Abstract Increasing use of the marine environment and changes in weather extremes from climate change are altering patterns of sediment deposition on benthic habitats. There is a need to understand behavioural responses to such stressors, especially in sessile species that are of conservation, ecological or commercial interest. We investigated how two biogenic reef-forming, epifaunal mussels, Modiolus modiolus (horse mussel) and Mytilus edulis (blue mussel) responded to gradual burial by sediment. Here we used experiments to assess behavioural strategies for surviving modest, but regular sediment deposition regimes (0.5, 1.0 or 1.5 cm d−1 of coarse, medium-fine or fine sediment for 2, 4, 8 or 16 days), that result in gradual burial. M. modiolus was only capable of maintaining contact with the sediment-water interface during slow rates of deposition for short durations (tested in fine sediment only). M. edulis, however, were capable of vertical migration through sediment in all experimental sedimentation rates, sediment fractions and durations, but the frequency of burial increased with increasing sedimentation rate and duration. In this study, the sediment fraction was not influential on the levels of burial observed in M. edulis. Inter-individual variation in the ability of M. edulis to vertically migrate was investigated to understand sub-lethal effects of exposure to sedimentation. In M. edulis a molecular approach was used to assess variation in the condition and protein turnover in tissues with different functional roles (gill, adductor and foot tissue). Concentrations of RNA in the muscular foot were positively associated with the frequency of burial and the total depth of burial, indicating that burial stimulates protein production, most likely associated with byssus production used in the burial escape response. These findings contribute to a better understanding of how mussels respond to, and survive gradual burial by sediment and provide insight into how ongoing changes in sediment dynamics may influence these ecologically and commercially important reef-building species. These findings can be used to assist in managing activities which may result in sedimentation around these important species.

中文翻译：

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两种海洋贻贝对沉积物逐渐掩埋的生存策略和分子响应

摘要 海洋环境的日益利用和气候变化导致的极端天气变化正在改变底栖栖息地的沉积物沉积模式。有必要了解对此类压力源的行为反应，尤其是具有保护、生态或商业利益的无柄物种。我们研究了两种生物成礁形成的表层贻贝，Modiolus modiolus（马贻贝）和 Mytilus edulis（蓝贻贝）如何对沉积物的逐渐掩埋做出反应。在这里，我们使用实验来评估在适度但规则的沉积物沉积状态（0.5、1.0 或 1.5 cm d-1 的粗、中细或细沉积物 2、4、8 或 16 天）中生存的行为策略，这导致逐渐埋葬。M。modiolus 只能在短时间的缓慢沉积速率期间保持与沉积物-水界面的接触（仅在细沉积物中进行测试）。然而，M. edulis 能够在所有实验沉降速率、沉积物分数和持续时间下通过沉积物垂直迁移，但埋藏频率随着沉降速率和持续时间的增加而增加。在这项研究中，沉积物分数对 M. edulis 中观察到的埋藏水平没有影响。研究了 M. edulis 垂直迁移能力的个体间差异，以了解暴露于沉积物的亚致死效应。在 M. edulis 中，使用分子方法来评估具有不同功能作用的组织（鳃、内收肌和足组织）的状况和蛋白质周转的变化。肌肉足部的 RNA 浓度与埋葬频率和埋葬总深度呈正相关，表明埋葬刺激蛋白质生产，最有可能与埋葬逃逸反应中使用的胼胝体生产有关。这些发现有助于更好地了解贻贝如何响应沉积物并在逐渐被沉积物掩埋后存活下来，并深入了解沉积物动力学的持续变化如何影响这些具有生态和商业重要性的造礁物种。这些发现可用于协助管理可能导致这些重要物种周围沉积的活动。最有可能与埋葬逃生反应中使用的byssus生产有关。这些发现有助于更好地了解贻贝如何响应沉积物并在逐渐被沉积物掩埋后存活下来，并深入了解沉积物动力学的持续变化如何影响这些在生态和商业上具有重要意义的造礁物种。这些发现可用于协助管理可能导致这些重要物种周围沉积的活动。最有可能与埋葬逃生反应中使用的byssus生产有关。这些发现有助于更好地了解贻贝如何响应沉积物并在逐渐被沉积物掩埋后存活下来，并深入了解沉积物动力学的持续变化如何影响这些在生态和商业上具有重要意义的造礁物种。这些发现可用于协助管理可能导致这些重要物种周围沉积的活动。