July 1, 2004
Due to rough seas there were few humpback sightings today, and in between watches I had an opportunity to spend some time working below decks on the "matching" efforts, to match the whales identified on our trip to those in other catalogues. Today I focused my matching efforts primarily on the catalogues published by researchers surveying areas in the North Pacific. For example, Jan Straley's research team has compiled an extensive catalogue of humpbacks in Southeast Alaska. One goal of this project is to determine the percentage of the individuals that are "resighted," which can then be used to estimate population size.
Another goal of the matching efforts is to further understanding of the migratory patterns of humpback whales. Based on prior research, it is thought that three distinct migration patterns exist among humpbacks in the Pacific Ocean. One group appears to breed in winter waters off Japan and feed during the summer months off the Aleutian Islands and Bering Sea. Another group appears to breed in Hawaii and spend summers feeding in Southeast and Southcentral Alaska. The third group appears to breed off of Baja, west of Mexico and feed off the coast of California. By matching individual humpbacks photographed in the northern waters of our survey to catalogues from those in southern climes, such as Hawaii or Revillagigedo, we will further understanding of these migrations. Two members of our SPLASH team, Siri Hakala and Alan Lignon, have worked for several years in the Hawaiian whale sanctuary and have in fact contributed greatly to the cataloguing efforts of humpbacks in those waters. Their stories and anecdotes helps me to complete the picture of the life history of the humpbacks that we've encountered.
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