金重点资助项目( 40 2 31 0 0 2 );国家自然科学基金资助项目 ( 40 0 76 0 32 )~~

摘　　要：首次报道了南极地区金图企鹅、阿德利企鹅、黑背鸥和巨海燕 4种海鸟 ,以及象海豹、威德尔海豹、毛皮海狮等 3种海豹新鲜粪便中的全 Hg含量 ,并对比了该区风化土壤的 Hg含量 ,其中 Hg含量水平依次为 :土壤背景值 <黑背鸥粪 <金图企鹅粪 <阿德利企鹅粪 <威德尔海豹粪 <象海豹粪 <巨海燕粪 <毛皮海狮粪 ,可见 ,相对于背景土壤生物粪明显富集 Hg元素。此外 ,结合上述粪便样品的 δ15 N测定结果 ,讨论了南极生物粪对 Hg的生物放大作用。研究表明 ,随着 δ15 N升高 ,即生物营养级的升高 ,其粪便的全 Hg含量有逐步增高的趋势 ,这证实了生物粪和生物肌体一样存在对 Hg的生物放大作用。文中还对南极阿德雷岛一个经过企鹅粪污染的 Y2湖泥芯剖面上 15个样品的 2 6种元素进行了聚类分析 ,结果表明 ,沉积物中的汞和企鹅粪的标型元素具有同源性 ,即沉积物中的汞主要是由企鹅粪带入的 ,由于生物粪对汞的生物富集作用 。Mercury (Hg) is a well known global contaminant. 98% of atmosphere mercury exists in the form of Hg^0. Due to its chemical inertness, vaporizable nature and a low solubility in water, Hg^0 has a long atmospheric residence time of about 1 year, allows the long range atmospheric transport and has global distribution^([1^3]). Bargagli et al. discussed the biomagnification of mercury in an Antarctic marine coastal food web. In this paper, we report Hg concentrations and δ^(15)N in the fresh scats of four kinds of Antarctic sea birds and three kinds of seals. The Hg concentrations of these scats have the order: weathering soil<black-backed gull (Larus dominicanus dominicanus)<Gentoo Penguin (Pygoscelis Gentoo)<Adelie Penguin (Pygoscelis adelie)<Weddell seal (Leptonychotes Wedellii)<elephant seal (Mirounga leonina)<Southern giant petrel (Macronectes giganteus)<fur seal (Arctocephalus gazella). All the scats have a significantly higher Hg concentration than the weathering soil, indicating a strong bioconcentration of Hg in them. The average Hg concentration of 473ng/g (on dry weight basis, d.w.) in seal scats is remarkably higher than that of 189ng/g (d.w.) in seabird scats. The Hg level in Southern giant petrel scat has a very high value of 605±15ng/g (d.w.), because of his scavenging of other birds/mammals and opportunistic/generalist feeder. Meanwhile, a positive correlation (r=0.363, n=8) between δ^(15)N, which is related to animal trophic level, and Hg concentrations is observed, confirming a similar biomagnification of Hg in animal tissues. We also performed clustering analysis on the concentrations of 26 elements in lake sediments amended by penguin droppings from Ardley Island, Antarctica. The results show that Hg element and the typical bio-elements in the sediments (such as, Sr, S, P_2O_5, Se, Ba, Ca, Cu, Zn) are of the same origin, indicating that the bioconcentration of Hg in penguin droppings led to the rise of Hg in lake sediments through the transporting and mixing of penguin droppings.

关 键 词：南极地区 生物粪 汞 生物放大 生物富集 企鹅 湖泊沉积物 重金属污染 

分 类 号：X171[环境科学与工程—环境科学]