SPLASH: Progress Report – Winter/breeding areas 2004

Sampling of humpback whale wintering areas has been conducted in four regions (Asia, Hawaii, Mexico, and Central America). At the time of this progress report fieldwork was still underway in some regions but a majority has been completed. Funding for the effort in all areas except Hawaii is from a contract from NFMS to Cascadia Research. The Hawaiian Islands Humpback Whale National Marine Sanctuary is coordinating photographs from waters off Hawaii as part of the SPLASH program. A detailed report will be provided after the end of the field season and compilation of data has been conducted.

Mexico and Central America

Sampling has been conducted in all three main winter aggregations in the Mexican Pacific: 1) the southern end of Baja California Peninsula (Baja); 2) Bahia Banderas area including the Islas Tres Marias and Isla Isabel (Mainland); and 3) the Revillagigedo Archipelago. Field effort in most areas will continue into April. Jorge Urban is the regional coordinator for the field sampling in Mexico.

Field sampling in Baja: The primary field organizations for this region is UABCS. Surveys have been conducted from several platforms including a panga with 3-4 people, a medium size boat EL AMIGO (35′), and effort in coordination with surveys by the Scripps ship Sproul and a Cascadia RHIB.

Through 29 March, 54 days of surveys totaling over 400 hours of effort had been conducted from the different platforms. Humpback whales were identified an estimated 367 times and 155 biopsy samples obtained. The number of identifications and biopsies already exceeds the target for the whole season of 250 photo-IDs and 75 biopsies. The fieldwork has covered the area from La Paz to Cabo Falso in the southern tip of Baja California Peninsula.

Mainland Mexico: Field effort in mainland Mexico is being coordinated by Luis Medrano of UNAM. The primary platform for effort has been a panga with 3-4 people. Most of the effort has been conducted around Bahia de Banderas with some surveys conducted to the area around the Isla Tres Marias.

Field effort began in mid-January and is continuing. Estimated numbers of identifications and biopsies obtained were not available at the time of this progress report. It is expected that the effort will be able to meet the target of 200 identified individuals and 60 biopsy samples.

Revillagigedos: Effort in the Revillagigedos is being coordinated by Jeff Jacobsen and involves effort by personnel associated with Humboldt State University, Cornell University, and UNAM. The primary platforms have been zodiacs with 2-3 people each.

Effort began on 29 January and was continuing through the end of March. Through 27 March, 148 surveys had been conducted totaling over 1,000 hours of effort. Over 1,000 identifications had been made of humpback whales and 149 skin samples collected. This far exceeds the minimum target of at least 150 individuals identified and 50 biopsy samples collected.

Central America: The waters from southern Mexico south along the Central America coast down to Panama are used as a wintering area for humpback whales coming almost exclusively from feeding areas off California. Cascadia Research coordinated surveys in this region. To cover this broad low-density area, surveys were conducted in a number of ways: 1) dedicated surveys were made from small chartered boats, 2) a network of local collaborators were set up to try and obtain opportunistic identifications, 3) identification photographs were collected during several weeks of surveys in collaboration with Oceanic Society Expeditions trips in southern Costa Rica, and 4) arrangements were made with several boats transiting the area to try and obtain identification photographs.

Dedicated photo-ID surveys have been conducted in Guatemala, El Salvador, Nicaragua, and Costa Rica. Forty-one surveys were conducted between 14 January and 22 March 2004, well over the 30 days of effort planned. As expected, permit arrangements to collect biopsies could only be arranged for Costa Rica, our principal sampling area. Identifications have been obtained of 22 whales and skin samples from 12. While this is more identifications that had been obtained in past years and represents the first skin samples collected from this area, it is less than anticipated for this amount of effort. This reflected the low density of whales in many areas, extremely poor weather in our area of highest whale concentration (N Costa Rica), and a high presence of mother-calves from which fluke photographs could not be obtained. Additional photographs may be obtained or available from some of our collaborators.

Western North Pacific

Research areas included several areas of Ogasawara, Okinawa, and the Philippines around Babuyan Islands. Effort in this region was coordinated by the Ogasawara Marine Center (Manami Yamaguchi). Sampling was conducted in the following areas: 1) Ogasawara including Chichi-jima (where OMC locates), Haha-jima (50km from Chichi-jima), and Muko-jima (70km from Chichi-jima) 2) Okinawa including Okinawa mainland and Zamami Islands (40km from Okinawa mainland) and 3) Philippines around the Babuyan Islands.

Through 3 April 2004, 60 days of effort had been conducted, 21 in Ogasawara, 12 in Okinawa, and 27 in the Philippines. To date 205 identifications have been obtained and 17 biopsies. Due to improving weather later in the season, it is anticipated that more identifications and samples will be possible late in the season. The number of identifications is ahead of the target while the number of biopsy samples has not quite achieved the target for the season.


Sampling for the SPLASH project in Hawai’i is being coordinated and funded by NOAA’s Hawaiian Islands Humpback Whale National Marine Sanctuary. The Sanctuary and its partner, the State of Hawai’i, has contracted local humpback whale researchers, who have been consistently active in the region, to collect geographically and temporally representative data for SPLASH. These represent eight teams on Kaua’i (1), Oahu (1), Penguin Bank (1), Maui (4) and the Big Island (1). Early season sampling began on December 8, 2003 and it is anticipated that sampling will continue into early May. Most sampling is progressing well and it is anticipated that Hawai’i will attain its target sampling goals. Through 27 March 2004, the different groups had conducted 104 days of surveys with another 32 days anticipated. To date, an estimated 737 identifications had been made and 355 biopsies collected. One area that has encountered some problems is the Penguin Bank team that has been hampered by appropriate vessel availability and weather, but should still obtain a reasonable sample from that area.