Documenting and assessing dolphin calls and ambient and anthropogenic noise levels via PAM and a SPL meter

Abstract

Song Meter SM2M marine recorders were deployed to document dolphin calls and ambient and anthropogenic noise. Recordings from Bimini were split into 2-h segments; no segment was without dolphin calls. At Dolphin Encounters, average noise levels ranged from 110 to 125 dB; the highest source level was 147.98 dB re 1 μPa at 1 m. Average ambient-noise levels documented at 4 sites in Guam were below 118 dB re 1 μPa at 1 m. These data were compared with values from a custombuilt sound pressure level (SPL) meter and confirm that the SM2M recorder is a useful tool for assessing animal calls and ambient and anthropogenic noise levels.