Ocean soundscapes reveal climatic and economic oscillations

An accumulation of 26 859 days of acoustic recordings (spanning over 74 years at six sites) was processed and analyzed to investigate the interannual, seasonal, and diel patterns within six ocean soundscapes. Biological sound levels (18-25 Hz and 40–45 Hz) quantified acoustic energy from fin and blue whales, ambient sound levels (63-Hz and 800-Hz one-third-octave) quantified energy from ships and wind, and broadband spectra (15 Hz to 1 kHz) identified changes across time and space. Biological sound levels varied seasonally and correlated with large-scale climatic patterns and long-term ocean fluctuations. During marine heatwaves, baleen whale associated sound levels decreased in southern sites and increased in sites adjacent to the California Current. Ship sound levels at high-traffic sites reflected economic events such as the financial crisis, labor shortages and negotiations, and changes to port flows. Wind speeds and associated sound levels reflected on-shore/off-shore relationships and decreased during the morning hours. Understanding marine soundscapes aids in understanding the ocean’s ecological health amidst the ever-changing impact of climate change.