Centre d'Études Biologiques de Chizé (CEBC), UMR 7372 CNRS-La Rochelle Université, 79360, Villiers en Bois, France.
Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, 17000, La Rochelle, France.
Arch Environ Contam Toxicol. 2021 Jul;81(1):15-24. doi: 10.1007/s00244-021-00846-y. Epub 2021 Apr 26.
Mercury (Hg) is a global environmental contaminant that affects ecosystems. It is known to biomagnify through food webs and to bioaccumulate especially in the tissues of top predators. Large-scale comparisons between taxa and geographic areas are needed to reveal critical trends related to Hg contamination and its deleterious effects on wildlife. Yet, the large variety of tissues (keratinized tissues, internal organs, blood) as well as the variability in the units used to express Hg concentrations (either in wet- or dry-tissue weight) limits straightforward comparisons between studies. In the present study, we assessed the moisture content that could influence the total Hg (THg) concentrations measured in several tissues (claws, scutes, total blood, and red blood cells) of three caiman species. We evaluated the moisture content from the different tissues to provide information on THg concentrations in various matrices. Our results show a difference of THg concentrations between the tissues and intra- and interspecific variations of moisture content, with the highest THg values found in keratinized tissues (scute keratinized layers and claws). For the three species, we found positive relationships between body size and THg concentration in keratinized tissues. In the blood, the relationship between body size and THg concentration was species-dependent. Our results emphasize the need for a standardized evaluation of THg concentration and trace elements quantification based on dry weight analytical procedures. In addition, the use of both blood and keratinized tissues offers the possibility to quantify different time scales of THg exposure by non-lethal sampling.
汞 (Hg) 是一种全球性的环境污染物，会影响生态系统。它通过食物链而生物放大，并在食物链顶端的捕食者的组织中特别生物累积。需要在分类群和地理区域之间进行大规模比较，以揭示与 Hg 污染及其对野生动物的有害影响相关的关键趋势。然而，大量的组织（角质组织、内部器官、血液）以及表达 Hg 浓度的单位（湿组织或干组织重量）的可变性限制了研究之间的直接比较。在本研究中，我们评估了水分含量，这可能会影响三种凯门鳄物种的几个组织（爪子、鳞片、全血和红细胞）中总汞 (THg) 浓度的测量。我们评估了不同组织的水分含量，以提供有关各种基质中 THg 浓度的信息。我们的结果显示，组织之间的 THg 浓度存在差异，以及水分含量的种内和种间变化，角质组织（鳞片角质层和爪子）中的 THg 值最高。对于这三个物种，我们发现角质组织中 THg 浓度与体型之间存在正相关关系。在血液中，体型与 THg 浓度之间的关系取决于物种。我们的结果强调了需要基于干重分析程序标准化评估 THg 浓度和痕量元素定量。此外，血液和角质组织的使用都提供了通过非致死性采样定量不同时间尺度的 THg 暴露的可能性。
