Figure 9. Acoustic analysis of ambient underwater sound at field experiment sites.

a) Spectral composition of sound recorded at the reef and off-reef field sites during the field larval settlement experiments in August 2012. Power spectral density estimated via Welch's method (Hamming window, 1-sec averages with 50% overlap). b) Comparison of broadband root-mean square sound levels (in dB re 1 µPa) measured at the reef and off-reef site for the duration of the August 2012 field settlement experiment. The root-mean-square sound level was calculated in a series of non-overlapping 10-sec duration windows.