Blue Whale Habitat Associations in the Northwest Pacific: Analysis of Remotely-Sensed Data Using a Geographic Information System

Detection of stereotypic call sequences are now commonly used to locate blue whales (Balaenoptera musculus) in the North Pacific (e.g., Watkins et al., 2000a; Stafford et al., 1998; 2001; McDonald et al., 1995). Offshore hydrophones, such as those of the U.S. Navy Sound Surveillance System (SOSUS), have extended our monitoring capability to unprecedented spatial and temporal scales, providing the foundation for descriptions of basin-wide seasonal call patterns (Stafford et al., 1999; Clark, 1995). Consistent seasonal patterns of blue whale calling have been described for both the Northeast (NE) and Northwest (NW) regions of the Pacific basin (Watkins et al., 2000a), with clear differences in call structure suggestive of separate populations (Stafford et al., 2001). Overall, blue whale calls