Acoustic Signatures of Shipping, Weather and Marine Life: Comparison of NE Pacific and Arctic Soundscapes

Acoustic signatures of shipping, weather and marine life are relatively well constrained, but there are strong variations with their oceanographic context and human activities. We investigate two contrasted settings, for timescales up to a year and frequencies up to 2 kHz. Arctic data from NOAA Noise Reference Station(NRS) NRS01, 500 m deep in the Arctic Chukchi Sea and away from major shipping areas is compared with measurements from Folger Deep, part of the Ocean Networks Canada network, 95 m deep and close to shipping lanes. PAMGuide is used to quantify broadband Sound Pressure Levels (SPLs), Third-Octave band Levels (TOLs), Power Spectral Densities (PSDs) and percentile contributions. The Acoustic Complexity Index (ACI) is an emerging metric to measure the apparent acoustic biodiversity, and we use its Seewaveimplementation. We compare the third-octave bands centred on 63 Hz and 125 Hz (“shipping” bands of the European Marine Strategy Framework Directive) in each environment and assess their use in the presence of heavy ice and little to no shipping. Metrics designed for open waters are not directly applicable to icyenvironments, or at least not on their own. They must be supplemented with multivariate analyses of context-specific third-octave bands

Arctic Acoustic Environments – Federating observations and analyses with the International Quiet Ocean Experiment

Arctic waters are experiencing rapid changes due to global warming, affecting ecosystems and leading to increasing economic activities. Many of these changes can be measured directly or indirectly with underwater acoustics. The Working Group on the Arctic Acoustic Environment (AAE) of the International Quiet Ocean Experiment (IQOE) aims to stimulate observations of sound (levels and distribution) in the Arctic Ocean and its impacts. We organised a virtual conference in November 2020 to share recent results from the international community and discuss common issues and possible solutions. The COVID-19 pandemic amplified the challenges of Arctic deployments and recoveries, curtailing access to ships at very short notice, but also opening the way for more direct collaboration. The post-COVID task will be to establish more resilient international back-up mechanisms for Arctic operations to support acoustic (and other) observations. The increasing length of the measurements, spanning several decades now, with sampling rates often close to 100,000 samples/second, results in “big data” challenges of storage, sharing, data retrieval and long-term archiving. Discussions also addressed the emerging trends in acoustic propagation models across complex terrains and machine learning (with the need for accessibility and traceability). Finally, the embedding of local and traditional knowledge must be accomplished through dialogue and co-ownership of the science and results