Abstract:
Snapping shrimp are among the major contributors of biological noise in shallow bays, harbors, and inlets located in temperate and tropical waters. Snapping shrimp sounds can severely limit the use of underwater acoustics by humans and other animals such as dolphins, whales, and pinnepeds. They produce sounds by rapidly closing their frontal chela, or claws, snapping the two ends together to generate a loud click. The acoustics of the species Synalpheus paraneomeris was studied by measuring the sound produced by individual shrimp housed in a small cage located 1 m from an H-52 broadband hydrophone. Ten clicks from 40 specimens were digitized at a 1-MHz sample rate and the data stored on disk. Various acoustic parameters such as source level, spectral content, and center frequency were correlated with claw size and body length. Peak-top-peak source levels varied from 183 to 189 dB re: 1 (mu)Pa. A typical spectrum had a low-frequency peak between 2 and 5 kHz and energy extending out to 200 kHz.