SPLASH is an international cooperative effort involving researchers from the United States, Japan, Russia, Mexico, Canada, the Philippines, Costa Rica, Panama, Nicaragua and Guatemala. The aims of the three-year project are to understand the population structure of humpback whales across the North Pacific, and to assess the status, trends in abundance and potential human impacts to this population.

From 2004 to 2006 (three winter breeding seasons and two summer feeding seasons), tail fluke photographs (for individual identification), skin biopsy samples (for genetic and pollutant analyses) and photographs of flanks and tail stocks (for human impact assessment) were collected from thousands of whales across the North Pacific. For more detailed information about the SPLASH project visit: http://hawaiihumpbackwhale.noaa.gov/special_offerings/sp_off/splash/spla....

The Cetacean Conservation and Genetics Laboratory is conducting the primary genetic analyses associated with the SPLASH project. Our interests are:

• To describe the population structure of maternally inherited mitochondrial (mt) DNA and of biparentally inherited nuclear (nu) DNA diversity among feeding and breeding
• To compare mtDNA and nuDNA differentiation among feeding and breeding grounds for evidence of sex-biased dispersal or geneflow at the individual demographic scale (see below) and the long-term evolutionary scale
• To provide information on regional frequencies of mtDNA haplotypes or haplogroups, with the intent of detecting components of the oceanic population that have remained under-represented in the surveys
• To test for deviation from Hardy-Weinberg equilibrium at nuDNA loci to detect seasonal or migratory overlap of reproductively distinct population units
• To improve estimates of demographic interchange, particularly of breeding to feeding grounds, using individual assignment tests based on multi-locus genotypes and mtDNA sequences
• To provide individual-specific microsatellite genotypes for the purposes of capture-recapture estimation of abundance in collaboration with SPLASH SC members

This research is funded by a grant from the National Fish and Wildlife Foundation (NFWF).

Initial results will be presented at the 17th Biennial Marine Mammal Society meeting in Cape Town, South Africa 29 November to 3 December, 2007 (abstract below).

A comprehensive description of complex mtDNA population structure in North Pacific humpback whales

Baker, C. Scott1, Steel, Debbie1, Vant, Murdoch2, Barlow, Jay3, Burdin, Alexander M.4, Calambokidis, John5, Clapham, Phillip J.6, Ford, John K. B.7, Gabriele, Christine M.8, LeDuc, Rick3, Mattila, David9, Quinn, Terrance J.10, Rojas-Bracho, Lorenzo11, Straley, Janice M.12, Urbán R., Jorge13, Wade, Paul R.6, Weller, David3, Witteveen, Briana H.14, Wynne, Kate14, Yamaguchi, Manami15

1. Marine Mammal Institute and Department of Fisheries and Wildlife, Oregon State University, 2030 SE Marine Science Drive, Newport, OR 97365 USA
2. School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
3. NOAA Southwest Fisheries Science Center, 8604 La Jolla Shores Dr., La Jolla, CA 92037 USA
4. Kamchatka Branch of Pacific Institute of Geography, Far East Branch of the Russian Academy of Sciences, Rybakov Prospect, 19-a Petropavlovsk-Kamchatsky 683024 Russia
5. Cascadia Research Collective, 218½ West Fourth Avenue, Olympia, WA 98501 USA
6. National Marine Mammal Laboratory, Alaska Fisheries Science Center, NMFS, NOAA, 7600 Sand Point Way NE, Seattle, WA 98115 USA
7. Fisheries and Oceans Canada, Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, BC V9T 6N7 Canada
8. Glacier Bay National Park, PO Box 140, Gustavus, AK 99826 USA
9. Hawaiian Islands Humpback Whale National Marine Sanctuary, 726 S. Kihei Road, Kihei, HI 96753 USA
10. Juneau Center for Fisheries and Ocean Sciences, University of Alaska, 11120 Glacier Highway, Juneau, AK 99801 USA
11. Instituto Nacional de Ecologia, c/p CICESE, Apto. Postal 2732, Ensenada, Baja California 22860, México
12. University of Alaska, Southeast Sitka Campus, 1332 Seward Avenue, Sitka, AK 99835 USA
13. Programa de Mamíferos Marinos. Universidad Autónoma de Baja California Sur. La Paz, B.C.S. 23080 México
14. University of Alaska Fairbanks, School Fisheries & Ocean Sciences, 118 Trident Way, Kodiak, AK 99615 USA
15. Ogasawara Marine Center, Byobudani, Chichijima, Ogasawara-mura, Tokyo 100-21, Japan

E-mail: scott.baker@oregonstate.edu

We report on initial analyses of mitochondrial (mt) DNA diversity and population structure among humpback whales from all known feeding and breeding grounds in the North Pacific. Using samples collected during the ocean-wide program on the Structure of Populations, Levels of Abundance and Status of Humpbacks (SPLASH) and prior to the initiation of this program in the winter of 2004, we have completed sequencing of the mtDNA control region for 1,318 individuals representing nine feeding grounds and eight breeding grounds. Sequence analysis of another 1,000 samples collected during the SPLASH program is under way. From a consensus region of 600 bp in length, we have identified 25 unique haplotypes representing two divergent lineages or clades, one of which is thought to have originated from a historical connection with the Southern Hemisphere. The frequency of haplotypes differed significantly among most regional feeding grounds, supporting previous characterization of maternal fidelity to migratory destinations. Breeding grounds showed significant but weaker differences in haplotype frequencies, consistent with photo-identification records showing the congregation of individuals from different feeding grounds on one or more breeding grounds. Thus the influence of fidelity operates somewhat independently on feeding and breeding ground, confounding a simple longitudinal division of seasonal habitats into "stocks." The potential to define multiple Genetic Management Units on both feeding grounds and breeding grounds presents the most complex pattern of population structure yet described for large whales.