Statistical analysis of fin whale vocalizations recorded by a seismic network at the Endeavour Segment of Juan de Fuca Ridge, N. E. Pacific Ocean.

Abstract

From 2003–2006, an eight-station seafloor seismic network was deployed along the Endeavour Segment of the Juan de Fuca ridge that recorded an extensive data set of 20-Hz fin whale calls. Algorithms have been developed to detect and track vocalizing whales that swim near the seismic network. During the first year of operation, more than 100000 fin calls that include ∼100 whale tracks were identified. Tracks comprise both single whales distinguished by a stereotyped ∼25 s interpulse interval and inferred multiwhale tracks characterized by more complex interpulse intervals. Whale tracks vary from individuals or groups that cross the network in a few hours to those that meander for up to 24 h. The call rates vary seasonally with the highest rates in winter and exhibit an apparent weak diurnal variation. The center frequencies range from 17–34 Hz, with the primary population centered at 20 Hz and a secondary population centered at 25 Hz. Statistical analysis of observed bandwidths and center frequencies, interpulse intervals, seasonality, and diurnal patterns will be presented. Additionally, the ∼100 whale tracks will be used for migration analysis and to quantify the swimming patterns in the network. [Funding from the ONR.]