Abstract：
There is considerable inconsistency in results pertaining to the biomagnification of PAHs in aquatic systems. Zooplankton specifically play an important role controlling the fate and distribution of organic contaminants up the food chain, particularly in large plateau reservoirs. However, it remains largely unknown how secondary factors affect the magnification of organic compounds in zooplankton. The present study assessed plankton species and nutrients affecting the trophic transfer of PAHs through the micro-food chain in plateau reservoirs, Guizhou Province China. Results show soluble ∑PAHs range from 99.9 - 147.3 ng L-1, and concentrations of ∑PAHs in zooplankton range from 1003.2 - 22441.3, with a mean of 4460.7 ng g-1 dw. Trophic magnification factors (TMFs) > 1 show biomagnifications of PAHs from phytoplankton to zooplankton. The main mechanisms for trophic magnification > 1 are 1) small Copepoda, Cladocera and Rotifera are prey for larger N. schmackeri and P. tunguidus, and 2) the δ15N and TLs of zooplankton are increasing with the increasing nutrients TN, NO3- and CODMn. As a result, log PAHs concentrations in zooplankton are positively correlated with the trophic levels (TLs) of zooplankton, and log BAFs of the PAHs in zooplankton are increasing with increasing TLs and log Kow. Temperature further enhances TMFs and biomagnifications of PAHs as noted by temperature related reductions in δ15N. There are also available soluble PAHs in the water column which are assimilated with increasing phytoplankton biomass within the taxa groups, diatoms, dinoflagellates and chlorophytes. Notable TMFs of PAHs in zooplankton in Guizhou plateau reservoirs are not significantly affected by phytoplankton and zooplankton biomass dilutions. The present study demonstrates the important roles of species selection, nutrients and temperature in the environmental fate of PAHs in freshwaters.
摘要：
与水生系统中PAHs的生物放大有关的结果存在相当大的不一致。浮游动物在控制食物链上有机污染物的命运和分布方面发挥着重要作用，特别是在大型高原水库。然而,次要因素如何影响浮游动物中有机化合物的放大倍数，目前还不清楚。本研究评估了浮游生物物种和营养物质影响PAHs通过高原水库微食物链的营养转移，中国贵州省。结果表明，可溶性∑PAHs的范围为99.9-147.3ngL-1，浮游动物中∑PAHs的浓度范围为1003.2-22441.3，平均值为4460.7ngg-1dw。营养放大因子(TMF)>1显示PAHs从浮游植物到浮游动物的生物放大。营养放大倍数>1的主要机制是1）小co足类，Cladocera和Rotifera是较大的N.schmackeri和P.tunguidus的猎物，2)浮游动物的δ15N和TLs随着营养元素TN的增加而增加，NO3-和CODMn。因此,浮游动物中的对数PAHs浓度与浮游动物的营养水平（TLs）呈正相关，浮游动物中多环芳烃的对数BAF随着TL和对数Kow的增加而增加。温度进一步增强了TMF和PAHs的生物放大作用，如温度相关的δ15N降低所示。水柱中也有可用的可溶性PAHs，这些PAHs随着分类单元内浮游植物生物量的增加而被同化，硅藻,鞭毛藻和绿藻。贵州高原水库浮游动物中PAHs的显著TMF不受浮游植物和浮游动物生物量稀释的影响。本研究证明了物种选择的重要作用，淡水中多环芳烃环境命运中的营养物质和温度。
