Structure of Populations, Levels of Abundance, and Status of Humpbacks (SPLASH)



The SPLASH Project collaboration brings together national research programs and independent whale researchers from the United States, Canada, Mexico, Russia and Japan. Major funding for this project is anticipated from the U.S. National Marine Fisheries Service, the U.S. National Marine Sanctuary Program, Canada's Department of Fisheries and Oceans, Mexico's Department of the Environment, and from private research foundations. The Southwest Fisheries Science Center will be directly involved in sampling the summer feeding areas in the Aleutian Islands, the Bering Sea, and the Gulf of Alaska in 2004.

Humpback whale (Megaptera novaeangliae) populations were depleted due to commercial exploitation and remain listed as endangered today. The most complete recent estimate of North Pacific humpback whale abundance was conducted using mark-recaptures of individual whales

Markings on the ventral (bottom) side of the flukes of a humpback whale are like a fingerprint that can be used to identify each member of a population. Subsequent photographs of the same individual allow us to determine movement patterns and to estimate abundance using a method called "mark-recapture".
photo-identified between 1990 and 1993 (Calambokidis et al., 1997, 2001). Data from photo-identification and genetics studies have provided some information on North Pacific stock structure, verifying a high degree of site fidelity to feeding areas and some intermixing in the wintering areas. However, only limited data exist on the numbers, sizes, and potential boundaries of most feeding areas in the North Pacific (Calambokidis et al., 2001). Given the limitations of past studies, a need exists for more accurate information. SPLASH proposes to conduct the first-ever comprehensive field study of humpback whales throughout the North Pacific. This research program will use consistent sampling effort in all known feeding and wintering areas. Photo-identification and biopsy sampling will be the primary field methods employed. Large areas of the North Pacific that have not been systematically and comprehensively sampled will be surveyed using methods employed in other areas. Though much valuable information has been learned about humpback whales in the North Pacific from previous research efforts, this integrated design should lead to a new understanding of the biology of humpback whales that is unobtainable from retrospective analysis of existing data.