Benthic foraminifera as indicators of river discharge in the Western South Atlantic continental shelf
Benthic foraminifera as indicators of river discharge in the Western South Atlantic continental shelf
复制标题
底栖有孔虫作为南大西洋西部大陆架河流流量的指标
DOI：
10.1016/j.margeo.2019.105973
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发表时间：
2019
期刊：
影响因子：
2.9
通讯作者：
H. Vital
中科院分区：
文献类型：
--
作者：
P. Eichler;A. R. Rodrigues;M. P. Gomes;H. Vital
目前的工作重点是利用有孔虫识别沉积物-水界面（1 cm）的淡水特征。样品是在南半球冬季和夏季沿南大西洋西部大陆边缘27°至37°S之间的11个纵向样带采集的，水深为11.7至250 m。研究表明，深度、盐度、温度、氧气、粒度（泥砂百分比）、悬浮颗粒物、有机质、SiO4、NO2和NO3对有孔虫和变形虫的分布有重要影响。这些微化石的存在表明了在Itajaí-Açu河、拉古纳河口系统、Patos泻湖和里约热内卢de la Plata （RdlP）四个大陆架板块的淡水涌入，并进行了进一步的详细探讨。大陆架沉积物中的淡水特征表明，大量污染物和由大陆架上的河流流出物输送的污染物最终在海洋中积聚的沉积地点。详细讨论了这些带内有孔虫微生境的分布。我们的结论是，与动物群一起，非生物参数在突出受污染河水输入引起的海洋影响的发生和程度方面很重要，包括大陆架上可能的缺氧环境。我们在大陆架沉积物中使用底栖生物作为生物指标的淡水特征的发现与世界上其他大陆架的报告相当，并且古记录研究可能对三个南美国家（巴西，阿根廷和乌拉圭）有用。
The present work focuses on freshwater signatures at the sediment-water interface (1 cm) identified using foraminifera. Samples were collected during both the Southern Hemisphere winter and summer along eleven longitudinal transects on the Western South Atlantic continental margin between 27° and 37°S, at water depths of 11.7 to 250 m. Here we show that depth, salinity, temperature, oxygen, grain size (mud and sand percentages), suspended particulate matter, organic matter, SiO4, NO2, and NO3, in this order of importance, are responsible for the distribution of foraminiferal species and thecamoebians. The presence of these microfossils, which indicate freshwater influx in four sectors over the continental shelf: Itajaí-Açu River, Laguna estuarine system, Patos Lagoon and Rio de la Plata (RdlP), are explored further in detail. A freshwater signature in the continental shelf sediments indicates deposition sites wherein large amounts of pollutants and contaminants transported by river outflows on the shelf eventually accumulate in the ocean. Foraminiferal microhabitat occupation within these zones is discussed in detail. We conclude that together with the fauna, abiotic parameters are important in highlighting the occurrence and degree of marine impact induced by inputs from polluted river waters, including possible hypoxic environments on the shelf. Our findings of freshwater signatures on the continental shelf sediments using benthic species as bioindicators are comparable to reports from other continental shelves worldwide, and a paleo-record study could be useful for three South American countries (Brazil, Argentina and Uruguay).
DOI：
10.1111/j.1442-9993.1993.tb00438.x
发表时间：
1993-03-01
期刊：
AUSTRALIAN JOURNAL OF ECOLOGY
影响因子：
--
作者：
CLARKE, KR
通讯作者：
CLARKE, KR