三峡库区蓄水初期大宁河重金属食物链放大特征研究  

Biomagnification of Heavy Metals in the Aquatic Food Chain in Daning River of the Three Gorges Reservoir During Initial Impoundment

作　　者：余杨[1,2] 王雨春[1,2] 周怀东[1,2] 高博[1,2] 赵高峰[1,2] 

机构地区：[1]中国水利水电科学研究院水环境所,北京100038 [2]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《环境科学》2013年第10期3847-3853,共7页Environmental Science

基　　金：国家自然科学基金项目(51179205);国家水体污染控制与治理科技重大专项(2009ZX07104-001)

摘　　要：三峡库区蓄水后重金属在库区沉积物中累积,为了解由此带来的鱼类重金属富集放大风险,于2012年3月以库区支流大宁河为例,采集16种代表性鱼类,利用稳定同位素技术对鱼类间营养关系和Cr、Ni、Cu、Zn、Pb、Cd、As和Hg等重金属元素在食物链中的生物放大情况进行了研究.结果表明,大部分重金属在鱼体中处于较低水平,但在不同种类鱼体中含量差异显著.鱼体样品δ13C与鱼类生活水层关系密切,分布范围为-22.80‰^-28.97‰,水体上层鱼类δ13C值较低,而水体底层鱼类δ13C值较高;而δ15N受鱼类食性影响明显,范围为6.41‰~13.88‰.在食物链的传递过程中,鱼体Hg浓度随营养等级的升高而显著增大,但放大效率较低.除Hg外的金属元素与δ15N的关系均不显著,未出现明显生物放大.但小个体鱼类体内金属含量较高,存在潜在污染风险.Heavy metals have been accumulated in sediment after impoundment in the Three Gorges Reservoir （TGR）. In order to evaluate the risk of biomagnification of heavy metals, we investigated the trophic relationships and heavy metal concentrations in fish from a tributary within TGR. Sixteen fish species were collected from Daning River, and concentrations of eight heavy metal elements （Cr, Ni, Cu, Zn, Pb, Cd, As, and Hg） were determined, as well as the ratios of stable carbon and nitrogen isotopes. Results showed that most heavy metal concentrations were low in TGR, but changed significantly among different species. The δ13C values varied significantly among different groups （ -22.80‰- -28.97‰） ; while the 81SN values （6.41‰-13.88‰） varied based on their feeding types. A significantly trophic level-dependent increase was found in concentrations of Hg, indicating an overall biomagnification of Hg; but the increase of Hg concentration per trophic level was lower than that in previous studies. No tendency towards trophie-level enrichment was observed for other elements studied. However, a much higher heavy metal concentration was observed in small-sized fish samples, indicating a potential risk in environment.

关 键 词：三峡 大宁河 重金属 生物放大 稳定同位素 

分 类 号：X524[环境科学与工程—环境工程]