Universidad Nacional del Comahue, Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA-CONICET), Quintral 1250, R8400FRF San Carlos de Bariloche, Río Negro, Argentina.
Centro Austral de Investigaciones Científicas (CADIC-CONICET), B. Houssay 200, V9410CAB Ushuaia, Tierra del Fuego, Argentina.
An Acad Bras Cienc. 2024 Aug 16;96(suppl 1):e20231342. doi: 10.1590/0001-3765202420231342. eCollection 2024.
The present study provides a detailed record of foraminiferal fauna and their ecological implications from surface sediments from Atlantic shelf of Tierra del Fuego, Argentina. The foraminiferal assemblage is mostly composed by four main hyaline genera, such as Cibicidoides, Cibicides, Globocassidulina and Buccella, which allowed the identification of three environmental zones. Zone 1 (Z1, 37 to 90 m) encompasses the eastern Beagle Channel and San Sebastian Bay. The assemblage reflected well-oxygenated marine inner shelf habitat, adapted to cold temperate waters. Zone 2 (Z2, up to 98.4 m), is located around the southern tip of Tierra del Fuego. The assemblage suggested a deeper marine environment, well oxygenated and with higher energy, probably due to the effect of tides and mainly by the influence of Malvinas Current. Finally, Zone 3 (Z3, up to 195 m) is located furthest from the Atlantic coast and the assemblage suggested an environment characteristic of outer shelf, with well-oxygenated cold waters and high-energy environment, reflected by species adhered to the substrate and coarse sediments. The distribution and abundance of certain species showed the influence of the Malvinas Current, while others evidenced a contribution of the Cape Horn waters.
本研究详细记录了来自阿根廷火地岛大西洋大陆架表层沉积物中的有孔虫动物群及其生态意义。有孔虫组合主要由四个主要的透明属组成,如 Cibicidoides、Cibicides、Globocassidulina 和 Buccella,这允许识别出三个环境带。第 1 带(Z1,37 至 90 米)包括比格尔海峡东部和圣塞瓦斯蒂安湾。该组合反映了含氧丰富的海洋内陆架生境,适应于冷温带水域。第 2 带(Z2,最高达 98.4 米)位于火地岛南端周围。该组合表明存在更深的海洋环境,含氧丰富且能量更高,可能是由于潮汐的影响,主要是由于马尔维纳斯寒流的影响。最后,第 3 带(Z3,最高达 195 米)位于离大西洋海岸最远的地方,组合表明具有外陆架特征的环境,具有含氧丰富的冷水和高能环境,这反映在附着在基质和粗沉积物上的物种上。某些物种的分布和丰度显示出马尔维纳斯洋流的影响,而其他物种则表明了合恩角水域的贡献。