Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095, USA.
Center for Mercury Studies, Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA.
Ecotoxicology. 2023 Oct;32(8):1096-1123. doi: 10.1007/s10646-023-02706-y. Epub 2023 Oct 31.
Environmental mercury (Hg) contamination of the global tropics outpaces our understanding of its consequences for biodiversity. Knowledge gaps of pollution exposure could obscure conservation threats in the Neotropics: a region that supports over half of the world's species, but faces ongoing land-use change and Hg emission via artisanal and small-scale gold mining (ASGM). Due to their global distribution and sensitivity to pollution, birds provide a valuable opportunity as bioindicators to assess how accelerating Hg emissions impact an ecosystem's ability to support biodiversity, and ultimately, global health. We present the largest database on Neotropical bird Hg concentrations (n = 2316) and establish exposure baselines for 322 bird species spanning nine countries across Central America, South America, and the West Indies. Patterns of avian Hg exposure in the Neotropics broadly align with those in temperate regions: consistent bioaccumulation across functional groups and high spatiotemporal variation. Bird species occupying higher trophic positions and aquatic habitats exhibited elevated Hg concentrations that have been previously associated with reductions in reproductive success. Notably, bird Hg concentrations were over four times higher at sites impacted by ASGM activities and differed by season for certain trophic niches. We developed this synthesis via a collaborative research network, the Tropical Research for Avian Conservation and Ecotoxicology (TRACE) Initiative, which exemplifies inclusive, equitable, and international data-sharing. While our findings signal an urgent need to assess sampling biases, mechanisms, and consequences of Hg exposure to tropical avian communities, the TRACE Initiative provides a meaningful framework to achieve such goals. Ultimately, our collective efforts support and inform local, scientific, and government entities, including Parties of the United Nations Minamata Convention on Mercury, as we continue working together to understand how Hg pollution impacts biodiversity conservation, ecosystem function, and public health in the tropics.
全球热带地区的环境汞（Hg）污染速度超过了我们对其生物多样性影响的理解。污染暴露的知识差距可能会掩盖新热带地区的保护威胁：该地区支持着全球一半以上的物种，但面临着持续的土地利用变化和通过手工和小规模采金（ASGM）排放汞。由于鸟类在全球范围内分布广泛，且对污染敏感，因此它们是评估加速汞排放如何影响生态系统维持生物多样性能力，以及最终影响全球健康的宝贵生物指标。我们提供了关于新热带鸟类 Hg 浓度的最大数据库（n=2316），并为跨越中美洲、南美洲和西印度群岛的九个国家的 322 种鸟类确定了暴露基线。新热带地区鸟类 Hg 暴露模式与温带地区的模式大致一致：功能组之间的生物积累一致，时空变化很大。占据较高营养位和水生栖息地的鸟类物种表现出较高的 Hg 浓度，这与繁殖成功率降低有关。值得注意的是，受 ASGM 活动影响的地点的鸟类 Hg 浓度比其他地点高出四倍以上，某些营养类群的浓度在不同季节有所不同。我们通过一个名为热带研究鸟类保护和生态毒理学（TRACE）倡议的合作研究网络来综合这些发现，该倡议体现了包容性、公平性和国际数据共享。虽然我们的研究结果表明迫切需要评估 Hg 暴露对热带鸟类群落的采样偏差、机制和后果，但 TRACE 倡议为实现这些目标提供了一个有意义的框架。最终，我们的集体努力支持和为当地、科学和政府实体提供信息，包括联合国汞问题水俣公约的缔约方，因为我们继续共同努力了解 Hg 污染如何影响热带地区的生物多样性保护、生态系统功能和公共健康。
