Low-frequency whale sounds recorded on hydrophones moored in the eastern tropical Pacific

TitleLow-frequency whale sounds recorded on hydrophones moored in the eastern tropical Pacific
Publication TypeJournal Article
Year of Publication1999
AuthorsStafford, Kathleen M., Nieukirk Sharon L., and Fox Christopher G.
JournalJournal of the Acoustical Society of America
Volume106
Pagination3687-3698
EndNote Rec Number6098
Abstract

An array of autonomous hydrophones moored in the eastern tropical Pacific was monitored for one year to examine the occurrence of whale calls in this region. Six hydrophones which recorded from 0–40 Hz were placed at 8° N, 0°, and 8° S along longitudes 95° W and 110° W. Seven types of sounds believed to be produced by large whales were detected. These sound types were categorized as either moan-type (4) or pulse-type (3) calls. Three of the moan-type calls, and probably the fourth, may be attributed to blue whales. The source(s) of the remaining calls is unknown. All of the call types studied showed seasonal and geographical variation. There appeared to be segregation between northern and southern hemispheres, such that call types were recorded primarily on the northern hydrophones in the northern winter and others recorded primarily on the southern hemisphere hydrophones in the southern winter. More calls and more call types were recorded on the eastern hydrophones than on the western hydrophones