Snapping shrimps are the major source of biological noise in shallow bays, harbors, inlets, and coral reefs in temperate and tropical waters. The sounds are impulsive with a very broad spectrum spanning from several hundred Hz to over 200 kHz. Peak frequencies are typically between 1–10 kHz with a very slow drop‐off in energy with increasing frequency. At 200 kHz, the intensity of the sound may be only 20 dB below the intensity at the peak frequency. The peak‐to‐peak source level can be higher than approximately 189 dB re 1 mPa. When a shrimp rapidly closes its snapper claw, a high‐velocity water jet that has speed exceeding cavitation conditions is produced. The sound is the result of a cavitating bubble collapsing. In a body of water, the overall level of snapping shrimp sounds can be as high as 20 dB above the noise level typical of sea state 6. The noise is present continuously, with little diurnal and seasonal variations and its broad frequency extent make it extremely difficult to filter this noise. Therefore, snapping shrimp sounds can severely limit the use of underwater bioacoustic monitoring in a coral reef environment.