Journals 2004/2005

Katie Roberts
Hingham Middle School, Hingham, Massachusetts

"Structure of Populations, Levels of Abundance,and Status of Humpback whales (SPLASH)" NOAA Ship McArthur II June 27-July 26, 2004

Journal Index: June Intro - 27 - 28 - 29 - 30 July 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10       11 - 12 - 13 - 14 - 15 - 16 - 17 - 18       19 - 20 - 21 - 22 - 23 - 24 - 25

July 13, 2004

Photo: Protected Resouces Division, Southwest Fisheries Science Center, La Jolla, California. swfsc.nmfs.noaa.gov/PRD/

Today, we leave the Yakutat hole in hopes of further humpback encounters. After a quiet morning watch, the afternoon proved a bit more interesting when distinctive "witch hat" dorsal fins, indicating the presence of an orca pod, approached the McArthur II. One pod of four individuals approached within close range and we were able to witness a range of behaviors including breaching, tail slapping and bobbing. This pod was also fairly vocal and the acoustics department successfully recorded a fair amount of tape time of this group. Interestingly, a second pod surfaced and interacted with the first group, possibly indicating they were two sub-pods of a larger group. The social dynamics of the orcas have been fairly well documented in these waters and the structure of these groups seems to be very stable over the course of many generations.

This same group was resighted later in the afternoon, many miles from our original location. The distinctive saddle patches allowed us to identify the individuals as belonging to our first sighting, as distinctive for the orcas as the fluke is to the humpback.