Research on Large Whales off California, Oregon, and Washington in 2003

Abstract

Abstract : This report summarizes fieldwork conducted by Cascadia Research and collaborators in 2003 on humpback, blue, fin and gray whales off California, Oregon, and Washington and also summarizes work conducted under NMFS permit no. 540-1502-00 in 2003. Principal support for this research was from Southwest Fisheries Science Center to assess population size and trends (Contract no. 50ABNF100065) with additional support from Office of Naval Research, Office of Naval Operations, National Marine Mammal Laboratory, and the Olympic Coast National Marine Sanctuary. Identification photographs in 2003 came from a number of sources and survey types including 65 days of dedicated research surveys under Permit 540-1502-00 conducted by Cascadia Research off California, Oregon, and Washington. Photographic identification was also conducted on either an opportunistic basis by others who provided photographs to Cascadia or as part of collaborative research under other permits. Tagging in 2003 consisted of 41 deployments of four instrument packages on blue, fin, and humpback whales. The vast majority of the tag deployments in 2003 were of the Burgess acoustic tag. Deployments in Monterey Bay were conducted in collaboration with Scripps Institute of Oceanography, Moss Landing Marine Labs, and UC Santa Cruz and yielded dive data in conjunction with hydro-acoustic mapping of prey fields. Combined dive, pitch, and roll data from the Burgess tags have provided insights into the diving dynamics of blue whales. These tags have also contributed insights into the vocal behavior of blue whales including indications that it is only the males that produce the long loud repeated calls generally described for blue whales but that both sexes produce the shorter more variable D-type call. Satellite tag data for the five humpback and two blue whales provided movement data on both species over only about a 2-week period.