Evaluation of trophic magnification and ecological risk of persistent toxic substances by integration of bio-geochemistry and numerical analysis

我们分析了多氯联苯，溴化阻燃剂（PBDEs和六溴环十二烷）和微量元素积累在海洋生物在不同的营养级从日本和加利福尼亚州附近的开放沃茨，以评估其污染状况，生态效应和营养放大的食物网。在所调查的地区中，在濑户内海和宫城近海发现了大量六溴环十二烷污染。在濑户内海江豚中，肝吸虫感染个体体内PCBs浓度显著高于未感染个体，提示其可能存在免疫抑制。考虑到碳和氮同位素分析结果以及其他生物和物理化学参数，每个食物网的营养循环和物种结构以及生物体的异构体特异性代谢/排泄以及它们的营养级可以被认为是食物网放大的关键因素。

We analyzed PCBs, brominated flame retardants(PBDEs and HBCDs) and trace elements accumulated in marine organisms at various trophic levels from open waters around Japan and off-California to evaluate their contamination status, ecological effect and trophic magnification in the food webs. Among the areas surveyed, considerable contamination of HBCDs was found in the Seto-Inland Sea and off-Miyagi. In finless porpoises from the Seto-Inland Sea, concentrations of PCBs in liver trematodeinfected individuals were significantly higher than those in non-infected ones, implying their possible immune depression. Considering the results of carbon and nitrogen isotope analyses and other biological and physicochemical parameters, nutrients cycles and species structures of each food web and isomer specific metabolism/excretion by organisms as well as their trophic levels can be suggested as key factors for the food web magnification.