Importance and Challenges of Offshore Platform and Rig Data in Acoustic Monitoring Studies: A Case Study on Harbor Porpoises

Summary Marine environmental consultancies and academics involved with the upstream phase of the oil and gas (O&G) production process can be quickly overwhelmed by multifaceted jargon and inimitable metrics used throughout the industry. Environmental monitoring around offshore O&G installations remains logistically complex and often poorly integrated into operational frameworks. This study examines the potential of using an autonomous passive echolocation click detector (C-PODs) to assess harbor porpoise (Phocoena phocoena) acoustic activity in relation to offshore rig and platform operations. Focusing on the A18 gas production platform and three drilling campaigns (2015–2018), we analyzed rig-derived daily drilling reports (DDRs), operational phase records, and vessel/helicopter logs alongside high-resolution acoustic data from 12 C-PODs deployed at distances of 70 m, 5 km, and 10 km. Despite extreme challenges in securing consistent operational data, DDRs provided the most temporally resolved insights. However, high-temporal-resolution operational information, often described as being as rare as “hen’s teeth,” was largerly limited to rig-derived DDRs, which became essential for aligning acoustic detections with offshore activities. C-PODs showed limitations during high-noise activities, particularly anchoring, which correlated with marked reductions in porpoise detections. These effects diminished at greater distances and over time. The study highlights the need for operational data standardization and integration between environmental monitoring and offshore activities. Our findings offer a practical framework for future acoustic monitoring efforts in industrial contexts while also identifying technological and methodological constraints that require attention.