In coastal upwelling ecosystems, understanding of environmental factors regulating the structure of benthic foraminiferal communities is fundamental to enhance our knowledge of their ecology and to validate their use in palaeoceanographic studies. In this study, we assess the influence of organic matter (quantity/quality) and subsurface oxygenation on living (stained) calcareous benthic foraminifera inhabiting a coastal upwelling ecosystem influenced by Oxygen Minimum Zone (OMZ) off Inglesa Bay, Northern Chile. Benthic foraminifera and their environment (i.e. biochemical/elemental sediment composition and subsurface water column oxygenation) were sampled along a transect perpendicular to the coastline consisting of three stations (30, 70 and 120 m) and covering two seasons (winter and summer). The geochemical composition of surface sediments and subsurface oxygenation reveal a typical pattern of marine ecosystems associated with coastal upwelling centers influenced by OMZ. Forty-seven species of living calcareous benthic foraminifera were identified, in which Bolivinella seminuda, Buliminella elegantissima, Bulimina marginata, and Nonionella miocenica were found as the most abundant species. Total abundance increases remarkably with depth while taxonomic richness and evenness decrease. Multivariate analyses show three benthic foraminiferal associations strongly linked to nutritive organic matter and subsurface oxygenation, regardless of the sampling period. Assemblages “A” (22 species, 4 dominant) and “C” (5 species, 1 dominant) are associated with the shallow (30 m) and deep (120 m) station, and present contrasting subsurface oxygenation and organic matter content. Assemblage “B” (19 species, 3 dominant) is associated with the intermediate station (70 m) characterized by mixed subsurface oxygenation and organic matter content. Our results suggest that local environment conditions (i.e. OMZ intensity, organic matter quality/quantity) govern the structure and composition of the living calcareous benthic foraminiferal assemblages of Inglesa Bay. Such assemblages have similarities and differences with other benthic foraminifera assemblages found in other coastal upwelling ecosystems impinged by an OMZ.

在沿海上升流生态系统中，了解调节底栖有孔虫群落结构的环境因素对于增进我们对其生态学的了解并验证其在古海洋学研究中的应用至关重要。在这项研究中，我们评估了有机物质（数量/质量）和地下氧化作用对生活在（染色的）钙质底栖有孔虫的影响，该生石灰栖息在受智利北部英格萨湾附近的最低限氧区（OMZ）影响的沿海上升生态系统中。底栖有孔虫及其环境（即生化/元素沉积物组成和地下水柱充氧）是在与三个海岸线（30、70和120 m）垂直的海岸线上进行采样的，覆盖两个季节（冬季和夏季）。表层沉积物的地球化学组成和地下氧化作用揭示了与受OMZ影响的海岸上升中心有关的海洋生态系统的典型模式。确定了47种活的钙质底栖有孔虫，其中半裸玻氏菌（Bolivinella seminuda），东方短孢菌（Buliminella Elegantissima），边缘蟾蜍（Bulimina marginata）和七叶紫薇（Nonionella miocenica）被发现为最丰富的物种。总丰富度随深度显着增加，而分类学丰富度和均匀度降低。多变量分析显示，与采样有机体和营养性有机物紧密相关的三个底栖有孔虫关联。集合“ A”（22种，占优势的4种）和“ C”（5种，1种占优势的）与浅层（30 m）和深层（120 m）站相关，并呈现出对比之下的地下氧和有机质含量。组合“ B”（19种，占主导地位的3种）与中间站（70 m）相关，该站的特征是混合的地下氧化和有机质含量。我们的结果表明，当地环境条件（例如OMZ强度，有机质的质量/数量）控制着英格萨湾活生的钙质底栖有孔虫组合的结构和组成。这种组合与在OMZ撞击下的其他沿海上升生态系统中发现的其他底栖有孔虫组合具有相似性和差异性。