State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Res. 2024 Nov 15;261:119641. doi: 10.1016/j.envres.2024.119641. Epub 2024 Jul 23.
Mercury (Hg), especially methylmercury (MeHg), is a pervasive contaminant that poses significant risks to birds occupying high trophic levels. However, we have little knowledge about the mercury exposure and its risks for birds in Poyang Lake basin, China. Therefore, during 2020-2021, we investigated MeHg concentrations in breast feathers of wintering migratory birds (n = 430 from 43 species belonging to 9 orders) in Poyang Lake Nanji Wetland and Jiangxi Nanfengmian National Nature Reserve, China. MeHg concentrations in breast feathers varied greatly by species, foraging guilds and taxonomic orders, among which the highest concentration was detected in great egret (8849 ± 5975 ng g dw). Comparing with studies worldwide, high MeHg concentrations in feathers of Ardeidae from Pelecaniformes were found in this area. Moreover, herons migrating between northern and southern China had lower MeHg concentration than residents in southern China related to habitat Hg. Considering the applicability and sensitivity of the equations for the transformation of MeHg concentrations in feathers to blood-equivalent total Hg (THg) values, method CJ that the equation based on songbirds was used for the transformation of the songbirds and the equation based on seabirds for the others performed better than other three for risk assessment of bird Hg in this study. 23.1% of birds from Poyang Lake were at risk of Hg exposure based on the method CJ. Carnivorous birds from Pelecaniformes had the highest risk levels, with 37.2% categorized as no risk (≤200 ng g ww), 48.9% as low risk (200-1000 ng g ww), 11.1% as moderate risk (1000-3000 ng g ww), 1.1% as high risk (3000-4000 ng g ww), and 1.7% as severe risk (>4000 ng g ww). These risks suggest long-term monitoring and further advanced studies about freshwater waterbirds Hg exposure is necessary.
汞（Hg），特别是甲基汞（MeHg），是一种普遍存在的污染物，对处于高营养级的鸟类构成重大风险。然而，我们对中国鄱阳湖流域鸟类的汞暴露及其风险知之甚少。因此，在 2020-2021 年期间，我们调查了中国鄱阳湖南矶湿地和江西南丰棉国家自然保护区越冬候鸟（来自 9 个目 43 种的 430 只）胸羽中的 MeHg 浓度。胸羽中 MeHg 浓度因物种、觅食群和分类目而异，其中大白鹭（8849±5975ng·g dw）的浓度最高。与全球范围内的研究相比，本地区来自鹳形目鸟类的羽毛中 MeHg 浓度较高。此外，在中国南北迁徙的鹭类的 MeHg 浓度低于在中国南方栖息的鹭类，这与栖息地汞有关。考虑到将羽毛中 MeHg 浓度转化为血等效总汞（THg）值的方程的适用性和敏感性，本研究中，对于雀形目鸟类，采用基于雀形目鸟类的方程（方法 CJ）进行转化，对于其他鸟类，采用基于海鸟的方程进行转化，用于评估鸟类 Hg 风险的效果优于其他三种方法。根据方法 CJ，鄱阳湖的 23.1%的鸟类有暴露于汞的风险。来自鹳形目的肉食性鸟类的风险水平最高，其中 37.2%被归类为无风险（≤200ng·g ww），48.9%为低风险（200-1000ng·g ww），11.1%为中度风险（1000-3000ng·g ww），1.1%为高风险（3000-4000ng·g ww），1.7%为严重风险（>4000ng·g ww）。这些风险表明需要对淡水水鸟的汞暴露进行长期监测和进一步的深入研究。
