Figure 1:

Power spectral density of the sound treatments to which Amblyglyphidodon curacao embryos were exposed: 2-stroke powered boat noise, 4-stroke powered boat noise and natural ambient conditions. Spectral content is shown in sound pressure (left) and particle acceleration (right). Analyses were conducted in paPAM using one minute tracks that combined three separate recordings of each treatment to give the average sound profile of the three recordings. For boat tracks, each of the three recordings used in a track were from a different boat to account for variability between boats with the same engine type.