Abstract：
Many man-made marine structures (MMS) will have to be decommissioned in the coming decades. While studies on the impacts of construction of MMS on marine mammals exist, no research has been done on the effects of their decommissioning. The complete removal of an oil and gas platform in Scotland in 2021 provided an opportunity to investigate the response of harbour porpoises to decommissioning. Arrays of broadband noise recorders and echolocation detectors were used to describe noise characteristics produced by decommissioning activities and assess porpoise behaviour. During decommissioning, sound pressure spectral density levels in the frequency range 100 Hz to 48 kHz were 30-40 dB higher than baseline, with vessel presence being the main source of noise. The study detected small-scale (< 2 km) and short-term porpoise displacement during decommissioning, with porpoise occurrence increasing immediately after this. These findings can inform the consenting process for future decommissioning projects.
摘要：
许多人造海洋结构（MMS）将在未来几十年内退役。虽然有关于构建MMS对海洋哺乳动物影响的研究，尚未对其退役的影响进行研究。2021年苏格兰的一个石油和天然气平台的完全拆除为调查港口海豚对退役的反应提供了机会。宽带噪声记录器和回声定位检测器的阵列用于描述退役活动产生的噪声特性并评估海豚的行为。在退役期间，100Hz至48kHz频率范围内的声压频谱密度水平比基线高30-40dB，船舶的存在是主要的噪声源。该研究发现了退役期间的小规模（<2km）和短期海豚位移，此后海豚的发生率立即增加。这些发现可以为未来退役项目的同意过程提供信息。
