School of Molecular and Life Sciences, Curtin University, Brand Drive, Bentley, Western Australia, 6102, Australia.
School of Earth and Planetary Sciences, John de Laeter Centre, Curtin University, Perth, Australia.
Environ Pollut. 2021 Apr 1;274:116547. doi: 10.1016/j.envpol.2021.116547. Epub 2021 Jan 23.
Wetland snakes, as top predators, are becoming globally recognised as bioindicators of wetland contamination. Livers are the traditional test organ for contaminant exposure in organisms, but research is moving towards a preference for non-lethal tissue sampling. Snake scales can be used as an indicator of exposure, as many metals bind to the keratin. We used laser ablation with inductively coupled plasma-atomic emission spectroscopy and mass spectrometry (LA-ICP-MS) to quantify the concentrations of 19 metals and metalloids (collectively referred to 'metals' hereafter) in Western tiger snake (Notechis scutatus occidentalis) scales from four wetlands along an urban gradient, and compared them to concentrations measured in captive tiger snake scales. We conducted repeat measures to determine the concentration accuracy of each metal using LA-ICP-MS. Concentrations in wild Western tiger snake scales were significantly higher than in reference tiger snake scales for most metals analysed, suggesting accumulation from environmental exposure. We compared the scale concentrations to sediment concentrations of sampled wetlands, and found inter-site differences between mean concentrations of metals in scales parallel patterns recorded from sediment. Four metals (Mn, As, Se, Sb) had strong positive correlations with liver tissue contents suggesting scale concentrations can be used to infer internal concentrations. By screening for a larger suite of metals than we could using traditional digestive methods, we identified additional metals (Ti, V, Sr, Cs, Tl, Th, U) that may be accumulating to levels of concern in tiger snakes in Perth, Western Australia. This research has progressed the use of LA-ICP-MS for quantifying a suite of metals available in snake scales, and highlights the significance of using wetland snake scales as a non-lethal indicator of environmental contamination.
湿地蛇作为顶级掠食者，正逐渐成为全球公认的湿地污染生物指示剂。肝脏一直是生物体内污染物暴露的传统检测器官，但研究正在转向对非致死性组织采样的偏好。蛇鳞可以作为暴露的指示剂，因为许多金属与角蛋白结合。我们使用激光烧蚀与电感耦合等离子体质谱法（LA-ICP-MS）来量化沿城市梯度的四个湿地中的西部虎蛇（Notechis scutatus occidentalis）鳞片中 19 种金属和类金属（统称为“金属”）的浓度，并将其与圈养虎蛇鳞片中的浓度进行比较。我们进行了重复测量，以使用 LA-ICP-MS 确定每种金属的浓度准确性。在大多数分析的金属中，野生西部虎蛇鳞片中的浓度明显高于参考虎蛇鳞片中的浓度，这表明是从环境暴露中积累的。我们将鳞片浓度与采样湿地的沉积物浓度进行了比较，发现鳞片中金属的平均浓度与沉积物中记录的模式存在站点间差异。四种金属（Mn、As、Se、Sb）与肝脏组织含量呈强烈正相关，表明鳞片浓度可用于推断内部浓度。通过筛选比传统消化方法更多的金属，我们确定了其他可能在西澳大利亚珀斯的虎蛇中积累到令人担忧水平的金属（Ti、V、Sr、Cs、Tl、Th、U）。这项研究推进了使用 LA-ICP-MS 量化蛇鳞中一系列可用金属的方法，并强调了将湿地蛇鳞作为环境污染非致死性指示剂的重要性。
