IFREMER (French Research Institute for Exploitation of the Sea), Laboratory of Biogeochemistry of Organic Contaminants, Rue de L'Ile D'Yeu, BP 21105, 44311, Nantes Cedex 3, France.
StatSC, ONIRIS, INRA, 44322, Nantes, France.
Environ Res. 2020 Sep;188:109761. doi: 10.1016/j.envres.2020.109761. Epub 2020 Jun 10.
Tuna and billfish are large pelagic fish of ecological importance in open oceans. As top predators with a long lifespan, they are prone to exposure to various contaminants such as persistent organic pollutants (POPs) and contaminants of emerging concern. In this study, three pollutant families were investigated, including polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and perfluoroalkyl substances (PFASs), including perfluorooctane sulfonate (PFOS) and perfluorocarboxylic acids (PFCAs). Contamination was investigated in individuals from three tropical tuna species, namely bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis) and yellowfin (Thunnusalbacares) tunas and the billfish swordfish (Xiphias gladius), collected from various areas of the western Indian Ocean (WIO) in 2013-2014. Contamination levels and profiles were examined in fish muscle, together with biological parameters (fish length / age, sex, lipid content) and ecological tracers (carbon and nitrogen stable isotopes). POP levels were low in all species in comparison to other locations worldwide, revealing a low impact of anthropogenic organic contaminants in the WIO. A predominance of OCPs (especially DDTs) versus PCBs was highlighted in all species; PFASs were predominant over chlorinated POPs in tunas. Among the studied PFASs, long-chain PFCAs were found to prevail over PFOS in all species. Organic contaminant profiles differed across species according to their foraging habitat; swordfish and bigeye tuna, which both feed in deep oceanic layers, showed similarities in their contaminant profiles. Geographically, the distinct DDT profiles of fish from the Mozambique Channel suggested an exposure to different DDT sources, in line with regional use of this insecticide and coupled with an extended residence time of fish in the Channel. To our knowledge, the data presented here are among the first obtained for legacy and emerging organic contaminants in various species of large pelagic predators from the WIO.
金枪鱼和旗鱼是海洋中具有重要生态意义的大型远洋鱼类。作为具有长寿命的顶级掠食者，它们容易接触到各种污染物，如持久性有机污染物（POPs）和新兴关注的污染物。在这项研究中，研究了三种污染物家族，包括多氯联苯（PCBs）、有机氯农药（OCPs）和全氟烷基物质（PFASs），包括全氟辛烷磺酸（PFOS）和全氟羧酸（PFCAs）。在 2013 年至 2014 年间，从印度洋西部（WIO）的不同地区收集了三种热带金枪鱼（大眼金枪鱼、鲣鱼和黄鳍金枪鱼）和旗鱼（剑鱼）个体，研究了它们的污染情况。在鱼类肌肉中检查了污染水平和分布情况，同时还检查了生物学参数（鱼的长度/年龄、性别、脂肪含量）和生态示踪剂（碳和氮稳定同位素）。与世界其他地区相比，所有物种的 POP 水平都较低，这表明 WIO 中人为有机污染物的影响较低。所有物种中都以 OCPs（特别是滴滴涕）为主，而以 PCBs 为主；在金枪鱼中，PFASs 比氯化 POPs 更为普遍。在所研究的 PFASs 中，长链 PFCAs 比所有物种中的 PFOS 更为普遍。根据其觅食栖息地，研究物种的有机污染物分布不同；在深海层觅食的旗鱼和大眼金枪鱼在污染物分布上具有相似性。在地理上，莫桑比克海峡鱼类的独特滴滴涕分布表明它们接触到了不同的滴滴涕来源，这与该杀虫剂在该地区的使用情况相符，并且鱼类在海峡中的停留时间延长。据我们所知，这里提出的数据是首次获得的有关印度洋西部各种大型远洋掠食者的传统和新兴有机污染物的数据。
