Modern microfossil distributions reflect site-specific habitats and provide an opportunity to assess sediment transport pathways in the nearshore environment. When applied to overwash deposits in the geological record, they provide insight into sediment provenance and transport, factors important for understanding patterns of frequency and intensity of past storms and tsunamis. Modern distribution studies are rare and often the first established ones occur immediately after an overwash event as part of a post-event field survey. This is problematic because it is unclear what effect overwash events have on nearshore microfossil assemblages and what time interval is necessary for them to return to pre-event conditions. This study documents the impacts of Hurricane Irma on nearshore sediments off the coast of Anegada, British Virgin Islands, using distributions of Homotrema rubrum, an encrusting foraminifer with a defined provenance in coral reefs. At four sampling intervals spanning two years, from six months pre-Hurricane Irma to eighteen months after, surface sediment was collected from three transects on the northern and southern shores of the island. Partitioning Around Medoids cluster analysis revealed that Hurricane Irma introduced an influx of well-preserved fragments into the reef flat and made the sediments more uniform, limiting the foraminifer’s utility as a known sediment transport indicator. The mixing of sediments along the two northern transects (reef proximal) persisted for seven to eighteen months before returning to near pre-hurricane conditions. However, the southern transect (absence of reef), where Homotrema rubrum concentrations are significantly less, failed to recover within the time period assessed by this study, indicating a variable recovery period between Atlantic Ocean and Caribbean Sea facing shorelines. Results from this study suggest that a waiting period of at least eighteen months after a major storm is recommended before collecting surface sediment from the nearshore environments of reef-dominated coastlines.

中文翻译：

---

加勒比珊瑚礁环境中的近岸微化石组合在飓风艾尔玛之后显示出不同的恢复率

现代微化石分布反映了特定地点的栖息地，并为评估近岸环境中的沉积物迁移路径提供了机会。当应用于地质记录中的过冲沉积物时，它们可以深入了解沉积物的来源和运输，这些因素对于了解过去风暴和海啸的频率和强度模式很重要。现代分布研究很少见，并且作为事后实地调查的一部分，通常在过冲事件之后立即发生第一个确定的分布研究。这是有问题的，因为不清楚过冲事件对近岸微化石组合有什么影响，以及它们恢复到事件前条件所需的时间间隔。这项研究记录了飓风艾尔玛对英属维尔京群岛阿内加达海岸近岸沉积物的影响，Homotrema rubrum，一种在珊瑚礁中具有明确来源的结壳有孔虫。从飓风艾尔玛前的六个月到飓风后的十八个月，在跨越两年的四个采样间隔内，从该岛北部和南部海岸的三个样带中收集了表层沉积物。围绕 Medoids 进行分区聚类分析表明，飓风艾尔玛将保存完好的碎片大量涌入礁滩，并使沉积物更加均匀，从而限制了有孔虫作为已知沉积物运输指标的效用。沿两个北部样带（近礁）的沉积物混合持续了七到十八个月，然后恢复到接近飓风前的条件。然而，南部的样带（没有礁石），红色红斑浓度显着降低，未能在本研究评估的时间段内恢复，表明大西洋和加勒比海面向海岸线之间的恢复期可变。这项研究的结果表明，在从以珊瑚礁为主的海岸线的近岸环境中收集表层沉积物之前，建议在大风暴之后至少等待 18 个月。