A benthic monitor for coastal water dissolved oxygen variation: Mn/Ca ratios in tests of an epifaunal foraminifer
A benthic monitor for coastal water dissolved oxygen variation: Mn/Ca ratios in tests of an epifaunal foraminifer
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沿海水域溶解氧变化的底栖监测：表层有孔虫测试中的锰/钙比
DOI：
10.1029/2021jc017860
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发表时间：
2021-12
期刊：
影响因子：
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通讯作者：
Z. G. Yu
中科院分区：
文献类型：
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作者：
Xiaoyi Guo;Qinsheng Wei;Bochao Xu;William C. Burnett;Joan M. Bernhard;Haiming Nan;Ergang Lian;Shouye Yang;Z. G. Yu
适当的代理可以帮助更好地了解过去溶解氧的变化，有助于预测未来环境变化的潜在结果。在长江口（中国），有孔虫 Cribrononion subincertum (C. subincertum) 在最顶部的沉积物中显示出明显的种群数量最大值，这表明其属于表层动物物种。因此，C. subincertum 测试的地球化学成分可以记录该地区底层水化学的变化。我们的结果表明，通过 LA-ICP-MS 分析的活体（玫瑰孟加拉染色）C. subincertum 测试中的 Mn/Ca 比值对底层水溶解氧浓度的变化有响应，低氧时期有孔虫的平均 Mn/Ca 比值比冬季高三倍。在沉积物最上层厘米处，夏季有孔虫锰/钙的范围比冬季范围更广。我们的结果表明，这种表层底栖有孔虫物种可以作为有用的底栖监测器，其锰/钙比代表过去缺氧的可靠指标。
An appropriate proxy could help to better understand dissolved oxygen variations in the past, helping to predict potential outcomes of future environmental changes. In the Changjiang Estuary (China), the foraminifer Cribrononion subincertum (C. subincertum) shows a distinct population maximum in the topmost sediment, an indication of an epifaunal species. Therefore, the geochemical composition of C. subincertum tests could record changes in the region’s bottom water chemistry. Our results showed that Mn/Ca ratios in tests of living (Rose-Bengal stained) C. subincertum analyzed by LA-ICP-MS were responsive to variations of bottom water dissolved oxygen concentrations, with average foraminiferal Mn/Ca ratios three times higher during low-oxygen period than in winter. In the uppermost centimeters of sediment, wider ranges of foraminiferal Mn/Ca occurred in summer compared to winter ranges. Our results imply that this epifaunal benthic foraminiferal species could serve as a useful benthic monitor with the Mn/Ca ratios representing a reliable proxy of hypoxia in the past.