Table 1. Correlation between benthic algal cover and coral reef soundscapes.

Pearson’s correlation coefficients between the percentage of benthic macroalgal cover at 17 reef sites throughout the Hawaiian Islands and ambient acoustic pressure spectral density in three bands between 2 and 20 kHz, obtained simultaneously at the same locations. Intensity-filtered spectra were averaged over one hour beginning at the indicated times.

Time of day	Acoustic frequency band, kHz	Pearson’s correlation coefficient, ρ
Pre-dawn, 2 h before local sunrise	2–7	0.33
	7–13	0.50
	13–20	0.48
Morning, 1 h after local sunrise	2–7	0.63
	7–13	0.70
	13–20	0.68
Afternoon, 2 h before local sunset	2–7	0.67
	7–13	0.68
	13–20	0.67
Evening, 1 h after local sunset	2–7	0.35
	7–13	0.56
	13–20	0.55