长江口潮滩湿地贝类污染物水平及评价

Assessment of the Pollutant Residual Levels of Benthic Shellfishes in the Tidal Flats of the Changjiang River Estuary

本文对2014-2016年在长江口潮滩采集的10份贝类样品污染水平进行评价,采集区域分别为崇明东滩、南汇边滩和金山边滩,评价方法分别采用单因子评价法和内梅罗综合指数法。研究结果表明,部分样品中Cd, Cr, Cu, Zn, Pb, As和Oil含量超过第一类海洋生物质量标准,所有样品中Hg, 666, DDTs和PCBs均未超标。近江牡蛎中Cd, Cu, Zn, Hg的标准指数远远高于缢蛏、泥螺和四角蛤蜊。贝类生物体中仅有As与沉积物中As具有显著相关性(P<0.05),其余污染物残留水平与采集区域的沉积环境均无明显相关性。贝类体内重金属Cd与Hg, Cu和Zn均具有非常显著相关性(P<0.01),表明Cu, Hg, Cd和Zn之间具有一定协同机制或共同的污染来源。以贝类污染水平评价,崇明东滩生态环境总体优于南汇边滩和金山边滩,但与2002-2003年的研究结果相比,崇明东滩的环境质量总体有所下降。

The pollutant residual levels of 10 shellfish samples collected in the tidal flats of the Yangtze River Estuary from 2014 to 2016 were evaluated.The samples were collected in the tidal flats of Chongming eastern shoal,Nanhui nearshore and Jinshan nearshore,respectively.The contents of Cd,Cr,Cu,Zn,Pb,As and Oil in some samples exceeded the first class of Marine Biological Quality(GB 18421-2001),and the contents of Hg,666,DDTs and PCBs in all samples did not exceed the standard.The pollution indices of Cd,Cu,Zn,Hg in Crassostrea ariakensis were much higher than those of Sinonovacula constrzcta(Lamarck),Bullacta exarata(Philippi)and Mactra veneriformis,Reeue.Only As in shellfishes was significantly correlated with As in sediments(P<0.05),while the other pollutant residue levels were not significantly correlated with the sedimentary environment of the same collection area.There was a significant correlation among Cd and Hg,Cu,Zn in shellfishes(P<0.01),indicating that Cu,Hg,Cd and Zn should have some synergy mechanism or a common pollution source.Generally,the ecological environment of Chongming eastern shoal was better than that of Nanhui nearshore or Jinshan nearshore,but the environmental quality of Chongming eastern shoal declined by comparison with that from 2002 to 2003.