Acoustic Soundscapes and Biodiversity - Comparing Metrics, Seasons and Depths with Data from the NEPTUNE Ocean Observatory offshore British Columbia

Acoustic soundscapes are made of the complex interplay of weather processes
(rain, wind, and sea states), animal noises (from fish to marine mammals) and acoustic signatures of anthropogenic activities (from shipping to mapping/ prospection and other offshore actions). There is mounting concern about the effects of increases in shipping and variations induced by climate change on the biodiversity in the oceans, and this will be investigated using large-scale and long-term measurements acquired by Ocean Networks Canada. NEPTUNE is the largest cabled ocean observatory and it has been gathering data since 2007, across several nodes offshore British Columbia. Broadband, high-fidelity
measurements of sound are accessible across a range of environments and depths, from the coast of Vancouver Island to canyons and abyssal plains. Selected datasets are processed with the standard PAMGuide Matlab/R package (Merchant et al., 2015) and associated to weather, shipping and other acoustic processes. Acoustic diversity indices are computed with the Seewave R package (Sueur et al., 2016), originally developed for terrestrial acoustics but increasingly used in marine environments. We compare the variations of standard acoustic metrics (broadband SPL and frequency-dependent values) with acoustic biodiversity measurements, investigating the effects of integration times, frequency ranges, depths and seasonal variability.