Todd, V.L.G., Warley, J.C., Williamson, L.D., Todd, I.B.
https://doi.org/10.1007/978-3-031-10417-6_165-1
Energy companies have been exploring for (and extracting) oil and gas (O&G) from offshore hydrocarbon fields since the late 1890s. Yet, relatively little research has been conducted into how marine megafauna interact with, and are subsequently impacted by anthropogenic structures in the marine environment. Utilizing passive acoustic monitoring equipment (C-PODs), this study investigated harbor porpoise (Phocoena phocoena) occurrence in the vicinity of a new O&G platform, recording click data between 2015 and 2020, at control and impact sites, pre-platform installation, during construction, and once the platform was in situ. Within five months, porpoise detections per day had returned to pre-platform levels. Drilling-noise measurements of a nearby drilling installation produced a Sound Pressure Level of 120 dB re 1 μPa at 2–1400 Hz. Porpoise forage regularly near offshore O&G installations and are exposed to various noise sources while travelling through the water column, and may hear high-frequency noise from drilling activities up to 70 m from the stem. Findings have important consequences for decommissioning, which does not presently consider impacts of anthropogenic infrastructure on marine megafauna in anything other than a noise-mitigation milieu.
