Offshore human activities lead to increasing amounts of underwater noise in coastal and shelf environments, which may affect commercially-important benthic invertebrate groups like the re-stocked Helgoland European lobster (Homarus gammarus) in the German Bight (North Sea). It is crucial to understand the impact tonal low-frequency noises, like maritime transport and offshore energy operations, may have on substrate choice and lobsters' behavior to assess potential benefits or bottlenecks of new hard-substrate artificial offshore environments that become available. In this study, we investigated the full factorial effect of a tonal low-frequency noise and predator presence on young-of-year (YOY) European lobsters' in a diurnal and nocturnal experiment. Rocks and European oyster shells (Ostrea edulis) were offered as substrate to YOY lobsters for 3 h. Video recordings (n = 134) allowed the identification of lobsters' initial substrate choice, diel activity and key behaviors (peeking, shelter construction, exploration and hiding). To ensure independence, YOY lobsters in the intermolt stage were randomly selected and assigned to the experimental tanks and used only once. We provide the first evidence that stressors alone, and in combination, constrain YOY lobsters' initial substrate choice towards rocks. During nighttime, the joint effect of exposure to a constant low-frequency noise and predator presence decreased antipredator behavior (i.e., hiding) and increased exploration behavior. Noise may thus interfere with YOY lobsters' attention and decision-making processes. This outcome pinpoints that added tonal low-frequency noise in the environment have the potential to influence the behavior of early-life stages of European lobsters under predator pressure and highlights the importance of including key benthic invertebrates' community relationships in anthropogenic noise risk assessments. Among others, effects of noise must be taken into consideration in plans involving the multi-use of any offshore area for decapods’ stock enhancement, aquaculture, and temporary no-take zones.

近海人类活动导致沿海和大陆架环境中水下噪音不断增加，这可能会影响具有重要商业价值的底栖无脊椎动物群体，例如德国湾（北海）重新放养的黑尔戈兰欧洲龙虾（Homarus gammarus）。了解音调低频噪声（如海上运输和海上能源运营）可能对基质选择和龙虾行为的影响，以评估可用的新硬基质人工海上环境的潜在好处或瓶颈，这一点至关重要。在这项研究中，我们在昼夜实验中研究了音调低频噪声和捕食者存在对欧洲年幼龙虾 (YOY) 的全因子效应。岩石和欧洲牡蛎壳（牡蛎) 作为 YOY 龙虾的底物提供 3 小时。视频记录 (n = 134) 可以识别龙虾的初始底物选择、昼夜活动和关键行为（偷看、建造庇护所、探索和隐藏）。为确保独立性，随机选择处于换羽期的YOY龙虾并分配到实验池中，并且仅使用一次。我们提供了第一个证据，表明压力源单独和组合会限制 YOY 龙虾对岩石的初始基质选择。在夜间，暴露于恒定的低频噪声和捕食者存在的联合效应减少了反捕食者的行为（即隐藏）并增加了探索行为。因此，噪音可能会干扰 YOY 龙虾的注意力和决策过程。这一结果表明，环境中增加的音调低频噪声有可能影响欧洲龙虾在捕食者压力下的早期生命阶段的行为，并强调了将关键底栖无脊椎动物的群落关系纳入人为噪声风险评估的重要性。其中，在涉及将任何近海区域用于十足目动物种群增殖、水产养殖和临时禁区的计划中，必须考虑噪音的影响。