TBM Environnement, Auray, France; Université de Brest, Laboratoire des Sciences de l'Environnement Marin (LEMAR - UMR 6539 CNRS, UBO, IRD, IFREMER), LIA BeBEST, Institut Universitaire Européen de la Mer, Plouzané, France.
Muséum National d'Histoire Naturelle, Biologie des Organismes et Écosystèmes Aquatiques (BOREA), UMR 7208 MNHN/SU/UNICAEN/UA/CNRS/IRD, Paris, France.
Mar Environ Res. 2023 Sep;190:106106. doi: 10.1016/j.marenvres.2023.106106. Epub 2023 Jul 22.
With the progress of the offshore renewable energy sector and electrical interconnection projects, a substantial rise in the number of submarine power cables is expected soon. Such cables emit either alternating or direct current magnetic fields whose impact on marine invertebrates is currently unknown and hardly studied. In this context, this study aimed to assess potential short-term exposure (30 min) effects of both alternating and direct magnetic fields of increasing intensity (72-304 μT) on the behavior of the high-ecological value velvet crab (Necora puber). Three experiments were designed to evaluate whether the strongest magnetic field intensities induce crabs' attraction or repulsion responses, and whether foraging and sheltering behaviors may be modified. We extracted from video analyses several variables as the time budgets crabs spent immobile, moving, feeding, or sheltering as well as total and maximal distance reached in the magnetic field (MF) gradient. The crabs exposed to artificial MF did not exhibit significant behavioral changes compared with those exposed to the "natural" MF. Overall, our results suggest that, at such intensities, artificial magnetic fields do not significantly alter behaviors of N. puber. Nevertheless, future studies should be conducted to examine the effects of longer exposure periods and to detect potential habituation or resilience processes.
随着海上可再生能源领域和电力互联项目的进展，预计很快将有大量海底电力电缆投入使用。这些电缆会产生交流或直流磁场，其对海洋无脊椎动物的影响目前尚不清楚，也很少有研究。在这种情况下，本研究旨在评估海洋无脊椎动物的短期（30 分钟）暴露于不断增强的交流和直流磁场（72-304 μT）的潜在影响，实验对象为具有高生态价值的绒螯蟹（Necora puber）。设计了三个实验来评估最强磁场强度是否会引起螃蟹的吸引或排斥反应，以及觅食和庇护行为是否会发生改变。我们从视频分析中提取了几个变量，如螃蟹在磁场梯度中处于静止、移动、进食或庇护状态的时间预算，以及螃蟹在磁场中移动的总距离和最大距离。与暴露在“自然”磁场中的螃蟹相比，暴露在人工磁场中的螃蟹没有表现出明显的行为变化。总体而言，我们的结果表明，在这种强度下，人工磁场不会显著改变绒螯蟹的行为。然而，未来的研究应该进行更长时间的暴露实验，以检测潜在的习惯化或恢复过程的影响。
