Abstract
Sound production by white shrimp (Penaeus setiferus) was studied acoustically and behaviorally. Another crustacean-like signal from the Gulf of Mexico was analyzed, and the use of passive sonar for the detection and stock assessment of shrimp fisheries species was discussed. Video and audio recordings were made of captive white shrimp. Audio recordings were made of wild populations in the bays and channels of Galveston, TX, and simultaneously taken trawl data were used to verify species. Results showed that captive white shrimp make detectable sound via three behaviors. The most important signal was produced when shrimp were eating (40 ms, 2-8 kHz, 112 dB re 1 [ ] at 1 m). Wild and captive spectra were similar (r=0.7 to 0.8), suggesting that accurate passive sonar detection of wild shrimp is possible. Data from recordings made in the Gulf of Mexico of another crustacean-like signal were analyzed and compared to white shrimp signals. Waveforms and acoustic envelopes were similar (r=0.9). The unknown had a slightly narrower bandwidth than white shrimp at 3 dB down of the magnitude spectrum squared (2.42 kHz vs 3.5 kHz) and showed an upward shift in peak frequency (5.6 kHz vs 4.7 kHz). Acoustic data, water depth, and location suggested that the unknown signal might be produced by a deepwater shrimp, possibly royal red shrimp (Pleoticus robustus), but verification of the species was not possible. The data further support the use of passive sonar for the detection of fisheries shrimp. Assessment of shrimp population densities may be possible using either the number of signals /time/area, or amplitude changes/area . Research with either of two methods was suggested: (1) captive research tested with field studies, or (2) modeling of population densities using towed hydrophone array directionality and beam patterns.
Berk, Ilona M. (1997). Sound production by white shrimp (Penaeus setiferus) analysis of another crustacean-like sound from the Gulf of Mexico, and the possible use of passive sonar for dedication and stock assessment of shrimp. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1997 -THESIS -B46.