Photosynthetic oxygen bubble stream sounds from aquatic macrophytes, and their consequences for acoustic biodiversity inventories and acoustic communication in shallow freshwater settings

PLOS ONE | https://doi.org/10.1371/journal.pone.0317424 April 23, 2025 7 / 13 PLOS ONE Photosynthetic oxygen bubble stream sounds from aquatic macrophytes Fig 1. Exemplar 1 spectrogram and waveform. Recorded in Gull Lake, Alberta, Canada, July 22, 2023. Waveform view (top) shows time in seconds on the x-axis, and amplitude in kilounits (kU) on the y-axis. Spectrogram view (bottom) shows time in seconds on the x-axis, frequency in kilohertz (kHz) on the y-axis, and intensity represented by colour (blue = low intensity; yellow = medium; red = high). A short-time Fourier transform size with a 50% overlap parameter was used. https://doi.org/10.1371/journal.pone.0317424.g003 Fig 2. Exemplar 2 spectrogram and waveform. A macrophyte bubble stream sound recorded at Gull Lake, Alberta, Canada, June 20, 2021. See Fig 1 for axis descriptions. https://doi.org/10.1371/journal.pone.0317424.g004