ACOUSTIC STUDIES ON SHARKS, RANGIROA ATOLL, JULY, 1969.
Abstract
Attractions to both artifically produced and naturally recorded low-frequency, pulsed sounds were observed in the blacktip reef shark, Carcharhinus melanopterus; the gray reef shark, C. menisorrah; and the reef whitetip, Triaenodon obesus, in the lagoon at Rangiroa Atoll, French Polynesia. Responses were observed to the following sounds: 50-200 Hz, hand pulsed (4-7 pulses/sec) - hand trained; 25-50 Hz, electronically pulsed (15/sec.) - hand trained; 50-100 Hz, elect. pulsed - hand trained; 50-100 Hz, elect. pulsed - untrained; recorded speared-fish sound; and recorded fish stampede sound. For whitetip sharks, habituation was observed to both natural and artificial sounds. The speared and stampeded fish sounds were recorded from a group of bonefish, Albula sp., in a fish trap (pen) in the lagoon. Analysis indicates peak acoustic pressure at 50-150 Hz (speared) and at 80 Hz (stampeded). The primary pulse rate for the speared-fish sound appeared to be 5-10/sec., while the stampede sound was more irregularly pulsed at about 7-30/sec. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1970
- Accession Number
- AD0709104
Entities
People
- Donald R. Nelson
- Richard H. Johnson