Epifaunal Foraminifera in an Infaunal World: Insights Into the Influence of Heterogeneity on the Benthic Ecology of Oxygen-Poor, Deep-Sea Habitats
Epifaunal Foraminifera in an Infaunal World: Insights Into the Influence of Heterogeneity on the Benthic Ecology of Oxygen-Poor, Deep-Sea Habitats
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动物体内的表层有孔虫：洞察异质性对缺氧深海生境底栖生态的影响
DOI：
10.3389/fmars.2018.00344
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发表时间：
2018
影响因子：
3.7
通讯作者：
W. Ziebis
中科院分区：
文献类型：
--
作者：
R. Venturelli;A. Rathburn;A. Burkett;W. Ziebis
全球气温升高的预计后果之一是海洋栖息地溶解氧可用性的减少。了解过去的氧合对于预测未来最低氧区 (OMZ) 范围和分布的变化至关重要。底栖有孔虫已被用来评估古氧合的变化，根据普遍的观点，缺氧的海洋底栖栖息地以沉积物内动物有孔虫为主，而含氧较多的环境则栖息着更多的表层动物类群。然而，在这项研究中，我们发现缺氧栖息地的表层动物类群密度升高。在南加州湾 OMZ 的深度横断面（360-3000 m）上拍摄了一系列 16 个多核样本，以研究活体（玫瑰孟加拉染色）底栖有孔虫的生态。采样点底层水中的溶解氧浓度从21 mol/l 到162 mol/l 不等。采样重点是测深高点，以便在通常不作为采样目标的区域收集含有粗沉积物的海底表面物质。平均粒径从约 131m（砾石砂）到约 830μm（粗砂和细砾石）不等。垂直分布模式（0-2厘米）与其他地方报道的同种一致，并再次证实Cibicidoides wuellerstorfi和Hanzawaia nipponica在沉积物-水界面或附近具有生活偏好。正如预期的那样，组合以动物类群为主，例如 Uvigerina 和 Bolivina，传统上与过饱和、松散的泥浆（OMZ 栖息地的特征）相关，这表明这些类群对基质类型不敏感。然而，尽管存在缺氧条件（21 mol/l 至 28 mol/l），表层动物类群在平均颗粒尺寸最粗的五个地点仍占染色种群的 36%，而其他测量的环境参数保持相对恒定。我们认为，这些表层动物类群，包括 C. wuellerstorfi，更喜欢具有粗颗粒的栖息地，使它们能够停留在沉积物-水界面或之上。这些结果表明海底栖息地的异质性有助于底栖有孔虫的分布，包括在低氧环境中。我们认为，使用动物表层指示类群的古充氧方法需要重新考虑动物表层类群的溶解氧需求。
A reduction in dissolved oxygen availability in marine habitats is among the predicted consequences of increasing global temperatures. An understanding of past oxygenation is critical for predictions of future changes in the extent and distribution of oxygen minimum zones (OMZs). Benthic foraminifera have been used to assess changes in paleo-oxygenation, and according to prevailing thought, oxygen-poor marine benthic habitats are dominated by sediment-dwelling infaunal foraminifera, while more oxygenated environments are populated with more epifaunal taxa. However, in this study we found elevated densities of epifaunal taxa in oxygen-poor habitats. A series of sixteen multicores were taken on depth transects (360-3000 m) across an OMZ in the Southern California Bight to investigate the ecology of living (rose Bengal stained) benthic foraminifera. Dissolved oxygen concentrations in bottom water at sampling sites varied from 21 mol/l to 162 mol/l. Sampling focused on bathymetric highs in an effort to collect seafloor surface materials with coarse sediments in areas not typically targeted for sampling. Mean grain size varied from about 131m (gravelly sand) to about 830μm (coarse sand with fine gravel). Vertical distribution patterns (0-2 cm) were consistent with those of conspecifics reported elsewhere, and reconfirm that Cibicidoides wuellerstorfi and Hanzawaia nipponica have a living preference at or near the sediment-water interface. As expected, assemblages were dominated by infaunal taxa, such as Uvigerina and Bolivina, traditionally associated with the supersaturated, unconsolidated mud, characteristic of OMZ habitats, suggesting that these taxa are not sensitive to substrate type. However, despite dysoxic conditions (21 mol/l to 28 mol/l ), epifaunal taxa comprised as much as 36 percent of the stained population at the five sites with the coarsest mean grain size, while other measured environmental parameters remained relatively constant. We suggest that these epifaunal taxa, including C. wuellerstorfi, prefer habitats with coarse grains that allow them to remain at or above the sediment-water interface. These results suggest that seafloor habitat heterogeneity contributes to the distribution of benthic foraminifera, including in low-oxygen environments. We submit that paleo-oxygenation methods that use epifaunal indicator taxa need to reconsider the dissolved oxygen requirements of epifaunal taxa.
影响因子：
56.9
作者：
Stramma, Lothar;Johnson, Gregory C.;Mohrholz, Volker
通讯作者：
Mohrholz, Volker