Table 1. Recordings specifications for data collection protocols from North Pacific and North Atlantic foraging grounds.

Year	1976	2007 & 2008	2008
Hydrophone model	Unknown	ITC 8215A	HTI-94-SSQ
Sampling rate	44.1 kHz	44.1 kHz	2 kHz
System sensitivity	Unavailable	−174 dB ± 2 dB re 1 V/μPa	−168 dB ± 1 dB re 1 V/μPa
Deployment method	Dipping (20 m)	Bottom-mounted (52 m)	Bottom-mounted (∼60 m)
Location	Frederick sound	Glacier Bay	Stellwagen Bank National Marine Sanctuary
Recording cycle	Non-standardized	30 seconds from every hour	Continuous
Data format	Continuous	30-second recordings	5-minute recordings
Recording days	4	72	10
Date range	July 1976	June–September 2007 June–September 2008	June–August 2008