Kwon Tae-Dong, Fisher Susan W, Kim Gene Wook, Hwang Haejo, Kim Jang-Eok
Department of Entomology, The Ohio State University, 318 West 12th Avenue, Columbus, Ohio 43210, USA.
Environ Toxicol Chem. 2006 Apr;25(4):1068-78. doi: 10.1897/05-180r.1.
Trophic transfer of polychlorinated biphenyl (PCB) congeners in zebra mussels (Dreissena polymorpha), round gobies (Neogobius melanstomus), and smallmouth bass (Micropterus dolomieu) were assessed in four sites along the south shore of the west and central basin of Lake Erie (all sites were in OH, USA). Total PCB levels in smallmouth bass (1,091-1,520 ng/g wet weight) and round gobies (118-256 ng/g wet weight) were similar among sites despite a west-to-east decrease in total PCB concentrations in zebra mussels (29-97 ng/g wet weight). At all sites, PCB body burden increased three- to fivefold at each successive trophic level, suggesting biomagnification in this nonnative food chain. Whereas fish species were dominated by the hexachlorine homologue, zebra mussels were dominated by penta- and hexachlorine homologues; the average degree of chlorination of PCBs was 56.1% for zebra mussels, 60.4% for round goby, and 59.9% for smallmouth bass bodies. Predictive structure-activity relationships based on chemical characteristics, such as the octanol-water partition coefficient (log K(ow)), had little predictive power on bioaccumulation and biotransformation of PCB congeners because of nonlinearity, threshold relationships, and species-specific differences. Calculated trophic transfer for the smallmouth bass-round goby linkage was higher than for the round goby-zebra mussel linkage. Only when PCB congeners were grouped by chemical structure first (vicinal [adjacent] H-atom position in the phenyl ring) were linear relationships achieved. It appeared that the chemical group to which each congener belonged influenced biotransformation more than species-specific (round gobies vs smallmouth bass) differences. Biotic changes at midtrophic levels, such as exotic species invasions, may have an increasingly important role in determining pollutant cycling and hence pollutant residues in top predators.
在伊利湖西部和中部流域南岸的四个地点（所有地点均位于美国俄亥俄州），评估了多氯联苯（PCB）同系物在斑马贻贝（多形饰贝）、圆口鲈（黑口新虾虎鱼）和小嘴鲈（小口黑鲈）中的营养级转移情况。尽管斑马贻贝中总PCB浓度从西向东呈下降趋势（湿重为29 - 97 ng/g），但各地点小嘴鲈（湿重1,091 - 1,520 ng/g）和圆口鲈（湿重118 - 256 ng/g）中的总PCB水平相似。在所有地点，每个连续营养级的PCB体内负荷增加了三到五倍，表明在这条非本地食物链中存在生物放大作用。鱼类物种以六氯同系物为主，而斑马贻贝以五氯和六氯同系物为主；斑马贻贝中PCB的平均氯化程度为56.1%，圆口鲈为60.4%，小嘴鲈为59.9%。基于化学特性（如正辛醇 - 水分配系数（log K(ow)））的预测结构 - 活性关系，由于非线性、阈值关系和物种特异性差异，对PCB同系物的生物积累和生物转化几乎没有预测能力。计算得出的小嘴鲈 - 圆口鲈食物链的营养级转移高于圆口鲈 - 斑马贻贝食物链。只有当首先按化学结构（苯环上邻位[相邻]氢原子位置）对PCB同系物进行分组时，才会出现线性关系。似乎每个同系物所属的化学基团对生物转化的影响大于物种特异性（圆口鲈与小嘴鲈）差异。中营养级的生物变化，如外来物种入侵，在决定污染物循环以及顶级捕食者体内的污染物残留方面可能发挥越来越重要的作用。
