西太平洋海斗深渊区沉积物和钩虾中持久性有机污染物的分布特征和来源示踪

The hadal trench (>6000 meters deep) has been considered as pristine environments far from anthropogenic influences. However, a recent study reported extraordinary levels of persistent organic pollutants (POPs) in the endemic amphipod fauna from two of the deepest ocean trenches (Mariana Trench and KermadecTrench). These hardly degradable and easily enriched contaminants may be seriously harmful to the ecosystem at the hadal. Therefore, it is urgent to have more knowledge on whether there are other POPs in gammarideas or similar pollution in other trenches and on the origin and distribution of these high-concentration POPs if any. Thus, this project will analyze sediments and gammarideas samples from Mariana Trench, New Britain Trench, and Mussau trench in the Western Pacific Ocean. GC×GC-TOFMS, LC-MS/MS, GC-MS/MS will be utilized to screen the POPs in the hadal trenches and identify their composition and distribution in the sediments and gammarideas. The pollution characteristics of typical POPs will be revealed. Through receptor-model with feature of chirality, the source and metabolic conversion of POPs will be recognized. The proposed project has great implications for understanding the organic pollution in hadal zones.

水深大于6000米的深渊通常被认为是一片远离人类影响的原始净土。然而，最新研究表明马里亚纳海沟与克马德克海沟的钩虾体内存在高含量持久性有机污染物(POPs)。这些难降解易富集的POPs将给深渊区脆弱的生态系统带来严重威胁。关于这些钩虾体内是否存在其他类型的POPs，其它海沟深渊区是否有相似的污染，以及这些高浓度POPs的来源和传播机制等关键科学问题有待深入探究。申请项目拟以已有西太平洋马里亚纳海沟、新不列颠海沟、玛索海沟三个深渊区海底沉积物和钩虾样品为研究对象，利用GC×GC-TOFMS、LC-MS/MS、GC-MS/MS等定性筛查深渊区POPs类型，定量查明其组成与分布，揭示深渊区典型POPs的污染特征，并通过浓度和组成特征比对、多元统计等受体模型分析，结合手性特征，探讨深渊区POPs的来源及在钩虾中的代谢转化，深入认识海斗深渊区有机污染现状及其地球化学过程，为深渊科学提供一些新认知。

海斗深渊通常被认为是一片远离人类影响的原始净土。最新研究却表明深渊区域已受到各种污染，但缺少对污染物在深渊中环境行为、富集影响因素和污染来源解析。本项目针对西太平洋马里亚纳海沟、新不列颠海沟和玛索海沟中沉积物和钩虾开展海沟持久性有机污染物（POPs）赋存及来源研究。项目同时采集近海、远洋、马里亚纳海沟表层水体浮游生物开展POPs来源研究。结果表明，1）深渊沉积物存在较轻的POPs污染，新不列颠海沟污染大于马里亚纳海沟和玛索海沟。污染水平一定程度上受总有机碳（TOC）影响。深渊沉积物POPs污染源自海表面输入，且存在非工业多氯联苯（PCBs）污染；2）深渊钩虾POPs污染较为严重，主要受区域和物种影响。马里亚纳海沟钩虾中有机氯农药（OCPs）和多氯联苯（PCBs）富集程度大于玛索海沟和新不列颠钩虾。钩虾Alicella gigantea污染富集能力大于钩虾Hirondellea gigas。生物-沉积物富集因子（BSAF）和δ13 C同位素结果表明钩虾中POPs来源于与上层生物发生物质交换，而非直接来自于生存环境的沉积物中。本项目的研究结果揭示了深渊区生物和非生物介质中有机污染现状、主导因素、污染物在介质中的传递过程和环境行为，并为揭示污染来源提供理论依据。