Understanding scales and drivers of ecological variability is essential to a full understanding of ecosystem functioning. At remote deep-sea hydrothermal vents, infra-annual dynamics remain poorly described. This study aims to characterise the factors that drive the dynamics of a vent faunal assemblage dominated by Bathymodiolus azoricus mussels from infra-daily to monthly time steps. We analysed a 7-year time series of images and environmental data collected at a depth of 1695 m at the base of the active Eiffel Tower edifice in the Lucky Strike vent field (Mid-Atlantic Ridge). Using images acquired by the TEMPO ecological module connected to the EMSO-Azores observatory, we assessed the dynamics of key species inhabiting the faunal assemblage in relation to changes in environmental conditions monitored daily.

Our results show that habitat conditions were generally stable over the 7-year period, with small-scale variability related to tidal periodicity and local temperature anomalies. Likewise, the mussel and zoanthid assemblages exhibited remarkable stability. Changes in fluid exposure and substratum instability induced decimetre-scale movements of the mussel assemblage. Microbial mats displayed infra-annual changes characterised by aperiodic growth and decline. Their development patterns could not be entirely attributed to environmental conditions, because other factors, including biotic interactions, appeared to be involved. The crab population preferentially occupied the mussel habitat, but no predation was observed. Scales of variation and driving factors were compared with those governing intertidal zones. The outcomes question the assumption that vent fauna experience extreme and highly variable conditions. On the MAR, mussel assemblages appear to experience relatively stable and mild environmental conditions compared with their coastal counterparts.

了解生态变化的尺度和驱动因素对于全面了解生态系统功能至关重要。在偏远的深海热液喷口，对年下动态的描述仍然很差。本研究旨在描述驱动以深水深蓝贻贝为主的喷口动物群从近日到月的时间步长动态变化的因素。我们分析了 7 年时间序列的图像和环境数据，这些图像和环境数据是在 Lucky Strike 通风口场（大西洋中脊）活跃的埃菲尔铁塔底部 1695 m 深处收集的。使用连接到 EMSO-亚速尔群岛天文台的 TEMPO 生态模块获取的图像，我们评估了栖息在动物群落中的关键物种与每天监测的环境条件变化相关的动态。

我们的研究结果表明，栖息地条件在 7 年期间基本稳定，与潮汐周期性和局部温度异常相关的小尺度变化。同样，贻贝和zoanthid组合表现出显着的稳定性。流体暴露和底层不稳定性的变化引起了贻贝群的分米级运动。微生物垫表现出以非周期性增长和下降为特征的年下变化。它们的发展模式不能完全归因于环境条件，因为似乎涉及其他因素，包括生物相互作用。螃蟹种群优先占据贻贝栖息地，但没有观察到捕食。将变化尺度和驱动因素与控制潮间带的尺度进行了比较。结果质疑喷口动物群经历极端和高度可变条件的假设。在 MAR 上，与沿海同类相比，贻贝组合似乎经历了相对稳定和温和的环境条件。